Acoustic tumors: atypical features and recent diagnostic tests.

About one-third of patients with acoustic tumor (AT) initially seek medical attention for nonaudiologic complaints. The nonspecific early symptoms of AT require the inclusion of AT in many neurologic differential diagnoses. Advances in electrophysiologic and radiographic tests have allowed earlier diagnosis of AT at a time when abnormal physical findings other than hearing loss are present in less than half of patients. The availability of brainstem auditory evoked response testing, fourth-generation CT, and air-CT cisternography have changed the approach to the diagnosis of AT. Neurologists should be cognizant of recent diagnostic advances.