Botulinum Toxin for the Treatment of Motor Imbalance in Obstetrical Brachial Plexus Palsy

Abstract

Residual muscle imbalance is a common problem affecting obstetrical brachial plexus palsy patients. The goal of this study was to examine the efficacy of botulinum toxin type A (Botox) in improving this muscle imbalance. The authors retrospectively reviewed obstetrical brachial plexus palsy patients treated with Botox for muscle imbalance as an isolated procedure. Outcomes were the change in Active Movement Scale scores from pre-Botox scores to scores at 1 month after Botox and 1 year after Botox. Twenty-seven patients were included, 19 treated for shoulder imbalance and eight treated for elbow imbalance. Active Movement Scale scores (mean±SD) for shoulder external rotation improved from 0.6±1.0 before Botox to 2.6±2.14 (p<0.01) at 1 month after Botox, and declined to 1.3±1.2 (p<0.01) at 1 year after Botox. Scores for elbow flexion were 3.3±2.1 before Botox, unchanged at 4.4±1.8 (p=0.07) 1 month after Botox, and improved to 5.8±0.5 (p<0.01) at 1 year after Botox. Scores for elbow supination were 2.9±1.7 before Botox and 3.4±1.5 (p=0.2) at 1 month after Botox, and improved to 3.9±2.0 (p<0.01) at 1 year after Botox. Botox for shoulder movement imbalance produces improvement in external rotation that is not sufficiently sustained over time to be of clinical benefit. However, Botox for elbow movement imbalance produces a sustained and clinically useful improvement. Therapeutic, IV.