Botulinum toxin for ocular tics

Abstract

Introduction: Onabotulinum toxin A is an effective treatment for a variety of movement disorders; yet, results of efficacy in patients with medically-resistant tic disorders are insufficient. We aimed to assess the efficacy of Onabotulinum toxin A in patients with ocular tics in an observational study. Methods: Patients with ocular tics, regularly treated with Onabotulinum toxin A injections at our clinic, were enrolled for 2 visits, one of which was for baseline assessment and a single injection session and the second -a follow-up visit one month after treatment for evaluation of outcome. The assessment tools consisted of a 10-minute videotape recording which was scored later by a blinded rater. The calculated ocular tic frequency was the primary end-point of this study. Secondary outcome measures consisted of additional items obtained from the video recording as well as the motor subset of the Yale Global Tic Severity Scale (YGTSS-M) and the Clinical Global Impression of change (CGI-C). Results: Six patients were enrolled.Video recordings and rating of the ocular tics before and after treatment revealed a 37% reduction in mean tic frequency, a 2.18-fold prolongation of the time to the first tic following suppression and a reduction in tic frequency during and after suppression by 45% and 52%, respectively. The mean YGTSS-M decreased by 39%. Five patients reported an improvement in CGI-C while one reported no change. Conclusions: In this observational study, Onabotulinum toxin A was found to be an effective treatment for ocular tics, providing both subjective and objective benefit for a subset of patients.