HEMIFACIAL SPASM - MAGNETIC-RESONANCE ANGIOGRAPHY

Twenty-three consecutive patients with hemifacial spasm were studied. Magnetic resonance imaging angiography of the brain was performed in 2 0 patients and 15 controls. The angiograms were evaluated by two indep endent observers and blinded for side-location of the spasm. Contact b etween an artery from the vertebrobasilar circulation and the intracra nial part of the facial nerve was observed ipsilaterally to the spasm in 17 patients (85%) and in two of 30 control half-brains (7%), respec tively. Treatment is discussed. The study confirms that arterial relat ion to the facial nerve root is the most frequent cause of hemifacial spasm. Magnetic resonance imaging is recommended to exclude mass lesio ns in the posterior cranial fossa, and magnetic resonance angiography is recommended in preoperative evaluation and in research.