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DNB Otorhinolaryngology — Paper (Otology Focus)

Complete 10-Mark Answers

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Q1. [10 Marks]

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a) Intratemporal Facial Nerve — Branches and Diagram [5 marks]

• Runs from the fundus of IAC to the geniculate ganglion
• Located between the cochlea (anteriorly) and vestibule (posteriorly)
• Branch: Greater Superficial Petrosal Nerve (GSPN) — arises from the geniculate ganglion; carries preganglionic parasympathetic fibres to the pterygopalatine ganglion → lacrimal gland, nasal glands

• Runs from geniculate ganglion to the pyramidal eminence
• Branch: Lesser Petrosal Nerve (via tympanic plexus, Jacobson's nerve)
• Branch: Nerve to Stapedius — arises from proximal mastoid segment; supplies stapedius muscle

• Runs from pyramidal eminence to stylomastoid foramen
• Branch: Chorda Tympani — arises 5–6 mm above stylomastoid foramen; carries taste from anterior 2/3 tongue and preganglionic fibres to submandibular/sublingual glands

                     ┌─────────────────────────────────┐
IAC → Labyrinthine   │  GSPN (geniculate ganglion)      │
      Segment        └─────────────────────────────────┘
           ↓
      Tympanic       ─── Nerve to Stapedius (pyramidal eminence)
      Segment        
           ↓
      Mastoid        ─── Chorda Tympani (5–6mm above stylomasoid foramen)
      Segment        
           ↓
    Stylomastoid     ─── Posterior Auricular Nerve
      Foramen             (occipital belly of occipitofrontalis, auricular muscles)
           ↓
    Extratemporal branches (Temporal, Zygomatic, Buccal, Marginal Mandibular, Cervical)

• The geniculate ganglion is the genu (bend) where GSPN exits
• The nerve runs horizontally above the oval window in the tympanic segment
• The second genu (posterior genu) is where it turns inferiorly
• Chorda tympani passes through the middle ear between malleus and incus, exits via the petrotympanic fissure

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b) Electrodiagnostic Tests in Facial Palsy — Significance for Prognosis [5 marks]

• A constant current is applied to the main trunk of the facial nerve at the stylomastoid foramen
• The minimum current (mA) required to produce visible muscle twitch is recorded and compared with the normal side
• Significance: Difference >3.5 mA between sides = degeneration occurring; >20 mA difference = poor prognosis. Simple screening test, but crude.

• Supramaximal stimulation applied bilaterally; response graded: Equal / Slightly reduced / Markedly reduced / Absent
• Significance: Absent or markedly reduced response on affected side suggests > 90% degeneration → poor prognosis.

• The most reliable electrodiagnostic test
• Supramaximal stimulation at stylomastoid foramen → compound muscle action potential (CMAP) recorded from nasolabial fold
• Significance: Compares amplitude of CMAP on affected vs. normal side

  • 90% degeneration within 14 days of complete palsy → poor prognosis → indication for surgical decompression

  • <90% degeneration → good prognosis, conservative management
• Limitation: Only reliable in complete paralysis; not valid for partial paralysis

• Direct recording of muscle electrical activity using needle electrodes into facial muscles
• Findings:
  • Fibrillation potentials / positive sharp waves = complete degeneration (appear 10–14 days after injury)
  • Polyphasic reinnervation potentials = nerve regeneration occurring (good prognostic sign)
  • Normal motor units = intact neural continuity
• Significance: Most useful for detecting early reinnervation; can be performed at any stage; guides timing of decompression

• Measures conduction time from stylomastoid foramen to orbicularis oculi
• Normal latency = 3–4 ms
• Significance: Increased latency or absent response = poor prognosis

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Q2. [10 Marks]

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a) Clinical Features of Cerebellar Abscess [5 marks]

• High-grade fever with rigors
• Severe headache (occipital and suboccipital)
• Nausea and vomiting (projectile in nature due to raised ICP)
• Altered sensorium, drowsiness, lethargy
• Neck stiffness (meningism if meningeal irritation)

• Bradycardia with hypertension (Cushing's response)
• Papilloedema (seen on fundoscopy)
• Diplopia due to 6th nerve palsy (false localizing sign)

• Ataxia — wide-based, staggering gait (inability to walk in tandem)
• Dysmetria — finger-nose test, heel-shin test abnormal
• Dysdiadochokinesia — inability to perform rapid alternating movements
• Intention tremor — worsens on approaching target
• Nystagmus — ipsilateral horizontal nystagmus (slow phase toward lesion)
• Hypotonia — ipsilateral limb hypotonia
• Positive Romberg test — falls toward the side of the lesion
• Dysarthria (scanning speech) — slurred, staccato speech
• Limb ataxia — ipsilateral arm and leg incoordination (past-pointing)

• Bruns nystagmus — coarse nystagmus looking toward lesion (cerebellar compression) and fine nystagmus away from lesion (vestibular involvement)
• Obstructive hydrocephalus may develop from 4th ventricle compression → sudden deterioration

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b) Management of Otogenic Cerebellar Abscess [5 marks]

1. Airway, breathing, circulation — ICU care
2. IV antibiotics: high-dose penicillin G or cefotaxime + metronidazole (covers anaerobes from ear)
3. Control raised ICP: IV mannitol 20% (1g/kg), head elevation 30°, restricted fluids
4. Steroids: Dexamethasone to reduce cerebral edema
5. Anticonvulsants if seizures occur
6. Neurosurgery consult immediately

1. CT scan brain with contrast (ring-enhancing lesion in posterior fossa — FIRST DONE)
2. MRI brain — better delineation, satellite lesions, differentiates from tumor
3. Stereotactic aspiration — preferred for accessible, well-formed abscess
   • CT/MRI-guided needle aspiration of pus
   • Pus sent for C/S, gram stain, AFB, fungal culture
4. Craniotomy and open drainage — for:
   • Large abscess
   • Failed aspiration
   • Posterior fossa decompression needed
   • Multiloculated abscess
5. External ventricular drain (EVD) — if hydrocephalus develops

• Timing: Ear surgery (mastoidectomy) is performed after the abscess is controlled and patient is stable
• Procedure: Modified radical mastoidectomy (MRM) / Canal wall down mastoidectomy
  • Removes the focus of infection (cholesteatoma, infected mastoid)
  • Drained via mastoid route if abscess is extradural
• Simultaneous surgery is considered if patient is fit and abscess is accessible via posterior mastoid approach

• IV cefotaxime 2g TDS + metronidazole 500mg TDS for 6–8 weeks
• Modified based on culture/sensitivity
• Transition to oral antibiotics after clinical improvement

• Serial CT scans to monitor resolution
• Repeat aspiration if needed
• Audiological rehabilitation after recovery

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Q3. [10 Marks]

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a) Clinical Examination for Spontaneous Nystagmus in OPD [2 marks]

1. Frenzel Glasses (+20 diopter lenses) — preferred; removes visual fixation which suppresses peripheral nystagmus, making it visible
2. Alternatively, examine in dim room with patient asked to fixate on a distant point
3. Observe eye movements in primary gaze (straight ahead), then with gaze 30° to right, left, up, and down (not >30° to avoid endpoint nystagmus)
4. Note: direction (defined by fast phase), amplitude, frequency, plane (horizontal/vertical/torsional), effect of gaze direction
5. Perform with and without fixation to determine if fixation suppresses nystagmus

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b) Differentiation Between Central and Peripheral Nystagmus [5 marks]

• Head Impulse test: Negative in central
• INystagmus: Direction-changing in central
• Test of Skew: Present in central → One central feature = stroke until proven otherwise

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c) Grades of Nystagmus (Alexander's Classification) [3 marks]

• Nystagmus is present only when the eye looks in the direction of the fast phase
• Absent in primary gaze and gaze away from fast phase
• Mildest form — usually indicates early or resolving peripheral vestibular lesion

• Nystagmus present when looking in the direction of the fast phase AND in primary (straight) gaze
• Absent only when looking in direction of slow phase
• Moderate severity

• Nystagmus present in all three directions of gaze — including when looking in the direction of the slow phase
• Most severe
• Indicates significant vestibular imbalance or central pathology

• Most spontaneous peripheral nystagmus starts as Grade II–III acutely and resolves to Grade I with compensation
• Grade III nystagmus persisting beyond 6–8 weeks suggests central pathology
• Asymmetric slow-phase velocity (measured by ENG/VNG) quantifies vestibular hypofunction

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Q4. [10 Marks]

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a) Define Otosclerosis [1 mark]

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b) Clinical Features and Audiological Evaluation of Otosclerosis [3 marks]

• Progressive bilateral conductive hearing loss (bilateral in 75%), typically starting in 3rd decade
• Female predominance (2:1), worsened by pregnancy
• Paracusis Willisii — paradoxical improvement of hearing in noisy environments (because others raise their voice)
• Tinnitus — low frequency, pulsatile
• Normal tympanic membrane — no scarring, perforation or effusion
• Schwartze sign — reddish-pink blush through the tympanic membrane due to increased vascularity of active otospongiotic focus on promontory (flamingo pink sign)
• Negative Rinne test (BC > AC) with 512 Hz fork
• Weber lateralizes to the worse ear (or bilaterally to the more involved ear)

1. Pure Tone Audiometry (PTA):
   • Air-bone gap (ABG) — predominantly in low frequencies
   • Carhart notch — mechanical depression of bone conduction at 2000 Hz (~15 dB) due to stapes fixation impairing mechanical advantage of ossicular chain (disappears after stapedectomy)
   • ABG usually >25 dB
2. Immittance Audiometry (Tympanometry + Acoustic Reflexes):
   • Tympanogram: Type As (shallow/reduced compliance) due to stiffness of ossicular chain
   • Acoustic stapedial reflexes: Absent (ipsi and contralateral)
   • On-off effect / Diphasic reflex — early finding: brief negative deflection at onset/offset of tone (indicates early fixation)
3. Speech Audiometry: Good speech discrimination score (SDT ~25 dB, excellent word recognition)

