Satoru Hosokawa

Otoneurological findings in three patients with brainstem neoplasms who presented with symptoms of acoustic tumors.

Three patients with brainstem neoplasms had cerebellopontine angle symptoms and unilateral cerebellopontine angle shadows on conventional CT scans. As there were involved facial, acoustic and trigeminal nerves in clinical symptoms, cerebellopontine angle syndrome was diagnosed and acoustic tumor was suspected. Otoneurological tests showed unilateral perceptive deafness with retrocochlear lesions, and the gaze test showed Bruns-Cushing type nystagmus.In 19 patients with brainstem lesions, the ABR test results were all abnormal: loss of each component in 74% and prolonged latency of wave V in 24%. Most of the ABR test results in cases of intramedullary lesions with space-occupying effects in the brainstem were abnormalities in the presence and latency of wave V. It is concluded that the ABR test is helpful in determining the sites of intrinsic brainstem lesions.