drtbalu's otolaryngology resources

Infections of Waldayer's ring an open educational resource

2012-01-22T04:23:00.000-08:00

Infections of "Waldayer's ring" is the commonly taught topic in undergraduate Medical curriculum. This topic is not only exhaustively dealt with but also used to evaluate the students during their university examinations.This open tutorial discusses this topic thread bare. It is interactive ed and has been designed in such a way that it encourages self learning.You can view the complete tutorial here.

online journal of otolaryngology jorl volume 2 issue 1

2012-01-12T01:22:00.000-08:00

Nasal polyposis in a child

2012-01-05T04:58:00.000-08:00

Tuning fork tests

2012-01-01T23:24:00.001-08:00

Introduction:

These tests are performed in order to subjectively assess a person’s hearing acuity. This test can in fact be performed by using tuning forks of the following frequencies (254 Hz, 512 Hz, and 1024 Hz). Frequencies below 254 Hz are better felt than heard and hence are not used. Sensitivity for frequencies above 1024 Hz is rather poor and hence is not used.

Prerequisites for an ideal tuning fork:

1. It should be made of a good alloy

2. It should vibrate at the specified frequency

3. It should be capable of maintaining the vibration for one full minute

4. It should not produce any overtones

Methodology of using tuning fork:

The tuning fork must be struck against a firm surface (rubber pad / elbow of the examiner). The fork should be struck at the junction of upper 1/3 and lower 2/3 of the fork. It is this area of the fork which is capable of maximum vibration.

The vibrating fork should be held parallel to the acoustic axis of the ear being tested.

Advantages of tuning fork tests:

1. Easy to perform

2. Can even be performed at bed side

3. Will give a rough estimate of the patient’s hearing acuity

The following tests can be performed using a tuning fork:

1. Rinne test

2. Weber test

3. ABC test

4. Bing test

5. Politzer test

6. Bing Entotic test

7. Stenger’s test

8. Gelle test

9. Chimani-Moos test

Rinne test:

Rinne's test: is a tuning fork test used to clinically test hearing deficiencies in patients. It is designed to compare air conduction with bone conduction thresholds. Under normal circumstances, air conduction is better than bone conduction.
Ideally 512 tuning fork is used. It should be struck against the elbow or knee of the patient to vibrate. While striking care must be taken that the strike is made at the junction of the upper 1/3 and lower 2/3 of the fork. This is the maximum vibratory area of the tuning fork. It should not be struck against metallic object because it can cause overtones. As soon as the fork starts to vibrate it is placed at the mastoid process of the patient. The patient is advised to signal when he stops hearing the sound. As soon as the patient signals that he is unable to hear the fork anymore the vibrating fork is transferred immediately just close to the external auditory canal and is held in such a way that the vibratory prongs vibrate parallel to the acoustic axis. In patients with normal hearing he should be able to hear the fork as soon as it is transferred to the front of the ear. This result is known as Positive Rinne test. (Air conduction is better than bone conduction). In case of conductive deafness the patient will not be able to hear the fork as soon as it is transferred to the front of the ear (Bone conduction is better than air conduction). This is known as negative Rinne. It occurs in conductive deafness. This test is performed in both the ears.

If the patient is suffering from profound unilateral deafness then the sound will still be heard through the opposite ear this condition leads to a false positive Rinne.

Use of Rinne test in quantifying conductive deafness:

Conductive deafness of more than 25 dB is indicated by negative Rinne with 512 Hz fork, while it is positive for 1024 Hz. If Rinne is negative for 256, 512 and 1024 Hz then conductive deafness should be greater than 40dB.

Weber's test:

Is a tuning fork test (quick) used to assess hearing levels in an individual. This can easily detect unilateral conductive and unilateral sensorineural hearing loss. This test is name after Ernst Heinrich Weber (1795 – 1878).
Procedure:

Tuning forks used - 256 Hz / 512 Hz

Commonly used frequency is 512 Hz.

A vibrating fork is placed over the forehead / vertex / chin of the patient. The patient should be instructed to indicate which ear hears the sound better. In normal ear and in bilateral equally deaf ears the sound will be heard in the mid line. This test is very sensitive in identifying unilateral deafness. It can pick out even a 5 dB difference between the ears.

Theory:
A patient with a unilateral (one-sided) conductive hearing loss would hear the tuning fork loudest in the affected ear. This is because the conduction problem masks the ambient noise of the room, whilst the well-functioning inner ear picks the sound up via the bones of the skull causing it to be perceived as a louder sound than in the unaffected ear.

Inadequacies:

This test is most useful in individuals with hearing that is different between the two ears. It cannot confirm normal hearing because it does not measure sound sensitivity in a quantitative manner. Hearing defects affecting both ears equally, as in Presbycusis will produce an apparently normal test result.

Absolute Bone conduction test:

This test is performed to identify sensorineural hearing loss. In this test the hearing level of the patient is compared to that of the examiner. The examiner's hearing is assumed to be normal. In this test the vibrating fork is placed over the mastoid process of the patient after occluding the external auditory canal. As soon as the patient indicates that he is unable to hear the sound anymore, the fork is transferred to the mastoid process of the examiner after occluding the external canal. In cases of normal hearing the examiner must not be able to hear the fork, but in cases of sensori neural hearing loss the examiner will be able to hear the sound, then the test is interpreted as ABC reduced. It is not reduced in cases with normal hearing.

Bing test:

This is actually a modification of weber’s test. The vibrating fork is placed over the mastoid process and when it ceases to be heard the examiner’s finger is used to occlude the external auditory canal. In normal individuals the sound will be heard again. This is because by occluding the external auditory canal the examiner is preventing sound from escaping via the external canal. The external auditory canal acts as a resonating chamber. If the vibrating fork is not heard again after the external canal is occluded then it is construed that the middle ear conduction is the cause for deafness. In patients with pronounced deafness if the vibrating fork is heard after occlusion of external canal then deafness is construed to be due to labyrinthine causes.

Politzer test:

In this test the vibrating fork is held in front of open mouth and the patient is asked to swallow. If the Eustachian tubes are patulous then sound will be intensified during swallowing. If only one tube is patulous then sound will be accentuated only in that ear. Sometimes normal persons too may not hear the vibrating fork.

Bing Entotic test:

Hypothetically this test is supposed to differentiate between deafness due to ankylosis of foot plate of stapes from that of conditions interfering with mobility of other ossicles. This test is actually of historic value only. Eustachian catheter is passed and to one of its ends is attached a speaking tube. If the patient is able to hear the fork better via this tube than that from the external auditory canal then middle ear ossicles other than foot plate of stapes is supposed to be at fault.

Stenger’s test:

This test is performed to identify feigned hearing loss and malingering. This test is based on the auditory phenomenon known as “Stenger’s principle”. This principle states that when two similar sounds are presented to both ears only the louder of the two would be heard. Patients usually are not aware of this phenomenon. When two similar tuning forks of same frequencies are made to vibrate and held simultaneously in the acoustic axis of both ears only the louder fork will be heard. Loudness of vibrating fork can be adjusted by adjusting the distance of the fork from the external canal. Usually the vibrating fork is held closer to the allegedly deaf ear of the patient. The patient will not acknowledge hearing in that ear. According to Stenger’s principle he should be able to hear the louder fork. If the hearing loss in worse ear is genuine, patient will respond to the signal presented to the better ear. This is known as negative Stenger’s test. Feigning patient will not acknowledge hearing when louder sound is presented to the worse ear. This is known as positive Stenger’s test.

Gelle test:

In this test, the air pressure in the external canal is varied using a Siegle’s speculum. The vibrating fork is held in contact with the mastoid process. In normal individuals and in those with sensorineural hearing loss, increased pressure in the external meatus causes a decrease in the loudness of the bone conducted sound. In stapes fixation no alteration in the hearing threshold is evident.

Chimani-Moos test:

This is actually a modification of Weber test. When the vibrating fork is placed on the vertex, the patient indicates that he hears it in the good ear and not in the deaf ear. The meatus of the good ear is then occluded. A genuine deaf patient will still be able to lateralize the sound to the good ear, where as a malingerer will deny hearing the sound at all.

Velopharyngeal insufficiency and its management

2011-12-28T06:17:00.000-08:00

Velopharyngeal insufficiency and its management

Blow out fracture orbit current management concepts

2011-12-13T02:57:00.001-08:00

Lingual thyroid

2011-12-05T02:30:00.001-08:00

Respiratory medicine for nurses and paramedics

2011-12-03T06:13:00.001-08:00

Foundation otolaryngology for nurses

2011-12-03T06:10:00.001-08:00

Lingual thyroid and its management

2011-12-02T16:56:00.000-08:00

Orbital disorders

2011-12-02T16:55:00.000-08:00

Eosinophilic otitis media a literature review

2011-11-30T08:50:00.001-08:00

Abstract:

Eosinophilicotitis media is actually a recent introduction. These patients maymanifest with sudden hearing loss. There may be associated bronchialasthma and allergic rhinitis. Diagnostic criteria of this conditionare rather vague. A review of literature shows that demonstration ofeosinophils in the middle ear secretion of these patients could beconsidered to be pathognomonic of this condition.

Introduction:

Eosinophils areconsidered to be effectors for allergic reactions. Eosinophilicotitis media ¹is a newly recognised entity causingintractable middle ear pathology. This condition is characterised byexcessive accumulation of eosinophils in the middle ear cavity and isassociated with persistent middle ear effusion. These patientsusually suffer from bronchial asthma. The first description of thiscondition should be credited to Koch ² who first reportedsome patients with middle ear effusion which contained lots ofeosinophils. He also added that these secretions were highly viscousand the middle ear mucosa was pinkish in color. The termeosinophilic otitis media was coined by Tomioka et al ³ in1993.

Pathophysiology:

Pathophysiologyof this condition is obviously allergy. These patients commonly hadassociated allergic rhinitis and branchial asthma. Eosinophils couldhave been probably attracted to the middle ear cavity by the presenceof IL 5 ⁴ inside the middle ear cavity.

Features ofEosinophilic otitis media ⁵:

Sudden deterioration of hearing
Bronchial asthma
Allergic rhinitis
Intractable otitis media
Persistent otorrhoea

Incidence:

Incidence ofeosinophlic otitis media is not clearly known. Literature searchputs it to be rather common cause of otitis media with effusion.

Managment:

Patientsdiagnosed with this condition should be warned of the possibility ofsudden deterioration of hearing.

Administrationof systemic / topical steroids ⁶could be of benefit inthese patients.

Antihistaminesand leukotreine receptor antogonists can also be used with benefit.

Grommetinsertion is indicated in patients with acute sudden hearing loss.

References:

Iino Y, Kakizaki K, Katano H, Saigusa H, Kanegasaki S. Eosinophil chemoattractant in middle ear patients with eosinophilic otitis media. Clin Exp Allergy 2005;35:1370–6.
Koch H. Allergical investigations of chronic otitis. Acta Otolaryngol 1947;62(Suppl.):1–201.
Tomioka S, Yuasa R, Iino Y. Intractable otitis media in cases with bronchial asthma. Recent advances in otitis media. In: Mogi G, HonjoI, Ishii T, Takasaka T, editors. Proceedings of the second extraordinary international symposium on recent advances in otitis media. Amsterdam, New York: Kugler Publications; 1993. p. 183–186.
NonakaM, Fukumoto A, Ozu C, Mokuno E, Baba S, pawankar R, et al. IL-5 and eotaxin levels in middle ear effusion and blood from asthmaticswith otitis media with effusion. Acta Otolaryngol 2003;123:383–7.
Suzuki H, Matsutani S, Kawase T, Iino Y, Kawauchi H, Gyo K, et al. Epidemiologic surveillance of ‘‘eosinophilic otitis media’’ in Japan. Otol Jpn 2004;14:112–7 (In Japanese).
Iino Y, Nagamine H, Kakizaki K, Komiya T, Katano H, Saruya S, et al. Effectiveness of instillation of triamcinolone acetonide into middle ear for eosinophilic otitis media associated with bronchial asthma. Ann Allergy Asthma Immunol 2006;97:761–6.

VOL 1, NO 1 (2011) ONLINE JOURNAL OF OTOLARYNGOLOGY ISSN 2250- 0359

2011-11-14T08:08:00.001-08:00

First volume of Online journal of otolaryngology (JORL) is given here.VOL 1, NO 1 (2011) ONLINE JOURNAL OF OTOLARYNGOLOGY ISSN 2250- 0359

Online journal of otolaryngology (JORL) First issue

2011-11-04T08:17:00.000-07:00

First issue of online journal of otolaryngology (JORL) is available. This free to access and free to publish e journal will be published 4 times a year. You can start submitting your work to the next issue right now following author submission guidelines mentioned in the website.

Just click on the image below to access the first issue of the journal.

Maxillectomy a review

2011-10-31T03:23:00.001-07:00

Maxillectomy a review

View more presentations from Balasubramanian Thiagarajan

Retrotympanic Recesses

2011-10-29T23:22:00.000-07:00

Introduction:

The posterior wall of middle ear cavity (Tympanum) is also known as retrotympanum. Important anatomic structures are lodged in this area. This area has assumed significance because of the difficulties encountered in clearing cholesteatoma from this area. This area is so narrow and has lot of crevises, it is very difficult to clear disease from this area.