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c) Methods for Fenestration of Stapes Footplate and Advantages of LASER [2 marks]

1. Manual perforators (picks/needles) — traditional method; risk of plunging and sensorineural hearing loss
2. Microdrill (rosette drill or trapeze drill) — controlled; risk of vibration trauma
3. LASER — preferred modern technique

• Non-contact technique — no mechanical pressure transmitted to inner ear fluids
• Bloodless — vaporizes tissue with minimal hemorrhage
• Precise and controlled perforation — reduces risk of plunge injury to inner ear
• Reduced vibration trauma to cochlear structures compared to drill
• Can vaporize a thickened/obliterated footplate safely
• Reduces risk of floating footplate
• Stapes crurotomy (vaporization of stapes arch) also possible with laser, avoiding manual fracture
• Shorter learning curve; reproducible results

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d) Complications of Stapedectomy [4 marks]

1. Perilymph gusher — sudden flooding of perilymph (associated with X-linked progressive mixed deafness, Mondini malformation, wide IAC)
2. Floating footplate — the entire footplate sinks into vestibule (requires Gelfoam packing and abandonment of procedure)
3. Depressed footplate fragment — fragment pushed into vestibule
4. Facial nerve injury — especially if dehiscent facial canal
5. Chorda tympani injury — taste disturbance, dry mouth
6. Tympanic membrane tear
7. Incus subluxation / dislocation during prosthesis placement

1. Sensorineural hearing loss (SNHL) — most feared complication; due to perilymph leak, acoustic trauma, infection
2. Vertigo — mild transient vertigo is expected; severe prolonged vertigo suggests inner ear injury
3. Perilymph fistula — prosthesis displacement with fistula at footplate
4. Infection / labyrinthitis — may cause profound SNHL
5. Reparative granuloma — eosinophilic mass around prosthesis, presents with SNHL + vertigo at 2–6 weeks; requires surgical removal

1. Prosthesis displacement or extrusion — re-conductive hearing loss
2. Re-fixation of stapes / ossicular chain — recurrence of otosclerosis
3. Adhesions — tympanosclerosis around prosthesis
4. Tympanic membrane retraction / perforation
5. Delayed perilymph fistula
6. Cochlear otosclerosis progression — progressive SNHL despite successful surgery

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Q5. [10 Marks]

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a) Impedance Audiometry Curves and Clinical Significance [5 marks]

• Peak compliance between −100 and +50 daPa
• Normal peak height (0.3–1.6 mL)
• Clinical significance: Normal middle ear pressure and mobility → Normal middle ear
  • Type As (Shallow/Stiff): Reduced compliance peak (<0.3 mL); normal peak pressure
    • Clinical significance: Increased stiffness — Otosclerosis, tympanosclerosis, malleus fixation
  • Type Ad (Deep/Hypermobile): Exaggerated compliance peak (>1.6 mL)
    • Clinical significance: Hypermobility — Ossicular discontinuity, flaccid TM, thin TM, monomeric membrane

• No discernible compliance peak; flat tracing across all pressures
• Clinical significance:
  • Middle ear effusion (otitis media with effusion) — most common cause
  • Large TM perforation (with large ear canal volume >2 mL)
  • Occluded/obstructed probe tip
  • Adhesive otitis

• Peak compliance is significantly negative (< −100 daPa)
• Clinical significance: Eustachian tube dysfunction — negative middle ear pressure due to failure of ET to equalize; early OME, resolving OME, aerotitis media

• Stapedius muscle contracts reflexly to loud sounds (85 dB above pure tone threshold)
• Tested at 500, 1000, 2000, and 4000 Hz
• Absent ipsilateral reflex + Present contralateral reflex = conductive hearing loss in probe ear
• All reflexes absent = severe SNHL or ossicular fixation (otosclerosis)
• Acoustic reflex decay (Carhart decay test): Reflex amplitude decays >50% within 10 seconds at 500 or 1000 Hz = retrocochlear pathology (acoustic neuroma)

• If reflex present at normal threshold or slightly elevated = cochlear SNHL
• If reflex absent or elevated >20 dB above PTA threshold = retrocochlear

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b) Stenger's Principle [2 marks]

"When two tones of the same frequency are presented simultaneously to both ears, the person is only aware of the tone in the ear in which it is louder."

• Used when there is a claimed unilateral hearing loss
• A tone is presented 10 dB above the claimed threshold of the "bad ear" AND 10 dB below the threshold of the "good ear"
• Positive Stenger test (confirms malingering):
  • The patient with true unilateral deafness would hear the tone in the better ear and respond
  • The malingerer, being aware only of the louder tone in the "deaf ear" (which they claim not to hear), will not respond even though the tone is audible in the good ear
  • No response = Positive Stenger = Malingering confirmed
• Negative Stenger test: Patient responds → genuine hearing loss in that ear

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c) Clinical and Audiological Tests to Establish Malingering [3 marks]

• History inconsistent with audiometric findings
• Exaggerated, dramatic responses
• Audiogram: flat, unvarying thresholds; inconsistent thresholds on repeat testing
• Normal speech discrimination despite claimed severe loss

1. Stenger Test (described above) — most specific; for unilateral claimed loss
2. Lombard Test: Patient reads aloud; white noise played into both ears; a hearing person automatically raises voice (Lombard effect); a malingerer claiming deafness who raises voice is detected
3. Chimani-Moos Test / Bing Weaver Test: Tuning fork (512 Hz) placed on vertex; in a true unilateral deafness, patient hears in good ear; in malingering, may deny hearing it
4. Doerfler-Stewart Test: Uses white noise and spondee words; measures "noise interference level" vs. "speech reception threshold"; if noise interference level < SRT = malingering
5. Delayed Auditory Feedback (DAF): Speaking voice fed back to the patient with a delay; normal-hearing subjects automatically slow speech and stutter; a malingerer claiming deafness will show this effect, exposing them
6. Puretone Audiometry Inconsistency:
   • Threshold varies >±10 dB on repeated tests at same frequency
   • Shadow curve absent in claimed total unilateral deafness (should appear at 50–60 dB due to cross-hearing)
7. Objective tests (conclusive):
   • Otoacoustic Emissions (OAEs) — present in normal cochlear function despite claimed hearing loss
   • Auditory Brainstem Response (ABR/BERA) — objective threshold estimation; patient cannot fake this

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Q6. [10 Marks]

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a) Differentiation Between Case Control and Cohort Study [4 marks]

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b) Odds Ratio and Relative Risk [4 marks]

• RR = 1: No association (exposure has no effect)
• RR > 1: Positive association (exposure increases risk)
• RR < 1: Protective association

• OR ≈ RR when the disease is rare (rare disease assumption)
• OR = 1: No association
• OR > 1: Positive association
• OR < 1: Protective association

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c) Impact Factor and Its Relevance [2 marks]

1. Research quality assessment: High-IF journals (e.g., NEJM IF ~80, Lancet IF ~60) publish more frequently cited, influential research
2. Career advancement: Publication in high-IF journals carries more academic weight for promotions, grants, fellowships
3. Library decisions: Institutions use IF to decide journal subscriptions
4. Peer review quality indicator: Journals with higher IF tend to have more rigorous peer review

• Varies by specialty (ENT journals typically IF 2–5, basic science >20)
• Does not measure individual article quality
• Can be gamed (self-citation, review articles inflate IF)
• Not applicable to conference papers, books, case reports
• Alternative metrics: H-index, CiteScore, Altmetric

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Q7. [10 Marks]

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a) Composition of Endolymph and Perilymph [2 marks]

• Maintained by the stria vascularis (metabolically active epithelium)
• Endolymphatic potential: +80 mV (endocochlear potential)
• Volume: ~3 μL (cochlear) + small vestibular volume

• Communicates with CSF via the cochlear aqueduct (scala tympani perilymph)
• Volume: ~78 μL
• Membrane potential: ~0 mV

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b) Etiological Factors for Primary Endolymphatic Hydrops (Menière's Disease) [3 marks]

1. Endolymphatic sac dysfunction — most widely accepted; impaired endolymph resorption by the endolymphatic sac and duct → accumulation
2. Viral etiology — herpes simplex virus (HSV-1) DNA found in endolymphatic sac; EBV, CMV implicated; viral endolabyrinthitis causing sac fibrosis
3. Autoimmune mechanism — antibodies against inner ear antigens; associated with autoimmune diseases (Hashimoto's thyroiditis, SLE, rheumatoid arthritis); responds to steroids
4. Genetic factors — familial Menière's disease in ~10%; HLA-Cw7 association; endolymph homeostasis gene mutations (AQP2, aquaporin channels, SLC26A4/pendrin)
5. Allergy — food allergies and inhalant allergies may trigger attacks via immune-mediated endolymphatic sac inflammation
6. Vascular ischemia — microvascular compromise of stria vascularis or endolymphatic sac affecting Na/K-ATPase pump function
7. Anatomical abnormalities — narrow vestibular aqueduct, small endolymphatic sac
8. Hormonal — association with hypothyroidism, ADH dysregulation (water retention)
9. Psychosomatic — stress and anxiety trigger attacks via sympathetic stimulation affecting cochlear blood flow

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c) Surgical Modalities for Managing Menière's Disease [5 marks]

