Los Angeles, California (CBS News) -- Gloria Gates suffers from Multiple sclerosis. Desperate for relief, the 69-year-old uses a marijuana extract.
"I can use the medical marijuana to alleviate excruciating cramps that I can get in my muscles and my leg muscles," says Gates.
Many patients with debilitating brain diseases turn to marijuana after traditional treatments fail. Now, a new review from the American Academy of Neurology shows that marijuana pills or spray can help some MS symptoms.
"The ones that were helped the most were pain, spasticity which is tightness of the muscles, and difficulty walking which is usually related to spasticity," says Dr. Barbara Koppel, professor of neurology at New York Medical College.
But the findings suggest marijuana is not effective in treating Parkinson's disease or epilepsy seizures. Dr. Koppel says that doesn't mean the drug doesn't work, it's just that at this point, there isn't enough research in those areas, including smoked marijuana.
"There were too few patients studied in the rigorous manner that we need in order to classify and say something conclusive. There is lots of literature about smoking because that is what most people do but it's all anonymous questionnaires and it's patient testimonials we can't use," Koppel says.
Gloria says she tried medical marijuana as a last resort.
"It worked the very first time, and has been an absolute blessing for me," she says.
Now that marijuana is legal in many places, researchers hope it will be easier to conduct more studies.