Botulinum toxin in the treatment of facial synkinesis and hyperkinesis

Facial synkinesis and hyperkinesis commonly impair the outcome of facial nerve palsy. Botulinum toxin type A has shown positive results in the treatment of these symptoms. Our experience is reported in this article.

Prospective study.

Forty-one patients affected by facial synkinesis and hyperkinesis due to facial palsy were treated. The etiology of the facial palsy was: 28 Bell's palsy cases, nine iatrogenic cases (seven acoustic neuroma surgeries, one tympano-jugular glomus tumor removal, and one middle ear surgery), three herpes zoster virus cases, and one case of Melkersson-Rosenthal syndrome. Botulinum toxin type A was used in the treatment. Clinical evaluation was obtained through the Sunnybrook Grading Scale and an author's modification of this method purposely designed for evaluation of hyperkinesis. Further evaluation through a self-administered synkinesis questionnaire was also performed.

All patients showed some improvement of synkinesis and hyperkinesis after treatment. The mean values of the data obtained, regardless of the method of evaluation, gave statistically significant results. Correlation between objective and subjective evaluation methods was also statistically positive.

This work stresses the importance of considering synkinesis and hyperkinesis separately because they are different conditions. These two symptoms showed improvement after botulinum toxin treatment, but only hyperkinesis showed a positive correlation when objective and subjective evaluations were performed. This treatment is effective in the management of facial synkinesis and hyperkinesis due to facial palsy, thus improving quality of life. It is a safe, minimally invasive treatment that can be repeated.