Conductive hearing loss with intact TM.Dr Javed shah FRCS.

Causes of conductive .Hearing loss with intact TM...6: 

Causes of conductive .Hearing loss with intact TM...6 1/ Otitus media with effusion. 2/Tympanosclerosis 3/Ossicular discontinuity 4/congenital choleasteatoma 5/ Otosclerosis.

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Otosclerosis: it is hereditary localised disease of the ottic capsule, resulting in progressive deafness.

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Heredity: 50%,positive family history,helps in diagnosis Race; fair colored are affected more Sex: Females are more affected? age of onset; rare below 5 yr. ,starts in teens and present in clinic between 20 -30 yrs.. Pregnancy. aggravates otosclerosis in 33% ..63%

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History Valsalva 1741, postmortem examination of deaf child when he died Josef Tony 1861, noted ankylosis of stapes in 39 out of 1959 temporal bone dissection Politzer 1894 introduced the term otosclerosis and described the histopathology.

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Hereditary in 70% of caes Autosomal dominant incomplete penetrance

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Slowly progressive hearing loss Bilateral but in 10-15%cases unilateral ages 15-45 woman 2:1 pregnancy /estrogen therapy

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Histopathology: Woven bone/lamellar bone Cells: osteoblasts cells/osteoclasts cells otospongiosis: active disease ,woven bone vascular,..schwatze sign/flimingo

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The presence of residual cartilage or defective cartilagea/ fisula ante fenestra,fisula postfenestram.round window,scc and cochlea

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Ossicular discontinuity - conductive loss of 60 db usually without sensorineural component - flaccid tympanic membrane on pneumatic otoscopy - type Ad tympanogram Congenital stapes fixation - Family history less likely (10%) - usually detected in the first decade of life - 25% incidence of other congenital anomalies (3% for juvenile otosclerosis) - non-progressive CHL Malleus head fixation - when congenital, associated with other stigmata (aural atresia) - presence of tympanosclerosis - pneumatic otoscopy - almost always associated with type As tympanogram (only in advanced otosclerosis) Paget’s disease - diffuse involvement of the bony skeleton - elevated alkaline phosphatase - CT  - diffuse, bilateral, petrous bone involvement with extensive de-mineralization - More commonly crowds the ossicles in the epitympanum, partially fixing the ossicular chain Osteogenesis imperfecta - presence of blue sclera - h/o of multiple bone fractures - CT – more common involves the otic capsule and to a greater extent Superior semicircular canal dehiscence

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Types of otosclerosis 1/stapedial

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Cochlear: spiral ligament atrophy, toxins, vascularity Young and middle age with s/n hearing loss, family hx of otosclerosis. CT scan finding

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Symptoms, 1/hearing loss, slowly progressive Paracusis, 2/ Tinnitus. 80% pulsatile,worse in patients with cochlear involvement. 3/ verigo, positional or associated with minieres disease.

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Signs: otoscope, normal TM or flimingo tint ,Schawartze Rhinne test weber test PTA, tympanometry

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Treatment, Medical sodium fluoride vitamin D Calcium carbonate

Audiology: 

Audiology Sound: it is form of energy ,produced by vibrating object,A wave consist of compression and rarefaction in a medium Frequency; number of cycles/second. the unit is Hz. Pitch: subjective sensation produced by frequency.

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Pure tone : a single frequency sound is called pure tone Intensity: strength of sound which determines its loudness Decibels: intensity is measured in db. its logrithmatic ratio. ratio between two sounds, the sound being described and the reference sound

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Masking: definition, why its necessary in audiometry speech frequency, 500,1000,2000 hz

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Assessment of hearing: 1/ conductive hearing loss; 2/ sensorineural hearing loss 3/ Mixed hearing loss

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Clinical Tests of hearing 1/Finger friction test 2/watch test 3/whisper test

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Tuning fork test Rinne test. Positive, negative, False negative Rinne

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Pure Tone Audiometry: PTA , audiologist, audiometer, sound proof room otoscope ears are clean ,there is no wax in EAM Explain the procedure to patient so that he knows what to expect and his response to sound When to mask the not test ear