• Complete removal of membranous labyrinth
• Indications: Unilateral Menière's with non-serviceable hearing (PTA >50 dB, SDS <50%)
• Approaches: Transcanal (endaural), transmastoid
• Results: Eliminates vertigo in >95%
• Cons: Permanent profound ipsilateral hearing loss; contralateral compensation required

• Selective section of the vestibular nerve (via middle cranial fossa or retrosigmoid approach) while preserving cochlear nerve
• Indications: Serviceable hearing with disabling vertigo
• Results: Vertigo control ~90%; hearing preserved
• Cons: Major intracranial procedure; risks of SNHL, CSF leak, meningitis

• Aminoglycoside selectively toxic to type I vestibular hair cells
• Delivered via intratympanic injection through TM
• Low-dose protocols: Single injection + wait for response (reduces risk of SNHL)
• Results: 80–90% vertigo control; ~15–30% risk of SNHL
• Preferred for elderly, unfit for general anesthesia, non-serviceable hearing

• Most common hearing-preserving surgery
• Approaches: Endolymphatic sac decompression (removal of bone over sac) or endolymphatic sac shunting (subarachnoid or mastoid shunt)
• Results: Vertigo control in 60–70%; hearing preserved or improved in majority
• Advantages: Least destructive; can be repeated; hearing preservation
• Evidence: Controversial — some RCTs show placebo effect (Bretlau, 1984)

• Rupture of cochlear duct and saccule via cochleostomy
• Rarely performed today; risk of profound SNHL

• Increasingly used as hearing-preserving alternative
• Reduces endolymphatic sac inflammation (autoimmune mechanism)
• Less effective for vertigo than gentamicin but hearing preservation better

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Q8. [10 Marks]

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a) Acoustic Reflex Pathway — Schematic Diagram [4 marks]

SOUND
  ↓
[Cochlea] → [CN VIII] → [Cochlear Nucleus]
                              ↓
                    [Superior Olivary Complex]
                         ↙           ↘
              [VII Motor         [VII Motor
               Nucleus]           Nucleus]
               ipsilateral       contralateral
                   ↓                   ↓
              [Stapedius           [Stapedius
               muscle]              muscle]
              ipsilateral          contralateral
              contraction          contraction

• Ipsilateral reflex: Same ear stimulated and measured
• Contralateral reflex (crossed reflex): One ear stimulated, stapedius measured in opposite ear — crosses midline via SOC
• Reflex arc passes entirely through the brainstem — does NOT ascend to cortex
• Normal reflex threshold: 70–100 dB HL (typically 85 dB above pure tone threshold)
• Latency: ~150 ms; duration sustained for several seconds

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b) Acoustic Reflex Decay Test — Principle and Application [3 marks]

1. Reflex threshold is measured at 500 Hz and 1000 Hz
2. Tone is presented at 10 dB above reflex threshold for 10 seconds
3. Compliance change is recorded
4. Positive test: Amplitude decays to 50% or less of original within 10 seconds

1. Differentiation of cochlear vs. retrocochlear SNHL:
   • Cochlear loss: Decay absent (negative test) — no adaptation
   • Retrocochlear (acoustic neuroma): Decay present (positive test) — neural fatigue
2. Early detection of acoustic neuroma/vestibular schwannoma before MRI — used as a screening tool
3. Diagnosis of multiple sclerosis (MS) — abnormal reflex decay in MS due to demyelination of the VIII nerve
4. Assessment of retrocochlear involvement in Menière's disease, auditory neuropathy

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c) Diagnostic Applications of the Acoustic Reflex [3 marks]

• CHL: Ipsilateral reflex absent (stapes cannot move); contralateral may be present if contralateral ear is normal
• SNHL: Reflex present but at elevated threshold if cochlear; may show recruitment (reflex present despite pure tone hearing loss)
• Mixed loss: Pattern reflects degree of each component

• Absent ipsilateral reflex with Type As tympanogram = stapes fixation
• Early otosclerosis: On-off (diphasic) reflex effect
• Reflexes help differentiate from ossicular discontinuity (Type Ad + absent reflex)

• Absent reflex despite mild-moderate SNHL
• Positive reflex decay test
• Elevated reflex threshold relative to PTA threshold

• If lesion is proximal to the nerve to stapedius (i.e., above the stapedius branch in the mastoid segment) → Ipsilateral reflex absent
• If lesion is distal to stapedius branch → Reflex present
• Helps localize site of facial nerve lesion (useful in Bell's palsy, trauma)

• Type B tympanogram + absent reflex = middle ear effusion

• Reflex present at normal sensation levels despite claimed hearing loss
• Validates that cochlea and brainstem pathway are intact

• Reflexes present above estimated threshold → provides objective threshold estimate

• Post-implant: Electrically elicited acoustic reflex (EAOR) used for programming

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Q9. [10 Marks]

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a) Limitations and Fallacies of Pure Tone Audiometry [6 marks]

1. Subjective test — requires patient cooperation, attention, and truthful responses; unreliable in malingerers, young children, cognitively impaired
2. Frequency range — standard PTA tests only 250–8000 Hz; does not evaluate ultra-high frequencies (8–20 kHz) which may show early ototoxic or noise damage
3. Pure tones are non-physiological — real-world sounds (speech, music) are complex and broadband; PTA may not reflect functional hearing ability
4. Threshold is not function — a person with similar PTAs may have very different speech understanding (reflected by speech audiometry, not PTA)
5. Inter-octave frequency gaps — notch at 3000 Hz or 6000 Hz may be missed if only octave frequencies tested
6. Masking required — failure to mask can lead to cross-hearing (shadow curves); complex masking problems in dead ears (no contralateral masking plateau)

1. Carhart Notch — mechanical depression of bone conduction at 2000 Hz in otosclerosis mimics SNHL; disappears after stapedectomy — is a test artifact, not true SNHL
2. Occlusion effect — during bone conduction testing without masking, the occluded (non-test) ear hears better; proper masking avoids this artifact
3. Shadow curve phenomenon — in total unilateral deafness, the deaf ear appears to have 50–65 dB thresholds due to cross-transmission to the better ear via bone conduction; mistaken for residual hearing if not masked
4. False bone conduction improvement — after PL fistula or stapes surgery, BC improves due to altered cochlear mechanics, not actual neural improvement
5. Pseudoconductive hearing loss — superior semicircular canal dehiscence causes abnormal bone conduction enhancement (BC thresholds appear better than normal) creating an apparent ABG — pure air-bone gap is artifact

1. Exaggeration/Malingering — voluntary elevation of thresholds; detected by special tests (Stenger, OAEs, ABR)
2. Learning effect — thresholds improve with practice; reproducibility requires standard technique
3. Fatigue — threshold elevation after prolonged exposure to loud sounds (temporary threshold shift)
4. Test-retest variability — ±10 dB variation acceptable; beyond this is considered unreliable

1. Calibration errors — audiometers must be calibrated against ISO standards; uncalibrated equipment gives erroneous thresholds
2. Headphone placement — incorrect positioning over the tragus instead of the ear canal gives artificial BC responses
3. Background noise — ambient noise in test room above ANSI standards affects thresholds (minimum 30 dB SPL background)

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b) Pathways of Bone Conduction [4 marks]

• Vibration of skull bones causes secondary vibration of the meatal walls of the external auditory canal
• Sound radiates from canal walls into the air in the canal → reaches TM → middle ear → cochlea
• Occlusion effect — blocking the EAC increases this component (by 20–30 dB at low frequencies) as trapped air resonates more effectively
• Most important at low frequencies (250–500 Hz)

• Skull vibrates, but due to inertia, the ossicular chain (malleus, incus, stapes) lags behind the skull
• This relative movement of the ossicles against the oval window creates stapes movement → perilymph movement
• Important at low frequencies (500–1500 Hz)

• Skull vibration compresses and expands the cochlear capsule directly
• Due to differential compliance: oval window (covered by stapes footplate) and round window have different impedances
• Compression creates fluid pressure gradient → basilar membrane deflection
• Dominant pathway at high frequencies (>2000 Hz)
• Hearing occurs even without ossicles or middle ear

• Due to high density of fluid, inner ear fluids lag behind skull vibrations
• Creates relative movement between basilar membrane and tectorial membrane → shear displacement of stereocilia
• Contributes at higher frequencies

• Vibrations conducted along skull to brainstem → direct stimulation of auditory nerve pathways
• Responsible for true sensorineural (neural) hearing
• Explains why bone conduction persists even after complete obliteration of inner ear fluid spaces

• BC audiometry measures the functional status of the cochlea and auditory nerve (bypassing middle ear)
• BC threshold = sensorineural reserve
• Air-Bone Gap (ABG) = AC threshold − BC threshold → measures conductive component
• Masking noise (narrow band noise) to the non-test ear is essential during BC testing to prevent cross-hearing

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Q10. [10 Marks]

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a) Define Otic Barotrauma [1 mark]

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b) Differences Between Inner Ear Barotrauma and Inner Ear Decompression Illness [4 marks]

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c) Management of Barotrauma-Induced Perilymphatic Fistula [5 marks]

• Sudden SNHL + tinnitus + vertigo following barotrauma
• Positive fistula test (+ Hennebert sign)
• Fluctuating hearing, pressure-sensitive symptoms

1. Strict bed rest with head elevated at 30° — reduces perilymph pressure; allows spontaneous healing of membrane
2. Avoid all pressure-increasing activities:
   • No Valsalva maneuver
   • No nose blowing
   • No heavy lifting, straining, or strenuous activity
   • No coughing forcefully (treat cough)
   • No bending over
3. Stool softeners — prevent straining at defecation
4. Avoid flying and diving until healed
5. Nasal decongestants — for any concomitant ET dysfunction or nasal congestion
6. Hearing protection — avoid loud noise exposure
7. Serial audiometry — monitor for improvement of SNHL at 2-week intervals
8. Oral steroids — some centres use methylprednisolone 1mg/kg tapering over 10 days to reduce cochlear inflammation and improve hearing recovery

