Vestibular schwannoma: when to look for it?
OBJECTIVE
(1) To compare audiometric parameters in patients with vestibular schwannoma and in those with asymmetric hearing loss from other causes; and (2) to assess proposed screening criteria by comparing published protocols.


METHODS
Audiometric data from 199 vestibular schwannoma patients and 225 non-tumour patients were compared. Eight screening protocols were tested on these 424 patients.


RESULTS
Vestibular schwannoma and non-tumour patients with little or no hearing loss in the unaffected ear were inseparable; however, vestibular schwannoma patients with hearing loss in the unaffected ear had greater audiometric asymmetry, compared with non-tumour patients with the same pattern of hearing loss. The sensitivity of screening protocols varied from 73 to 100 per cent; parallelism was observed between sensitivity and screening rate.


CONCLUSIONS
As regards vestibular schwannoma screening protocols, the best compromise between sensitivity and screening rate was offered by a criterion comprising either: (1) > or =20 dB asymmetry at two neighbouring frequencies, or unilateral tinnitus, or (2) > or =15 dB asymmetry at two frequencies between 2 and 8 kHz.
Gimsing
S
S
Department of Audiology, Vejle Hospital, Denmark. juul_gimsing@dadlnet.dk
D000368:Aged; D001299:Audiometry; D003718:Denmark; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D046088:Hearing Loss, Unilateral / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000175:diagnosis* / Q000503:physiopathology; D018579:Patient Selection; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D013063:Speech Discrimination Tests; D013198:Stapedius / Q000502:physiology; D014012:Tinnitus / Q000209:etiology