Atypical presentation of acoustic neuroma.

Unilateral progressive sensorineural hearing loss, tinnitus, and unsteadiness are the usual initial symptoms of acoustic neuroma. Of the last 100 consecutive cases of acoustic neuroma detected at our Centre, 14 had atypical symptoms, Five patients manifested sudden hearing loss; one of these had complete recovery. Three patients reported long-standing unilateral hearing loss, ranging from 10 to 20 years. Six patients had normal hearing, one of whom was diagnosed incidently when the investigations were performed for contralateral glomus tumor. A second patient, a young woman, experienced weakness of lower limbs. The remaining four patients had only subjective symptoms of hearing loss or tinnitus. Acoustic tumors could have been overlooked easily in these patients. It is important to have a high index of suspicion in all cases of sudden hearing loss, asymmetric sensorineural loss of any duration, subjective sensation of hearing loss, and tinnitus. It is mandatory to investigate these cases with auditory brainstem responses, any abnormality of which makes it necessary to perform magnetic resonance imaging with gadolinium.