1. Failure of conservative management after 4–6 weeks
2. Progressive or profound SNHL
3. Severe, persistent incapacitating vertigo
4. Positive fistula test with confirmed history of barotrauma

1. Performed under GA (local anaesthesia risks Valsalva from patient movement)
2. Tympanomeatal flap raised → middle ear exposed
3. Round window niche inspected first (commonest site): look for pulsating perilymph, tympanic membrane bubbles with pressure
4. Oval window / stapes footplate-annular ligament inspected
5. Any visible fistula is patched with fat, perichondrium, temporalis fascia, or connective tissue graft
6. Even if no fistula is visible, empirical patching of round window is performed if clinical suspicion is high
7. Packing with Gelfoam; tympanomeatal flap replaced; dressing applied

• Bed rest for 5–7 days post-surgery
• All Valsalva precautions continued for 6 weeks
• Serial audiometry at 2, 6, 12 weeks
• Diving permanently contraindicated in most cases; clearance after 6–12 months with audiometric evidence of healing

• Hearing improvement in ~50–70% after surgery
• Vertigo resolves in >80%
• SNHL may be permanent if delayed >6 weeks

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DNB Otorhinolaryngology — Paper 3 (Laryngology Focus)

Complete 10-Mark Exam Answers

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Q1. [10 Marks]

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a) FEES — Flexible Endoscopic Evaluation of Swallowing [3 marks]

1. Patient positioned upright; scope passed transnasally along the floor of the nose
2. Scope positioned in the hypopharynx just above the epiglottis — allows clear view of larynx, hypopharynx, and piriform sinuses
3. Pre-swallow assessment: Anatomy of larynx inspected — vocal fold mobility, secretion pooling, structural anomalies noted
4. Swallowing trials: Patient given varied consistency boluses (food colored blue with food dye for contrast); examiner observes:
   • Pharyngeal residue in valleculae and piriform sinuses
   • Laryngeal penetration (bolus enters laryngeal vestibule above cords)
   • Aspiration (bolus passes below vocal folds into trachea)
   • Velopharyngeal closure
5. Post-swallow: Cough, throat clear, residue, silent aspiration noted
6. Sensory testing (FEESST): air-pulse stimulation of aryepiglottic folds assesses laryngopharyngeal sensory thresholds

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b) Advantages and Disadvantages of FEES over Video-Fluoroscopy (VFS/MBSS) [4 marks]

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c) Mendelssohn Maneuver [3 marks]

• During swallowing, the larynx rises and moves anteriorly, which opens the upper esophageal sphincter (UES/cricopharyngeus) through hyolaryngeal traction
• Simultaneously, the epiglottis deflects posteriorly, protecting the airway
• In patients with reduced hyolaryngeal excursion, UES opening is incomplete → residue, aspiration

1. Patient is asked to swallow saliva and feel the Adam's apple (thyroid cartilage) rise and fall
2. Once familiar, the patient is instructed: "When you feel your voice box go up during swallowing, squeeze and hold it up at the highest position for 2–3 seconds before letting it drop"
3. Practiced first with saliva, then with food/liquid

• Prolonged laryngeal elevation → Prolonged opening of UES → More complete bolus transit through pharyngoesophageal segment
• Improved hyoid excursion → Better epiglottic deflection → Reduced laryngeal penetration/aspiration
• Increases duration and width of UES opening

1. Reduced laryngeal elevation and excursion (post-stroke, neurological dysphagia)
2. Incomplete UES relaxation / cricopharyngeal dysfunction
3. Post-total laryngectomy (tracheoesophageal voice, neoglottic phonation)
4. Zenker's diverticulum (adjunct to surgical treatment)
5. Post-radiotherapy pharyngeal weakness

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Q2. [10 Marks]

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a) Criteria for Diagnosis of Subglottic Stenosis in Term and Preterm Neonate [3 marks]

• Term neonate (>37 weeks): 4.5–5.5 mm (≥4.5 mm is normal)
• Preterm neonate (<37 weeks): 3.0–4.0 mm depending on gestational age/weight

• Term neonate: Subglottic diameter <4.0 mm = subglottic stenosis
• Preterm neonate: Subglottic diameter <3.0 mm = subglottic stenosis

1. History:
   • Biphasic stridor (inspiratory > expiratory) — present from birth (congenital) or after prolonged intubation (acquired)
   • Recurrent croup episodes (>2 attacks before age 3 years with no other cause)
   • Difficulty with extubation after neonatal intubation
   • Cyanotic episodes, feeding difficulties, failure to thrive
2. Endoscopic Diagnosis (Gold Standard):
   • Direct laryngoscopy and bronchoscopy under general anesthesia (spontaneous ventilation maintained)
   • Sizing with age-appropriate endotracheal tubes (ETT):
     • The largest ETT that passes through the subglottis with a leak at ≤20 cm H₂O determines adequacy
     • Stenosis graded if smaller-than-expected ETT is needed
   • Measured with rigid telescope: Direct measurement of subglottic lumen
3. Radiological Criteria:
   • Anteroposterior (AP) soft tissue neck X-ray: "steeple sign" (funnel-shaped subglottis)
   • CT scan neck: measures subglottic lumen — CT is particularly useful for planned surgical intervention
   • Airway fluoroscopy: dynamic airway assessment
4. Sizing Criteria by ETT (Clinical Rule):
   • Normal term neonate should accept a 3.5 mm (ID) ETT
   • If only a 2.5 mm or 3.0 mm ETT passes → at least Cotton-Myer Grade II–III SGS

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b) Cotton-Myer Classification and Management of Type 4 Subglottic Stenosis [4+3 marks]

• Complete or near-complete obliteration of subglottic lumen
• Soft (immature) or hard (mature, calcified) scar
• Always presents with severe airway compromise requiring tracheostomy
• Almost never amenable to endoscopic management alone
• Associated with: prolonged intubation, trauma, high-dose steroid/radiation, granulomatosis with polyangiitis

• Performed as the initial emergency/elective procedure
• Provides stable airway, allows recovery, and prepares for definitive reconstruction
• Decannulation is the long-term goal

• CT scan of neck (3D reconstruction) — assesses length, level, and nature of stenosis
• Endoscopy under GA — assess length, softness, concurrent glottic or tracheal involvement
• Pulmonary function assessment
• Nutritional optimisation (NGT/PEG if needed)
• Control of GERD (a major contributor to scar recurrence)

• Single-stage LTR (without tracheostomy at end) vs. Double-stage LTR (tracheostomy maintained post-op)
• For Grade IV: double-stage LTR preferred
• Anterior and posterior cartilage grafting both usually needed:
  • Anterior graft: Costal cartilage graft split and placed anteriorly via laryngofissure to expand the anterior subglottic lumen
  • Posterior graft: Posterior costal cartilage graft to open posterior glottis/subglottis; technically demanding
• Graft held in place with stent (LT-mold, Montgomery T-tube, or endotracheal tube stent) for 4–6 weeks
• Success rate: 80–95% decannulation in experienced hands

• Resection of the entire stenotic segment including the cricoid (partially or completely)
• End-to-end thyrotracheal or cricotracheal anastomosis
• Single-stage procedure with better outcomes in adults and older children
• Contraindicated if stenosis extends into glottis

• Mitomycin C (antimitotic) — applied topically to raw surfaces to prevent restenosis
• Intralesional steroids (triamcinolone) — at time of surgery or endoscopic dilation
• Anti-reflux therapy: PPI mandatory post-operatively
• Stenting with Montgomery T-tube for mature scars

• Decannulation rate: ~70–80% with LTR; ~85–90% with CTR
• Multiple procedures often needed
• Phonation and swallowing rehabilitation essential post-decannulation

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Q3. [10 Marks]

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Differences Between LPR and GERD [2 marks]

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Clinical Features of LPR [2 marks]

1. Globus pharyngeus — sensation of lump or foreign body in the throat (most common)
2. Dysphonia / Hoarseness — worse in the morning (irritation of vocal folds overnight)
3. Chronic throat clearing — due to posterior pharyngeal irritation/mucus
4. Chronic cough — dry, nonproductive; often triggers on talking/eating
5. Dysphagia — mild; due to posterior pharyngeal edema
6. Excess mucus/postnasal drip sensation
7. Odynophagia — throat pain, especially in the morning

1. Subglottic edema ("pseudosulcus vocalis") — edema extending below vocal folds — highly specific for LPR
2. Posterior commissure hypertrophy — cobblestoning of posterior glottis
3. Vocal fold edema (Reinke's edema in chronic cases)
4. Diffuse laryngeal edema
5. Erythema/hyperemia — arytenoids, posterior glottis
6. Interarytenoid swelling — "pachydermia laryngis"
7. Thick endo-laryngeal mucus
8. Granuloma — at vocal process of arytenoid (contact granuloma)
9. RFS > 7 = significant laryngoscopic evidence of LPR

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Diagnosis of LPR [3 marks]

• RSI ≥ 13 + RFS ≥ 7 → Empiric treatment with PPI is both diagnostic and therapeutic

• Dual-probe pH monitoring: Distal (5 cm above LES) and proximal/hypopharyngeal (1 cm above UES) sensors
• LPR diagnosed if proximal pH < 4.0 for >0.9% of monitoring time (Koufman criterion)
• pH-impedance monitoring: Detects both acid and non-acid (weakly acidic, weakly alkaline) reflux events throughout the esophagus — current gold standard as ~40% of LPR events are non-acid

