CT and hemifacial spasm.

Forty-six patients with typical hemifacial spasm had CT. Thirty-eight (83%) were abnormal, including two with surgically documented tumors. Thirty-six had a characteristic dolichoectatic vertebrobasilar artery, with the convexity pointing to the side of the spasm in 92% of the scans. This study suggests that CT is worthwhile procedure in the evaluation of hemifacial spasm and that dolichoectatic vertebrobasilar arteries are very frequently associated with hemifacial spasm.