Background and importance: Hemifacial spasm is usually caused by compression of the facial nerve at the root exit zone (REZ), whereas fusiform aneurysmal compression is extremely rare. The authors describe symptomatic hemifacial spasm caused by a contralateral fusiform aneurysm of the vertebral artery (VA) that was treated by endovascular coil embolization.
Clinical presentation: A 55-year-old woman developed left hemifacial spasm that had gradually worsened over a period of 2 years before admission to our hospital. Cerebral angiography showed an elongated right VA fusiform aneurysm near the VA union that inclined toward the left side. The cause of the facial spasm was considered to be compression of the left facial nerve REZ by the aneurysm. Endovascular parent artery embolization including the aneurysm was performed. The hemifacial spasm disappeared within 3 months.
Conclusion: Hemifacial spasm caused by contralateral VA fusiform aneurysm can be treated by intravascular parent artery occlusion with coil embolization.