This area is supposed to contain 4 important recesses. Each of these four recesses could hide cholesteatoma causing the surgeon to leave residual disease which could later recur. Precise knowledge of anatomy of this region is vital for the surgeon who wants to clear disease from this area. The recesses present in the retrotympanic area are:

Sinus tympani
Lateral tympanic sinus
Posterior tympanic sinus
Facial recess

Pyramidal eminence is the most prominent anatomical landmark of this area. This eminence hold the pyramidalis muscle. There are other prominences arising from this area projecting in various directions. They include:

External: Chordal ridge
Inferior: Pyramidal ridge
Superior: Suprapyramidal ridge
Internal: Ponticulus

The 4 types of retrotympanic recesses are found under these eminences.

Sinus tympani:

This is the most common and constant depression present in the retrotympanic area. Anatomically this sinus is located at the junction of the lateral and posterior walls of the tympanic cavity. Phylogentically this recess is considered to ba analogue of bulla tympanica seen in mammals. It lies between ponticulus superiorly and subiculum inferiorly. This recess is bounded by pyramidal ridge externally and promontory internally. Visualization of this area during middle ear surgery proves to be a challenge. During yester years small angled mirrors known as zinne mirrors were used. Now angled telescopes serves this function rather brilliantly. The sinus tympani is known to extend posteriorly up to the round window niche.

Types of sinus tympani:

Sinus tympani has been classified into three types depending on its depth. Note in type III it extends up to the level of lateral semicircular canal.

Lateral tympanic sinus:

Proctor described this sinus in 1969. This sinus lies between three eminences of styloid prominence. These eminences include:

Pyramidal eminence

Styloid eminence

Chordal eminence

Posterior tympanic sinus:

Posterior sinus of middle ear cavity is one of the recently identified anatomical sinus inside the middle ear cavity.
Serial temporal bone dissections have shown that it is present in nearly 90% of dissected bones.

Position: It lies just posterior to the oval window.

Depth: 1mm or less
Width: 1.5 mm or less

In nearly 60% of dissected specimen a ridge of bone arising from the floor of middle ear cavity separates it from sinus tympani.

In 8% of dissected specimen, the sinus tympani and posterior sinus merged together to form one confluent sinus.

It has been demonstrated that cholesteatoma / granulation tissue may lie within this sinus making removal difficult leading on to residual disease.
Retraction pockets may also occur close to this area.

Facial recess:

This recess lies between the promontory and tympanic annulus. It is bounded medially by the facial nerve and laterally by tympanic annulus. Running between these two structures at varying angulations is the chorda tympani nerve. Chorda tympani nerve always runs medial to the ear drum. Drilling in this area between the facial nerve, annulus and the angle formed by the chorda tympani nerve will lead into the middle ear cavity without causing a breach in the ear drum. This approach is used in cochlear implant surgery to place the electrode in the round window area. Hypotympanum can also be approached through this approach.

Subiculum:

This is the posterior extension of promontory separating oval and round windows.

Ponticulus:

Rarely a spicule of bone arises from the promontory above the subiculum and runs to the pyramid on the posterior wall of the middle ear cavity. This spicule of bone is known as the ponticulus.

Submission of articles to online journal of otolaryngology

2011-10-27T03:26:00.000-07:00

Introduction:

Online journal of otolaryngology has been started. It is free to access and free to publish. You can read / submit articles to this journal by going through a simple registration process which is free. Articles submitted will be peer reviewed before publication. Publication of selected articles is absolutely free.

Click on the image below to read a short tutorial on article submission to this journal.

Click on the image below to access the journal.

Effect of altered core body temperature on glottal closure force. Can it explain SIDS (Sudden Infant death syndrome?)

2011-10-27T03:18:00.001-07:00

Introduction:

The importantbasic function of larynx is to provide sphincteric protection to thelower airway. This is achieved by adduction of vocal folds inresponse to stimulation from the internal division of superiorlaryngeal nerves. This mechanism is initiated by complex brain stemresponse which is polysynaptic in nature. This reflex is sensitiveto variations in body core temperature. In febrile neonates, ahypersensitive glottal closure reflex have been known to cause suddeninfant death syndrome.

Role of animalstudies in verifying this hypothesis:

Haraguchi etalin their canine experiments demonstrated that hyperthemia enhancesthe glottal closure reflex by decreasing the latency of nervestumulation thereby aumenting their conduction. In hypothermicconditions they also demonstrated depression of glottal closurereflex. The following are the inferences of this study:

When the core body temperature raises axonal body temperature also raises.
Conduction of sodium and potassium ions increase nearly 3 times with every 10 ° C increase in body temperature.
Temperature drop caused delay in the release of neurotransmitters at the neuronal junctions.

Velopharyngeal insufficiency and its management

2011-10-23T23:19:00.001-07:00

velopharyngeal_insuff

Mandibular swing approach a step by step guide

2011-10-20T04:12:00.001-07:00

Mandibular Swing

Grommet insertion Current conceptsIntroduction: Myringotomy with grommet insertion was introduced by Poltizer of Vienna in 1868. He used this procedure to manage “Otitis media catarrhalis”. Soon it became the common surgical procedure performed in children. Indications: Bluestone and Klein (2004) came out with revised indications for grommet insertion which took into consideration the prevailing antibiotic spectrum. 1. chronic otis media with effusion not responding to antibiotic medication and has persisted for more than 3 months when bilateral or 6 months when unilateral. 2. Recurrent acute otitis media especially when antibiotic prophylaxis fails. The minimum episode frequency should be 3/4 during previous 6 months / 4 or more attacks during previous year. 3. Recurrent episodes of otitis media with effusion in which duration of each episode does not meet the criteria given for chronic otitis media but the cumulative duration is considered to be excessive (6 episodes in the previous year) 4. Suppurative complication is present / suspected. It can be identified if myringotomy is performed. 5. Eustachean tube dysfunction even if the patient doesnt have middle ear effusion. Symptoms are usually fluctuating (dysequilibrium, tinnitus, vertigo, autophony and severe retraction pocket). 6. Otitis barotrauma inorder to prevent recurrent episodes. Problems with Grommet insertion: This procedure is not without its attendant problems. Common problems include: 1. Segmental atrophy of tympanic membrane 2. Tympanosclerosis 3. Persistent perforation sydrome (rare) Before treating patients with otitis media with effusion the following factors should be borne in mind. Pneumatic otoscopy should be used to differentiate otitis media with effusion from acute otitis media. Duration of symptoms should be carefully documented. Children with risk for learning / speech problems should be carefully identified. Hearing should be evaluated in all children who have persistent effusion for more than 3 months. Grommet insertion can be performed under local anesthesia. Incision is made in the antero inferior quadrant of ear drum. The incision is given along the direction of radial fibers of the middle layer of ear drum. This causes minimal damage to the radial fibers. It also enables these fibers to hug the grommet in position.

2011-10-17T08:40:00.000-07:00

Introduction:

Myringotomywith grommet insertion was introduced by Poltizer of Vienna in 1868. He used this procedure to manage “Otitis media catarrhalis”. Soon it became the common surgical procedure performed in children.

Indications:

Bluestone andKlein (2004) came out with revised indications for grommet insertionwhich took into consideration the prevailing antibiotic spectrum.

chronic otis media with effusion not responding to antibiotic medication and has persisted for more than 3 months when bilateral or 6 months when unilateral.
Recurrent acute otitis media especially when antibiotic prophylaxis fails. The minimum episode frequency should be 3/4 during previous 6 months / 4 or more attacks during previous year.
Recurrent episodes of otitis media with effusion in which duration of each episode does not meet the criteria given for chronic otitis media but the cumulative duration is considered to be excessive (6 episodes in the previous year)
Suppurative complication is present / suspected. It can be identified if myringotomy is performed.
Eustachean tube dysfunction even if the patient doesnt have middle ear effusion. Symptoms are usually fluctuating (dysequilibrium, tinnitus, vertigo, autophony and severe retraction pocket).
Otitis barotrauma inorder to prevent recurrent episodes.

Problems withGrommet insertion:

This procedureis not without its attendant problems. Common problems include:

Segmental atrophy of tympanic membrane
Tympanosclerosis
Persistent perforation sydrome (rare)
Before treating patients with otitis media with effusion the following factors should be borne in mind.

Pneumaticotoscopy should be used to differentiate otitis media with effusionfrom acute otitis media.

Duration ofsymptoms should be carefully documented.

Children withrisk for learning / speech problems should be carefully identified.

Hearing shouldbe evaluated in all children who have persistent effusion for morethan 3 months.

Grommetinsertion can be performed under local anesthesia.

Incision ismade in the antero inferior quadrant of ear drum. The incision isgiven along the direction of radial fibers of the middle layer of eardrum. This causes minimal damage to the radial fibers. It alsoenables these fibers to hug the grommet in position.

Management of vestibular schwannomas current trends

2011-10-16T09:00:00.001-07:00

Introduction:

Managementof vestibular schwannomas has undergone lots of changes during the pastdecade. Review of published literatureexemplifies this fact. Various currentlyavailable management modalities to treat this condition are:

1 Observation

2 Stereotactic radiosurgery

3 Microsurgery

Among thesethree modalities stereotactic radiosurgery is evincing keen interest because ofthe precision of the procedure and lesser incidence of side effects. Advances in imaging technology have enabledearly diagnosis of these lesions. Abouta decade back the sensitivity of imaging techniques used to identify lesionsmeasuring 30 mm. Recent imaging modalitiesare accurate enough to identify even lesions measuring less than 10 mm. A stage has reached when surgeons aremanaging more intracanalicular lesions than ever before.

The currentmanagement modality of these tumors focusses on:

Preservationof hearing

Preservationof facial nerve functions.

Observation/ Watchful waiting: This modality ispreferred in managing patients with small asymptomatic / minimally symptomaticintracanalicular tumors. Since tumordoubling time of these lesions is prolonged (1-2 mm / year) this methodwarrants a trial. Advantages of thismethod are preservation of hearing and facial nerve function in thesepatients. Studies have also revealedthat growth rates between intracanalicular and extracanalicular tumors are notsignificantly different. It is ideal toperform imaging at least twice a year within the first year of diagnosis andonce a year from there on.

Positivefeatures that could warrant this management modality include:

1 Excellent speech discriminationscores

2 Growth rate of less than 2.5 mm /year

Microscopicsurgery:

This isindicated for small intracanalicular lesions with vestibular symptoms. Amount of tumor growth also is one importantfactor that could force the hands of a surgeon. Growth rate of more than 3mm / year is an indication for surgicalintervention. Hearing can be conservedby using retrosigmoid / middle cranial fossa approach.

Stereotacticradiosurgery:

This isindicated in residual lesions after microscopic excision or rapidly enlargingcanalicular lesions. Advantages ofradiosurgery include:

1 Hearing preservation

2 Conservation of facial nerve function

Susac syndrome

2011-10-12T00:06:00.001-07:00

Introduction:

Susac syndromewas first described by Susac etal in 1979. This syndrome ischaracterised by rapidly progressing encephalopathy, blindness andhearing loss.

Pathophysiology:

This isactually an endotheliopathy affecting precapillary arterioles. Thisendotheliopathy could probably be immune mediated. This causes rapidtissue infarction which leads to these problems.

Women arecommonly affected than men. Typical vulnerable age group is between20 – 40.

Clinicalfeatures:

Severe head ache
Rapid dementia
Micro infarcts seen in corpus callosum demonstrable in MRI scans
Photopsia and black spots due to retinal artery occlusion
Scintillating scotoma
Rapidly progressive sensori neural hearing loss on both sides
Vertigo
Nystagmus

Management:

High dosesteroid therapy is the main treatment modality.

Intravenousadministration of immunoglobulin.

Cyclophosphamideadministration.

Rituximab isthe currently used drug in the management. This is a monclonalantibody against CD20 protein. This receptor protein is found on thesurface of B lymphocytes.

Recent management concepts in the management of Atrophic rhinitis and empty nose syndrome

2011-09-30T03:18:00.001-07:00

Introduction:

The presence of normal sized nasal turbinates covered by normal moist mucosa is vital for the normal function of the nose. It should also be remembered that the receptors for initiating nasobronchial / nasal cardiac reflexes are found embedded in the mucosal lining of the nasal turbinates. Surgical augmentation of atrophied turbinates and nasal mucosa will help in the restoration of nasal function and regeneration of nasal mucosa. Usually various types of implant materials are considered for this purpose.

Commonly used implant materials:

1. Bone
2. Cartilage
3. skin
4. Fat
5. Plastic
6. Calcium hydroxyapatite

Role of Hyaluronic acid as an implant:

Hyaluronic acid is a naturally found polysaccharide consisting of a linear chain of fragments of D-glucoronic acid and N-acetlyglucosamine that alternate in the structure. In its pure form it is not an allerge and does not stimulate immunogenic rejection process. In view of its negative struture it absorbs large quantities of water. On absorption of water hyaluronic acid forms a gel like structure. It is extensively being used in plastic and reconstructive surgical procedures. Its important unique property is that it maintains its liquid form when it is under pressure, the moment the pressure reduces it solidifies. Hence it can be injected through a small needle. It has another important property i.e. Isovolumetric degradation, which indicates single molecules of this substance undergoes periodic degradation while the remaining molecules absorb large amounts of water thereby enabling it to maintain its volume. The overall volume of the gel maintains a constancy.

