Subjective and Objective Measures in the Treatment of Hemifacial Spasm With OnabotulinumtoxinA

Purpose: To evaluate the Sunnybrook Facial Grading System (SFGS) and Facial Clinimetric Evaluation (FaCE) Scale Instrument outcomes when treating hemifacial spasm (HFS) with onabotulinumtoxinA. Methods: An Institutional Review Board-approved retrospective review of records of 66 HFS patients treated with onabotulinumtoxinA. SFGS and FaCE surveys were completed prior to onabotulinumtoxinA therapy and at 1 month follow up. Surveys were analyzed for differences using paired Student t tests, with statistical significance set at p < 0.05. Correlations were determined using Spearman correlation (r(s)), with coefficients of 0.40 or -0.40 considered significant. Results: There were 22 complete data sets. SFGS composite score improved from mean, 56.9 (SD, 12.3) to 63.6 (SD, 12.3), p < 0.01. SFGS subdomain synkinesis score significantly improved (p < 0.01). The FaCE scale subdomain oral function significantly worsened (p = 0.05). The pre-/post-SFGS composite score did not correlate with the pre-/post-FaCE composite score (r(s) = 0.24). There was a significant positive correlation between SFGS composite score and FaCE social function score (r(s) = 0.462, p = 0.03) and between SFGS voluntary movement score and FaCE social function score (r(s) = 0.477, p = 0.03). Subgroup analysis of single FaCE questions demonstrated no statistical change in subjective dry eye (p = 0.30). Conclusions: There was an improvement in social functioning in treated HFS patients, which positively correlated with improvement in overall objective voluntary facial movement. There was no statistical difference in subjective dry eye symptoms. The overall SFGS composite score improved following treatment of HFS with botulinum toxin. This information can be used when counseling expected outcomes in HFS patients treated with onabotulinumtoxinA.