Two case reports of bilateral vertebral artery tortuosity and spiral twisting in vascular vertigo

BACKGROUND Tortuous blood vessels are commonly seen in the cerebral arteries. The association between vertebrobasilar artery tortuosity and vascular vertigo remains obscure. CASE PRESENTATION We describe two patients with vascular vertigo who had bilateral curving and spiral looping in multiple segments of the vertebral arteries and also exhibited basilar artery tortuosity. Both patients had cerebrovascular risk factors and exhibited clinical features of vertigo with high severity, slow recovery, and recurrent tendencies. Contrast enhanced magnetic resonance angiography of the neck showed bilateral tortuosity in the V2 segments and spiral twisting in the V4 segments of the vertebral arteries, and basilar artery curving. No obvious sign of atherosclerotic stenosis was found in the vertebrobasilar arteries and no abnormalities were observed in the internal carotid arteries. Transcranial Doppler ultrasound showed decreased blood flow in tortuous vertebrobasilar arteries. Brainstem auditory evoked potentials showed that the interpeak latencies (IPL) of waves III-IV were prolonged, with a ratio of IPL III-V/IPL I-III > 1. CONCLUSIONS Vertebrobasilar tortuosity in combination with cerebrovascular risk factors may lead to vascular vertigo in these patients.