Eleven cases of surgically confirmed acoustic neurinoma were analyzed clinically. They were four males and seven females, ranging from 49 years old to 69 years old the average of which was 59.7. Tumor sizes ranged from 8 mm to 30 mm. Five of the eleven cases had a history of slowly progressive unilateral hearing loss, and 6 had vertigo for which they referred to see our hospital.
Two of the cases were operated on by the translabyrinthine approach and the others by the middle cranial fossa approach. The tumor arose from the inferior vestibular nerve in 8 cases and the superior vestibular nerve in 3 cases. No significant reduction of the caloric response was found in 4 cases in which the tumors arose from the inferior vestibular nerve. In most of the cases in which the tumor size were less than 15 mm, no remarkable abnormality in equilibrium examinations was obtained. Anatomical preservation of the facial nerve after the surgery was 73 percent. Most cases showed profound hearing loss on the lesion side. However 4 cases with moderate hearing loss showed more than a 50% speech discrimination. Preoperative hearing level was preserved in 2 of the 4 cases.
