Here is what the researchers say about their own discovery: Chronic migraine sufferers saw significant pain relief after four weeks of electrical brain stimulation in the part of the brain responsible for voluntary movement, the motor cortex, according to a new study by researchers from the University of Michigan School of Dentistry, Harvard University and the City College of the City University of New York. The researchers used a noninvasive method called transcranial direct current stimulation (tDCS) as a preventative migraine therapy on 13 patients with chronic migraine, or at least15 attacks a month. After 10 sessions, participants reported an average 37 percent decrease in pain intensity.
The effects were cumulative and kicked in after about four weeks of treatment, said Alexandre DaSilva, assistant professor at the U-M School of Dentistry and lead author of the study, which appears in the journal Headache.
The researchers also tracked the electric current flow through the brain to learn how the therapy affected different regions.
They did this by using a high-resolution computational model. They correctly predicted that the electric current would go where directed by the electrodes placed on the subject's head, but the current also flowed through other critical regions of the brain associated with how we perceive and modulate pain.
Other studies have shown that stimulation of the motor cortex reduces chronic pain. However, this study provided the first known mechanistic evidence that tDCS of the motor cortex might work as an ongoing preventive therapy in complex, chronic migraine cases, where attacks are more frequent and resilient to conventional treatments.
While the results are encouraging, any clinical application is a long way off, DaSilva said.