Blood flow in common carotid and vertebral arteries in patients with sudden deafness.

Blood flow was measured in the common carotid artery (CCA) and the vertebral artery (VA) by the ultrasonic Doppler method in 14 male patients with sudden deafness and 70 normal adults. In the patients, blood flow on the affected side was slower than that on the normal side or that of the control group. Although these differences were not statistically significant in the CCA or in the VA, significant differences in the blood flow were noted between the group with a hearing loss of greater than 50 dB and the group with a loss of less than 50 dB. A negative correlation was found between blood viscosity and blood flow in both CCAs and both VAs. After stellate ganglion block (SGB), the blood flow of the CCA and VA increased on the side of the SGB and decreased on the opposite side. The changes in blood flow after SGB decreased with age, presumably because of changes in the blood vessel walls and a weaker response to sympathetic nerve receptors in the arterial wall.