BOSTON – Transcranial magnetic stimulation may be a promising new weapon in the pain relief arsenal of patients with chronic migraine with aura, findings of a clinical trial show.
Brain stimulation with magnetic pulses, delivered via a portable stimulation device held to the back of the head, eliminated migraine pain in about 39% of patients who were randomized to its use, according to data presented by Dr. Richard Lipton, professor of neurology and epidemiology at the Albert Einstein College of Medicine, New York.
Transcranial magnetic stimulation (TMS) is a method of focal brain simulation based on the principle of electromagnetic induction, whereby a powerful, rapidly changing extracranial magnetic field generates small intracranial currents, Dr. Lipton explained. The technology has shown promise in the treatment of various neurologic and psychiatric diseases. It is thought to interrupt neuronal excitability in the motor cortex of the brain, which has been implicated as a trigger in the cascade of migraine events, he said.
Previous studies have shown that early treatment with TMS, delivered in the clinic via a large, tabletop device, reduces pain in patients who experience migraine with aura, Dr. Lipton reported at the annual meeting of the American Headache Society.
The current study sought to assess the efficacy of the treatment when it was delivered via a portable, handheld device designed specifically to facilitate at-home treatment. In a multicenter, double-blind, parallel-group sham controlled study, 201 outpatients aged 18-68 years with a history of migraines with aura (as defined by the International Classification of Headache Disorders, 2nd ed.) were randomized to either active treatment with the TMS device or sham treatment with an identical device that similarly buzzed and vibrated but did not emit magnetic pulses. Patients were included in the study if they experienced one to eight migraines per month, and if they did not overuse headache medications.
All of the patients were directed to use their devices at the onset of aura by holding the device to the back of the head and pushing the button two times to emit two brief pulses. The patients recorded their levels of pain and symptoms in an electronic diary both at the time of treatment and then after treatment at 30 minutes, 1 hour, 2 hours, 24 hours, and 48 hours. The primary end point for the current study was pain elimination at 2 hours.
The final analysis included 164 patients, mean age 39 years, who completed the study. The majority of patients treated themselves when they were either pain free (31%) or had mild pain (40%). Nearly one-third of the patients applied the treatment when they were in moderate (23%) or severe (6%) pain, noted Dr. Lipton.
The 2-hour pain-free rates were 39% for the TMS group and 22% for the sham treatment group, yielding an absolute risk reduction of 17%, Dr. Lipton reported. “In other words, for every seven people who use a transcranial magnetic stimulator to treat a migraine attack, one person will be pain free at 2 hours,” he said.
The rates of associated symptoms “were equal or lower than the sham treatment rates,” and the number of adverse events and the number of patients experiencing adverse events were similar between both groups, Dr. Lipton reported.
The results are not as good as those achieved with standard antimigraine drugs, such as aspirin, antiemetics, triptans, or some of the new investigational drugs, but the availability of a noninvasive, nondrug treatment is important because it avoids the side effects of migraine medications, Dr. Lipton said. Future studies in patients with migraine without aura are on the horizon, he said.
Funding for this study was provided by Neuralieve Inc., developers of the TMS device, which has not yet received marketing clearance from the Food and Drug Administration.
The 2-hour pain-free rates were 39% for the TMS group and 22% for the sham treatment group. DR. LIPTON