Presentation on theme: "Otosclerosis Dr. Vishal Sharma. Definition Hereditary disease of bony labyrinth showing replacement of lamellar enchondral bone by irregularly laid new."— Presentation transcript:
Otosclerosis Dr. Vishal Sharma
Definition Hereditary 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.
Antonio Valsalva First described ankylosis of stapes in 1741
Adam Politzer Coined the term Otosclerosis in 1893
Friedrich Siebenmann Coined the term Otospongiosis in 1912
Epidemiology Exact etiology is unknown (? Viral) Autosomal dominant: variable penetrance Race: common in white races & Indians Female : Male = 2 : 1 Age: Common in 20 - 40 years Hormonal influence: es in pregnancy, menopause, stress (trauma, surgery)
Van der Hoeve syndrome Otosclerosis + osteogenesis imperfecta + blue sclera
Types of Otosclerosis A. Stapedial B. Cochlear: otosclerotic focus is seen over Round window Promontory C. Stapedial + cochlear: mixed type D. Malignant: rapidly progressing cochlear lesion with severe sensori-neural deafness.
Types of Stapedial Otosclerosis 1. Anterior focus (commonest): 2 mm anterior to oval window. 2. Posterior focus: 2 mm behind oval window. 3. Circumferential: involves footplate margin only.
Types of Stapedial Otosclerosis 4. Biscuit type: footplate involved, margin is free. 5. Obliterative: obliterates oval window completely.
Symptoms of Otosclerosis 4. Paracusis Willisii: Pt has better hearing in noisy surroundings (people increase their voice intensity & pts speech discrimination becomes better).
Thomas Willis (1621-1675)
Otoscopy Normal T.M. is seen in most cases. Pinkish colour over promontory seen in otospongiosis (2 - 10 % cases) Schwartze sign / Flamingo pink blush.
Tuning Fork Tests RinneWeberA.B.C. StapedialNegative (BC > AC) Lateralizes to Deaf ear Normal CochlearPositive (AC > BC) Lateralizes to Better ear Decreased MixedNegative (BC > AC) Lateralizes to Better ear Decreased
Gelle & Bing Tests Vibrating tuning fork placed over mastoid & then: External auditory canal is blocked in Bing test or E.A.C. pressure ed by Siegalization in Gelle test BingGelle OtosclerosisNo change Normal / SNHL Intensity es
Pure Tone Audiometry Low frequency conductive deafness Carharts notch in bone conduction at 2 KHz
Carharts 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 immobility 3. Mechanical artefact Carharts notch reverses with stapes surgery
Speech Audiometry Speech 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.
Impedance Audiometry A s curve seen in 40 % cases of otosclerosis. Normal middle ear pressure + decreased middle ear compliance. Others have A curve.
Stapedial reflex present
Stapedial reflex absent
C.T. scan temporal bone 20 0 coronal oblique cuts are taken
Stapedial otosclerosis (coronal)
Cochlear otospongiosis (axial)
Differential Diagnosis Otitis Media with Effusion: type B tympanogram Adhesive Otitis Media: absence of T.M. mobility Tympanosclerosis: white patch on T.M. Ossicular discontinuity: type Ad tympanogram Congenital ossicular chain fixation: tympanotomy Malleus head fixation: tympanotomy
Inclusion criteria for surgery Pure Tone Average between 30 - 60 dB Air bone gap > 15 dB Speech discrimination score > 60 % Absence of sensorineural deafness
Contraindications for surgery Only hearing ear Menieres disease Otitis media Otitis externa Extremes of age Pregnancy Professions: divers, high construction workers, frequent travelers, noisy surroundings
Surgical steps for Stapedotomy
Right T.M. (upright)
Right T.M. (supine)
Tympanomeatal flap raised
Bony overhang curetted
Chorda tympani preserved
Chorda tympani separated
Confirm footplate fixation Checking for absence of round window reflex
Depth measurement prosthesis
Incudo-stapedial joint broken
Footplate perforation made
Fenestration with burr
Posterior crus fractured
Teflon piston Length of piston = medial surface of incus to stapes footplate + 0.25 mm Range = 3.75 – 4.25 mm 1 cm
Piston placed in perforation
Stapedius tendon cut
Piston crimped around incus
Anterior crus fractured
Stapes superstructure removed
Footplate perforation sealed
Tympanomeatal flap put back
Stapes superstructure removed
Prosthesis placed over vein graft
Complications of stapes surgery
Intra-operativePost-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
Sodium Fluoride Given in cochlear otosclerosis & active focus of otospongiosis (Schwartze sign). Acts by: a. Decreases bone resorption b. Increases bone formation c. Prevents enzymatic damage to cochlea 20 mg orally, thrice daily for 3 - 6 months
Hearing Aid For patients who: Are unfit for surgery Refuse surgery