EN4.{3-4,6-8,10-11,15} | Otitis Media and Middle Ear Surgery — Glossary

Tuning fork comparison of the patient's bone conduction with the examiner's bone conduction (assumed normal); a reduced ABC on the affected side suggests sensorineural or mixed hearing loss beyond the conductive component of CSOM.

A carbonic anhydrase inhibitor that reduces CSF production; used in otitic hydrocephalus (and benign intracranial hypertension) to reduce intracranial pressure; also induces metabolic acidosis as a side effect.

Cholesteatoma arising from pars flaccida retraction (without perforation) — the retraction pocket invaginates into Prussak's space and expands medially; no TM perforation is present initially.

The most common type (~70%): squamous epithelium migrates medially through a marginal TM perforation into the middle ear and forms a cholesteatoma sac.

Acute bacterial infection of the middle ear cleft with middle ear effusion, TM hyperaemia or bulging, and systemic signs of infection (fever, otalgia); progresses through four pathological stages; resolves after antibiotic therapy or surgical drainage.

The pharyngeal tonsil — a lymphoid mass in the nasopharyngeal roof and posterior wall; when hypertrophied it obstructs the ET orifice and acts as a bacterial biofilm reservoir, contributing to recurrent OME and ASOM.

Enlargement of the pharyngeal tonsil in the nasopharynx, causing mechanical obstruction of the ET orifice and acting as a bacterial biofilm reservoir; the most common surgically addressable cause of recurrent OME and ASOM in children.

Surgical removal of the adenoid; reduces recurrence of OME by removing the ET orifice obstruction and bacterial biofilm reservoir; added to grommet insertion in children ≥4 years with recurrent OME or documented adenoid hypertrophy.

The difference between air conduction and bone conduction thresholds on PTA; in conductive hearing loss (OME, ASOM), air conduction is impaired while bone conduction is normal — producing a gap, typically 25–40 dB in OME.

First-line oral antibiotic for ASOM (beta-lactam); high-dose regimen 80–90 mg/kg/day in 2 divided doses; amoxicillin-clavulanate is used if beta-lactamase-producing H. influenzae or M. catarrhalis suspected.

The quadrant of the pars tensa of the TM anterior to the malleus handle and below the umbo level; the sole safe site for myringotomy incision.

A TM perforation in the pars flaccida (Shrapnell's membrane, superior slacker portion); characteristic of squamosal (unsafe) CSOM; allows squamous epithelium to migrate medially and form cholesteatoma.

Removal of discharge, crusts, and debris from the external auditory canal and through the TM perforation using dry mopping, wicking, or gentle suction; the most effective conservative measure in mucosal CSOM.

Non-invasive technique for treating OME: the child inflates a nasal balloon with one nostril, raising nasopharyngeal pressure to force the ET open; modest evidence of benefit in cooperative children ≥4 years.

The sensation of hearing one's own voice abnormally loudly or resonantly inside the head; the most characteristic symptom of patulous ET — caused by sound transmission directly through the permanently open tube into the middle ear.

An extracranial complication of mastoiditis in which pus perforates the mastoid tip and tracks into the neck along the sternocleidomastoid muscle; presents with deep neck swelling and limited neck movement.

The medial one-third of the Eustachian tube; rigid bony walls; always patent; connects the tympanic orifice of the ET to the isthmus.

The most dangerous intracranial complication of CSOM; two most common sites: temporal lobe (from middle ear via tegmen) and cerebellum (from mastoid via posterior fossa); CT shows ring-enhancing lesion; treated by neurosurgical drainage + mastoidectomy.

The lateral two-thirds of the Eustachian tube; has a J-shaped cartilage with a passive fibrous lateral wall; lumen is normally closed at rest and opens only when the tensor veli palatini contracts; the portion most susceptible to inflammation-induced obstruction and to loss of closure in patulous ET.

A TM perforation completely surrounded by a rim of intact TM tissue on all sides, located within the pars tensa; the annulus fibrosus is intact; characteristic of mucosal (safe) CSOM.

A destructive cyst of desquamating keratin-producing squamous epithelium in the middle ear; characteristic of unsafe CSOM; secretes collagenases that erode bone (ossicles, tegmen, labyrinthine capsule, facial canal).

