Cannabis: An Infamous Treatment

Marijuana treats multiple sclerosis spasticity and pain with cognitive side effects

/ Author:  / Reviewed by: Robert Carlson, M.D

(RxWiki News) Multiple sclerosis (MS) can be both painful, crippling and difficult to treat. But medical marijuana may provide some relief.

Marijuana has long been considered a folk remedy for the muscle stiffness caused by MS. This has now been confirmed by clinical data.

"MS patients should discuss cannabis treatments with their healthcare provider."

Jody Corey-Bloom, MD, of the University of California in San Diego’s Department of Neuroscience, led a team of colleagues from UCSD School of Medicine in this Center for Medical Cannabis Research (CMCR) funded study.

This study, which took place at the CMCR in San Diego, was based on clinical trials using MS patients recruited from MS clinics and referred by private practice physicians.

The trials included 30 patients suffering from treatment-resistant spasticity related to MS. These patients were seen a total of eight times over a two week period. All patients were pre-screened to exclude participants with previous substance abuse and psychiatric disorders.

During these visits physicians measured the extent of the patient’s spasticity using a method called the Modified Ashworth Scale, a guideline for measuring stiffness in limbs on a scale of one to ten based on manual examination.

Patients rated their own pain on a scale of one to 20 based on the visual analogue scale, a questionnaire used to assess pain.

After two initial screenings, each patient’s third session would randomly be either a marijuana cigarette or a THC-free placebo. Spasticity and pain were measured before smoking as well as after.

After smoking marijuana, there was an average drop of 2.75 points on the Ashworth Scale, indicating a significant increase in flexibility. Pain was also rated significantly less, with people in the marijuana group reporting more than 50 percent less pain after smoking.

The placebo group, on the other hand, did not experience any significant change in either spasticity or pain levels. People in the placebo group performed slightly better on both a timed walk and a cognitive test involving quick memory skills and math.

People in the marijuana group did not score outside the average for others in their age range on these tests though. Their scores were only slightly lower after smoking, which correlates with a reported feeling of being “high”.

There were several limitations to this study. The sample size was relatively small; further research should include a larger sample group.

Researchers should also assess the effect of different doses to potentially minimize the cognitive effects while maintaining the therapeutic effects on pain and spasticity.

Another limitation is that most the participants could tell if they were smoking real marijuana (with THC) or not, though Corey-Bloom and her team did not believe this would affect the results of objectively assessed spasticity tests.

Though still federally illegal, 16 states and the District of Columbia license and regulate cannabis as a medicine. For residents of these states, marijuana looks like an effective tool for maintaining a normal life in spite of a disease like multiple sclerosis.

For legal users suffering from MS spasticity, smoking marijuana offers many short term benefits.

In the opinion of Corey-Bloom and her team, objective benefits were measurable. More research may lead to better dosing techniques that eliminate the cognitive effects all together while retaining the desired effects for pain and spasticity.

This clinical research was published on May 14 in the Canadian Medical Association Journal. The funding for this research came from grants given through the University of California’s Center for Medicinal Cannabis Research.

This research was given approval by both federal and California state authorities, including the Drug Enforcement Agency, the US Food and Drug Administration and the National Institute on Drug Abuse. There were no reported conflicts of interest.

Reviewed by: 
Review Date: 
June 3, 2012
Last Updated:
October 1, 2012