[A clinical study of vertebrobasilar insufficiency using the ultrasonic Doppler technique].

Forty-one cases of vertebrobasilar insufficiency (VBI) were investigated. All cases had repeated vertigo attacks. The ultrasonic Doppler technique was used to measure the vertebral arterial blood flow in patients and healthy adults. In cases of VBI, low and asymmetric blood flow velociety was found more often than in healthy adults. This result suggests that the difference in the vertebral arterial blood flow between the right and left sides increases the susceptibility to circulatory disturbance of the brain and inner ear. This noninvasive technique is helpful in the diagnosis of VBI and may be useful for the evaluation of the therapeutic effects and prognosis.