The clinical utility of intraoperative blink reflex monitoring and its synergistic value with lateral spreading response monitoring in predicting postoperative outcomes in patients with hemifacial spasm following microvascular decompression

Background Microvascular decompression (MVD) is the current definitive treatment for achieving a radical cure of primary hemifacial spasm (pHFS). The current study aimed to integrate blink reflex (BR) monitoring into MVD for pHFS to assess surgical efficacy and explore its predictive value for postoperative spasm when combining with lateral spread response (LSR) monitoring.Methods A prospective cohort study included 105 patients with pHFS undergoing MVD. Intraoperative zygomatic LSR (ZYG-LSR), mandibular LSR (MAN-LSR), and BR were monitored. Multivariate logistic regression was used to assess independent predictors of postoperative spasm at 3 months after surgery. Two predictive models (Model 1: LSR; Model 2: LSR plus BR) for postoperative spasm were compared using Receiver Operating Characteristic (ROC) curve analysis at four postoperative time points: 1 day, 1 week, 1 month, and 3 months, with the area under the curve (AUC) quantifying overall accuracy and the DeLong test for comparison.Results BR showed a higher elicitation rate (99.0%) than ZYG-LSR (97.1%) and MAN-LSR (91.4%). Persistent ZYG-LSR (odds ratio 28.99), MAN-LSR (odds ratio 12.06), and BR (odds ratio 10.38) were identified as independent predictors for postoperative spasm at 3 months after surgery (all p < 0.05). Regarding the two predictive models, their performance improved over time. At 3 months, Model 2 showed a numerically higher AUC than Model 1 (0.955 versus 0.901), while the DeLong test still did not reach statistical significance (p = 0.083).Conclusion In conclusion, intraoperative BR monitoring appears to be a feasible and potentially useful adjunct to conventional LSR monitoring in MVD for pHFS, and warrants further evaluation in larger studies.