Acoustic neuroma and non-tumour retrocochlear patients: audiological features.

Seventeen surgically confirmed acoustic neuroma subjects and seventeen radiologically confirmed non-tumour subjects with retrocochlear pathology of unknown aetiology were selected to investigate retrospectively the diagnostic yield of basic audiological test procedures. Puretone audiometry, tympanometry, reflexometry and auditory brainstem response audiometry were used in the identification of acoustic neuromas versus non-tumour retrocochlear disorders. All subjects had been referred originally for neuroaudiological assessment because of suspected acoustic neuroma and had been found to have a range of abnormal ABR findings consistent with retrocochlear pathology. Detailed retrospective analysis of audiological results following surgical and radiological classification showed subject similarities for most parameters of the individual audiological tests for both acoustic neuroma and non-tumour groups. A significant difference was noted, however, between the two clinical populations for the ABR Wave V absolute interaural latency difference parameter.