Cannabinoids in the treatment of movement disorders: A systematic review of case series and clinical trials

We performed a systematic review of the scientific literature assessing the use of exogenous cannabinoids in the treatment of movement disorders including Huntington's disease, Parkinson's disease, Tourette's syndrome, tics, essential tremor, tremor associated with multiple sclerosis, Wilson's disease, dystonia, and myoclonus. Databases searched for articles published in English include: Pubmed, Web of Science, PsycINFO, and Clinicaltrials.gov. A total of 21 case series and clinical trials evaluating the use of cannabinoids in the treatment of movement disorders were identified. All studies either consisted of small sample sizes, or the primary outcome was not the effect of exogenous cannabinoid treatment on a specific movement. None of the studies reviewed were powered to detect a difference with the treatment of a cannabinoid agonist. Therefore, currently no conclusions can be made on the efficacy of cannabinoids in the treatment of movement disorders.