HTHSCI 2F03 Lecture Notes - Lecture 4: Vestibular Schwannoma, Cerebellopontine Angle, Eustachian Tube
26 Dec 2020
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Document Summary
Impaired conduction anywhere between auricle and round window. Defects of cochlea, cohlear n. or brain. Benign, slow-growing tumour of superior vestibular n. Slow onset, unilat snhl, tinnitus vertigo. Mri all pts. c unilateral tinnitus / deafness. Ad condition characterised by fixation of stapes at the oval window. Hl improved in noisy places: willis" paracousis. Pta shows dip (caharts notch) @ 2khz. Anomalies of pinna, external auditory canal, tm or ossicles. Detection and mx of hearing loss before 6mo improves language. Malfusion accessory tags/auricles and preauricular pits, fistulae or sinuses. Sinuses may get infected, mimicking a sebaceous cyst. Can ischaemic necrosis of cartilage and subsequent fibrosis to cauliflower ears . Mx: aspiration + firm packing to auricle contour. Smooth, symmetrical bony narrowing of external canals. Secreted in outer 3rd of canal to prevent maceration. Syringing after 1wk softening with olive oil. T1hs ige-mediated inflam from allergen exposure mediator release from mast cells.
