Objective and importance: To illustrate that decompression of the facial nerve by transvenous endovascular treatment may relieve hemifacial spasm (HFS) caused by dilated veins.
Clinical presentation: A 35-year-old man suffered severe chronic right HFS associated with a dilated right lateral mesencephalic vein lying in the vicinity of the facial nerve. This nonessential vein was recruited as a secondary collateral drainage from an inoperable left temporo-occipital arteriovenous malformation.
Intervention: The lateral mesencephalic vein was reached through the superior petrosal sinus using a transfemoral venous approach and was occluded with interlocking detachable coils (Target Therapeutics, Freemont, CA). There was complete remission of HFS without recurrence after 2.5 years of follow-up.
Conclusion: This case report supports vascular compression in the pathogenesis of HFS and suggests that facial nerve injury is not essential for the therapeutic effect of surgical decompression.