A CLINICAL, GENETIC AND AUDIOLOGICAL STUDY OF PATIENTS AND FAMILIES WITH UNILATERAL VESTIBULAR SCHWANNOMAS .2. AUDIOLOGICAL FINDINGS IN 93 PATIENTS WITH UNILATERAL VESTIBULAR SCHWANNOMAS

Ninety-three patients with histologically or radiologically confirmed unilateral vestibular schwannomas were recruited. Audiological testing for retrocochlear pathology was undertaken. Patients' hospital record s were examined for previous audiological and radiological results. Th e audiometric configuration was designated as one of the following: no rmal, sloping, low frequency, peak, trough or flat. A sloping sensorin eural audiometric configuration was present in 68 per cent of cases. N o significant correlation was found between tumour size and average pu re tone threshold 500 Hz to 4000 Hz, optimum discrimination score or i nteraural differences for wave V. Ninety-one per cent of cases had abn ormalities on auditory evoked potential; 92 per cent of cases showed a bnormalities on stapedial reflex testing. The limitations of audiologi cal testing in the investigation of patients with suspected unilateral vestibular schwannomas are discussed. A protocol for the investigatio n of such patients is presented.