Tizanidine for the treatment of intention myoclonus: a case series.

Objective: To evaluate the effectiveness of tizanidine in treating intention myoclonus.

Design: Case series.

Setting: Inpatient rehabilitation center.

Participants: Three subjects whose activities of daily living were impaired due to intention myoclonus related to mitochondrial encephalomyopathy, stroke, and multiple sclerosis (MS).

Intervention: Tizanidine.

Main Outcome Measures: Reduction in intention myoclonus and change in score on the FIM instrument.

Results: The patient with mitochondrial encephalomyopathy had left upper- and lower-extremity intention myoclonus; the patient with stroke had left upper intention myoclonus; and the patient with MS had right upper- and left lower-intention myoclonus. In the patient with mitochondrial encephalomyopathy, the FIM score increased from 90 to 103 points over 2 days of tizanidine. The stroke patient's FIM score improved only from 74 to 79 after 4 weeks of tizanidine. The patient with MS improved from 83 to 101 after 6 days of tizanidine. All 3 patients had almost full resolution of the intention myoclonus. All continued on tizanidine except the patient with stroke, who had minimal gains and a low systolic blood pressure. None of the patients experienced significant sedation or hypotension.

Conclusions: Tizanidine may be a safe and effective option for treating intention myoclonus that occurs in a variety of neurologic conditions.