BackgroundThis study evaluates the effect of incobotulinumtoxinA in the acute and chronic phases of facial nerve palsy after neurosurgical interventions. MethodsPatients received incobotulinumtoxinA injections (active treatment group) or standard rehabilitation treatment (control group). Functional efficacy was assessed using House-Brackmann, Yanagihara System and Sunnybrook Facial Grading scales, and Facial Disability Index self-assessment. ResultsSignificant improvements on all scales were seen after 1month of incobotulinumtoxinA treatment (active treatment group, р<0.05), but only after 3months of rehabilitation treatment (control group, р<0.05). At 1 and 2years post-surgery, the prevalence of synkinesis was significantly higher in patients in the control group compared with those receiving incobotulinumtoxinA treatment (р<0.05 and р<0.001, respectively). ConclusionsIncobotulinumtoxinA treatment resulted in significant improvements in facial symmetry in patients with facial nerve injury following neurosurgical interventions. Treatment was effective for the correction of the compensatory hyperactivity of mimic muscles on the unaffected side that develops in the acute period of facial nerve palsy, and for the correction of synkinesis in the affected side that develops in the long-term period. Appropriate dosing and patient education to perform exercises to restore mimic muscle function should be considered in multimodal treatment.