Date of Award


Degree Type

Selective Evidence-Based Medicine Review

Degree Name

Master of Science in Health Sciences - Physician Assistant


Physician Assistant Studies

Department Chair

Laura Levy, DHSc, PA-C


OBJECTIVE: The objective of this selective EBM review is to determine whether or not cannabis is effective in reducing muscle spasticity and body pain amongst patients with Multiple Sclerosis (MS).

STUDY DESIGN: A systematic review of three peer-reviewed studies published between the years of 2003 and 2012.

DATA SOURCES: Three randomized control trials (RCTs) evaluating if cannabis can reduce muscle spasticity and body pain for patients diagnosed with Multiple Sclerosis. All three sources were selected from PubMed and examined for outcomes that were patient oriented.

OUTCOMES MEASURED: The two primary outcomes measured include: muscle spasticity measured by the Ashworth scale, and the patient’s perception of body pain measured by a subjective Category Rating Scale (CRS).

RESULTS: The study conducted by Bloom et al.7 showed a significant reduction in muscle spasticity by an average of 2.74 points more than the placebo group on the Ashworth scale. Furthermore, the treatment reduced body pain by an average of 5.28 points more than the placebo group when assessed on a Visual Analogue CRS. The MUSEC trial conducted by Zajicek et al8 showed the relief from muscle stiffness after 12 weeks was almost twice as high with cannabis extract than with placebo (29.4% vs 15.7%; OR 2.26; 95% CI 1.24 to 4.13; p=0.004, one sided). Patient-reported body pain was also improved. The CAMS study conducted by Zajieck et al9 found that treatment with cannabinoids did not have a beneficial effect on spasticity when assessed with the Ashworth scale, but did find subjective improvement in spasticity and pain via CRSs and asking patients direct questions about their overall opinion of symptom improvement.

CONCLUSIONS: The result of three RCTs reveals conflicting evidence in regards to muscle spasticity assessed by the Ashworth scale. However, clinically significant improvements of patient-reported muscle spasticity and pain were recorded via use of CRSs in each trial. Due to the limitations of these studies, further research is warranted.

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