Tags: Cannabis; Huntington Disease; HD; movement disorders, neurological symptoms

 

Thumbnail: This study reviews available literature to look at the effects of cannabis on movement disorders, such as Huntington Disease (HD). The authors found that medical cannabis showed strong evidence of significant improvement in neurological symptoms. They also found a significant increase in the average number of hours slept. Based on the studies analyzed in this review, the authors suggest that medical cannabis may be a useful part of management strategies for patients with movement disorders, including HD.

 

The problem: In neurodegenerative diseases like HD, patients experience worsening involuntary movement disorders, behavioral and psychiatric disturbances and dementia. Preclinical research suggests that cannabinoids may have protective effects against a variety of neurologic conditions, including movement disorders like HD. It is thought that cannabidiol (CBD), a cannabinoid which is one of the primary compounds in cannabis, may have neuroprotective effects. CBD affects the endocannabinoid system, which has been implicated in a number of different functions, including motor control, cognition, and food.

 

The study: The authors in this study conducted a systematic review of available literature to evaluate the effectiveness of medical cannabis in patients with HD.  A total of 22 studies were reviewed, including 5 randomized placebo-controlled clinical studies, 2 case-control studies, 2 cross-sectional studies, 2 cohort studies, 2 experimental observational studies, 1 open-label pilot study, and 1 case report. The review also considered relevant studies in animal models. In these studies, the authors examined the effects of cannabis on signs and symptoms relevant to HD including spasm and spasticity, tremors, sleep quality, chorea, motor function, cognitive function, behavior abnormalities and functional capacity.

 

Main Points:

• The authors found strong evidence for significant improvement of spasms, tremors, spasticity, chorea and quality of sleep following treatment of medical cannabis.

• There was significant improvement in tremors and rigidity, specifically, after cannabis treatment.

• Additionally, there was a significant increase in the average number of hours slept with either pretreatment or post-treatment.

• As cannabis has been suggested to help with pain relief, the authors suggest that cannabis may be effective at treating the pain experienced by many HD patients. However, this is not directly evaluated in this report.

 

Conclusions: Medical cannabis appears to have beneficial effects for patients with HD and the authors recommend that physicians consider prescribing it as part of their management strategy for symptomatic treatment of these patients. However, larger studies are needed to better evaluate the benefits of medical cannabis for HD patients, especially those who may be at different stages of disease progression.

 

Why this is a good study:

• This report surveyed a large number of published studies to identify those relevant to cannabis and HD, providing a comprehensive view of the field

• This study evaluated a wide range of symptoms, providing a solid recommendation for use in a disease that is characterized by an array of symptoms.

 

Why this isn’t a perfect study:

• Different studies used different formulations, and different routes of ingestion, of cannabis/CBD/THC, so it is difficult to directly compare results from different studies

• Some studies used controlled formulations of CBD/THC while others relied on surveys of self-reported use; again, making it difficult to directly compare results

• This study does not report about any additional medications that patients may be on, making it difficult to assess whether cannabis is solely responsible for patient improvement.

 

What this study adds:

• This study provides a snapshot of the current field of research relating to Huntington Disease and cannabis. It identifies what uses are currently supported by clinical research and which areas we should focus on for more research.

 

What it doesn’t:

• This study does not add any new data to the field of cannabis and HD

 

Funder: None stated

 

Author conflicts: None declared