Clinical records late onset sensorineural hearing loss following stapedectomy (an uncommon cause)

Pitfalls in the diagnosis of acoustic neuroma

The patient with an acoustic neuroma may present to the otologist with a variety of clinical features. Classically these include a retrocochlear pattern of sensorineural hearing loss, reduced vestibular response on caloric testing and radiological asymmetry of the internal auditory canals (IAC). The absence of any or all of these features, however, does not exclude the presence of tumour. Five cases are presented to illustrate the potential for diagnostic delay unless a routine battery of investigations is undertaken in patients with neuro-otological disorders. All patterns of subjective audiometry are encountered, auditory brain stem response testing may be unreliable where hearing loss is profound, vestibular testing is normal in half of small tumours and the intracanalicular tumour may be radiologically undetectable unless IAC meatography is employed.

Cochlear deafness in the presentation of a large acoustic neuroma

It is exceptional for a large tumour, as presented, to present a cochlear pattern of hearing loss. Only a rigid adherence to a battery of audiological, vestibular and radiological tests can exclude neuroma. The possibility of hearing conservation in neuroma surgery (Clemis et al., 1981) demands further understanding of the mechanism of cochlear damage produced by CP angle tumours.