Smoking medical marijuana could help relieve some symptoms of multiple sclerosis, a small new study suggests.
Researchers from the University of California, San Diego, found that people with MS who smoked cannabis had decreased pain and muscle tightness, called spasticity. However, the researchers warned that smoking the cannabis also led to problems with focus and attention.
The study, published in the Canadian Medical Association Journal, included 30 people -- 63 percent of them women -- with an average age of 50. More than half the participants needed aids for walking, and 20 percent of them were in wheelchairs. Some of the study participants were randomly assigned to have the cannabis, while others received a placebo.
At the end of the study, researchers found that people who smoked the cannabis had lower numbers on a spasticity scale, as well as a 50 percent decrease in pain scores.
But researchers found that the people who smoked the cannabis had decreased cognitive functioning, in that they scored lower on a test that measured their focus. This effect was only seen for a short term.
"Smoked cannabis was superior to placebo in symptom and pain reduction in participants with treatment-resistant spasticity," researchers wrote in the study. "Future studies should examine whether different doses can result in similar beneficial effects with less cognitive impact."
Just last year, a study in the journal Neurology also showed that multiple sclerosis patients who smoked medical marijuana have a doubled risk of developing cognitive impairments.
"Whatever benefits patients feel they might be getting from smoking marijuana might come at the cost of further cognitive compromise," the researcher of that study, Dr. Anthony Feinstein, M.D., Ph.D., of the University of Toronto, told WebMD.
Marijuana use is currently legal for medical purposes in 16 states and Washington, D.C., the New York Times reported.
Multiple sclerosis is an autoimmune disease of the brain and spinal cord, according to the National Institutes of Health. It occurs when the myelin sheath, which is responsible for protecting nerve fibers, is damaged, causing symptoms of cognitive problems, muscle weakness, disturbed vision, strange touch sensations and balance and coordination problems.
While there's no cure for the condition, current treatments for multiple sclerosis attacks include taking drugs called corticosteroids and undergoing plasma exchange (where blood cells and plasma are mechanically separated), according to the Mayo Clinic. Other drugs and even physical therapy can help reduce symptoms or even slow the disease down.