Aqueductal stenosis--results of vestibular function tests.

A case of aqueductal stenosis is reported. The patient was a 14-year-old Japanese girl who was suffering from bilateral tinnitus and unsteadiness of gait. A series of neuro-otological tests revealed prolonged acoustically evoked brain stem response (ABR) latency, disturbed standing reflex, inhibited optokinetic nystagmus (OKN) and ataxic eye tracking test (ETT). Marked distension of the lateral and third ventricles was noticed on CT examination of the brain. A positive contrast ventriculogram using iotalamic acid showed occlusion of the cerebral (Sylvian) aqueduct. All of these results are suggestive of benign, non-neoplastic aqueductal stenosis with associated hydrocephalus. The patient underwent ventriculo-peritoneal shunt and, following the surgery, the results of neuro-otological, including radiological, re-examination indicated a remarkable recovery.