Classification of vertebral artery loop formation and association with cervicogenic dizziness.

OBJECTIVE: An examination was conducted of the number, level, clinical association and treatment approaches for vertebral arterial loop formation in patients with this condition with and without concurrent cervicogenic dizziness, and classified them according to the vertebral artery segment in which it was present.

METHOD: A cross-sectional retrospective study.

RESULTS: Thirty-seven patients who had undergone double-sided magnetic resonance angiography were examined; vertebral arterial loop formation was observed at only 1 level in 26 patients and at several levels in 9 patients. Segment one (V1) was involved in 78.3 per cent of cases and segment two (V2) was involved in 21.6 per cent. Symptoms in patients with vertebral arterial loop formation included: positional vertigo, in 100 per cent; and pulsatile tinnitus, in 83.7 per cent.

CONCLUSION: Loop formation at the vertebral artery was observed most often on the proximal side in patients with cervicogenic dizziness (78.3 per cent). The incidence on the left side was twice as high as on the right side.