After a short survey on the diagnostic work-up for acoustic neuroma, the authors underline the importance of magnetic resonance (MRI), enhanced by gadolinium, for otoneurological pathology. Through the presentation of a clinical case, the pros and cons for the routine application of MRI in suspect cerebellopontine angle (CPA) tumours in particular are reviewed. The possibility of false-positive MRI findings is discussed, although in this specific case a proper therapeutic approach was eventually carried out in order to resolve the associated Vllth nerve disturbance.

A patient with neurofibromatosis two (NF2) presented with bilateral acoustic neuroma. Pre-operative audiometry revealed a dead right ear and severe left-sided sensorineural hearing loss. Following surgical removal of the larger right acoustic neuroma we have documented a sensorineural improvement of 45 dB in the contralateral ear on pure tone audiometry, which as far as the authors are aware has not previously been described.

A series of 151 patients with 154 acoustic schwannomas have been operated upon in Manchester Royal Infirmary by a joint Otological and Neurosurgical team, employing either the translabynnthine or the sub-occipital approach. The perioperative mortality rate was 3 per cent. Anatomical preservation of the facial nerve was achieved in 89 per cent of tumour removals and a good to normal functional result in 79 per cent of cases. Attempts at hearing preservation have been unsuccessful, largely because of the small number of patients in the series in whom useful hearing was present preoperatively. Complications included major brain stem ischaemia (1.2 per cent), CSF fistula (5 per cent) and facial dysaesthesia (7 per cent). The incidence of mortality and morbidity is directly related to tumour size and to the experience of the surgeons. A number of patients experienced an unusual type of post-operative dreamlike state which appeared to be a form of hypnagogic hallucination, and the possible neurophysiological mechanism responsible for this phenomenon is discussed. The continuing failure to attain the ideal of early diagnosis is lamented, and the importance of a flexible bidisciplinary surgical approach emphasized.