Chronic infection of the middle ear cleft with TM perforation and persistent or recurrent ear discharge for more than 12 weeks; classified as mucosal (safe/tubotympanic) or squamosal (unsafe/atticoantral) types.

First-line topical antibiotic for CSOM; safe for use in a perforated TM (non-ototoxic); active against the common pathogens in CSOM (Pseudomonas aeruginosa, S. aureus, Proteus). Aminoglycosides are contraindicated in perforated TM.

A craniofacial anomaly in which abnormal tensor veli palatini attachment impairs ET opening; virtually all patients with unrepaired cleft palate develop chronic OME requiring long-term grommet management.

Matrix metalloproteinases (especially MMP-2 and MMP-9) secreted by the cholesteatoma matrix epithelium and surrounding inflammatory cells; directly dissolve bone collagen, explaining the osteolytic bone erosion characteristic of cholesteatoma.

Two-stage mastoidectomy preserving the posterior canal wall: Stage 1 removes cholesteatoma; Stage 2 at 9–12 months confirms no residual disease and reconstructs the ossicular chain; higher recurrence risk due to limited access.

Sequelae of CSOM arising from spread of infection beyond the middle ear cleft; classified as extracranial (intratemporal — mastoid, facial nerve, labyrinth, neck) or intracranial (through the dura into the cranial cavity).

Hearing impairment caused by a mechanical barrier to sound transmission through the outer or middle ear; in OME produced by fluid impeding TM and ossicular vibration; reversible once fluid is drained.

Triangular light reflection in the anteroinferior quadrant of a normal flat tympanic membrane; its loss on otoscopy indicates middle ear fluid, increased pressure, or mucosal swelling (Stage 2 onwards in ASOM).

Cholesteatoma behind an INTACT TM in a child with no prior ear disease; arises from embryological squamous cell rests; presents as a white mass in the anterosuperior or posterosuperior quadrant.

Opening the mastoid cortex and exenterating mastoid air cells without taking down the posterior canal wall; used for acute mastoiditis, as the first step in combined approach, or for inflammatory disease without cholesteatoma.

CT contrast finding in lateral sinus thrombophlebitis: on axial contrast-enhanced CT, the non-opacifying thrombus in the sigmoid sinus appears as a hypodense 'delta' surrounded by the enhancing dural walls of the sinus, resembling an empty triangle.

A minimally invasive procedure in which a balloon catheter is passed into the cartilaginous ET under endoscopic guidance and inflated for 2 minutes to dilate the ET lumen; used for adult chronic obstructive ET dysfunction unresponsive to conservative measures.

Cartilaginous-bony channel connecting the nasopharynx to the middle ear; shorter (17–18 mm) and more horizontal in children than adults (35–37 mm), predisposing children to ascending bacterial infection from the nasopharynx.

Fibrocartilaginous channel ~35–37 mm long in adults connecting the nasopharynx to the middle ear; two portions: bony (medial, always patent) and cartilaginous (lateral, normally closed at rest); three functions: ventilation, drainage, and protection of the middle ear.

Impaired ventilation, drainage, and protective function of the Eustachian tube; the primary mechanism in OME; caused by adenoid hypertrophy, mucosal oedema from allergy/URTI, cleft palate, or anatomical factors.

Assessment of ET patency before tympanoplasty; methods include Valsalva observation (air bubbling through perforation), Toynbee test, or tympanometric assessment after middle ear pressure manoeuvres; poor ET function predicts graft failure.

Pus collection between the inner table of the temporal bone and the dura; often clinically silent; detected on CT as lenticular low-density collection; drained at the time of mastoidectomy.

Ipsilateral lower motor neuron facial palsy caused by cholesteatoma erosion of the facial nerve canal (most commonly the tympanic or mastoid segments); a surgical emergency requiring immediate mastoidectomy with facial nerve decompression.

Clinical test for labyrinthine fistula: pneumatic pressure applied to the EAC — positive if nystagmus is induced, indicating cholesteatoma erosion of the lateral semicircular canal wall.

Endoscopic examination of the nasal cavity, nasopharynx, and ET orifice using a flexible fibreoptic scope; mandatory in adult unilateral OME to exclude nasopharyngeal carcinoma or other mass.