Hyaluronic acid can be injected submucosally thereby enlarging the size of the turbinates. It can also be injected under the septal mucosa. This not only cause narrowing of the nasal cavity but also promotes regeneration of nasal mucosal lining. If a cannula is used to inject hyaluronic acid instead of needle it causes less mucosal trauma thereby minimizing the risk of accidental intravascular injection. It would be better if the quantity of hyaluronic acid injected is the same on both sides. Studies conducted by Marek Modrzynski, M.D.
showed promising results.

Parapharyngeal tumor removal using Mandibular swing approach a digital atlas

2011-09-28T00:19:00.000-07:00

Preauricular sinus compete excision is the only way out.

2011-09-20T23:26:00.000-07:00

Preauricular sinus is an embryologicalaberration involving the developing pinna.

Theories of preauricular sinusformation:

Embryological fusion theory:

This commonly accepted theory suggeststhe preauricular sinus develops due to fusion defects involving the 6hillocks which develop into the future pinna.

Ectodermal infolding theory:

This theory attributes preauricularsinus to ectodermal infolding defects that occur during developmentof pinna. Ofcourse this theory has no takers. This theory assumesthat preauricular sinus forms part of other branchogenicmalformations.

Various syndromes associated withpreauricular sinus formation are:

Branchio oto renal syndrome
Branchio oto urethral sundrome
Branchio otic syndrome
Branchio oto costal syndrome
Cat eye syndrome
Trisomy 22

Surgical options for management ofpreauricular sinus:

Jensma technique is commonly preferredsurgical treatment modality. In this technique the tract isidentified after injecting dye (GV paint) via the punctum. Acircular incision is made to encircle the opening of the preauricularsinus and the whole sinus is followed using dye diffusion as a guide. Major problem of this technique is that the recurrence rate is veryhigh. It is not a suitable approach in patients with infectedpreauricular sinus.

Common causes of recurrence:

Incomplete removal of lesion
Failure to use magnification during surgery
Skill of the surgeon

Supra auricular approach:

This is a more radical approach. Majorbenefit of this procedure is it low recurrence rate. This surgery isperformed using a comet incision. The head of the comet incision isaround the external opening of the sinus. The tail of the comet isfashioned in such a way that it passes anterior to the helix,superior to the pinna over the temporal area. The temporalis fasciais the medial limit of the dissection. All the tissue superficial tothe temporalis fascia should be removed. It is also important toremove a cuff of cartilage around the outer opening of thepreauricular sinus.

Picture showing preauricular sinus

Comet incision shown

Removal of sinus along with a bit of helical cartilage

View of wound closure

You can view the procedure below;

Pleomorphic adenoma parotid gland

2011-09-18T22:18:00.000-07:00

Clinical details:

13 years old boy came with complaints of:

Swelling over left side of cheek - 3 years duration
Swelling showed progressive increase in size

The swelling was non tender, not associated with febrile illness.

FNAC report:

Fine needle aspiration cytology from the mass was reported as pleomorphic adenoma.

Surgery:

Since this is a surgical problem the patient was taken up for surgery under general anesthesia.

Discussion:

Pleomorphic adenoma is the commonest benign tumor involving the salivary glands. This is characterised by proliferation of glandular cells along with myoepithelial components. This tumor has a tendency for malignant transformation.

Histologically this tumor is highly variable and variations are evident even within individual tumors.
Classically these tumors show biphasic manifestation with admixture of varying amounts of polygonal salivary gland cells and spindle shaped myoepithelial cells. The underlying stroma could be mucoid / myxoid / cartilagenous / hyaline. Even though these tumors are not encapsulated but thickening of parotid fascia around the mass gives it an encapsulated appearance (pseudocapsule).

The main cause for this tumor is juxtapositioning of PLAG gene to the gene for beta catenin. This causes activation of catenin pathway leading on to inappropriate cell division.

An interesting case of metallic foreign body (Nail) right orbit being removed

2011-09-13T17:05:00.000-07:00

Case report:
13 years old male patient came to the OPD with h/o injury just below right eye. When he came the injury was 4 days of duration. He had undergone wound suturing as soon as he sustained the injury.

On examination:
Proptosis (mild) of right eye+
Sutured wound seen just below right orbit. wound had healed.
Upwards movement of eye was restricted.
Lateral movements of the eye was normal

Imaging:

Plain x-ray skull lateral view was taken immediately.

It showed the presence of metallic foreign body

CT scan showed:

Metallic foreign body in the floor of right orbit with evidence of # of orbital floor

Patient was taken up for surgery under general anesthesia. The metallic foreign body was removed via right infraorbital incision. This was preferred because he already had the sutured scar in that area.

Surgical video clipping:

Discussion:

This case is presented for its rarity. Without proper history it is very difficult to diagnose orbital foreign bodies inside the orbit. Retained foreign bodies in the orbit can cause:

1. Orbital hematoma
2. Orbital cellulitis
3. Ocular dysmotility
4. Proptosis
5. Orbital abscess
6. Blindness

2011-09-08T23:23:00.001-07:00

Olfactory groove meningioma

Introduction:

Meningiomas arebenign and rather slow growing tumor arising from arachnoidal capcells. Statistically speaking meningiomas constitute about 20% ofall primary intracranial tumors. Out of these 20% olfactory groovemeningiomas constitute 10%. It was the Italian surgeon FrancescoDurante who first reported the first successful resection ofolfactory groove meningioma in 1885. In 1938 Cushing reported thelargest series of olfactory groove meningioma which were resected viafrontal craniotomy / subfrontal approach. It is really worthwhile todifferentiate olfactory groove meningioma from other intracranialmenigiomas as they differ in their presentation, symptomatology andmanagement.

Sex ratio:

The female :male ratio is 2:1. Exact explanation for this variation is notavailable.

Pathophysiology:

Meningiomasarise from meningothelial cap cells that are largely distributedthrough the arachnoid trabeculations. The greatest concentration ofmeningothelial cells are seen in the arachnoid villi lining the duralsinuses, cranial nerve foramina, middle cranial fossa and cribriformplate area. This accounts for the common location of meningiomasi.e. Over the convexity, along the skull base and along the falx. Meningiomas are usually attached to the dura and are wellencapsulated. Blood supply to these tumors arise usually from thedura and the anterior and posterior ethmoidal arteries.

Histology:

Histologicallythese tumors show features of bening lesions. These lesionsclassically appear as whorls of arachnoid cells surrounding a centralhyaline material that eventually calcifies. These calcified areasare known as Psammoma bodies. These cells are arranged in sheathsseparated by connective tissue trabeculations.

Subtypes ofmeningiomas:

Meningotheliomas

Fibrous types

Transitionaltypes – Psammamatous tumors

Secretorymeningiomas – Secretes Vascular endothelial growth factor. Thesetumors are characterized by the presence of marked oedema. They maybe papillary or rhabdoid variants. These tumors are usuallyconsidered to be malignant in nature.

WHOhistological grading of meningiomas:

Grade I: Thisgrade is usually benign and 90% of all meningiomas belong to thiscategory. They also carry the best prognosis and a very lowrecurrence rate.

Grade II:Atypical meningiomas come under this category. About 5% of allmeningiomas belong to this grade. Tumors belonging to this gradehave a high recurrence rate (about 50%).

Grade III: Thisgrade of meningioma is frankly malignant constituting about less than3% of all meningiomas.

Molecularbiology:

Majority ofmeningiomas are associated with one / more focal chromosomaldeletions. Malignant versions of meningiomas involve multiplechromosomal aberrations. These multiple chromosomal abberationscause extreme instability to the genomic structure thereby increasingthe risk of malignant transformation.

Deletion andinactivation of NF2 gene on chromosome 22 is the predominant featurein sporadic meningiomas.

Risk factorscontributing to meningioma:

Exposure to ionizing radiation – Studies have demonstrated that survivors of atom bomb explosion showed increased incidence of meningioma
Role of Hormones – Histologically meningiomas present with oestrogen, progesterone and androgen receptors. This could explain the increased incidence of menigioma in females.
Head injuries have been shown to increase the incidence of meningiomas.

Location ofolfactory groove meningioma:

These tumorsare seen in the midline and arise over the cribriform plate andfrontosphenoidal suture area. A majority of these tumors occupy thefloor of anterior cranial fossa extending from crista galli up to thetuberculum sella. Extension to ethmoidal sinuses occur in about athird of these patients. There are obvious similarities existingbetween posteriorly extending olfactory groove meningiomas andtuberculum sellae meningiomas. These two masses can bedifferentiated by studying their relationship with that of the opticapparatus. Olfactory groove meningiomas have a tendency to pushoptic nerves and chiasma downwards and posteriorly as they grow,where as tuberculum sellae meningiomas push the optic nerves andchiasma upwards and superolaterally as they grow because of theirsubchiasmal position.

Blood supply ofolfactory groove meningiomas:

These tumorsare supplied by:

Anterior ethmoidal artery
Posterior ethmoidal artery
Anterior branches of middle meningeal artery
Meningeal branches of ophthalmic artery

Clinicalfeatures:

These tumorsare very slow growing ones and they are seen in the silent area. Hence to become symptomatic they need to enlarge their size to agreat extent. Usually these lesions are incidental findings duringroutine imaging.

MRI is the mostpreferred imaging modality as this would clearly show the origin ofthe tumor from dura. These lesions appear isointense / hypointenseto gray matter of brain in T1 weighted images and isointense tohyperintense in T2 weighted images. When gadolinum is used ascontrast these lesions demonstrate homogenous enhancement.

Majority of meningiomas show marginaldural thickening that tapers peripherally. This tapering isclassically known as the dural tail which is the characteristicfeature which is revealed in the images.

Management:

This entirely depends on the age andphysical fitness of the patient. If the tumors are small and seen inelderly and ill patients then serial imaging and observations woulddo. In symptomatic cases irradiation can be resorted to,

Surgical resection is the best option. Removal of these lesions is similar to that of any other skull basetumor.

Surgical management:

Cushing was the first to describesurgical resection of the tumor via unilateral frontal craniotomy. Other approaches available include:

Bifrontal craniotomy
Subfrontal approach
Pterional approach
Endoscopic approach

Bifrontal craniotomy combined withsubfrontal approach: This approach provides wide exposure forcomplete removal of tumor. In this approach it is easy to drill outthe hyperostotic area in the cribriform plate area. In this approachoptic nerves also can be deroofed if need be. Major disadvantage ofthis approach is the amount of brain retraction that is needed.

Unilateral frontal craniotomy withsubfrontal approach: This approach has the advantage of sparing theopposite frontal lobe and superior saggital sinus. The disadvantagesinclude:

Smaller exposure

Excessive brain retraction

Pterional approach:

This is a rather new approach. It isless invasive than frontal craniotomy approaches. It avoids CSFleaks because the frontal sinus is not damaged. The optic nerve canbe localised and exposed before tumor manipulation. Majordisadvantage of this approach is the lack of working space. Thewole dissection process needs to be carried out within a narrowangle.

Endoscopic resection:

This procedure is performed binaurallywith the endoscope introduced through one nose and the surgicalinstruments via the other.

This procedure involves:

Bilateral maxillary antrostomies
Complete ethmoidectomies
Sphenoidotomies
Frontal sinusotomy

Unilateral / bilateral nasal septalflaps are harvested first. This helps in covering the duraldefect.These flaps are tucked into the nasopharynx well out of theway of surgical field.

Modified Lothrop procedureis performed. The frontal intersinus septum should be completely removed.

Controlling the bleeding to the mass isthe top most priority. The anterior ethmoidal artery should beidentified and ligated. Anterior ethmoidal arteries should be soughtand ligated on both sides. Posterior ethmoidal arteries also shouldbe drilled out and ligated. Image guidance is used to identigy theanterior and posterior extent of the mass. The anterior cut isusually made at the level of posterior wall of frontal sinus andcontinued along the fovea ethmoidalis using drills and kerrisonpunch. The posterior resection is made as posterior as possible. This is usually governed by the posterior extent of the mass. It canbe as posterior as the planum of sphenoid.

Dura is incised exposing the entireolfactory groove meningioma. Dissection is completed using acombination of blunt dissection, debrider and CUSA. Tumors involvingthe medial wall of the orbit may be considered to be rathersuboptimal for endoscopic resection. While performing the resectionof the tumor care should be exercised to dissect it between the tumorand arachnoid plane. The defect in the skull base is repaired usingabdominal fat, reinforced with fascia lata and tissue glue is used tofix them in place.

Advantages of endoscopic approach:

The main site of recurrence i.e. The floor of the anterior cranial fossa is completely resected / drilled out.
Allows two surgeons to operate simultaneously there by ensuring clear surgical field
Very useful from the cosmetic point of view.

Role of irradiation in the managementof meningiomas:

RT is indicated only in patients with recurrent tumors following surgical resection
In patients with atypical / malignant meningiomas after surgical extirpation of the tumor

Role of stereotactic radio surgery:

The major advantage of this procedureis that the irradiation dose at the edge of the neoplasm is greatlyreduced thereby sparing the normal adjacent tissues. This procedurecan be safely used to treat even large volume tumors close tocritical intracranial structures.

Targetted molecular therapy:

This type of therapy aims at blockingthe various signals leading to unbridled proliferation of cells.These include:

Inhibitor of PDGFR – This is infact a key driver of cell proliferation in meningiomas. Drugs that block this can help in arresting the growth of meningiomas. Classic example of these drugs is Imatinib.
Inhibitors of angiogenesis factor – Sorafenib and Sunitinib are examples of drugs belonging to this group

Role of viruses and vaccines in head and neck malignancies

2011-08-31T06:40:00.000-07:00

Introduction:
Oncovirus is a virus that causes cancer. Majority of viruses dont cause tumors due to their long evolutional history and coexistance with the human host. It has been estimated that about 20% of all malignant lesions are caused by oncogenic viruses. These oncogenic viruses can either be a RNA virus or DNA virus. Oncogenic tumors can hence be prevented by developing vaccines against appropriate oncoviruses.

