RESUMO
The purpose of this study was to determine the relationships between the pattern of vertebral artery flow and the alignment of the cervical spine in a study group of 25 subjects with signs and symptoms related to vertebral artery insufficiency, compared with 25 age-and sex-matched healthy subjects (control group). The relative amplitude of pulsatile flow of extracranial vertebral arteries was measured by using a Grass photoelectric pulse sensor. The procedures comprised: (a) measurement of vertebral flow when the subjects were sitting with heads in the neutral, flex, extend and rotate positions; (b) an electromyogram (EMG) of the trapezius muscle in both neck and shoulder by disc electrodes; and (c) evaluation of the alignments from radiographs of the anterior, posterior, lateral and oblique view of the cervical spine. Results: Statistically, the extracranial vertebral flow (EVBF) in the study group was significantly lower than that in the control group. The frequency of vertebral asymmetry (more than 50%) was significantly higher in the study group (16 out of 25 subjects) than in the control group (seven out of 25 subjects). A statistically significant reduction of the vertebral flow was found in both groups when the head was flexed, extended and rotated (p < 0.05). However, a further reduction of the vertebral flow accompanying changes in head position in the study group, who initially had low blood flow, frequently resulted in dizziness, neck pain and blurred vision. The present results revealed that attenuation of the vertebral flow in the study subjects was associated with a significant increase in contraction of the trapezius muscle. The frequency of mild cervical spondylosis was similarly found in both groups (six out of 20 in the control group and 10 out of 20 in the study group). However, the vertebral flows of the 16 subjects with mild cervical spondylosis were significantly lower than in the subjects with normal cervical spine alignment.