The pharyngeal recess on the lateral wall of the nasopharynx, posterior and superior to the ET orifice; the most common site for nasopharyngeal carcinoma; must be examined on nasoendoscopy in every adult with unilateral ET dysfunction.

Absorbable haemostatic sponge soaked in antibiotic solution; placed in the middle ear at tympanoplasty to support the fascia graft in position against the TM remnant during the initial healing phase.

The colloquial term for the mucoid subtype of chronic OME, characterised by thick viscous mucinous fluid produced by goblet cells following mucoid metaplasia of the middle ear mucosa.

Triad of CSOM complications from petrous apex infection: (1) persistent ear discharge, (2) deep retroorbital pain in V1 distribution (ophthalmic trigeminal), (3) ipsilateral CN VI palsy (lateral rectus weakness, diplopia on lateral gaze).

A small flanged tube inserted through the TM at myringotomy to provide long-term Eustachian tube bypass ventilation; indicated for recurrent ASOM or persistent OME, not for simple acute ASOM.

Six-point clinical grading of facial nerve function (Grade I = normal, Grade VI = complete paralysis); used to document and follow facial palsy severity in CSOM complications; guides surgical urgency of decompression.

A six-grade clinical classification of facial nerve function: Grade I = normal; Grade VI = complete paralysis; used to document and follow facial nerve function in CSOM patients with suspected cholesteatoma erosion of the facial canal.

Topical anti-inflammatory nasal sprays (fluticasone, mometasone, budesonide) that reduce mucosal oedema at the ET orifice; first-line pharmacological treatment for obstructive ET dysfunction associated with allergic rhinitis or chronic rhinosinusitis.

The narrowest point of the Eustachian tube at the junction of the bony and cartilaginous portions; the site where mucosal oedema most readily causes complete ET obstruction.

The superior bulge of the internal jugular vein forming part of the hypotympanum floor; an abnormally high jugular bulb may approach the TM level — reason why the posteroinferior quadrant must always be avoided during myringotomy.

An erosion of the bony labyrinth (usually the lateral semicircular canal) by cholesteatoma; causes vertigo and a positive fistula test; managed surgically by removing cholesteatoma over the fistula under microscopic control without disturbing the membranous labyrinth.

Infection of the labyrinth from CSOM; serous type (toxic, reversible) vs suppurative type (bacterial invasion → permanent deafness); presents with acute SNHL + vertigo; risk of spreading to meningitis in suppurative type.

Septic thrombosis of the sigmoid sinus from CSOM; classic presentation: spiking picket-fence fever with rigors, positive blood cultures; MR venography shows sigmoid sinus filling defect ('empty delta sign' on contrast CT); treated with IV antibiotics + mastoidectomy.

A TM perforation in which the edge reaches the annulus fibrosus, leaving no TM rim at one or more margins; characteristic of squamosal (unsafe) CSOM; allows keratinocyte migration.

Acute mastoiditis with suppurative infection of mastoid air cells without classic clinical signs (systemic signs suppressed by prior antibiotics); suspect in CSOM with persistent low-grade mastoid tenderness; diagnosed by CT.

The combined space created after MRM or radical mastoidectomy when the posterior canal wall is removed; communicates with the EAC; requires lifelong outpatient cleaning and water precautions.

Intratemporal complication of ASOM in which infection spreads from the middle ear cleft into the mastoid air cell system; presents with post-auricular pain, swelling, erythema, and displacement of the pinna outward and forward.

The most common intracranial complication of CSOM; caused by gram-negative organisms and anaerobes (different from community-acquired pattern); presents with headache, fever, neck stiffness; CSF shows neutrophilic pleocytosis, elevated protein, reduced glucose.

The most common surgical treatment for cholesteatoma: the posterior external auditory canal wall is taken down to create an open cavity communicating with the EAC; mastoid and attic disease is removed while residual middle ear structures are preserved where possible.

Transformation of the normally flat cuboidal middle ear mucosa into a secretory epithelium with goblet cells and subepithelial mucus glands — the pathological basis for the thick effusion of glue ear.

The 'safe' CSOM variant: central perforation in the pars tensa of the TM, mucosal disease, NO cholesteatoma, no bone erosion; low complication risk; managed by conservative means then elective tympanoplasty.