• Probe placed transnasally at oropharyngeal level
• Detects liquid and aerosolized acid droplets above the UES
• Normal: pH < 4.0 for <0.9% upright time, <0% supine time
• Non-invasive but clinical utility still being validated

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Management of LPR [3 marks]

• Avoid: coffee, alcohol, carbonated drinks, fatty/spicy food, chocolate, mint
• Avoid eating 3 hours before bedtime
• Weight loss (obese patients)
• Elevate head of bed 30°
• Avoid tight clothing
• Stop smoking

• Omeprazole 20 mg or Esomeprazole 40 mg, twice daily (30 min before breakfast AND dinner) — twice daily essential in LPR (unlike GERD)
• Duration: Minimum 3–6 months (longer than GERD)
• Monitored with RSI and RFS at 3 months
• If no response after 3 months on maximum PPI → consider pH-impedance study

• Ranitidine or famotidine at bedtime — added for nocturnal acid breakthrough

• Laparoscopic Nissen fundoplication — indicated when:
  • Confirmed LPR on pH-impedance study
  • Failure of maximum medical therapy after 6+ months
  • Non-acid/alkaline reflux causing laryngeal injury (PPIs ineffective)
• Effective in 70–80% for LPR symptoms after failed medical therapy

• Contact granuloma → PPI + voice rest; if persistent >6 months → micro-suspension laryngoscopy + excision
• Reinke's edema → Smoking cessation + reflux control + microsurgery (decortication) if persistent
• Vocal fold leukoplakia → Biopsy mandatory; reflux control + close surveillance

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Q4. [10 Marks]

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a) Management of Laryngomalacia with Failure to Thrive [5 marks]

• Increased work of breathing → caloric expenditure
• Feeding difficulty — interrupts feeds to breathe; poor suck-swallow-breathe coordination
• Obstructive sleep apnea → poor sleep → growth hormone deficiency
• Aspiration → recurrent chest infections

1. Flexible nasopharyngoscopy (awake) — confirms supraglottic collapse pattern
2. Direct microlaryngoscopy and bronchoscopy (MLB) under GA — gold standard:
   • Confirms diagnosis
   • Assesses severity
   • Rules out synchronous airway lesions (secondary airway anomalies in 15–58% of severe LM)
3. Assess for GERD (associated in 65–100% of severe LM) → pre-op pH study
4. Polysomnography (PSG) — if OSA suspected
5. Nutritional assessment — may need pre-op NG feeding to optimize condition

1. General anesthesia, spontaneous breathing maintained; patient supine with neck extended
2. Rigid laryngoscope (Lindholm or Dedo) suspends larynx; operating microscope used
3. Procedure depends on anatomical type:
   • Short aryepiglottic (AE) folds (most common): Division of AE folds bilaterally (releases epiglottic tethering)
   • Redundant mucosa over arytenoids: Excision of redundant cuneiform/corniculate cartilage tissue with cold microscissors or CO₂ laser
   • Omega-shaped epiglottis: AE fold division usually corrects epiglottic folding; direct epiglottoplasty only if fold division alone insufficient
4. CO₂ laser or cold steel + bipolar — cold steel preferred to reduce edema
5. Avoid bilateral posterior glottic trauma → risk of posterior glottic stenosis
6. Hemostasis with adrenaline soaked pledgets; larynx inspected after each step

1. Observation in ICU overnight; stridor typically improves within 24–48 hours
2. Decadron (dexamethasone) IV — reduces edema
3. High-flow humidified oxygen; pulse oximetry monitoring
4. Resumption of oral feeds when stridor settles (usually 24–48 hrs)
5. Aggressive GERD treatment: Omeprazole + ranitidine post-operatively (GERD worsens post-supraglottoplasty if untreated)
6. Follow-up laryngoscopy at 6–8 weeks
7. Nutritional support — dietitian; catch-up growth monitoring

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b) Spreader Graft in Rhinoplasty [5 marks]

• The internal nasal valve = the narrowest point of the nasal airway; angle between the ULC and dorsal septum (normally 10–15°)
• In rhinoplasty (particularly after dorsal hump removal), the ULCs collapse medially → internal nasal valve stenosis → nasal obstruction
• Spreader grafts prevent and correct this collapse

1. Internal nasal valve stenosis — angle <10° causing nasal obstruction
2. Post-rhinoplasty middle vault collapse — inverted-V deformity correction
3. Dorsal septal deviation involving middle vault
4. Narrowed middle vault (narrow nose/tension nose) — primary rhinoplasty
5. After dorsal hump reduction — restores middle vault width
6. Crooked nose correction — asymmetric spreader grafts straighten the dorsum

• Septal cartilage — ideal; firm, straight; harvested from posterior septum (L-strut preserved: ≥15 mm dorsal, ≥10 mm caudal strut)
• Conchal cartilage — if septal insufficient; may be slightly curved
• Costal cartilage — for revision cases or large grafts needed

1. Approach: Open (external) rhinoplasty preferred (better visualization); can be closed
2. Mucoperichondrial tunnels created between dorsal septum and ULC bilaterally
3. Graft dimensions: typically 20–30 mm long × 3–5 mm wide × 2–3 mm thick (depending on nasal length and degree of correction needed)
4. Graft slid into tunnel between ULC and dorsal septum; sits flush with or just below the dorsal septal edge
5. Secured with 4-0 PDS or Vicryl sutures (mattress or simple interrupted through the septum, ULC, and spreader graft)
6. One or both sides may be used (bilateral most common for functional indications)
7. Asymmetric spreader grafts used for crooked nose — thicker on concave side to push deviation toward midline

• Widens internal nasal valve angle → reduces nasal resistance (Poiseuille's Law — resistance ∝ 1/r⁴)
• Restores dorsal width and support to ULC
• Prevents scar-mediated middle vault collapse post-operatively

• Asymmetry if grafts placed at different levels
• Palpable/visible graft edge
• Infection (rare)
• Inadequate correction requiring revision
• Over-widening → aesthetically unpleasant broad nose

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Q5. [10 Marks]

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a) Hirano's Body-Cover Theory of Phonation [3 marks]

• Cover: Epithelium + superficial layer of lamina propria (SLP/Reinke's space) — pliable, wave-propagating layer
• Body: Vocalis muscle — provides the tension and stiffness for pitch control
• Transition: Intermediate + deep layers of lamina propria (vocal ligament) — intermediate stiffness

• During phonation, expiratory air pressure forces the vocal folds apart
• A traveling mucosal wave propagates upward along the cover (from inferior to superior vocal fold surface) with each vibratory cycle
• The cover (pliable Reinke's space) moves independently of the stiffer body below
• The interface between cover and body allows differential vibration
• Bernoulli effect — airflow between cords creates negative pressure drawing them back together

• High pitch: CT muscle contracts → vocal fold elongated and thinned → cover stretched → cover stiffer → higher frequency vibration
• Low pitch: TA muscle contracts → folds shortened/thickened → cover becomes slacker → lower frequency
• Loudness: Increased subglottic pressure → larger amplitude of vibration

• Lesions in Reinke's space (nodules, polyps, Reinke's edema) alter the mucosal wave → dysphonia
• Stroboscopy assesses mucosal wave propagation — gold standard for diagnosis
• Microlaryngoscopy must preserve Reinke's space to restore normal phonation

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b) Benign Lesions of the Vocal Fold [3 marks]

• Bilateral, symmetric, sessile swellings at the junction of anterior 1/3 and posterior 2/3 of vocal folds (maximum vibration point)
• Cause: vocal abuse/misuse; reactive fibrosis in Reinke's space
• Stroboscopy: Bilateral mucosal wave reduction; hourglass glottic closure
• Management: voice therapy (first-line); microlaryngoscopy if refractory

• Usually unilateral; pedunculated or sessile; at anterior 1/3
• Cause: acute vocal trauma (single event — shouting, coughing); vascular rupture in Reinke's space
• Subtypes: edematous, fibrous, hyaline, hemorrhagic
• Management: Microlaryngoscopy + cold steel excision (mainstay); not responsive to voice therapy alone

• Bilateral diffuse edema of the SLP (Reinke's space) — "wet-fish" appearance
• Cause: smoking (most important) + voice abuse + GERD + hypothyroidism
• Voice: low-pitched, rough, "masculine" voice in women
• Management: Smoking cessation + acid control + microsurgery (decortication — remove epithelium, drain edema, redrape)

• Mucous retention cyst or epidermoid cyst within vocal fold
• Unilateral; appears as a smooth submucosal swelling; normal overlying epithelium
• Stroboscopy: Mucosal wave reduced on affected side
• Management: Microlaryngoscopy + complete excision (marsupialisation or enucleation)

• At vocal process of arytenoid (posterior glottis)
• Cause: GERD (most common), vocal abuse, intubation trauma
• Bilateral or unilateral; pink/erythematous granulation tissue
• Management: PPI + voice rest; surgery only if persists > 6 months + biopsy to exclude malignancy

• HPV-6 and HPV-11 (low-risk); warty growths on vocal folds and elsewhere
• Management: CO₂ laser or microdebrider debulking (not curative); cidofovir, bevacizumab as adjuvants

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c) Management of Vocal Nodules [4 marks]

• Adequate hydration (8 glasses water/day; steam inhalation)
• Avoid vocal abuse: shouting, excessive talking, loud singing while unwell
• Voice rest during acute laryngitis
• Avoid whispering (forced abduction is as traumatic as loud voice)
• Reduce caffeine and alcohol (dry vocal folds)
• Treat GERD aggressively

• Voice amplifiers for teachers/professionals
• Avoid background noise competition
• Reduce telephone use (muscular tension increases on phone)

