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.