Repair of the tympanic membrane perforation alone without ossicular reconstruction; equivalent to Wullstein tympanoplasty Type I; indicated when the ossicular chain is intact and mobile.

A surgical incision of the tympanic membrane to drain middle ear pus or fluid; in ASOM performed in the anteroinferior quadrant to avoid the ossicular chain (superior) and the jugular bulb (posteroinferior).

Surgical incision of the TM (in the anteroinferior quadrant) to drain middle ear fluid and insert a grommet; performed under general anaesthesia in children; provides immediate hearing improvement.

Malignancy arising from the nasopharyngeal epithelium; common in South-East Asian populations; frequently presents as unilateral OME from ET obstruction — the reason flexible nasendoscopy is mandatory in adult unilateral OME.

Failure of the Eustachian tube to open adequately, causing negative middle ear pressure, mucosal transudate, and — if chronic — OME, ASOM, and CSOM; most common cause of all forms of otitis media.

Raised intracranial pressure from CSOM (probably from sigmoid sinus thrombosis impairing CSF absorption) without an abscess; presents with headache and papilloedema; LP shows elevated opening pressure but NORMAL CSF chemistry; treated with acetazolamide + mastoidectomy.

Infection of the external auditory canal skin (not middle ear); distinguished from ASOM by tragal tenderness, canal wall oedema, and a normal tympanic membrane on otoscopy.

Chronic non-suppurative accumulation of fluid in the middle ear without acute inflammation; key differential from ASOM; managed by watchful waiting for 3 months then grommet insertion if persistent.

Ear discharge; in ASOM Stage 4 it represents drainage of middle ear pus through a spontaneous TM perforation, typically bringing immediate relief of the preceding severe otalgia.

Abnormal permanent patency of the ET; tube fails to close between swallows; causes autophony (resonant echoing of own voice) and synchronous breathing sounds transmitted directly to the middle ear; relieved by dependent head position.

Infection extending from the mastoid into the petrous apex air cells; when involving the petrous apex adjacent to CN VI (Dorello's canal) and CN V (trigeminal ganglion) → Gradenigo syndrome.

Characteristic spiking fever pattern of lateral sinus thrombophlebitis: repeated cycles of high temperature (>39°C) with rigors followed by drenching sweats and temperature normalisation; reflects episodic septic embolisation from the infected sinus thrombus.

Otoscopic technique using a pneumatic speculum to apply positive and negative pressure to the ear canal, assessing TM mobility; reduced or absent mobility confirms middle ear effusion; the most sensitive clinical test for OME.

A clinical ET function test: a Politzer bag is used to deliver a puff of air to the nostril while the patient phonates, closing the soft palate; if the ET opens, the examiner sees TM movement via otoscope.

Prosthesis used when the stapes superstructure is intact; connects the TM graft or remnant to the stapes head to transmit sound; used in ossicular reconstruction after cholesteatoma surgery.

Sterile middle ear fluid persisting after the acute inflammation of ASOM has resolved; one of the most common precursors of OME in children; should be assessed by tympanometry 6–8 weeks after an ASOM episode.

A curved incision behind the pinna, used to access the mastoid and posterior canal wall during tympanoplasty and mastoid surgery; provides wide exposure without visible external scarring when healed.

Stage 2 of ASOM: bacterial invasion triggers mucosal hyperaemia and serous transudate; TM becomes diffusely red with loss of cone of light but no bulging; otalgia worsening.

A small recess in the lateral epitympanum, bounded medially by the malleus neck and laterally by the pars flaccida; the first site of retraction pocket formation in acquired primary cholesteatoma.

Mastoidectomy with complete removal of the TM and all ossicles, creating a single open cavity (EAC + middle ear + mastoid); used for advanced or recurrent cholesteatoma; causes severe conductive hearing loss.

Rebound nasal congestion from prolonged use of topical nasal decongestants (oxymetazoline, xylometazoline); limits their use to no more than 7 days for ET dysfunction management.

Tuning fork finding where bone conduction (BC) is perceived louder than air conduction (AC) — indicates conductive hearing loss; in active ASOM caused by middle ear fluid impairing sound transmission across the TM-ossicular chain.

The sharp bony spur of the lateral wall of the epitympanum; its erosion by cholesteatoma is a classic early finding on HRCT temporal bone.

