Patients with multiple sclerosis can get relief from pain and muscle tightness by smoking marijuana, according to a new study in California. But the benefits from smoking pot came with side effects – patients in the study had shorter attention spans and reported they were getting “too high” or dizzy.
The study is being published in the Canadian Medical Association Journal.
Multiple sclerosis is an inflammatory disease that affects the ability of nerve cells in the brain and spinal cord to communicate with each other. There is no known cure. Many patients with multiple sclerosis suffer from spasticity, a common and disabling condition of the disease in which the muscles tighten and become difficult to control. There are drugs that relieve spasticity, but they can have adverse effects and do not always improve the condition in some patients.
Researchers at the University of California, San Diego School of Medicine, conducted a randomized, double-blind study with 30 participants to see whether smoked cannabis can relieve pain and muscle spasticity. Most previous trials focused on the effect of cannabis taken orally through pills and sprays.
“We found that smoked cannabis was superior to placebo in reducing symptoms and pain in patients with treatment-resistant spasticity, or excessive muscle contractions,” said lead researcher Jody Corey-Bloom, MD, PhD, professor of neurosciences and director of the Multiple Sclerosis Center at UC San Diego.
Researchers measured the spasticity of each participant’s joints using a modified Ashworth scale, an objective tool used to measure the intensity of muscle tone. Participants who smoked cannabis once daily for three days experienced an almost one-third decrease on the Ashworth scale compared to a placebo group. Pain scores also decreased by about 50 percent.
“We saw a beneficial effect of smoked cannabis on treatment-resistant spasticity and pain associated with multiple sclerosis among our participants,” wrote Corey-Bloom.
Although generally well tolerated, smoking cannabis did have mild effects on attention and concentration. About one in five complained of dizziness, headache or fatigue after smoking. Six percent said they felt “too high.”
The study is the fifth clinical test of cannabis reported by the University of California Center for Medicinal Cannabis Research (CMCR). Four other human studies on control of neuropathic pain also reported positive results.
“The study by Corey Bloom and her colleagues adds to a growing body of evidence that cannabis has therapeutic value for selected indications, and may be an adjunct or alternative for patients whose spasticity or pain is not optimally managed,” said Igor Grant, MD, director of the CMCR, which provided funding for the study.