Characteristics of oncogenic viruses:

1. The oncogenic viruses doesn't obey Koch's postulates
2. These viruses cause little or no symptoms after infection
3. Oncoviruses can either be DNA virus or RNA virus

Bradford Hill criteria is usually used to ascertain the association between oncogenic viruses and causation of tumors since oncogenic viruses don't fullfill Koch's criteria.

Hill criteria:

1. Strength – Also known as strength of assoication. A small association doesn't mean that it is not a causal effect. Larger the association more likely it is to be causal.
2. Consistency – Consistent findings observed by different examiners from different locations strengthens the likelihood of causal effect
3. Specificity – More specific the association between a factor and an effect the higher the probablity of causal relationship
4. Temporality – The effect has to occur after the cause
5. Biological gradient – Greater exposure leads to greater incidence of the effect
6. Plausibility – Plausible mechanism between cause and effect is helpful
7. Coherence – Between epidemiological and laboratory findings increases the likelihood of the effect
8. Experiment – If possible experimental evidence should be sought
9. Analogy – Effect of similar factors should always be considered

Classification of oncoviruses:

1. Viruses with DNA genome – Adenoviruses
2. Viruses with RNA genome – Hepatitis C virus
3. Retroviruses having both DNA and RNA genome – Human T lymphotrophic virus / Hepatitis B virus
4. Viruses that present as Eisomes / plasmids with an ability to replicate separately from host cell DNA e.g. Epstein Barr virus and Kaposi sarcoma associated herpes virus.

Mechanism of viral tumerogenecity:

1. Direct mechanism which involves insertion of oncogenetic material to the host cell
2. Enhancing already present oncogenetic genes (proto oncogenes) in the genome

Direct tumor viruses should atleast have one virus copy in each tumor cell. This viral genome is capable of expressing atleast one protein / RNA. These cells express surface viral antigens to which immune mechanism can be sensitized. In normal individuals the immune mechanism is capable of destroying these cells in a targetted manner. These type of viruses hence commonly cause tumors in patients who are immunosuppressed.

Common viruses causing Head and Neck malignancies:

1. Human papilloma viruses (Squamous cell carcinoma of oropharynx)
2. Epstein Barr virus (Nasopharyngeal carcinoma)
3. Kaposi sarcoma associated Herpes virus (Kaposi sarcoma)

Role of vaccines in preventing virus induced head and neck malignancies:

Most commonly available vaccine is HPV vaccine (Human Papilloma virus vaccine). It is of two types containing serotypes 16 and 18.

Hepatitis B and Hepatitis C vaccines are also commonly used to prevent Hepatitis B and C infections.

Another vaccine which is undergoing extensive clinical trial is the Epstein Barr virus vaccine. This again holds much promise.

Fat myringoplasty

2011-08-28T06:15:00.001-07:00

Introduction:

Various graft materials have been used to close tympanic membrane perforations. The commonly used being temporalis fascia. Among the other graft materials used Fat fits the billing appropriately. Ringenberg was the first to use fat tissue to seal ear drum perforations.

Advantages of using fat graft:

The surgical procedure is rather simple. It can be inserted through the perforation after freshening the edges. Fat tissue available in the lobule of the ear can be utilized for this purpose. It is really wonderful to use fat to seal small perforations of ear drum.
Fat from ear lobe is considered to be better than that present in the abdomen / buttock area by Ringenberg as it is more dense and exhibits better scafolding for epithelial and mucosal overgrowth over the perforation.

Fat plugging does not require support at the level of anterior annulus which is actually a bane in conventional temporalis fascia myringoplasty.

Fat is actually a highly active material which could promote scarring and revascularization of adjcent areas.

Role of physiological saline in the management of patulous eustachean tube

2011-08-28T01:22:00.001-07:00

Introduction:
The pharyngeal end of eustachean tube is normally closed. It usually opens temporarily during swallowing and yawning during which time middle ear drainage and pressure equalisation takes place. Abnormalities involving this opening mechanism may lead to middle ear pathologies like otitis media with effusion.

Patulous eustachean tube is a difficult entity to treat. The phenomenon of autophony which is caused by this condition is a difficult entity to treat. Patients have been driven to sucide because of this problem.

Patulous eustachean tube can be identified by the presence of the following features:

Aural fullness
Autophony
Hearing of self breathing

Sonotubometry is used to identify this condition.

Causes of patulous eustachean tube:

1. Weight loss (chronic)
2. Wasting disorders
3. Chronic inflammation followed by tissue atrophy at the pharyngeal end of eustachean tube

Management:

Various surgical modalities have been attempted with very little success.

Role of nasal topical instillation of physiological saline:

Instillation of physiological saline has been proved to be beneficial in nearly 60% of these patients. This therapy can be continued till there is sufficient weight gain which could obviate the need for this medication. Instillation of saline in the pharyngeal end of eustachean tube may cause it to close. This effect should be considered to be purely temporarly till normal saline is present close to the pharyngeal end of eustachean tube. The same can be instilled again if symptoms recur. Physiological saline administration can be continued till there is spontaneous recovery which is also common. Simple weight gain can obviate the symptoms.

Thyroid storm

2011-08-18T07:03:00.000-07:00

Introduction:

This condition is also known as thyrotoxic crisis caused by hypermetabolic state induced by excessive secretion and release of thyroid hormones in individuals with thyrotoxicosis. In children this could be the initial presentation of thyrotoxicosis. This is more so in neonates.

Clinical manifestations:

1. Marked hypermetabolism
2. Excessive adrenergic response
3. Hyperpyrexia (reliable finding)
4. Flushing / sweating / tachycardia /atrial fibrillations / elevated pulse pressure / cardiac failure
5. CNS symptoms include – agitation / psychosis / restlessness / delirium / coma.
6. GI symptoms include – diarrhoea / jaundice
7. Hypertension may be present. * Normal blood pressure doesn't rule out thyroid strom.
8. Elderly patients may manifest atypical symptoms like (apathetic thryoid strom).
9. Heat intolerance

Diagnosis is primarly made on clinical grounds, as no specific lab test is going to clinch the diagnosis.

Triggering factors include:

1. Thyroid surgery
2. Radio active iodine therapy
3. Pregnancy / during delivery
4. Acute iodine load
5. Trauma
6. Acute infection
7. Drug reaction
8. Trauma
9. Myocardial infarction (rare)
10. Graves disease

Incidence:

It is 5 times more common in women than in men.
It is more common in prepeubertal children.
Common in children born to mothers with Graves disease.
More common in adolescents.

Pathophysiology:

Thyroid crisis is the most extreme state of thyrotoxicosis. It should be considered to be a decompensated state of thyroid hormone. Studies have shown that there is no clear evidence that increased secretion of thyroid hormones lead to thyroid strom. Increased levels of catecholamines and increased sensitivity of catecholamine receptors have been suggested to play a role. Decreased binding to thyroid binding globulin can also play a vital role as this would lead to a relative increase in the risk of increasing levels of serum T3 and T4.

Management:

All patients with suspected thyroid strom should be managed only in an ICU setup.

Treatment should be considered to be a triangular one.

Iv life line is to be started.
Dextrose is to be administered because of the increasing biological demand for glucose.
Serum electrolytes should be estimated and abnormalities if any should be corrected.
Cardiac arrythmias if present should be treated aggressively.
Hyperthermia can be managed by ice packs / acetaminophen 15 mg/kg orally.
Propranalol should be administered to block sympathomimetic effects of thyroxine.
Anti thyroid medications are to be administered. High dose of propyl thiouracil is preferred because it blocks peripheral conversion of T4 to T3. Hepatic parameters should be monitored while administering propylthiouracil.
Administration of Lugol's iodine will help by blocking the release of thyroid hormones. Lugol's iodinee is preferred.
Glucocorticoids are also administered in order to reduce peripheral conversion of T4 to T3.
Plasma pheresis can be resorted to in cases of accidental / suicidal ingestion of large doses of thyroxine.
Underlying cause should be looked for and treated.

Theories explaining thyroid strom:

1. These patientts have relatively high levels of thryoid hormones than normal controls. This may not be the case always.
2. Adrenergic receptor activation theory. Sympathetic nerves are supposed to innervate thyroid gland. Increased sympathetic stimulation causes an increase in thyroid hormone synthesis and secretion. This increase in thyroid hormone levels increase the density of beta receptors.
3. Excess hormones could be liberated when the gland is manipulated during surgery.
4. Rapid reduction in the levels of thyroid binding globulin levels cause increased levels of thyroid hormones
5. Alterations in tissue tolerance to thyroid hormones.

Differential diagnosis:

1. Anxiety disorder
2. Cardiac failure
3. Hypertension
4. Hyperthyroidism
5. Phaeochromocytoma
6. Atrial tachycardia / fibrillation

History of thyroid surgery a presentation

2011-07-21T08:10:00.000-07:00

Thyroid history

View more presentations from Balasubramanian Thiagarajan

An interesting case record of a patient with glomus tympanicum

2011-07-15T07:20:00.000-07:00

Clinical details:

54 years old female patient came with complaints of:

1. Pulsating noise in her right ear - 5 years
2. Hard of hearing right ear - 5 years

Past history:

No history of trauma to the ear
No history of bleeding from the ear
Pt is not a known diabetic / hypertensive

Imaging:

These CT scan images show contrast enhancing soft tissrue lesion occupying the whole of the middle ear cavity. The same mass could be seen extending on to fill the attic, aditus and mastoid cavity. Tegmen plate appears to be eroded.

Provisional diagnosis:

Glomus tympanicum

Partial maxillectomy picture slideshow

2011-07-05T23:15:00.000-07:00

This is a slide show showing partial maxillectomy procedure.

Importance of debrider in endoscopic management of fungal sinusitis

2011-06-30T07:18:00.000-07:00

In this blog I wish to stress the importance of debrider in the endoscopic management of fungal sinusitis. Since debrider cuts only on one side the other normal areas of nasal cavity like the nasal septum are not traumatized. The other advantages include:

1. The debrider blade since it is attached to a suction apparatus sucks and holds the nasal polypi to the cutting surface.
2. The rotating blade cuts the tissue which is held by suction
3. The irrigation portal is connected to saline. This dripping saline prevents clogging of the debrider blade with debris.

This video clipping below amply demonstrates the role of debrider:

Thanks to drtbaluent videos.

An interesting otoscopic finding

2011-06-16T07:12:00.000-07:00

Introduction:

Erosion of outer attic wall has always been associated with cholesteatoma. Theoretically eustachean tube is found to be not functioning in these patients predisposing to the formation of attic retraction pocket.

Case report:

This case report would make us rethink the pathophysiology of outer attic wall (scutum) erosion.

40 years old female patient presented with hard of hearing right ear of 3 years duration.
She did not give any history of ear discharge / foul smell emitting from the affected ear. Even on prolonged questioning she denied history of ear discharge.
No history of previous ear surgery for any other ailment.

Video otoscopy showed:

1. Thinned out ear drum
2. Ear drum bulging on valsalva
3. The ear drum could be seen moving as the patient breaths indicating a patulous eustachean tube
4. Erosion of outer attic wall (scutum) without the presence of cholesteatoma

This video clipping would ensure that we start rethinking about the pathophysiology of scutum erosion.

Granulomatous lesions of nose and sinuses a presentation

2011-06-13T03:24:00.001-07:00

Granuloma nose

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Nasal cholesteatoma

2011-05-14T06:37:00.000-07:00

Nasal cholesteatoma is actually a misnomer. This is another name for Rhinitis caseosa. The term “Rhinitis caseosa” was coined by Duplay in 1868. Eggston and Wolff after a detailed study in 1947 concluded that this condition could occur secondarily following pent up secretions in the sinus cavities. Their studies revealed that this condition is more common in patients with extensive bilateral ethmoidal polyposis. The presence of polypi in the nasal cavities caused obstruction to the normal drainage mechanism of the paranasal sinuses. This led to accumulation of secretions. Whitish to yellow cheesy material were found within the nasal cavities of these patients behind the nasal polypi. This cheesy material also caused expansion of sinus cavities, erosion of bone and extension into orbit.

Could this actually be fungal infection? Now the consensus seems to be pointing towards this direction.

Case details:

30 years old male patient came with complaints of:

1. Foul smelling discharge left nasal cavity - 2 years

2. Head ache on and off - 2 years

3. Watering from left eye - 1 year

Patient gave no history of nasal bleed.
He was not a diabetic

Imaging:

CT scan plain of paranasal sinuses showed:

This coronal CT of nose and paranasal sinuses show opacification of
left maxillary sinus with expansion of its walls. The lesion appears to be
heterodense ? fungal sinusitis. Air shadow could be seen within the
maxillary sinus cavity on the affected side ? entrapment ? abscess.
Patient was taken up for surgery. Endoscopic sinus surgery was performed on this patient.
After middle meatal antrostomy the maxillary sinus L was found to be filled with cheesy material
which was removed. The walls of the maxillary sinus was found to be intact.
Probable diagnosis:
Fungal sinusitis
Nasal cholesteatoma

Video clipping of the surgical procedure:

Thymic Stromal Lymphopoietin in nasal polyposis

2011-05-09T10:00:00.001-07:00

Introduction:

Nasal polyposis is considered to be the end stage of mucosal inflammation. Nasal polyposis doesnt contribute siginficantly to the mortality, but causes a significant reduction in the quality of life of the patient. The development of nasal polyposis is associated with:

Chronic inflammation
Allergic responses
Autonomic nervous system dysfunction
Genetic predisposition

This article discusses the role played by Thymic stromal lymphopoietin in the pathogenesis of nasal polyposis.