• Resonance/forward-focused voice therapy — Lessac-Madsen Resonant Voice Therapy (LMRVT): trains easy phonation with vibration felt at lips/face, reducing vocal fold collision forces
• Semi-occluded vocal tract exercises (SOVT): Lip trills, tongue trills, straw phonation — reduces collision impact
• Confidential voice technique: Very soft, breathy phonation at a conversational volume — reduces fold impact
• Lee Silverman Voice Treatment (LSVT): High-effort phonation — for hypofunctional dysphonia (not for nodules)
• Manual circumlaryngeal massage therapy — reduces laryngeal muscle tension

• Children: >90% resolution with voice therapy alone (nodules in children are hyaline/immature)
• Adults: 60–80% resolution or significant improvement
• Persistent or fibrous/mature nodules in adults may require surgery

• GERD treatment: PPI bid (if reflux component identified)
• Nasal steroids/antihistamines if allergy-related postnasal drip causing chronic throat clearing
• Nebulized saline/steam inhalation for vocal fold hydration
• Oral mucolytics (guaifenesin)

• Mature, fibrous nodules not responding to 6–8 weeks of voice therapy
• Lesion causing significant professional disability (singers, teachers, actors)
• Suspicion of malignancy (biopsy needed)
• Unusually large nodules

1. GA with microlaryngoscopy setup (Kleinsasser or Lindholm laryngoscope)
2. Operating microscope (×400 magnification)
3. Cold steel technique preferred (micro-scissors, micro-cup forceps):
   • Minimal incision at the free edge
   • Subepithelial dissection to preserve Reinke's space
   • Avoid excessive resection (risk of scarring/dysphonia)
4. CO₂ laser — used in some centers; risk of thermal damage to Reinke's space
5. Bilateral lesions: Operated one side at a time to prevent anterior commissure webbing (avoid bilateral anterior commissure incisions)

• Complete voice rest 5–7 days
• Voice therapy resumed 2 weeks post-op (essential to prevent recurrence)
• Stroboscopy at 6 weeks post-op
• Nodules recur in up to 50% without behavioural change

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Q6. [10 Marks]

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Causes of Bilateral Vocal Fold Paralysis (BVFP) [2 marks]

• Thyroidectomy — most common cause; risk highest in total thyroidectomy, reoperations, cancer surgery
• Cervical spine surgery (anterior approach)
• Mediastinal surgery (thymectomy, esophagectomy)
• Cardiac surgery (PDL ligation, aortic arch procedures)

• Thyroid carcinoma — direct invasion of RLN
• Esophageal cancer — mediastinal spread
• Lung cancer (bilateral mediastinal lymph nodes)
• Mediastinal lymphoma
• Base of skull tumors

• Arnold-Chiari malformation — vagal nucleus compression
• Multiple sclerosis — brainstem demyelination
• Brainstem stroke (rare — other cranial nerves usually affected)
• Syringobulbia

• Prolonged intubation → cricoarytenoid joint subluxation/ankylosis (mechanical fixation mimicking paralysis)

• Lyme disease, sarcoidosis, syphilis
• Viral: Epstein-Barr virus, herpes zoster (Ramsay Hunt involving vagus)

• Arnold-Chiari in neonates (most common cause in infants)
• Hydrocephalus
• Birth trauma

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Clinical Features of BVFP [2 marks]

• Stridor — predominantly inspiratory; biphasic in severe cases
• Dyspnea — worse with exertion; may present as acute respiratory emergency
• Good voice quality (folds in midline → near-complete glottic closure → adequate voice)
• Cyanosis in severe bilateral median position
• No significant aspiration (glottis closes well)

• Aphonia or severe dysphonia — weak, breathy voice
• Aspiration — inadequate glottic protection during swallowing
• Dysphagia
• Minimal or no stridor (airway open)

• Acute post-thyroidectomy bilateral RLN palsy = emergency (stridor/respiratory distress)
• Recurrent aspiration pneumonia
• Voice fatigue

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Diagnosis of BVFP [3 marks]

• Visualizes bilateral fold immobility
• Assesses fold position (paramedian, median, lateral)
• Rules out supraglottic pathology

• Palpation of arytenoid cartilages — differentiates true paralysis from cricoarytenoid joint fixation (mechanical)
• Joint fixation → resistance to passive arytenoid movement

• Needle electrode into thyroarytenoid and posterior cricoarytenoid muscles
• Differentiates: paralysis (denervation potentials, absent volitional activity) vs. fixation (normal EMG)
• Assesses reinnervation potential — predicts prognosis
• Absent voluntary MUAPs + fibrillation = complete denervation
• Synkinetic activity = reinnervation without function

• Identifies structural cause: thyroid mass, mediastinal nodes, lung apex tumor, base of skull lesion
• Mandatory if no obvious surgical cause

• Thyroid function tests, serology (Lyme, syphilis, ANA), ACE level (sarcoid)
• Chest X-ray
• ENT assessment of aspiration (FEES, VFS)

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Management of BVFP [3 marks]

• Emergency reintubation or emergency tracheostomy if severe respiratory distress
• IV dexamethasone reduces post-operative oedema (may improve marginal cases)
• Wait and watch for 6–12 months — spontaneous recovery occurs in up to 60–70% if injury was neuropraxia (stretching/thermal, not transection)
• If known complete nerve section intraoperatively → immediate nerve repair at same sitting

• Tracheostomy — gold standard for securing airway; allows time for recovery; maintains voice capability with Passy-Muir valve
• Bilateral injection laryngoplasty (temporary) — NOT used in BVFP (worsens airway)

• CO₂ laser section of the posterior 1/3 of one vocal fold
• Enlarges posterior glottis → airway improved
• Advantage: Voice relatively preserved; reversible partial procedure
• Risk: Permanent voice change; hoarseness

• Removal of one arytenoid cartilage (or mucosa covering it) → lateralizes that fold
• Subtotal endoscopic arytenoidectomy with CO₂ laser
• Lateralization suture (King procedure): Suture passed externally to pull arytenoid laterally — reversible; preserves mucosa
• Risk: Irreversible; aspiration if too much tissue removed

• Woodman's operation (external arytenoidectomy via external approach) — historical
• Thornell's endoscopic arytenoidectomy

• Experimental; ansa cervicalis to PCA reinnervation to restore abductor function

• Aspiration: Swallowing therapy, thickened feeds, PEG if severe aspiration
• Dysphonia: Voice therapy; unilateral medialization if lateral fold (paradoxically improves both voice and swallowing)
• Decannulation goal: Achieved after definitive arytenoidectomy in most cases (70–85%)

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Q7. [10 Marks]

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a) Type 1 Laryngeal Cleft — Clinical Features, Diagnosis and Management [5 marks]

• Presentation in neonates/infants
• Aspiration with feeds — most characteristic: coughing, choking, cyanotic spells during feeding
• Stridor — inspiratory; due to supraglottic collapse/laryngomalacia-like picture (may coexist)
• Recurrent aspiration pneumonia / recurrent chest infections
• Weak cry — due to posterior glottic incompetence
• Gastroesophageal reflux (very common association — 60–80%)
• Failure to thrive — from aspiration and feeding difficulties
• Association with other anomalies: VACTERL sequence, H-type TEF, esophageal atresia, cleft palate

1. Flexible Nasopharyngoscopy: May reveal interarytenoid gap; mucus pooling in larynx; laryngomalacia-like picture
2. Direct Microlaryngoscopy and Bronchoscopy (MLB) — Gold Standard:
   • Under GA; spontaneous ventilation maintained
   • Palpation of the interarytenoid region: a probe (suction catheter or probe) can be passed posteriorly into the esophagus if a cleft exists
   • The interarytenoid mucosa is retracted anteriorly to visualize the cleft depth
3. Video Fluoroscopic Swallow Study (VFSS): Aspiration demonstrated; contrast may enter larynx
4. FEES (FEESST): Aspiration with feeds; laryngeal sensory threshold elevated
5. CT Neck: Structural anatomy; rarely needed for Type 1 but useful for Types 3–4
6. Barium swallow: H-type TEF or esophageal anomaly excluded
7. Echocardiogram + renal USS — associated anomalies

• Majority of Type 1 clefts are managed conservatively, especially if mild aspiration
• Thickened feeds (nectar/honey consistency) — reduces aspiration
• Upright feeding position (45°)
• Anti-reflux therapy: Omeprazole + ranitidine (GERD exacerbates aspiration)
• Speech-language therapy for feeding strategies
• Many Type 1 clefts improve spontaneously with maturation by 12–18 months
• Serial FEES/VFS monitoring

• Endoscopic repair under microlaryngoscopy:
  • Interarytenoid mucosa freshened bilaterally (laser or cold steel)
  • Closure with absorbable sutures (5-0 Vicryl) in two layers (mucosal and muscular)
  • Bilateral approach: right and left sides sutured separately
  • Injection laryngoplasty (Gelfoam or calcium hydroxyapatite) into the interarytenoid region — less invasive; temporarily augments interarytenoid area
• External approach (open surgery via laryngofissure) — for failed endoscopic repair or Types 2–4

• Type 1: Excellent with conservative or endoscopic repair; most children feed normally by 2 years
• Surgical success rate ~80–90% for endoscopic repair

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b) Disc Battery Ingestion in Oesophagus — First Aid and Management [5 marks]

• Disc batteries generate hydroxide ions via electrolysis (even if partially discharged): creates tissue liquefactive necrosis (alkali burn)
• Induces local tissue injury via:
  1. Electric current (low-voltage electrical burn) — direct current causes tissue electrolysis
  2. Alkali injury — OH⁻ generation → saponification of cell membranes
  3. Pressure necrosis — direct pressure on esophageal wall
  4. Mercury/heavy metal toxicity (older batteries)
• Esophageal perforation can occur within 2 hours; aortoesophageal fistula (catastrophic hemorrhage) in 4–6 hours

