MR-angiographic findings of patients with central vestibular disorders.

Magnetic resonance angiography (MRA) is a new, noninvasive, and useful method to estimate the posterior circulation in patients with vertigo. From June 1995 to May 1997, 180 patients were examined by magnetic resonance imaging (MRI) and MRA in our department. One hundred and forty-seven patients were vertiginous patients. We measured the displacement angle of the basilar artery with MRA, and examined the relationship between the findings from some neurological examinations and MRA findings in patients with vertigo and dizziness. One hundred and forty-seven patients with vertigo or dizziness were examined by MRI and MRA. They were diagnosed with MRI images in addition to several neurological examinations. MRA was not used for the diagnosis but rather for measuring the displacement angle of the basilar artery. Eighty-six cases with central vestibular disorders, 11 cases with vertebrobasilar insufficiency, and 26 cases with autonomic nerve disorders were recognized. In the cases of central vestibular disorders, the incidences of hyperlipidemia and hypotension were higher than the incidence of anemia. The average displacement angle of the basilar artery (n = 180) was 153.4 degrees +/- 39.4 degrees (mean +/- S.D.). MRA findings were classified into five categories. Ten patients were classified as category III, which represented unilateral partial vertebral artery stenosis. The detection rate for category III and IV abnormalities by neurological examination was higher than that for the other categories. MRI and MRA are important methods to examine patients with central nervous disorders. Distal vertebral artery stenosis may carry a higher risk of a stroke than brainstem infarction.