According to the Multiple Sclerosis Society of Canada, Canadians have the highest rate of multiple sclerosis (MS) in the world, with approximately 100,000 people living with the disease. People with MS are likely to experience extreme fatigue, lack of coordination, weakness, vision problems, cognitive impairments, and other symptoms. There is currently no definitive cure for MS, and we have only a limited understanding of its cause. However, a variety of medications and approaches exist to manage symptoms and improve quality of life for those with MS.
In 2007, The Union: The Business Behind Getting High, a documentary on the Canadian cannabis trade, included a moving clip of Greg Cooper, a man who suffers from both MS and ataxia (abnormal and uncoordinated bodily movements). The severity of his symptoms made it difficult for him to speak clearly and impossible for him to sit still. A few hits from a pipe, however, resulted in a transformation. Greg obtained significant relief from the symptoms he had displayed moments before, now able to sit completely still and speak clearly in response to the interviewer’s questions.
Stories like Greg Cooper’s, as well as that of American TV personality Montel Williams, have brought increasing public attention to the potential usefulness of cannabis for people living with MS, and the American Academy of Neurology has itself recognized the potential of cannabis extracts and synthetic THC for managing various MS symptoms.
Now a recent review article published in the January 2016 issue of Current Treatment Options in Neurology has taken a closer look at the effectiveness of cannabinoids for managing MS pain and spasticity (muscular stiffness and tightness, present in up to 84% of people with MS) by reviewing studies that have used a variety of formulations for this purpose, including oral cannabis extracts (OCEs), synthetic THC, smoked cannabis, and oral sprays like nabiximol (trade name Sativex).
For treatment of spasticity, OCEs containing a mix of THC and CBD were found to be effective in most trials. OCEs containing THC on its own showed mixed results: in some studies, it did not affect spasticity or the progression of the disability, while other studies did show decreases in patient-reported spasticity and pain. The oral spray nabiximol (Sativex) had generally positive results in treating spasticity, although some results only showed improvements in patients who rated spasticity as their worst MS symptom. Not much research has been done on smoked cannabis. One study did show positive decreases in muscle resistance, yet another study found worsened posture and balance 10 minutes after administration.
For treating pain, OCEs containing a mix of THC and CBD were generally effective in the short- term treatment throughout the trials that were reviewed, while OCEs containing only THC were deemed “probably effective”. The effectiveness of smoked cannabis is still unclear, although a small to moderate improvement was shown in one study. And a small study using nabilone (a synthetic analogue of THC) showed a significant improvement in pain reduction. Nabiximols were also found to be “probably effective” for treating pain, with an effect that was only slightly weaker than gabapentin, a drug used to treat neuropathic pain, such as that of MS. Significantly, a separate study found that patients treated with nabiximols no longer considered pain their most disturbing symptom, just moments after treatment.
Many of the studies reviewed either used varying dosage levels, or permitted participants to administer their own dosage to achieve symptomatic relief, so future work on specific dose levels will need to be done in order to provide critical dosing information for medical health professionals and their patients.
Overall, the research reviewed here only looked at the short-term effects of cannabis treatment. MS patients are already prone to impairments of short-term memory and processing speed, so it remains to be seen whether cannabis has a negative effect on this area in more long-term studies.
Additionally, some adverse effects were noted by the groups treated with cannabis, with varying frequencies These effects were focused around the central nervous system (dizziness, drowsiness, euphoria, disorientation, confusion) and the gastrointestinal system (dry mouth, nausea, vomiting, diarrhea). Future research on using cannabinoids to treat MS symptoms will help decrease the frequency and intensity of these effects, and weigh this against the improvements on pain and spasticity.
For interested readers, the journal article can be found here.
– Featured image via Dominik Golenia.