[Clinical investigations of five patients with intracranial lesions presenting tinnitus].

We investigated 5 patients with intracranial lesions. The initial complaint was tinnitus with normal hearing or sight sensorineural hearing loss. The lesions were 2 cerebello-pontine angle meningiomas, 1 cerebello-pontine angle epidermoid cyst, 1 supratentorial falx meningioma and 1 dural arteriovenous malformation at the temporal bone. Because of pulsatile or severe persistent tinnitus, we performed CT and MRI to determine the presence of intracranial lesions. Some patients had an episode of cerebral infarction and the complaint of headache or head heaviness. Quantitative measurement of tinnitus showed a low-frequency character in a pitch-match examination and moderate loudness in loudness balance. In the patients with falx meningioma and dural arteriovenous malformation, the tinnitus character was pulsatile and abnormal blood flow might have affected the peripheral auditory system. On the other hand, in the patients with a cerebello-pontine angle tumor, the tinnitus character was non-pulsatile and compression on the central auditory system by the tumor might have caused the tinnitus.