Thymic stromal lymphopoietin is actually a protein belonging to the cytokine family. This protein activates the antigen presenting cells which is of paramount importance in the maturation process of T cell population. This protein is secreted by fibroblasts, epithelial cells, stromal cells. Studies have demonstrated that this protein is secreted by non haemopoeitic cells.

Maturation of Helper T cells Type II is hastened by the presence of Thymic stromal lymphopoietin. These Helper T cells play a vital role in the pathogenesis of nasal polyposis.

How exactly thymic stromal lymphopoietin hastens the maturation process of Helper Type II T cells?

Nasal epithelium secretes thymic stromal lymphopoietin. This protein binds on the special receptor on the surface of dendritic cells. This binding causes release of OX40 ligand. This OX40 ligand causes the helper T cells to mature. These mature helper T cells secrete IL-4 and tumor necrosis factor alpha which are the well documented inflammatory mediators which could lead to the formation of nasal polyposis.

Role of staphylococcus aureus derived super antigens in nasal polyposis

2011-05-06T06:04:00.000-07:00

Introduction:

There are two types of staphylococcus aureus derived enterotoxins. In patients with nasal polyposis IgE antibodies to staphylococcus aureus enterotoxins A and B have been demonstrated. Now the definition of nasal polyposis has undergone a subtle change. It is now being referred to as chronic rhinosinusitis with nasal polyposis. This disorder is characterised by an eosinophilic T helper type II inflammation. IL-5 happens to be the driving force of inflammation in these patients. It is important to differentiate this disorder from chronic sinusitis without polyposis in which T1 helper cells mediated inflammation is seen. In this disorder gamma interferon and transforming growth factor beta are considered to tbe driving force of inflammation.

A short note on staphylococcus aureus:

Staphylococcus aureus has recognised as an important pathogen in various human diseases. Infections of this organism ranges from skin infections to enteric infections. This organism has been found inside the nasal cavity. Patients in whom these organisms are found in the nasal cavity can be divided into intermittent and persistent carrier states. Staphyloccous have been known to produce toxins. Staphylococcus aureus are capable of secreting super antigens. These superantigens helps the organims in evading the adaptive immune mechanism of the body. These superantigens can directly activate T cells via its ability to bind to the MHC class II molecule. Hence these super antigens need not be processed by the antigen presenting cells. Only when an antigen is processed by the antigen precenting cell the adaptive immune mechanism of the body can be kick started.

How nasal polyposis is formed due to the presence of staphylococcus superantigens like enterotoxin A and e.

T lymphocytes in response to the superantigens starts to proliferate. This proliferation is confined to the T lymphocytes bearing specific vβ domains. This significant clonal expansion of T cells bearing vβ domains is known as (vβ skewing). These T lymphocytes in turn causes increased production of IL-5. This causes oedema of the mucosal lining of the nasal cavity. Excessive and persistent oedema in turn leads to nasal polyposis. These superantigens also cause aspirin sensitivity due to its ability to upregulate eosinophilic inflammation.

Courtesy otolaryngology e news

Role of mucin expression in the pathology of nasal polyposis

2011-05-01T06:31:00.000-07:00

Introduction:

Rhinorrhea due to increased mucous secretion is one of the cardinal symptoms of nasal polyposis. Nasal polypi not only causes an increase in the amount mucin secretion but also changes its physical properties. It makes the mucin secretion thicker than usual hampering the normal mucosal transport mechanism. Changes in the physical properties of mucin involve changes in the relative amounts of sol and gel components. Nasal polypi expresses a wide spectrum of mucin genes. This genetic expression of mucin genes have been thought to play a role in the pathophysiology of nasal polyposis.

Causes of increased mucous secretion in patients with nasal polyposis:

1. Sinus infection coexisting / complicating nasal polyposis can cause increased mucous secretion. Studies have shown that 3 types of mucin have been expressed in these patients. They include MUC2, MUC5AC, and MUC5B. In patients with nasal polyposis there was inverse relationship between the levels of MUC2 and MUC5AC levels in the sinus secretion.

2. Increase in the surface epithelial area due to the presence of polypi could be one of the causes of increased mucous secretion. Even when squamous metaplasia is present due to exposure these squamous cells also express mucin.

3. Due to inflammation there is an increase in the number of mucous secretory elements like goblet cells / submucosal glandular cells. This could be due to the presence of increased levels of inflammatory mediators like IL-9, IL-13. These mediators increase the amount of secretion of mucin by goblet and submucosal glandular elements.

Mucin genes:

MUC1:

This gene has been demonstrated in normal inferior turbinate epithelium and nasal polypoidal tissue. Infact studies have not demonstrated any appreciable changes in this gene expression between these two tissue. One important issue that deserves mention is that this gene is found to be downregulated in the inferior turbinate of patients with vasomotor rhinitis when compared to normal individuals. This has led authors to postulate that decreased amounts of MUC1 expression in the mucosa over inferior turbinate some how trigger off neurogenic stimuli leading on to production of copious watery secretion from the nasal cavity. This feature is classically seen in patients with vasomotor rhinitis.

MUC2:

This gene is responsible for the production of large secretoy mucin. This mucin is commonly seen in intestinal epithelium serving to protect it from the luminal contents. MUC2 upregulation is seen in the mucosa of maxillary sinus in patients with nasal polyposis.

MUC 3 & MUC 6:

MUC3 gene encodes membrane bound mucin. This type of membrane bound mucin is seen in intestinal secretions. MUC6 gene encodes for secretory mucin which is commonly present in gastric secretions. It is this mucin which prevents self digestion of gastric mucosa by the HCL present in the stomach. Patients with nasal polyposis demonstrated MUC 3 upregulation with no increase in the amount of MUC6.

MUC4:

Studies have shown that this gene is the most predominantly expressed one in nasal polyposis. This gene is responsible for encoding membrane bound mucin which is commonly present in patients with nasal polyposis. This gene is also postulated to be involved in the process of epithelial hyperplasia and metaplasia.

A lot of work needs to be done in this direction to throw more light on this issue.

Courtesy news.otolaryngology.co.in

Pregnancy rhinitis

2011-04-14T03:24:00.000-07:00

Introduction:

Nasal congestion is common in pregnancy. It goes by the name pregnancy rhinitis. This condition is so common that it is seen in one in five pregnancies.

Clinical features:

Nasal congestion
Rhinorrhoea
These symptoms are aggravated by using nasal decongestant nasal sprays.

Definition:
Ellegard defined pregnancy rhinitis as nasal congestion which occurs during the last 6 weeks of pregnancy without other signs of upper respiratory infections / allergy. This disappears completely within 2 weeks after delivery.

Etiology:
1. Could be due to hormone effects
2. Elevated placental growth hormones have been implicated
3. Smoking is considered to be a risk factor
4. Autonomic nervous system imbalance as it occurs in vasomotor rhinitis
Diagnosis:

1. Watery rhinorrhoea
2. Nasal congestion
3. Secondary infections of paranasal sinuses

Management:

1. Reassurance
2. Elevation of head end during sleep
3. Ensuring normal humidity in the inspired air
4. Adequate hydration
5. Instillation of saline nasal drops
6. Mild to moderate exercise will reduce nasal congestion
7. Pseudoephidrine is the preferred decongestant used during prenancy if situation warrants
8. Minimally invasive surgical procedures like cauterizing the enlarged inferior turbinates can help in some cases.

MBBS Prefinal Otolaryngology Feb 2011 question paper of The Tamilnadu Dr MGR Medical University with solution

2011-04-13T03:19:00.000-07:00

mbbs_feb11

Medialization thyroplasty using Gor-Tex

2011-04-03T23:24:00.000-07:00

Introduction:
Vocal cord paralysis is a rather common problem causing speech problems to the patient. If the other cord doesn’t compensate adequately these patients may have troublesome aspiration also. Aspiration happens to be the most dreaded complication of vocal fold paralysis. Management of these patients is possible only by performing Medialization thyroplasty (Ishiki type I thyroplasty). Various graft materials have been used in this procedure. Presently lot of interest has been generated in Gor-Tex medicalization thyroplasty.
Advantages of Gor-Tex:
Gor-Tex is expanded polytetrafluroethylene has obvious advantages as an implant material in Medialization thyroplasty procedures.
1. It is malleable
2. Its position can easily be adjusted within the thyroid cartilage window
3. Only a small fenestration is necessary in the lamina of thyroid cartilage to introduce this material
4. This procedure is reversible and has very few complications
5. Creates less oedema when compared to that of silastic and hence over correction is not possible
6. Resultant quality of voice is really good
History:
Hoffman and McCullouch reported the first case of medialization thyroplasty using Gor-Tex in May 1996.

Indications of Gor-Tex Medialization thyroplasty:

1. Unilateral vocal fold immobility due to paralysis, paresis, atrophy
2. Unilateral vocal fold scarring / soft tissue loss
3. In select cases of Parkinson’s disease with vocal fold atrophy

Contraindications of Gor-Tex thyroplasty:
1. Previous history of irradiation
2. Malignant lesions involving larynx
3. Poor abduction of contralateral vocal fold as this would cause impairment of airway
Procedure:
This procedure is ideally performed under local infiltration anesthesia using 2% xylocaine mixed with 1 in 100,000 units’ adrenaline.
Incision:
Horizontal skin crease incision beginning at the mid portion of the thyroid cartilage extending to the paralyzed side.
The strap muscles are separated away from midline and held apart from the operating field using umbilical tape.
A tracheal hook is used at the level of laryngeal prominence and pulled medially. This helps in mobilizing the cartilage better.
The thyroid cartilage perichondrium is incised in the midline and extended laterally towards the paralyzed side. The thyroid lamina on the paralyzed side is skeletonized up to the level of cricothyroid membrane. Strips of cricothyoid muscle that come in the way are excised.

Dimensions of cartilage cuts:
Appropriate size of cartilage window is about 5mm x 10mm. The lower border of the window should be about 3mm above cricothyroid membrane. This ensures that the lower strut of thyroid lamina doesn’t fracture when window is being created. Anterior border of the window is about 8mm posterior to midline. If thyroid cartilage is calcified then fissure burr can be used to create the window.
The inner perichondrium is elevated from the under surface of thyroid lamina using scissors. The inner perichondrium incised posteriorly and inferiorly. It is not incised anteriorly. Now the cricothyroid membrane is incised in order to separate it from the lower border of thyroid cartilage. A septal elevator is introduced through the inferior margin of thyroid lamina and the paraglottic space is compressed medially while the voice of the patient is assessed. If the result is acceptable then 1 cm wide Gor-Tex strips dipped in bacitracin solution is introduced via the inferior margin of thyroid lamina and delivered via the window. The amount of Gor-Tex insertion is dependent on the improvement of quality of voice.
If necessary use prolene sutures passing via the inferior strut of thyroid lamina to stabilize Gor-Tex. Wound is closed in layers after keeping a penrose drain.

It is very important to perform pre operative and post operative video laryngeal examination.

Modified septoplasty

2011-03-29T06:15:00.000-07:00

Introduction:

Septoplasty is the commonly performed surgical procedure these days. It has been evolving for more than a century. It was in the early part of 20th century Freer and Killian first reported this procedure. The technique developed by them involved removal of the complete nasal septum (SMR). It was left to Cottle to fine tune their procedure of submucosal resection of nasal septum. During initial stages due to fear of complications and constraints of illumination septal deviations involving the anterior and middle portions alone were corrected adequately. Posterior deviations were left unattended. With the advent of excellent equipments like the nasal endoscope the whole of the nasal septum can be visualised and this led to removal of excess septal cartilage leading to complications like septal perforation, flappy nasal mucosa and nasal deformities like saddle nose etc. Inspite of being nearly a century old procedure the concepts governing septal surgery has undergone very few modifications. Metzenbaum recognized the importance of caudal portion of nasal septum and was instrumental in devising the first principles of septoplasty. His swinging door technique is still being followed with minor modifications in the septoplasty procedure performed even now.

Modified septoplasty procedure:
Wang etal suggested certain modifications in the currently performed septoplasty procedures. These modifications were aimed at:

1. Ability to deal with all types of septal deviations
2. Preservation of cartilagenous support framework
3. Avoidance of complications

Before suggesting these modifications they conducted extensive studies on the biomechanics of septal deviation. In their study they identified three key stress lines in the nasal septum. These stress lines are:

1. At the junction between the caudal septal cartilage and the medial crus of the alar cartilage. This often causes anterior deviation.
2. Between the quadrangular cartilage and the perpendicular plate of ethmoid. This often leads to superior deviation.
3. Between the quadrangular cartilage and vomer bone, palatine process of maxilla and nasal crest of palatine bone. Deviations in this area leads to inferior deviation.

The reasons for these stress lines can be accounted if the theory of differential septal ossification is considered to be the cause for septal deviation.

