Botulinum toxin therapy in facial synkinesis following facial nerve palsy: data analysis of the last 20 years

Introduction:

Treatment with botulinum toxin A (BoNT-A) is the therapy of choice for many patients with synkinesis. Repeated injections relieve hypertension and dyskinesis of synkinetic reinnervated mimic muscles. Aim of the study was to prove, if the injection regime and dosage of BoNT-A change during a long-time therapy.

Methods:

The charts of patients, who were treated for synkinesis with BoNT-A from 1998 to 2018, were retrospectively assessed. Patients consulted our department for the next treatment as soon as the symptoms recurred, at the latest after 3 months. We analyzed the change in dosage and injection schedule, characterized by the number of treated muscles, over the entire therapy period.

Results:

In total, 86 patients underwent 840 treatments. 73 patients were repeatedly injected. 11 times in average (95% CI 9 – 14). In 66 patients (78%), the BoNT-A was applied for the first time. During this initial treatment, orbicularis oculi muscle (OOC) was the most frequently injected muscle (94%), followed by major zygomatic (37,3%), mentalis muscles (34,4%) and platysma (34,4%). Three brands of BoNT-A were available for treatment. The initial dose was 24U (95% CI 22 – 27U) for OnaBoNT-A and IncoBoNT-A; and 69U for ABoNT-A (95% CI 44 – 94U). We observed a significant increase in dosage for all BoNT-A brands (all p < 0.0001) during the long-term therapy. Besides, the number of injected mimic muscles increased significantly (p < 0.0001).

Conclusion:

During the long-term therapy of synkinesis with BoNT-A we observed significant change in treatment dose and injection pattern. The consecutive increase of the treatment dose of BoNT-A occurred due to the increase of the number of injected mimic muscles.

Publication History

Publication Date:
23 April 2019 (online)