1. Honey administration (age ≥ 1 year, NOT infants <12 months — risk of botulism):
   • Give 2 teaspoons (10 mL) honey every 10 minutes while en route to hospital
   • Honey coats the battery, dilutes the alkali, and significantly reduces necrosis depth
   • Sucralfate — 10 mL liquid sucralfate can also be given (any age, including infants)
   • These are the ONLY substances to give; do NOT give water or other fluids
2. Do NOT induce vomiting — risk of aspiration
3. Immediate transfer to hospital — no delay; call emergency services
4. NPO (nil per os) — no food or other liquids except honey/sucralfate

1. Immediate Plain X-ray (AP chest + lateral) — if ingestion history:
   • Disc battery: bilaminar appearance — "double ring" or "halo sign" on AP view (the step-off on lateral view)
   • Differentiates from coin (coin is uniform density; battery has halo)
   • Location: esophagus (most dangerous), stomach, or lower GI tract

• EMERGENCY — Remove within 2 hours (ideally within 1 hour)
• Rigid oesophagoscopy under GA — gold standard for esophageal battery removal:
  • Rigid esophagoscope allows safe grasping and removal
  • Direct visualization of esophageal mucosa post-removal
  • Assess injury: redness, ulceration, perforation, bleaching
• Flexible endoscopy — can be used if rigid not available; use Roth net or rat-tooth forceps
• Post-removal: Inspect esophageal mucosa; assess depth of injury
  • If Grade 2b or 3 injury (deep ulcer, perforation) → nasogastric tube, IV antibiotics, NPO, contrast esophagram at 48–72 hours; surgical consultation
  • CT angiography of chest if proximity to aorta noted — risk of aortoesophageal fistula

• Children <5 years or battery >20 mm diameter: Remove within 24 hours via upper endoscopy
• Older children/adults with battery in stomach: Serial X-rays every 24 hours; if not passed in 48 hours → endoscopic removal

• Usually passes spontaneously; serial X-rays to confirm passage
• Surgical extraction if not passed in 5–7 days or symptomatic

• Esophageal stricture (weeks to months later) — serial dilation needed
• Tracheoesophageal fistula — late complication
• Aortoesophageal fistula — catastrophic; CT angiography if blood in gastric aspirate
• Vocal fold palsy — RLN injury from esophageal necrosis
• Follow-up esophagram at 4–6 weeks even if asymptomatic

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Q8. [10 Marks]

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Aetiopathogenesis of Oral Submucous Fibrosis (OSMF) [3 marks]

1. Areca nut (Betel nut) — the single most important and well-established etiological factor
   • Arecoline (major alkaloid) stimulates fibroblast proliferation and collagen synthesis
   • Arecoline inhibits collagenase → failure of collagen remodeling → excessive accumulation
   • Other areca alkaloids: arecolidine, guvacine, isoguvacine
   • Tobacco (when combined with areca in pan) — synergistic carcinogenic effect
   • Slaked lime (Ca(OH)₂) — generates reactive oxygen species, enhances mucosal penetration of arecoline
2. Nutritional Deficiencies:
   • Iron, vitamins B, C, and A deficiencies → impaired mucosal immunity and repair
   • Micronutrient deficiency worsens fibroblast dysfunction
3. Immunological / Autoimmune Mechanism:
   • Elevated IgA, IgG, IgM; autoantibodies against fibroblasts
   • HLA-DR association (HLA-DR3, HLA-DR7)
   • CD4+ T-cell mediated chronic inflammation in submucosa
4. Genetic Susceptibility:
   • Mutations in collagen genes (COL1A1/2)
   • Cytokine polymorphisms (TGF-β1 overexpression → the key mediator of fibrosis)

• Epithelial atrophy ± dysplasia (in advanced lesions)
• Juxta-epithelial hyalinization of connective tissue
• Dense hypocellular collagen bundles
• Reduction in vascularity
• Inflammatory infiltrate (T-lymphocytes, mast cells, macrophages)
• Ossification in advanced cases

• 7–30% risk of transformation to oral squamous cell carcinoma
• OSMF classified as a potentially malignant disorder (PMD) by WHO

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Medical Management of OSMF [3 marks]

• Areca nut, tobacco, pan cessation — de-addiction counselling, NRT (nicotine replacement therapy)
• Spontaneous partial improvement may occur with early-stage disease after habit cessation

• Iron, vitamins B-complex, A, C, E, zinc — correct deficiencies
• Lycopene (antioxidant) — 8 mg twice daily × 3 months → reduces burning sensation

• Triamcinolone acetonide 40 mg/mL or Dexamethasone 4 mg/mL
• Injected into fibrotic bands bilaterally, 1–2 mL per side per session
• Mechanism: Reduces inflammation, inhibits fibroblast activity
• Frequency: Weekly × 10–20 sessions
• Limitation: temporary relief; does not cure fibrosis

• 1500 IU in 1 mL normal saline; depolymerizes hyaluronic acid in fibrous bands → softening
• Used alone or combined with steroids
• Results: modest improvement in mouth opening

• Contains hyaluronidase + growth factors → promotes angiogenesis and reverses ischemia
• Injected weekly × 10 sessions; improves mouth opening and burning sensation

• Oxypentifylline (Pentoxifylline): Reduces fibrosis, improves microvascular flow; oral
• Colchicine: Anti-inflammatory; inhibits collagen cross-linking
• Interferon-γ: Downregulates TGF-β1; used in refractory cases
• Topical steroids (triamcinolone acetonide paste) for burning sensation

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Surgical Management of OSMF [4 marks]

• Stage I: Burning sensation; no fibrosis; mouth opening >40 mm
• Stage II: Fibrotic bands, restricted opening 20–40 mm
• Stage III: Severe trismus <20 mm; dysphonia, dysphagia
• Stage IV: OSMF with malignancy

• Simple incision of the fibrotic bands via:
  • Scalpel/scissors — limited access; risk of bleeding
  • CO₂ laser — precise; simultaneous hemostasis; reduced post-op scarring
  • KTP laser
• Limitation: Exposed raw area scarring leads to recurrence (50–80% without coverage)
• Must always be combined with a reconstructive procedure

• After band release, raw mucosal defect is covered with STSG (harvested from thigh)
• Historically used; poor results — skin graft contracts and keratinizes inappropriately in the oral cavity

• After bilateral fibrotomy → the buccal fat pad is exposed and advanced to cover the defect
• BFP is vascularized, undergoes spontaneous re-epithelialization with oral mucosa
• Excellent outcomes; donor site morbidity minimal
• Increases mouth opening by 15–25 mm

• Inferiorly based tongue flap used to cover the defect
• Limited by tongue mobility post-op; used when BFP is inadequate/unavailable

• Superiorly based nasolabial flap tunneled intraorally
• Pedicled random-pattern flap; good for anterior defects
• Two-stage procedure (pedicle division at 3 weeks)

• For extensive bilateral defects in severe stage III OSMF
• Thin, pliable, well-vascularized; allows wide resurfacing
• Used in centers with microvascular expertise

• For extreme trismus with inadequate condylar movement
• Coronoid process resection may be combined with temporalis flap

• Mouth exercises/physiotherapy: Forced mouth opening with Heister's dilator or tongue depressors from day 3–4 post-op
• Minimum 2–3 cm opening should be maintained with daily exercises
• Continuation of anti-fibrotic medications
• Regular surveillance (3–6 monthly) for malignant transformation — biopsy any suspicious areas

• Disease is progressive; recurrence after surgery possible especially if habit not stopped
• Malignant transformation in 7–30% — lifelong surveillance mandatory

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Q9. [10 Marks]

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a) Pattern of Spread of Glottic Laryngeal Cancer [3 marks]

1. Poor lymphatic drainage of true vocal folds → late nodal metastasis in early glottic cancer (N0 in T1/T2 ~90%)
2. Conus elasticus and quadrangular membrane — anatomical barriers to inferior and superior spread
3. Thyroid cartilage — barrier to extralaryngeal spread

• Toward the anterior commissure — the most critical point
• Anterior commissure has poor soft tissue barrier → cancer crosses to contralateral fold early
• From anterior commissure → invades thyroid cartilage at Broyle's tendon (no perichondrium here) → thyroid cartilage erosion → T4a disease

• Toward the posterior commissure and arytenoid cartilage
• Involvement of arytenoid → vocal fold fixation (T3 disease)
• Posterior commissure → subglottis → cricoid cartilage → T4a

• Through the ventricle toward the false cord and epiglottis
• Raises N-stage: supraglottic spread → nodes at Level II–III → higher N-positivity

• Downward through the conus elasticus into the subglottis
• Defined as extension >10 mm anteriorly or >5 mm posteriorly below the glottis
• Subglottic extension → paratracheal nodal metastasis (level VI) → risk of tracheostomal recurrence post-laryngectomy

• Into the paraglottic space — between the thyroid cartilage and the glottic/supraglottic mucosa
• Paraglottic space involvement → T3 disease (fixes fold via involvement of cricothyroid joint or direct muscle infiltration)
• From paraglottic space → preepiglottic space → supraglottis

• Thyroid cartilage: anterior commissure → Broyle's tendon → cartilage erosion → T4a
• Cricoid cartilage: subglottic extension → T4a
• Ossified cartilage is more susceptible to invasion

• T1/T2 glottic: N0 in ~90%
• T3/T4 glottic: N+ in ~20–30% (increases with paraglottic space, supraglottic extension)
• Drainage: Level II, III, IV (jugular chain); Level VI (paratracheal) for subglottic involvement

