2 DefinitionHereditary disease of bony labyrinth showing replacement of lamellar enchondral bone by irregularly laid new bone.New bone is spongy + more vascular in active Otospongiosis but thicker & more cellular in inactive Otosclerosis.
3 Antonio ValsalvaFirst describedankylosis of stapesin 1741
4 Coined the term Otosclerosis Adam PolitzerCoined the term Otosclerosisin 1893
5 Coined the term Otospongiosis Friedrich SiebenmannCoined the term Otospongiosisin 1912
6 Epidemiology Exact etiology is unknown (? Viral) Autosomal dominant: variable penetranceRace: common in white races & IndiansFemale : Male = 2 : 1Age: Common in yearsHormonal influence: es in pregnancy, menopause, stress (trauma, surgery)
7 Otosclerosis + osteogenesis imperfecta + blue sclera Van der Hoeve syndromeOtosclerosis + osteogenesis imperfecta + blue sclera
8 Types of Otosclerosis A. Stapedial B. Cochlear: otosclerotic focus is seen over Round window PromontoryC. Stapedial + cochlear: mixed typeD. Malignant: rapidly progressing cochlearlesion with severe sensori-neural deafness.
9 Types of Stapedial Otosclerosis 1. Anterior focus (commonest): 2 mm anterior to ovalwindow. 2. Posterior focus: 2 mm behind oval window.3. Circumferential: involves footplate margin only.
10 Types of Stapedial Otosclerosis 4. Biscuit type: footplate involved, margin is free.5. Obliterative: obliterates oval window completely.
16 Gelle & Bing Tests Vibrating tuning fork placed over mastoid & then: External auditory canal is blocked in Bing test orE.A.C. pressure ed by Siegalization in Gelle testBingGelleOtosclerosisNo changeNormal / SNHLIntensity esIntensity es
17 Pure Tone Audiometry Low frequency conductive deafness Carhart’s notch in bone conduction at 2 KHz
18 Carhart’s notch Proposed theories 1. Stapes fixation disrupts normal ossicular resonance (2000 Hz)2. Normal compression mode of bone conduction is disturbed because of relative perilymph immobility3. Mechanical artefactCarhart’s notch reverses with stapes surgery
19 Speech AudiometrySpeech Discrimination Score (maximum score achieved) is almost 100 %.Speech Reception Threshold (intensity at which 50 % words are heard) is increased by the amount of conductive hearing loss.
27 Differential Diagnosis Otitis Media with Effusion: type B tympanogramAdhesive Otitis Media: absence of T.M. mobilityTympanosclerosis: white patch on T.M.Ossicular discontinuity: type Ad tympanogramCongenital ossicular chain fixation: tympanotomyMalleus head fixation: tympanotomy
36 Inclusion criteria for surgery Pure Tone Average between dBAir bone gap > 15 dBSpeech discrimination score > 60 %Absence of sensorineural deafness
37 Contraindications for surgery Only hearing ear Meniere’s disease Otitis media Otitis externa Extremes of age Pregnancy Professions: divers, high construction workers, frequent travelers, noisy surroundings
73 Intra-operative Post-operative Floating footplate Otitis media Submerged footplate Oval window granuloma Dislocated incus Perilymph fistula Perforated TM Sensori-neural HL Damage to facial nerve Persistent air-bone gap or chorda tympani Vestibular dysfunction Persistent stapedial artery Delayed facial palsy in Perilymph flooding laser surgery
74 Sodium FluorideGiven in cochlear otosclerosis & active focus of otospongiosis (Schwartze sign).Acts by:a. Decreases bone resorptionb. Increases bone formationc. Prevents enzymatic damage to cochlea20 mg orally, thrice daily for months
75 Hearing AidFor patients who:Are unfit for surgeryRefuse surgery