Predictive value of intraoperative blink reflex monitoring for surgical outcome during microvascular decompression for hemifacial spasm

Abstract

Objective: To investigate the prognostic and predictive value of intraoperative blink reflex (BR) monitoring during microvascular decompression (MVD) for hemifacial spasm (HFS).

Methods: We retrospectively reviewed 41 patients with HFS undergoing MVD with intraoperative BR and lateral spread response (LSR) monitoring. Facial spasm was evaluated for six months postoperatively.

Results: The BR resolved in 38 patients and persisted in three after MVD. For patients who exhibited BR resolution, 1-day, 1-month, and 6-month follow-ups revealed that 35 (92.1%), 35 (92.1%), and 38 (100%) patients had spasm resolution, respectively. However, of the three patients with persistent BR, one (33.3%), one (33.3%), and zero (0%) patients exhibited spasm resolution at the three corresponding follow-ups. We found a statistically significant difference in spasm resolution between the persistent and resolved BR groups at six months postoperatively. A comparison between intraoperative BR and LSR monitoring revealed that BR was a better predictor of clinical outcomes.

Conclusions: Intraoperative BR monitoring is a potentially useful tool to help facilitate an adequate decompression and is a reliable prognostic predictor of surgical outcome.

Significance: This study is the first to document the relationship between intraoperative BR monitoring and surgical outcome in patients with HFS.

Keywords: Blink reflex; Hemifacial spasm; Intraoperative neurophysiological monitoring; Lateral spread response; Microvascular decompression.