“Anecdotal evidence suggests a beneficial effect of cannabis on spasticity as well as pain. Recently, randomized, double-blind, placebo-controlled studies have confirmed the clinical efficacy of cannabinoids for the treatment of spasticity in patients with MS. Based on these data, nabiximols (Sativex), a 1:1 mix of Δ-9-tetrahydrocannabinol and cannabidiol extracted from cloned Cannabis sativa chemovars, received approval for treating MS-related spasticity in various countries around the globe. In this article we review the current understanding of cannabinoid biology and the value of cannabinoids as a symptomatic treatment option addressing spasticity in patients with MS.

Based on individual case reports, the consumption of plant parts, specifically, the resin of the Cannabis sativa hemp plant, has, for years, been attributed to the capacity to reduce the symptoms of multiple sclerosis (MS), such as spasticity, neuropathic pain, tremor, and disturbed bladder function. As characterization of the endocannabinoid system and its role in the motor system and pain processing continue to advance, there is increasing evidence of a scientific basis for the postulated therapeutic effect of cannabis derivatives.

The oromucosal administration of THC and CBD in a 1:1 ratio has proven to be a well tolerated therapeutic option for treating spasticity in patients with MS who respond poorly to conventional antispastic drugs. Assessment of the efficacy is limited by the fact that spasticity as a symptom is very difficult to measure reliably, objectively, and validly. Current study data support the position that the beneficial effects of nabiximols on subjective and objective endpoints in a selected patient sample outweigh the adverse pharmaceutical effects. The effects of long-term nabiximols treatment on neuropsychological processes and the structure of the endocannabinoid system need to be further characterized.”

Full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3437528/