A planned second-stage mastoidectomy at 9–12 months after combined approach tympanomastoidectomy; performed to confirm complete cholesteatoma removal and to reconstruct the ossicular chain if no residual disease is found.

The 'unsafe' CSOM variant: attic or marginal perforation with cholesteatoma, bone erosion, and high risk of intracranial and extracranial complications; requires urgent mastoidectomy.

Pus between the dura and arachnoid mater; more dangerous than extradural; causes rapid neurological deterioration; crescentic collection on CT/MRI; requires neurosurgical drainage + mastoidectomy.

Pus collecting between the eroded mastoid cortex and the periosteum; presents with post-auricular fluctuant swelling, erythema, and pinna displacement outward and downward; managed by mastoidectomy + drainage.

Stage 3 of ASOM: pus accumulates under pressure, TM bulges outward and becomes cherry-red; all landmarks obscured; maximal otalgia — the prime indication for myringotomy if no improvement with antibiotics.

Thin bony plate forming the roof of the middle ear, separating it from the middle cranial fossa; its erosion by cholesteatoma or infection allows spread of pus into the cranial cavity (extradural/temporal lobe abscess).

The fascial layer overlying the temporalis muscle; the most commonly used graft material in myringoplasty — avascular, thin, and durable; harvested through the post-aural incision at the time of surgery.

The muscle responsible for active opening of the Eustachian tube during swallowing and yawning; its abnormal insertion in cleft palate patients prevents ET opening, causing chronic OME.

Prosthesis used when only the stapes footplate remains; connects the TM graft directly to the footplate; used when the entire ossicular chain is eroded.

Swallowing with the nose pinched; tests ET opening with a swallow; used in conjunction with Valsalva as a clinical ET function test.

Pain on pressing the tragus (the cartilaginous flap anterior to the EAC); a reliable clinical sign of otitis externa; absent in ASOM (middle ear infection does not inflame the tragal cartilage).

Stage 1 of ASOM: Eustachian tube blockage by mucosal oedema creates negative middle ear pressure, causing TM retraction; no suppuration yet; managed conservatively.

The eardrum — a trilaminar structure dividing the external auditory canal from the middle ear; divided into four quadrants by the malleus handle; the anteroinferior quadrant is the standard safe site for myringotomy.

Acoustic impedance test measuring TM compliance against varying ear canal pressure; Type B (flat) curve indicates middle ear fluid; Type A (normal tent shape) indicates patent air-filled middle ear; used to confirm ASOM effusion or diagnose OME.

Surgical reconstruction of the tympanic membrane and/or ossicular chain to restore hearing and seal the middle ear; classified by Wullstein into Types I–V according to the ossicular integrity and technique.

White chalky calcification of the TM or ossicular ligaments — a residual change from old otitis media or ear surgery; the TM is intact; may cause conductive hearing loss if it immobilises the ossicular chain.

Flat tympanometric curve with near-zero compliance across all ear canal pressures; indicates fluid in the middle ear behind the TM; the key investigation for OME.

Tympanometric curve with a peak shifted to negative pressures; indicates negative middle ear pressure (ET dysfunction) without frank effusion — a precursor state to OME.

Standard myringoplasty technique: the fascia graft is placed medial to (under) the TM remnant, in the middle ear space, supported by Gelfoam packing; allows native TM epithelium to grow over and fuse with the graft surface.

Forced expiration against a closed glottis and pinched nose, raising nasopharyngeal pressure to force the ET open and equalise middle ear pressure; used as a bedside test of ET patency and by patients to equalise pressure during altitude changes.

The evidence-based first-line management strategy for OME: observation without antibiotic or surgical intervention for 3 months, based on the high spontaneous resolution rate (~50% in 3 months, ~90% in 12 months) in healthy children.

In ASOM (unilateral conductive loss), the Weber midline tuning fork vibration is perceived louder in the affected ear because the fluid-filled middle ear paradoxically improves bone conduction relative to the blocked air conduction.

A five-type classification of tympanoplasty: Type I = TM repair only (myringoplasty, ossicles intact); Type II = graft on incus head; Type III = graft on stapes head (columellar); Type IV = graft over stapes footplate; Type V = semicircular canal fenestration.