Cannabis in the Treatment of Dystonia, Dyskinesias, and Tics.

Cannabis has been used for many medicinal purposes, including management of spasms, dystonia, and dyskinesias, with variable success. Its use for tetanus was described in the second century BCE, but the literature continues to include more case reports and surveys of its beneficial effects in managing symptoms of hyperkinetic movement disorders than randomized controlled trials, making evidence-based recommendations difficult. This paper reviews clinical research using various formulations of cannabis (botanical products, oral preparations containing ∆(9)-tetrahydrocannabinol and/or cannabidiol) and currently available preparations in the USA (nabilone and dronabinol). This has been expanded from a recent systematic review of cannabis use in several neurologic conditions to include case reports and case series and results of anonymous surveys of patients using cannabis outside of medical settings, with the original evidence classifications marked for those papers that followed research protocols. Despite overlap in some patients, dyskinesias will be treated separately from dystonia and chorea; benefit was not established beyond individual patients for these conditions. Tics, usually due to Tourettes, did respond to cannabis preparations. Side effects reported in the trials will be reviewed but those due to recreational use, including the dystonia that can be secondary to synthetic marijuana preparations, are outside the scope of this paper.