Microneurovascular decompression in patients with hemifacial spasm caused by vascular compression of facial nerve at cisternal portion

Abstract

BACKGROUND: Hemifacial spasm is commonly caused by arterial compression of the facial nerve. Although vascular compression usually occurs at the facial nerve exit zone, in some cases, the facial nerve is compressed more distally. We analyzed the clinical outcome of microneurovascular decompression in patients with hemifacial spasm caused by either distal or proximal compression. METHOD: From September 1978 to March 2009, 2,137 patients underwent microneurovascular decompression for hemifacial spasm due to vascular compression of the facial nerve, including 2,022 patients (94.6%) with proximal compression, 101 patients (4.7%) with both proximal and distal (mixed) compression, and 14 patients (0.7%) with only distal compression. FINDINGS: Complete remission of facial spasm occurred in 10 of 14 patients (71.4%) with compression of the cisternal portion, compared with 1,773 of 2,022 patients (87.7%) with proximal compression (P = 0.08) and 87 of 101 patients (86.1%) with mixed compression (P = 0.23). Permanent facial weakness occurred in one patient (7.1%) with compression of the cisternal portion, 18 patients (0.9%) with proximal compression, and one patient (1.0%) with mixed compression. Permanent hearing loss occurred in no patients with compression of the cisternal portion, 29 patients (1.4%) with proximal compression, and three patients (3.0%) with mixed compression. CONCLUSIONS: Outcomes after microneurovascular decompression for hemifacial spasm with compression of the cisternal portion were not statistically different than with proximal compression of the facial nerve. When the clinical diagnosis of hemifacial spasm is confirmed and vascular compression is seen only in the cisternal portion of the facial nerve, microneurovascular decompression for these patients provides outcomes similar to those with proximal compression of the facial nerve.