Researchers of the University of Innsbruck, Austria, conducted a crossover study with the synthetic cannabinoid nabilone in 13 patients who suffered from chronic pain related to spasticity in chronic upper motor neuron syndrome. Participants received both 1 mg nabilone per day in one treatment phase and a placebo in another phase. 11 patients completed the study. Nabilone caused a significant decrease of pain, while spasticity, motor function and activities of daily living did not change. Side effects were generally low. Of the two patients who did not complete the study, one patient experienced moderate transient weakness of the lower limbs and one experienced an acute relapse of multiple sclerosis.

Upper motor neurons are nerve cells that originate in the brain and send fibers through the spinal cord. Their degeneration due to multiple sclerosis or other causes may result in spasticity and muscle pain. Nabilone is synthetic derivative of THC with similar pharmacological profile.

(Source: Wissel J, Haydn T, Muller J, Brenneis C, Berger T, Poewe W, Schelosky LD. Low dose treatment with the synthetic cannabinoid Nabilone significantly reduces spasticity- related pain : A double-blind placebo-controlled cross-over trial. J Neurol. 2006 Sep 20; [Electronic publication ahead of print])