ABSTRACT
Nine-three patients with histologically or radiologically confirmed unilateral vestibular schwannomas were recruited. Audiological testing for retrocochlear pathology was undertaken. Patients' hospital records were examined for previous audiological and radiological results. The audiometric configuration was designated as one of the following: normal, sloping, low frequency, peak, trough or flat. A sloping sensorineural audiometric configuration was present in 68 per cent of cases. No significant correlation was found between tumour size and average pure tone threshold 500 Hz to 4000 Hz, optimum discrimination score or interaural differences for wave V. Ninety-one per cent of cases had abnormalities on auditory evoked potential; 92 per cent of cases showed abnormalities on stapedial reflex testing. The limitations of audiological testing in the investigation of patients with suspected unilateral vestibular schwannomas are discussed. A protocol for the investigation of such patients is presented.
Subject(s)
Neuroma, Acoustic/physiopathology , Adolescent , Adult , Aged , Audiometry, Evoked Response , Audiometry, Pure-Tone , Audiometry, Speech , Clinical Protocols , Female , Humans , Male , Middle Aged , Neuroma, Acoustic/diagnosis , Neuroma, Acoustic/pathologyABSTRACT
Ninety-three patients with unilateral vestibular schwannomas were examined in a clinical, genetic and audiological study, to determine whether they had features associated with neurofibromatosis Type 1 or neurofibromatosis Type 2. In 91 families, one patient only was found to be affected with a unilateral vestibular schwannoma. Patients did have a few café-au-lait macules, but fewer than six in number. None of the patients satisfied the cutaneous diagnostic criteria for neurofibromatosis Type 1. Neither Lisch nodules nor presenile posterior subcapsular lenticular opacities or cortical opacities were a feature. Five patients with unilateral vestibular schwannomas are described where the clinical findings raised the possibility of neurofibromatosis Type 2. It is suggested that certain individuals with unilateral vestibular schwannomas are at risk of developing neurofibromatosis Type 2. Furthermore, the possibility of neurofibromatosis Type 2 should be considered if more than one individual in a family is found to be affected with a unilateral vestibular schwannoma.
