January 14, 2004
Multiple Sclerosis Society
Up to 90% of people with MS experience muscle spasticity and spasms. Current treatments are not always effective at relieving these symptoms and can be toxic with long-term use, consequently there is a need for new treatments.
There is much anecdotal evidence from people with MS that cannabis can help relieve muscle spasticity, although there is little scientific evidence to substantiate this. The largest clinical trial investigating cannabis-based medicines for people with MS, to date, has just reported results. This clinical trial aimed to objectively test the effect of cannabinoids (the "active" part of the cannabis plant) on spasticity mainly, but also looked at other symptoms.
630 people with MS participated in one of three groups:
Results showed that neither cannabis-based medicine improved spasticity when measured objectively by the Ashworth scale. However, the majority of participants did report that they felt their spasticity had improved i.e. subjective measures showed improvement. Participants receiving either form of cannabis also reported improvements in pain and sleep, although the majority reported no benefit on tremor or bladder problems. There was also a small improvement in mobility in the treatment group, in addition to an unexpected lower number of relapses compared to the placebo group.
Although there was no objective benefit of either type of cannabis-based medicine on spasticity, the subjective evidence from participants suggests that this scale may be too insensitive to detect small, but significant, improvements. Also, a large number of participants correctly guessed which type of medication they were assigned and the investigators highlight that this might have affected people's perception of how they were feeling.
The authors suggest that cannabinoids could be useful in treating symptoms related to MS, but suggest that more research on cannabis-based medicines is needed, using more sensitive scales, in addition to other means of administration, to assess the effect on symptoms. In addition the apparent beneficial effect of cannabis on relapse rate might also warrant further investigation.
This report was published in The Lancet, 2003. Vol. 362, pages 1517-1526
Copyright © 2004, Multiple Sclerosis Society