Effect of neural mobilisation in Bell's palsy: A randomised controlled trial

Background: Neural mobilisation technique is effective in spinal nerve rehabilitation. However, no study has reported the effect of facial nerve mobilisation in acute Bell's palsy. Objectives: The objective of our study was to evaluate the effect of facial neural mobilisation over conventional therapy in improving facial symmetry in patients with acute Bell's palsy. Methods: A randomised controlled trial was conducted in the physical therapy department for 62 patients with acute Bell's palsy. The intervention included 10 days of drug therapy including 3 weeks of conventional therapy to the experimental and the control group. However, the experimental group received additional nerve mobilisation technique aimed at mobilising the facial nerve at the origin of external auditory meatus. All participants were assessed at baseline and after three weeks using the Sunnybrook facial grading system (SBS) and Kinovea Movement Analysis Software (KMAS). Results: For primary outcome, analysis of covariance with baseline data as covariate showed a significant difference between groups for the post-test mean scores of SBS after 3 weeks (between-group difference, 9.2 [95% CI, 5.1-13.3], p=0.001. Importantly, the effect size calculated by partial η2 for neural mobilisation was 0.258 (small effect size). For secondary outcomes, independent sample t-test showed a significant difference between groups for the scores on KMAS after 3 weeks for zygomatic muscle (between-group difference, -27.2 [95% CI, -31 to -22.6], p=0.001), frontalis muscle -16.7 [95% CI, -9.9 to -23.4], p=0.001, and orbicularis oris muscle -15.0 [95% CI, -11.1 to -18.8], p=0.001. Conclusion: Facial neural mobilisation is likely to be an effective adjunctive intervention in addition to conventional therapy in improving facial symmetry in acute Bell's palsy.