Diagram illustrating the three stress lines of nasal septum

During the development of nasal septum uneven ossification of the various parts of the septum can occur. The developing nasal septum is supposed to contain a membranous component anteriorly and cartilagenous and osseous component posteriorly. The posterior portion of nasal septum ossifies and forms perpendicular plate of ethmoid, nasal crests of palatine and maxillary bones and the vomer. Studies have shown that the septal cartilage is still in the process of continuous growth even after full maturation of maxilla and palatine bones. Due to the space constraint the growing cartilagenous portion of the nasal septum buckles.

In the modified procedure of septoplasty suggested by Wang etal the septum is surgically accessed via the standard Hemitransfixation incision. The septal cartilage is freed from its anterior, posterior and inferior attachements. Only the superior attachment is intact ensuring that the septal cartilage does'nt fall off. The cartilage can be shortened in order to fit in to the space. The shortening of the cartilage causes the septum to straighten. Since cartilage is fractured in order to correct the deviation healing takes a little longer. Splinting of the nasal septum is a must atleast for 10 days for optimal wound healing to occur.

Advantages of this modified procedure:

It maintains the thickness and rigidity of the nasal septum

Avoids synechiae formation

Prevents depression of nasal tip and pyramid

It reduces the incidence of septal perforation.

This procedure can safely be performed in adolescents also.

Drugs used in otology and their formulations

2011-03-27T05:57:00.001-07:00

Introduction: Various drugs and formulations are used in otological practice. Some of them may be of questionable value from the therapeutic stand point, still it is worthwhile knowing about these formulations. Topical otological preparations are so unique they need to be studied in detail.

Advantages of topical drug use in otology:

The drug can be administered right where it is needed
First pass metabolism doesnt come into play
Drug is delivered in a targetted manner, in adequate doses. Toxicity is not common
Chronic inflammatory diseases of middle ear cavity causes a certain amount of fibrosis preventing adequate concentrations of systemically administered drug reaching it.

Ear drops are solutions / suspensions of medicines in solvents like water, glycerol, diluted alcohol, or propylene glycol. These solutions can be instilled into the ear. For these ear drops to be effective sufficient contact time should be provided.

Indications for use of topical ear drops:

Bacterial / fungal infections of external auditory canal
Chronic suppurative otitis media with a large drum perforation
To liquefy accumulated wax in the external auditory canal
Myringitis granulosa

If drops are to reach the middle ear in adequate concentration the ear drum perforation should be fairly large. The method of administration of ear drops to reach the middle ear cavity is known as the displacement method. In this method the external ear is made dependent by turning the head to the opposite side, with the chin touching the shoulder. The external auditory canal is filled with ear drops. Pressure is applied to the external ear by alternate pressing of the tragus. This maneuver displaces the air from the middle ear cavity which is duly filled up by the ear drops.

Difference between solution and solvent ear drops:

Solution usually consists of a drug which is dissolved in a solvent where as suspension consists of an insoluble drug distributed in a liquid medium. Some of the ear drops can be used as eye drops also. To facilitate such multi usage certain adjuvant drugs are added to the drops in addition to the active drug. Commonly used adjuvants in such drops which can be used as eye and ear drops include:

0.01% Benzalkonium chloride – This acts as an antifungal agent
Sodium metabisulphite – This agent acts as a buffer maintaining the pH of the solution. This strict maintenance of pH prevents easy degradation of the active drug molecule present in the drops. It also minimizes the irritation caused due to application of the drops. It also retards the oxidation of the active drug there by prolonging the effect of the active drug.
Disodium edetate – This is another adjuvant commonly used. It also acts as an excellent buffering agent. This adjuvant drug increases the bactericidal and antifungal activity of Benzalkonium chloride.
Steroids – Beclamethazone is the commonly used steroid adjuvant drug in the ear drops for its antiinflammatory effect.

Some of the local drug preparations to be used in the external auditory canal may be in the form of creams / ointments. These ointments usually contain antibiotics and antiinflammatory agents in a suitable base like liquid paraffin, wool fat, yellow soft paraffin. Ointments usually have paraffin base. Ointaments are very useful in managing dry scaly skin conditions of external auditory canal. Ointment preparations with Lanolin as the base (wool fat) should be marked clearly on the tube because some patients may develop hypersensitivity reaction to this component of the medicine.

Acetic acid ear drops – Acetic acid in concentration of 2% is an excellent antibacterial and antifungal agent. Acetic acid ear drops can be used to treat mild otitis externa. This is commonly used in paediatric age group.

Aluminium acetate ear drops: This is an astringent drug which can be administered as ear drops or by dipping a cotton wick in the drug and inserting the same into the external auditory canal. Astringent belongs to a group of medicine that causes shrinkage of tissue on local application. Shrinkage of tissue is caused due to the hydroscopic effect of the drug. Hence it can be used to reduce oedema involving the external auditory canal. If this drug needs to be used for its astringent effect then it should be administered using a cotton wick. This drug is known to cause deposition of aluminium acetate crystals in the external auditory canal. Hence periodic cleansing of the ear is a must when this drug is used. This drug can be safely used even in pregnant mothers. In fact this is safest drug that can be administered during pergnancy.

Boric acid ear drops: Formerly this drug was used for their bacteriostatic and antifungal efects. It can be used in varying concentrations. Maxium concentration that can be safely used is 5%. This drug gets absorbed via the inflammed skin leading on to systemic toxicity due to the drug.

Antibiotic & steroid ear drops:

Betnesol / prednisolone sodium phosphate can be administered along with antibiotics like gentamycin / neomycin / quinolenes. When used in combination with these antibiotics they faciliate better effects due to their antiinflammatory effects.

Clotrimazole ear drops:

Clotrimazole is a broad spectrum antifungal agent. This drug inhibits ergosterol synthesis by the fungal cell wall. This destroys the fungus. Fungal infections involving the external auditory canal can also be caused due to inappropriate use of steroid ear drops. Administration of clotrimazole can cause burning sensation in the external auditory canal. Patient should be advised to tolerate it.

Ceruminolytic ear drops:

These are the most commonly used ear drops. Drugs belonging to this group include oil / aqueous preparations. These drugs are known to soften the wax facilitating its removal by aural syringing. 0.9% sodium choloride solution can be used as ceruminolytic agent. 5% sodabicarb solution can also be used as ceruminolytic agent.

Olive oil / coconut oil / liquid paraffin can also be used as ceruminolytic agents.

Organic solvents like chlorbutanol / paradichlorobenzene can also be used as solvents, but may cause irritation to meatal skin.

Indications for administration for systemic antibiotics:

Acute otitis media
Furunculosis of external auditory canal
Perichondritis of pinna
Acute mastoiditis
Malignant otitis externa

Drugs administered systemically include:

Amoxycillin
Flucloxacillin
Ciprofloxacillin
Penicillins

Drugs used in the management of vertigo:

Betahistine can be used in the management vertigo associated with meniere's disease. This drug reduces the endolymph pressure by improving microvascular circulation in the striavascularis of the cochlea. It also reduces the vertigenous sensation by inhibiting the firing rate of vestibular nuclei. Betahistine is known to reduce vertigo / tinnitus but does little to improve hearing. It is usually prescribed in doses of 16 mg thrice a day.

This drug should be used with caution in patients with bronchial asthma / peptic ulcer.

Dopamine antagonists: Prochlorperazine belongs to this group. Goes by the popular name Stemetil. It is a dopamine antagonist acting by blocking the chemoreceptor trigger zone. It is less sedating with fewer antimuscarinic effects.

Antihistamines: Drugs belonging to this group acts on H1 receptor at the level of chemoreceptor trigger zone thereby blocking the vomiting centre. Examples of drugs belonging to this group are cinnarizine and cyclizine. Cinnarizine can be used as prophylaxis for migraine in doses of 30 mg three times a day. Cyclizine is useful only during acute attacks and is given in doses of 50 mg thrice a day.

Diuretics in the management of meniere's disease: Thiazides and acetazolamide can be used in the management of acute symptoms of Meniere's disease. The cause decompression of the endolymphatic sac due to their diuretic effects.

Steroids in the treatment of sudden sensorineural hearing loss: Steroids have been used in the management of sudden sensorineural hearing loss with varying degress of success. Dosage regimen is as follows:

Prednisalone

60 mg on day I

50 mg on day II

40 mg for following three days

30 mg for subsequent three days

Use of antiviral drugs in otology:

Acyclovir is the classic example of drug belonging to this group. It can be administered in patients with Herpes Zoster oticus. It acts by inhibiting nucleic acid synthesis. It is administered orally in doses of 800 mg five times a day for 5 days. If administered within 72 hours after development of rash it reduces post herpetic neuralgia.

Use of sodium fluroide in otosclerosis:

sodium fluroide is used tto slow down the development of sensorineural hearing loss in a patient with otospongiosis. It acts due to its enzyme inhibiting activity there by preventing osteoclastic bone resorption. Usually it is administered in doses of 40 mg per day for a period of 3-6 weeks. This drug is really useful in patients with cochlear otosclerosis. It has propensity to cause gastric irritation and renal damage.

Endoscopic vidian neurectomy a video clipping

2011-03-25T16:51:00.000-07:00

This is a video clipping showing Endoscopic vidian neurectomy being performed.

Canine fossa trephination

2011-03-23T23:52:00.000-07:00

Introduction:

The key to any successful Endoscopic sinus surgery lies in clearing the residual disease from the maxillary sinus cavity. The diseased mucosa of the maxillary sinus cavity could cause formation of pus, eosinophilic fungal debris, polyps etc. These disorders dont reverse after performing a wide middle meatal antrostomy. They need to be cleaned out physically which can be rather difficult via the middle meatus as the anterior wall of the maxillary sinus and the high lateral walls are virtually not reacheable via the natural ostium. It is hence advisable to remove as much as diseased mucosa from the maxillary sinus in order to facilitate the rapid return of the sinus mucosa to normal. This is where maxillary sinus trephination has a role to play.

Optimal location for Canine fossa traphination:

Anatomical studies have shown that the best place to insert the trocar in the canine fossa is at the junction of the mid pupillary line and a horizontal line drawn through the floor of the nasal vestibule. At this site a 5mm hole can very easily be drilled thorough which a 4 mm nasal endoscope can easily be passed.

Illustration showing the exact location for placing the trocar in the canine fossa

Indications for canine fossa trephining:

Grade III maxillary sinus disease that cannot be addressed adequately via the enlarged natural ostium
Presence of excessive polypoidal mucosa within the maxillary sinus
Presence of mucopyoceles
Presence of a large antrochoanal polyp

Before proceeding with canine fossa trephining a large middle meatal antrostomy should be performed. A 70 degree endoscope can be used to inspect the interiors of the maxillary sinus cavity. This inspection will also help in grading the maxillary sinus disease.

Grade I – Normal or slightly oedematous mucosa

Grade II – Oedematous mucosa with small polypi without eosinophilic mucous

Grade III – Presence of extensive polypi and thick tenacious mucin

Anatomy of the canine fossa:

The canine fossa is the thinnest portion of the anterior wall of the maxillary sinus. Hence it is easy to breach this area and enter into the sinus. Boundaries of the canine fossa include:

Canine eminence formed by the canine tooth – medial
Root of the zygoma – laterally
Alveolar process of maxilla - inferiorly
Infraorbital foramen with the infraorbital nerve superiorly

The trephining of the canine fossa can be performed sublabially. After successful trephination using the trocar has been performed the opening can be widened using a burr. The opening should be wide enough to permit insertion of a 4 mm nasal endoscope. The maxillary sinus can be visualized from both angles i.e via the natural ostium using a 70 degree endoscope and via the opening in the anterior wall of maxilla. One port can also be used to introduce instruments to remove the diseased mucosa and pent up secretions.

Complications: Are very few if anatomy is respected.

Facial numbness
Numbness of upper dentition
Pain over the cheek
Hematoma over cheek

Most of these complications are self limiting and resolve within the first week after surgery.

Middle turbinate Implant

2011-03-23T05:09:00.000-07:00

Middle turbinate lateralization has been reported as the most common factor associated with the failure of primary endoscopic sinus surgery. Currently various techniques have been used to prevent lateralisation of middle turbinate like packing the middle meatal area with merocel or resorting to Bolgerisation. This middle turbinate implant helps in preventing lateralization of middle turbinate following endoscopic sinus surgery.

Role of imaging in the diagnosis of parapharyngeal and adjacent neck space lesions

2011-03-22T01:40:00.000-07:00

Introduction:

Parapharyngeal space is a suprahyoid neck space. It is surrounded by other important facial spaces. Old text books divided this space into prestyloid and post stymoid compartments. The prestyloid compartment lying infront of the styloid process and the post styloid one lying behind it. Current literature designates post styloid compartment as carotid space and the prestyloid compartment is considered to be the true parapharyngeal space. The parapharyngeal space contains fat. This is clearly visible in imaging and displacement of fat indirectly helps the radiologist to identify and quantify the extent of lesions involving parapharyngeal space. Parapharyngeal space is a hidden area that cannot be easily examined. Lesions of this space present rather late and in advanced stage. A surgeon will have to resort to imaging in order to visualize this area.

Paraph Imaging

Labyrinthitis ossificans

2011-03-20T22:49:00.000-07:00

Introduction:

The human bony labyrinth is composed of endosteal, enchondral and perisoteal layers. The endosteal layer consists of bone lined with a single layer of cells that have numerous gaps separating them. This layer is significantly thin. The enchondral layer is rather unique in that it reaches the adult size by 23 weeks of gestatation and undergoes minimal remodelling after the age of 2. The periosteal layer is composed of lamellar bone and is capable of bone remodelling and repair.

