Can methylphenidate objectively provide relief in patients with uncontrolled blepharospasm? A pilot study using surface electromyography

Abstract

Purpose: To determine whether there is an objective benefit to prescribing Ritalin for patients with uncontrolled blepharospasm exists.

Methods: Seven subjects with benign essential blepharospasm, who were being treated with botulinum toxin injections and Ritalin LA, were recruited for this pilot study. Patients were asked to participate during the period of time when symptoms were beginning to return. Subjects underwent video and surface electromyography (sEMG) monitoring before and 2 hours after the administration of Ritalin. Mean sEMG potential for each eye was compared before and after the administration of Ritalin. Subjects also rated their disability based on a previously developed and reproducible blepharospasm functional disability scale. Functional Disability Scores were compared, and post-Ritalin treatment benefit was determined.

Results: The mean voltage of the sEMG was lower in 13 of 14 eyes after the administration of Ritalin. For the right eye, the voltage decreased by 50% (106.4 ± 13.6 mV to 52.7 ± 7.1 mV, p = 0.015), and for the left eye, by 31% (81.9 ± 9.7 mV to 56.6 ± 6.1 mV, p = 0.031). The Functional Disability Scores were also lower after the administration of Ritalin than before (p = 0.016).

Conclusions: A significant decrease in mean voltage after the administration of Ritalin was found in this preselected group of patients. Subjective improvement with decreased disability and increased functional benefit was also found in all subjects. Based on the results of this study, a randomized, controlled study comparing Ritalin versus placebo is needed to determine whether Ritalin should be routinely prescribed for benign essential blepharospasm during the symptomatic window period.