Objective: The purpose of this study was to determine the usefulness of brainstem evoked potential (BAEP) in the diagnosis of cerebellopontine angle (CPA) tumors.

Method: Sixteen subjects in which BAEP study was compatible with CPA tumors were retrospectively reviewed and analyzed the results of BAEP, findings of CT and MRI, and clinical signs.

Result: Thirteen subjects were reviewed and three were lost in follow-up. 1) CPA tumors were confirmed with CT/MRI in 10 subjects and the other 3 patients had other lesions which could be differentiated from CPA tumors clinically. The positive hit rate of BAEP was 76.9% in 13 patients whose findings were compatible with CPA lesion. 2) Of 10 patients with CPA tumor, the tumors were bilateral in 4 patients and unilateral in 6 patients, and the diagnosis of the tumors were vestibular schwannoma in 9 patients and meningioma in 1 patient. 3) The major symptoms of the patients with CPA tumors were hearing loss, tinnitus, dizziness, facial nerve palsy, headache, cerebellar dysfunction, nystagmus, and vertigo. 4) The most common abnormal findings of BAEP in the patients with CPA tumors were increase in the interpeak latency I-III and I-V on the affected side and interpeak latency III-V on the unaffected side.

Conclusion: The BAEP considering clinical correlation is a useful study as a screening test in the diagnosis of CPA tumors because of its high positive hit rate and cost-effectiveness compared with CT/MRI.