Labyrinthitis ossificans is the pathologic new bone formation within the lumen of otic capsule. This condition is always associated with profound deafness and loss of vestibular function. Cochlear ossification in this condition doesnot cross the endosteal layer or alter the architecture of the enchondral bone.

Causes of labyrinthitis ossificans:

Bacterial meningitis
Vascular obstruction to labyrinthine artery
Temporal bone trauma
Autoimmune inner ear disease
Leukemia
Tumors of temporal bone
Suppurative labyrinthitis following CSOM

Commonly involved portion of cochlea in this condition is scala tympani portion of the basal turn of the cochlea. This is more severe in patients with bacterial meningitis. Infections from inflammed meninges reach the inner ear via the cochlear aqueduct. Usually the cochlear aqueduct drains into the scala tympani close to the round window region. This is the reason why predominant ossification of the inner ear occurs in this area following bacterial meningitis. This creates lot of problem during cochlear implant electrode introduction via the round window. This ossified area should be drilled out with a microdrill inorder to insert the electrode in these patients.

According to Paperella labyrinthitis ossificans can be divided into three stages:

Acute stage – This stage is characterised by pus which fills up the perilymphatic spaces, sparing the endolymphatic space. This is followed by the formation of serofibrinous exudate.

Stage of fibrosis – This stage is characterised by fibroblastic proliferation within the perilymphatic spaces which usually begins two weeks after the onset of infection. This stage is also associated with new bone formation (angiogenesis).

Stage of ossification – This stage is characterised by bone formation and is first observed at the basal turn of the cochlea.

Theories proposed to explain the pathogenesis of labyrinthitis ossificans:

Paperella's theory: This theory was proposed by Paperella and Sigiura in 1967. They hypothesized that bone lining cells of the cochlea are plueripotent stem cells that remain uncomitted till they are stimulated to differentiate into osteoblasts.
Linthicum theory: Linthicum in 1985 said that bone originates from osteoblasts within the otic capsule. He also suggested that ectopic bone forms on the endosteal layer after an inflammatory insult.
Pericyte theory: This theory suggests that pericytes associated with blood vessels that supply the modiolus and spiral ligament have been hypothesized as cells of origin.

Effects of sectioning chorda tympani nerve during middle ear surgery

2011-03-14T04:10:00.000-07:00

Introduction:

The chorda tympani nerve is a branch of facial nerve. It derives all its fibers from the nervous intermedius of wrisberg. The chorda tympani nerve contains gustatory fibers from the anterior two thirds of the tongue and parasympathetic fibers to all the salivary glands excepting the parotid. Sectioning the chorda tympani nerve not only affects the taste but also reduces the basal secretion of salivary glands causing xerostomia.

Discussion:

The sublingual and submandibular salivary glands are responsible for about two thirds of the basal saliva production. The parotid gland contributes to just a third of the basal salivary production. Destruction / trauma to chorda tympani nerve on both sides can definitly cause dryness of mouth due to a reduction in the amount of saliva secreted by sublingual and submandibular salivary glands. Usually sectioning of one chorda tympani nerve will go unnoticed. When middle ear surgery is contemplated on both ears then the patient should be warned of the realistic risks of xerostomia. Caution should be exercised in operating on the opposite ear of patients who have already undergone middle ear surgery in the ipsilateral ear.

Hence all otologists should take extra care to preserve this nerve during middle ear surgical procedures.

Novel way of managing Little's area bleed in the nose

2011-03-06T01:29:00.000-08:00

Many a time we would have faced problems cauterizing a Little's area bleed. This is basically due to the use of nasal speculum

which obscures the field and also keeps one hand occupied. Bray in his " How I do it" describes how he put to use the Mallet spint.

Procedure:

A Mallet splint is a common tool used to treat Mallet (Trigger) finger. This splint is available in different sizes. It can be cut and introduced into the anterior nares.

This keeps the nasal cavity open providing a good view of nasal septum area. It also has the advantage of leaving both the surgeon's hand free.

The most proximal part of the Mallet splint is cut and shaped into a "U" shaped splint. This splint can be readily inserted into the nasal cavity.

Since this splint is made of silastic, its memory holds the nasal cavity open.

Since both the hands of surgeon are free the bleeder can easily be cauterized either by electro or chemical cautery.

Stack's splint

Physiology of deglutition a presentation

2011-03-02T06:11:00.000-08:00

I have uploaded a presentation titled "Physiology of deglutition"

Physiology of deglutition

View more presentations from Balasubramanian Thiagarajan

Theories of nasal polyposis

2011-02-27T04:00:00.000-08:00

Introduction:

During the past century several theories have been proposed to explain the etiopathogenesis of nasal polyposis. The fact that so many theories have been proposed is the evidence of our poor knowledge of this topic. Majority of these theories are based on tissue oedema, increase in the number of tubulo-alveolar glands, presence of cysts of mucous glands.

Adenoma fibroma theory of Billroth:

Billroth in his studies found a large number of tubular glands in the nasal polypoidal tissue studied. He concluded that these glands were not normally seen in such large numbers in the nasal mucosa. He hence interpreted nasal polyp to be adenomas that began growing under the nasal mucosa pushing the epithelium and nasal glands outwards. However Hopmann disagreed with this hypothesis saying that the glandular tissue found in the tissue samples of nasal polypi studied contained only mucous glands normally found in the nasal mucosa and concluded that nasal polypi could be soft fibromas and used the term fibroma theory to explain this. These two theories are not currently accepted at present.

Figure showing increase in the number of nasal mucosal glands

Figure showing development of nasal polypi due to increase in the number of nasal mucosal glands (Adenoma theory)

Necrotizing ethmoiditis theory of Woakes:

This theory suggests that ethmoiditis causes periostitis and ostitis of ethmoid bone causing bone necrosis. The necrotic bone initiates mucosal reaction leading on to mucosal oedema and polyp formation. This theory has been flawed from the very begining as no evidence of bone necrosis could be found in the polypoidal tissue studied so far.

Glandular cyst theory:

Evidently this theory is based on the presence of cystic glands and mucous filled cysts in the nasal polypoid tissue. The probable cause for the formation of these glandular cysts could be oedema of submucosa causing obstruction to the drainage of mucoid glands present in the nasal mucosa. These mucous cysts expands outwards pushing the nasal mucosa causing the polyp to occur. Taylor in his meticulous study has proved that mucous glandular cysts usually occur after the polyp has formed and hence he believed that glandular cysts could be caused by nasal polyposis and not vice versa.

Mucosal exudate theory of Hayek:

Hayek beleived that nasal polyp formed due to accumulation of exudate localised deep in the mucosa. This accumulation of exudate causes the mucosa to bulge leading to polyp formation. Nasal mucosal glands and tubuloalveolar glands are also

displaced outwards. These glands are hence found in the distal part of the polyp.

Theory of cystic dilatation due to obstruction of excretory ducts of nasal glands and blood vessel obstruction:

Figure showing cystic enlargement of nasal mucosal glands

Figure showing cyst formation prior to nasal polyposis

In chronic inflammation involving nasal mucosa blocks the excretory ducts of nasal tubulo alveolar glands causing the glands to dilate due to pent up secretions within. The blood vessels (capillaries and veins) surrounding these distending glands are also stretched. Stretching of these blood vessels impedes blood circulation and causes tissue oedema due to transudation of fluid. This theory is not valid due to the fact that dilatation of mucous glands occur only after formation of nasal polypoidal tissue.

Blockade theory of Jenkins:

This theory is based on the premise that development of nasal polypi is almost always preceded by certain degree of nasal mucosal inflammation. The inflammation could be the result of either infection / allergy. Histologically polyp itself is accumulation of intracellular fluid dammed up in a localized tissue. If this blockage persists polyp develop, if the blockage covers a large area then multiple polypi forms. This theory doesnt explain why nasal polyp prefers certain areas of nasal cavity.

Periphlebitis / perilymphangitis theory of Eggston and Wolff:

This theory is based on the premise that recurrent infections of nasal mucosa blocks intercellular fluid transport mechanism in the mucosa. This is always associated with oedema of lamina propria. This theory is based on the demonstration of chronic vascular changes in the nasal mucosa in response to inflammation. Histologically these changes are supposed to be rather diffuse and hence cannot be used to explain the pathogenesis of nasal polypi which can always be localised to certain areas of nasal cavity.

Glandular hyperplasia theory of Krajina:

According to Krajina chronic inflammation of nasal mucosa cause local hyperplasia of nasal mucosal glands. These hyperplastic glands will cause bulging of nasal mucosa. In addition to glandular hyperplasia changes that occur in the blood vessels will cause oedema in the region of the middle meatus. This in turn increases nasal mucosal oedema. Studies have shown that the number of nasal mucosal glands are the same in polypoidal as in the normal tissue.

Epithelial rupture theory:

This is the currently proposed theory. In this theory the initial stage of nasal polyp formation starts of as epithelial rupture possibly due to inflammation and tissue oedema. This is followed by prolapse of lamina propria through the defect. The adjacent epithelium attempts to cover up the defect there by forming a lining for the polypoidal tissue. If the defect in the epithelium is not covered up real fast the prolapsed lamina propria continues to grow and the polyp complete with its stalk develops. After epithelization of the polyp the characteristic new long tubular glands are formed.

Figure showing Exudate forming under the nasal mucosa (Exudative theory)

Figure showing nasal polyp forming after accumulation of exudate

Figure showing rupture of epithelium

Figure showing development of nasal polyp following epithelial rupture

Role played by mucous glands:

The glandular elements seen in the nasal polypoidal tissue are nasal glands. Commonly seen glands are degenerated long glands. The entire long duct along with their lateral branches are distended due to filled up secretions. Due to the pent up secretion and distention the secretory epithelium of the nasal gland become cuboidal and flat losing their secretory ability. This is followed by degeneration of the gland.

Role played by cellular infilatrates:

Eosinophilic infiltration is an important feature in the pathogenesis of chronic rhinosinusitis and nasal polypi. Accumulation of eosinophils in the polyp stroma is basically caused by increased transendothelial migration, increased survival, and increased concentration of interleukin 5.

Role of imaging in nasal polyposis

2011-02-23T20:47:00.000-08:00

Introduction:

Imaging plays a crucial role in the diagnosis and management of nasal polypi. The following are some of the important contributions imaging is supposed to make:

It clinches the diagnosis
It helps in evaluation of progression of disease
Helps in surgical planning
Helps in monitoring for recurrence

CT scan is the primary imaging modality used to evaluate patients with chronic sinusitis with nasal polyposis. MRI has only a limited role to play and is used only sparingly. Imaging may be really vital and could even replace diagnostic nasal endoscopy in patients whose nasal cavities are completely filled with polypi and is virtually impossible to perform diagnostic evaluation using a nasal endoscope. This scenario is tailor made for imaging.

CT appearance of nasal polypi:

They appear as rounded bodies of soft tissue arising from the mucosal surfaces of nose and paranasal sinuses. They can be clearly differentiated from the surrounding inflammed mucosal lining and nasal secretion as they are more radio dense and hence appear brighter. Rarely a pedicle attaching the polypoidal mass to the nasal mucosal lining can be seen clearly in the CT scan (pedicle sign). If present it is virtually diagnostic of nasal polypi.

One important point that should be borne in mind while evaluating CT images from a patient with nasal polypi is that they never cause bone erosion. If soft tissue mass arising from the nasal mucosa is associated with bone erosion then it is a definite pointer towards the diagnosis of malignancy. Pressure effects of nasal polyp can be evidently seen in imaging. These effects include local bone remodelling causing a scalloping effect. This scalloping effect should not be confused with that of the scalloping of margins produced by the mucocele since it is always associated with enlargement of the sinus cavity. Rarely this bone remodelling may occasionally cause thinning of the bony septa of the ethmoidal sinus. This thinning could be so extreme that it could go even below that of the resolution of the CT scan. This creates a picture of bone erosion which is not a true one.

Appearance of nasal polyp when contrast CT is taken:

Nasal polypi do not show enhancement on injection of contrast media. The mucosa surrounding the nasal polyi may show enhancement causing an impression of rim enhancement around the nasal polypi.

Types of nasal polyp:

Ethmoidal polypi – arising from ethmoidal sinus and are multiple. They can be visualised in the CT scan of paranasal sinuses as multiple polypoid lesions. Polypi arising close to the cribriform plate area can cause olfactory disturbances.

Polyp arising from the maxillary sinus – is usually solitary. It exits the antrum via the natural / accessory ostium. This causes an enlargement of ostia. Radiologically it appears like a dumbbell because of the constriction present in the midline (ostial exit point). In these patients the medial wall of the maxillary sinus bows into the nasal cavity. This can be clearly visualised in the CT scan images. Obstruction caused by this polyp to the drainage channels of ethmoidal and frontal sinuses (middle meatus) can cause opacification of those sinuses also there by making it difficult to identify the exact origin of the nasal polyp. In this scenario the bone remodelling that takes place in the medial wall of maxillary sinus could be the clincher. If these polyp passes posteriorly to exit via the choana it could be clearly visualized in the axial cuts taken at the choanal level.

Fungal disease may coexist with nasal polypi. If present they could be visualized as hyperdense areas between the nasal polypi shadows.

