Brain stimulation relieves fibromyalgia pain

By Martha Kerr

NEW YORK (Reuters Health) - Electrical stimulation of the brain provides significant pain relief that can last for several weeks in patients with fibromyalgia -- a debilitating pain syndrome that affects 2 to 4 percent of the population.

Transcranial direct current stimulation (tDCS), as it is called, is simple to perform and has only rare and minimal adverse effects, results of the study, conducted at the University of Sao Paulo, Brazil, show.

Dr. Felipe Fregni of Beth Israel-Deaconess Hospital and Harvard Medical School in Boston, and colleagues divided 32 women with fibromyalgia and moderate to severe pain into three groups. One group received tDCS of the primary motor cortex, the main area of the brain that controls movement. Another group received tDCS of the dorsolateral prefrontal cortex, part of the frontal lobes involved in thinking, and the third received sham stimulation. Active and sham treatments lasted 20 minutes for 5 days.

The team found that tDCS of the primary motor cortex was significantly more effective for pain relief than tDCS of the dorsolateral prefrontal cortex or sham stimulation. The latter two groups achieved similarly lower levels of pain relief.

The effects of tDCS persisted through the 21-day follow-up period, although some diminishing of the effect was noticed after 21 days.

"The improvement that we have seen -- an average of almost 50 percent -- indicates a very significant reduction in pain, especially because these patients are very refractory to other types of medical treatment," Fregni told Reuters Health. "Furthermore, such improvement might motivate patients to resume usual daily activities that might enhance this improvement."

An improvement in motor function was, in fact, observed, Fregni said. This could be due to a reduction of pain and thus be a result of more physical activity or, alternatively, due to motor cortex stimulation.

The technique was well tolerated with only "minimal and rare" side effects reported, such as mild skin redness at the site of stimulation, sleepiness during stimulation and dizziness afterward.

SOURCE: Arthritis and Rheumatism, December 2006.