Abstract
Nineteen vertebral angiographies (VAG) of patients with hemifacial spasms (HFS) were compared with those from a control group. The mean ratio of the diameter of the affected side versus the healthy side at the 3rd and 4th segment of the vertebral artery (VA) was 0.92-1.23 for both groups, which indicated that there was no significant difference in the VA between the unaffected or affected side. The mean angle of the VA at the 4th segment was significantly more acute (74.6 deg±26.6) in the affected side of the HFS group than in the control group (affected side: 122.8 deg±25.1, healthy side 108.1 deg±12.5). The mean VA angle of the healthy side of the HFS group was not significantly different from that of the control group (94.9 deg±40.9). In addition, loop formations at the 4th segment were only seen on the affected sides of 4 cases of HFS. VAG shows the sharp angulation, or loop formation at the 4th segment of the VA on the affected side to be characteristic of HFS cases. These findings seem to imply elongation of the VA due to arteriosclerosis, and to suggest the possibility of neurovascular compression at the cerebello-pontine angle.