CT differences between acute sinusitis & nasal polypi:

Acute sinusitis causes a near uniform opacification of the paranasal sinuses whereas nasal polypi inaddition to the opacification show multiple convexities.

Mucous retention cyst can be safely eliminated if the polypo shows a pedicle radiologically. If there is associated bone remodelling then in all probability it could be nasal polyp rather than mucous retention cyst. In case of diagnostic dilemma MRI will clinch the diagnosis.

In cystic fibrosis in addition to the radio densities seen in the CT scan images there is also associated thickening of the maxillary sinus walls due to osteoneogenesis.

Coronal CT nose and paranasal sinuses showing nasal polyposis with associated bone remodelling

Axial CT paranasal sinuses showing mucous retention cyst of maxillary sinus

Coronal CT nose and PNS showing fungal sinusitis involving the maxillary sinus. Note hyperdense specs could be seen inside the cavity of the sinus in addition to soft tissue opacity

Squamous cell carcinoma of thyroid diagnostic & management dilemma

2011-02-20T01:28:00.001-08:00

Introduction:

Squamous cell carcinoma involving thyroid gland is an extremely rare condition. To label a thyroid tumor as squamous cellcarcinoma the tumor should be entirely composed of tumor cells with squamous differentiation. This condition should be differentiated from:

Papillary carcinoma thyroid containing patches of sqamous epithelium

Anaplastic carcinoma of thyroid containing patches of squamous elements

Adenosquamous carcinoma thryoid which may contain both adeno and squamous elements.

Causes of squamous cell carcinoma thyroid:

Primary squamous cell carcinoma thyroid

Secondary involvment of thyroid gland by tumor extention from adjacent structures

Metastatic involvmement of thyroid gland from adjenct sites like lungs, head and neck, GI tract

Primary squamous cell carcinoma involving thyroid gland is an extremely rare condition affecting about 1% of all the primary thryoid malignancies. Histologically the thyroid gland does not normally contain squamous epithelium that is the reason why this condition is pretty rare. Several hypothesis have been proposed to explain the genesis of squamous cell carcinoma in the thyroid gland.

Goldberg & Harvey theory:

This is one of the earliest theories proposed to account for the development of squmaous cell carcinoma in the thyroid gland. This theory is based on the concept that embryonic remnant of thyroglossal cyst contained squamous elements. Under normal circumstances thyroglossal duct involutes. Persistence of this duct and the related squamous elements happens to be the crux of this theory. Anatomically the lower portion of thyroglossal duct happens to be the pyramidal lobe of thyroid gland. If this theory is true then squamous cell carcinoma of thyroid gland should commonly involve the pyramidal lobe. In reality this tumor is commonly seen in the lateral lobes of thyroid thus puts a question mark on the validity of this theory.

Branchial arch theory:

Branchial arch elements which include ultimobranchial body and thymic epithelium could probably be the source for squamous elements in the thyroid gland.

Metaplastic theory:

This happens to be the more recent one. It says that squamous elements seen in the thyroid gland could have arisen due to metaplasia of normal thyroid cells. Even this theory has its own achilles tendon. The commonest cause for squamous metaplasia in thyroid gland happens to be Hashimoto's thyroiditis. Studies have shown that it is rare for these patients to develop squamous cell carcinoma of thyroid gland.

Gulisano theory:

Gulisano suggested that squamous elements could reach the thyroid gland as direct invasion from adjacent areas like larynx, pharynx and oesophagus. He demonstrated this theory by injecting methylene blue dye in the pyriform fossa before performing thyroidectomy. Superior portion of the thyroid gland was found stained by the dye. This demonstrates that there is a communication between these areas for potential tumor spread.

Clinical features:

Clinically these tumors are very aggressive, infact as aggressive as anaplastic carcinoma. These patients usually present with rapidly increasing neck mass with evidence of involvment of strap muscles, tracheal compression and oesophageal compression.

Role of Imaging:

Allows differentiation of thyroid mass from other neck lumps

Helps in assessing adjacent organs like larynx and oropharynx

Assess oesophageal and tracheal involvement

Prognosis:

Is very poor because of its radioresistance.

Management:

Total thyroidectomy followed by irradiation is the accepted modality. Patients with secondary deposits in the cervical nodes should undergo neck dissection procedures.

Role of inflammation in nasal polyposis

2011-02-19T08:56:00.000-08:00

Introduction:

Nasal polyp is not simple oedema of the mucous membrane of the lateral nasal wall, instead it is a denovo inflammatory growth of the mucosa of the lateral nasal wall in the area of uncinate process and bulla mucosa.
Characteristic features of nasal polyp include:

1. Basal cell hyperplasia
2. Goblet cell hyperplasia
3. Squamous metaplasia (rare)

Features seen in lamina propria:

1. Oedema
2. Lymphocytosis
3. Eosinophils
4. Degenerated cystic glands filled with mucin

Among the above mentioned factors eosinophils, lymphocytes, and oedema of lamina propria play important roles in the genesis of nasal polyp. Studies have demonstrated that risk of developing nasal polyp may be linked to the small arm of chromosome 6. This area of chromosome 6 contains

1. HLA antigens
2. Complement
3. Heat shock protein
4. Proinflammatory gene – TNF α

The HLA genes and the proinflammatory genes are transmitted together from parent to offspring.

Role played by Staph aureus exotoxins in the genesis of nasal polyp:

Exotoxins produced by Staph aureus act as super antigens. They stimulate IgE response against them. The presence of Staph aureus exotoxins and IgE response to them are two potent mediators that could trigger the mucosal lining of lateral nasal wall into developing nasal polyp. Studies have also demonstrated that TNF α levels in patients with nasal polyp was four times more than that present in normal controls. TNF α is a potent immunomediator and proinflammatory cytokine that has been implicated in a large number of human diseases that include nasal polypi, periodontal diseases, irritable bowel syndrome etc.

Cytokines in nasal polypoid mucosa:

The following cytokines have been demonstrated in large quantities in nasal polyp tissue:

1. TNF α
2. IL1-β
3. VCAM – 1
4. RANTES
5. Cotaxin

TNF α and VCAM -1:

TNF α is produced primarily by macrophages and T cells. It was initially known for its antitumor and cytotoxic activity. Studies have now revealed that they play a vital role in evoking inflammatory process. TNF α is known to upregulate VCAM – 1 in fibroblasts present in the nasal mucosa. This upregulation takes place via NF-kβ pathway in the nasal fibroblast. This upregulation of VCAM -1 in the nasal fibroblasts play a vital role in the pathogenesis of nasal polypi. Hence there is a strong rationale in the use of anti NF-kβ drugs in the management of inflammatory nasal polypi. The eosinophils that accumulate in the polypoidal tissue can also synthesize TNF – α causing the vicious cycle to continue. The presence of TNF-α can increase the secretion of chemokines which attracts eosionphils into the polypoidal tissue.
TNF-α increases the secretion of cotaxin and also expression of RANTES from the fibroblasts present in the nasal polypi.

Role of eosinophil changes in alterations of electrophysiology of nasal mucosa:

The substances produced by eosinophils i.e. Eosinophilic mediator and Major Basic Protein increases the permeability of nasal mucous membrane to water. This is caused due to changes that take place in the sodium gate mechanism present in the mucosal cell wall. This excess permeation of water into the nasal mucosa is the cause for mucosal oedema (the most prominent histopathological findings seen in nasal polypi). Polyp epithelia show increased sodium absorption which in turn is followed by water.

Role of eosinophils in Nasal polyposis

2011-02-19T02:37:00.000-08:00

Introduction:

Nasal polyposis is a difficult problem to manage because of its high recurrence rate, incomplete understanding of the various pathophysiological factors involved. No specific etiological factor has been attributed to the development of nasal polypi. Hence the current understanding is that it could be caused by multiple different diseases with varying degrees of severity. That is the reason why categorization of unique presentations of nasal polypi will help in better understanding of etiopathogenesis of nasal polypi.

Studies pertaining to different categories of nasal polypi have identified three disease categories of nasal polypi which show prominent tissue eosinophil infiltration. These include:

Chronic hyperplastic eosinophilic sinusitis
Allergic fungal sinusitis
Aspirin induced hypersensitivity

A brief account of development of eosinophils:

Eosinophils develop from the pleuripotent stem cells of bone marrow. These pleuripotent stem cells differentiates into eosinophil / basophil progenitors.

Transcription factors responsible for stimulating the stem cells to produce cells of eosinphil lineage:

GATA-1
PU.1
C/EPB

Among these three transcription factors GATA-1 is the primary transcription factor responsible for eosinophil differentiation of stem cells.

Cytokines responsible for development of eosinophil lineage:

IL-3
IL-5
Granulocyte macrophage colony stimulating factor

Among these cytokines IL-5 is responsible for selective terminal differentiation of eosinophils. It also stimulates the release of eosinophils from the bone marrow into the peripheral circulation. Studies have shown that anti IL-5 drugs when administered have reduced significantly the number of circulating eosinophils. Blocking the tissue effects of these cytokines may significantly lower the number of circulating / tissue eosinophils.

Factors responsible in attracting eosinophils into tissues:

The process of chemotactic migration of eosinophils to the tissues is known as recuritment. This process of recruitment is facilitated by:

Cytokines
Chemokines
Inflammatory mediators

Platelet activation factor is the most potent inflammatory mediator which induces migration of eosinophils (selective) to the tissues. This is usually secreted by mast cells, endothelial cells, macrophages, neutrophils and eosinophils. Eosinophils migrate preferentially to tissues exposed to environment i.e. (nose, gut and lungs). Human tissuee eosinophils is 100 times more in number than eosinophils circulating the the blood.

Many cytokines play a vital role in eosinophil mediated inflammtion by prolonging its life. The classic example of such substance is Tumor Necoris Factor alpha.

Activation of eosinophils causes release of various biological products, the most prominent of them is the granule protein which is cationic and toxic to numerous helminths thus playing a vital role in the body's defence against helminthic infections.

Substances produced by activated eosinophils:

Major basic protein
Eosinophil cationic protein
Eosinophil derived neurotoxin
Chemokines

Management of eosinophilic sinusitis:

Accumulation of eosinophils in the nasal mucosa is seen in:

1. Chronic hyperplastic eosinophilic sinusitis

2. Allergic fungal sinusitis

3. Aspirin induced hypersensitivity

These conditions can be pharmacologically manaaged by:

Leukotrienes modifiers – Drugs belonging to this group reduces eosinophil recruitment and activation. Zafirleukast and Monteleukast are classic examples of drugs belonging to this group.

IL-5 blocking – Mepolizumab. This is humanized anti IL-5 drug.

Etiopathogenesis of antrochoanal polyp various theories

2011-02-14T21:38:00.001-08:00

Etiopathogenesis: This disease is commonly seen only in non atopic persons. Its etiology is still unknown. Infact this disorder is not associated with nasal allergy.
Proetz theory: Proetz suggested that this disease could be due to faulty development of the maxillary sinus ostium, since it was always been found to be large in these patients. Hypertrophic mucosa of maxillary antrum sprouts out through this enlarged maxillary sinus ostium to get into the nasal cavity. The growth of the polyp is due to impediment to the venous return from the polyp. This impediment occur at the level of the maxillary sinus ostium. This venous stasis increases the oedema of the polypoid mucosa thereby increasing its size.

Bernoulli's phenomenon: Pressure drop next to a constriction causes a suction effect pulling the sinus mucosa into the nose.

Mucopolysaccharide changes: Jakson postulated that changes in mucopolysaccharides of the ground substance could cause nasal polyp.

Infections: Recurrent nasal infections have also been postulated as the cause for nasal polyp

Mill's theory:

Mills postulated that antrochonal polyp could be maxillary mucoceles which could be caused due to obstruction of mucinous glands.

Ewing's theory:Ewings suggested that an anomaly which could occur during maxillary sinus development could leave a mucosal fold close to the ostium. This fold could later be aspirated into the sinus cavity due to the effects of inspired air causing the development of antrochonal polyp.

Vasomotor imbalance theory: This theory attributes polyp formation due to autonomic imbalance

Polypoidal tissue from the maxillary antrum exits out through the accessory maxillary sinus ostium according to some workers. This accessory sinus ostium is placed posteriorly, which could be the reason for the polyp to present posteriorly. The accessory sinus ostium widens progressively, ultimately at one stage merging with the natural ostium of the maxillary sinus forming one huge opening into the maxillary antrum.

Infection / Inflammation:
This theory suggests that acinous mucous glands within the maxillary sinus cavity gets blocked due to infection / inflammtion involving the mucous lining of the sinus cavity. This leads to the formation of a cystic lesion within the maxillary sinus cavity. This cyst gradually enlarges to occupy the whole of the maxillary sinus cavity. It exits the sinus cavity by enlarging the accessory ostium and enters the nasal cavity. Usually these cysts arise from the antero inferior / medial wall of maxillary antrum.
Possible reasons for migration of antrochoanal polyp in to the post nasal space:

1. The accessory ostium through which the polyp gets out of the maxillary antrum is present posteriorly.

2. The inspiratory air current is more powerful than the expiratory air current thereby pushes the polyp posteriorly.

3. The natural slope of the nasal cavity is directed posteriorly, hence the polyp always slips posteriorly.

4. The cilia of the ciliated columnar epithelial cells lining the nasal cavity always beats anteroposteriorly pushing the polyp behind.