• Lung > bone > liver (late finding in advanced T3/T4)

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b) Management of T3 Glottic Cancer — Latest Guidelines [3 marks]

• Platinum-based chemotherapy (Cisplatin 100 mg/m² on days 1, 22, 43) + Radiotherapy (70 Gy in 35 fractions over 7 weeks)
• Based on VA Larynx Trial (1991) and RTOG 91-11 (2003) — CRT superior to induction CT + RT for organ preservation
• RTOG 91-11 conclusion: Concurrent CRT > sequential (induction CT → RT) > RT alone for laryngeal preservation
• Laryngeal preservation rate: ~85% at 2 years
• Overall survival comparable to total laryngectomy (TL) in most T3 cases
• Cetuximab + RT — alternative in cisplatin-ineligible patients (BONNER trial)

• TPF (Docetaxel + Cisplatin + 5-FU) × 2–3 cycles → evaluate response
• Complete/partial responders proceed to definitive RT (66–70 Gy)
• Non-responders → proceed to TL
• TAX 324 and GORTEC trials — TPF superior to PF induction for organ preservation

• Supracricoid partial laryngectomy with Cricohyoidoepiglottopexy (SCPL-CHEP):
  • Appropriate for selected T3 (unilateral fold fixation, no subglottic extension, no cartilage erosion)
  • Removes entire thyroid cartilage, false cords, paraglottic space bilaterally
  • Preserves one arytenoid → maintains phonation and swallowing
  • No permanent tracheostomy required
  • Oncological outcomes equivalent to TL for appropriately selected T3

• Indications:
  • T3 with cartilage invasion (inner cortex — still T3; outer cortex = T4a)
  • Bilateral arytenoid fixation
  • Significant subglottic extension
  • Failure of CRT (salvage laryngectomy — see below)
  • Poor lung function (high aspiration risk with partial laryngectomy)
  • Patient preference for definitive surgery
• TL followed by adjuvant radiotherapy (60–66 Gy) or adjuvant CRT (positive margins, pN2+, perineural invasion, lymphovascular invasion)

• CRT: Radiation covers elective nodal volumes bilaterally (Level II–IV, VI)
• Surgery: Selective neck dissection (Level II–IV) at time of TL or as post-CRT planned surgery

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c) Role of Salvage Laryngectomy [4 marks]

1. Residual disease — failure to achieve complete response 6–8 weeks after completing CRT/RT
2. Local recurrence after complete CRT response (most common indication)
3. Chondroradionecrosis — severe, non-resolving necrosis of laryngeal cartilage post-radiation
4. Aspiration larynx — non-functional, chronically aspirating larynx after CRT
5. Recto-laryngeal fistula or severe late radiation complications

• CT/MRI/PET-CT scan — defines extent of recurrence, cartilage invasion, lymph node status, skip lesions
• PET-CT (3 months post-CRT): Standard for response assessment; guides salvage decision
• Biopsy under GA — histological confirmation of recurrence (post-radiation fibrosis can mimic tumor on imaging)
• Nutritional assessment — most patients are malnourished post-CRT
• Dental review — pre-operative dental extractions if mandibular osteoradionecrosis risk

1. Total laryngectomy is performed as a minimum; often extended resection needed
2. Pharyngolaryngectomy if hypopharyngeal involvement
3. Neck dissection: Selective or modified radical neck dissection (at minimum Level II–IV; extend to Level VI for subglottic)
4. Tracheostomy becomes permanent (stoma formed at base of neck)
5. Primary tracheoesophageal voice puncture (TEP) can be performed at time of salvage laryngectomy
6. Wound closure:
   • Pectoralis major myocutaneous flap (PMMF): Most commonly used for pharyngeal closure and wound protection in the irradiated field; reduces fistula rates
   • Alternatively: Radial forearm free flap, anterolateral thigh (ALT) flap for pharyngeal reconstruction
   • Direct primary closure — acceptable if pharyngeal defect is small and radiation was not excessive

1. Pharyngocutaneous fistula (PCF) — most significant complication; rate 20–50% in salvage vs. <5% in primary TL; due to:
   • Radiation-induced vascular insufficiency
   • Poor wound healing in irradiated tissue
   • Salivary contamination
   • Management: NPO, IV antibiotics, wound packing; surgical closure if not healing
2. Wound breakdown and infection
3. Carotid artery blowout (1–3%) — erosion of carotid in infected/irradiated field; emergency
4. Chyle fistula
5. Hypothyroidism — post-total laryngectomy + prior irradiation to thyroid
6. Neopharyngeal stenosis — leads to dysphagia; requires dilation
7. Failure of TEP voice prosthesis — irradiated tissue

• 5-year OS: ~35–45% (lower than primary TL)
• Disease-specific survival: ~50–60%
• Local control: ~60–70%
• Complication rate significantly higher than primary TL
• Quality of life: Despite complications, most patients who achieve disease control have acceptable QoL with tracheoesophageal voice

• Best candidates: rT1–rT2 recurrence, > 6 months after completion of CRT, no distant metastasis, good performance status (ECOG 0–1), adequate nutritional status

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Q10. [10 Marks]

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a) Types of Prosthesis for Post-Laryngectomy Voice Rehabilitation [2 marks]

• Battery-powered vibrating device held against the neck or cheek
• Produces monotone, robotic-quality voice
• Used when TEP is not feasible or as immediate post-laryngectomy voice
• Types: Servox, TruTone, Western Electric (neck-type, intraoral)

• Patient swallows and traps air in the esophagus → releases it in a controlled manner to vibrate the PE segment
• Completely hands-free; no device needed
• Requires intensive speech therapy (months); success rate ~25–35%
• Poor voice quality; limited to ~3–6 words per breath

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b) Hypertonic PE Segment — Diagnosis and Management [2+2 marks]

1. Clinical: Patient unable to produce voice or produces strained, effortful voice despite correct prosthesis placement and patent valve; occlusion test: patient occludes stoma, phonates → no voice or minimal voice despite adequate pulmonary air reserve
2. Insufflation Test (Taub test): A catheter is passed transnasally into the esophagus → air insufflated at different rates → patient asked to sustain "ahhh":
   • Normal: fluent voice at low insufflation pressures (5–10 cm H₂O)
   • Hypertonic PE segment: voice only at high pressures (>20 cm H₂O) or no voice at all
3. Videofluoroscopy: Barium swallow in AP and lateral — reveals incomplete relaxation of PE segment; column of barium halted at the level of cricopharyngeus during phonation
4. Nasopharyngoscopy/Rigid endoscopy: Visualizes the neopharynx; narrowed/spastic segment

1. Botulinum Toxin Injection (First-line):
   • Botulinum toxin A (50–100 units) injected into the cricopharyngeus bilaterally
   • Transcervical approach (EMG-guided) or transoral endoscopic injection
   • Results: Voice improvement in 70–80%; duration 3–6 months; repeatable
   • Trial used to predict response to surgery
2. Pharyngeal Plexus Neurectomy:
   • Division of pharyngeal plexus branches to cricopharyngeus via external cervical approach
   • Permanent; success rate ~70%
3. Myotomy:
   • Cricopharyngeal myotomy — surgical division of the cricopharyngeus muscle
   • External approach; most definitive surgical option
   • May be combined with constrictor myotomy
   • Success rate ~75–85%
4. Endoscopic Dilation: Pneumatic dilation of the PE segment — less effective for hypertonicity (better for stricture)

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c) Central Leak and Peripheral Leak from Voice Prosthesis [2+2 marks]

1. Candidal biofilm accumulation on the valve — most common cause; fungal deposits prevent complete valve closure
2. Prosthesis lifetime exceeded — valve wear and degradation
3. Encrustation of valve by mineral deposits (calcium) — prevents closure
4. Wrong prosthesis length — excessive length → tip sits in posterior pharynx → valve held open
5. Reflux — acid degrades valve material faster

1. Antifungal prophylaxis: Nystatin oral suspension (swish and swallow) or fluconazole → treats candidal biofilm
2. Prosthesis replacement — elective or urgent depending on aspiration severity
3. Prosthesis brushing — specialized brush kit; patient cleans prosthesis daily
4. Acidic oral gel (Bepanthen, citric acid gel) — applied to prosthesis head to reduce biofilm
5. Switch to higher-resistance valve (e.g., Provox ActiValve) — magnetic valve more resistant to reflux/fungal colonization
6. NPO temporarily — if heavy aspiration risk

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1. Oversized fistula — fistula tract wider than prosthesis diameter (dilated/enlarged tract)
2. Wrong prosthesis size — too short or too narrow for the tract
3. Fistula granulation tissue — prevents sealing
4. Radiation-induced TE fistula enlargement — poor tissue integrity in the irradiated field
5. Excessive coughing/trauma — mechanical widening of tract
6. Weight loss — tissue volume reduction → fistula enlarges

1. Upsizing the prosthesis diameter — use a wider-diameter prosthesis to fill the enlarged fistula
2. Longer prosthesis — if TEF length is greater than estimated
3. Temporary prosthesis removal + fistula downsizing:
   • Catheter/Red Robinson catheter placed to maintain patency while tract contracts
   • Allow 24–48 hours for spontaneous narrowing; then resize prosthesis
4. Granulation tissue removal: Endoscopic or chemical cauterization (silver nitrate)
5. Surgical TEF revision:
   • If fistula is severely dilated → surgical closure and re-puncture at new site
   • Reinforcement with dermal matrix or local flap around the prosthesis
6. Pectoralis major myocutaneous or pedicled flap reinforcement — for severely irradiated tissues with persistent leak
7. Gelatin sponge (Gelfoam) packing around the prosthesis temporarily

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