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Occipital Nerve Stimulation May Be Safe and Effective for Chronic Migraine


 

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Although the trial missed its primary endpoint, patients reported a reduction in pain and disability.

LAS VEGAS—Patients who received 12 weeks of occipital nerve stimulation reported significantly fewer headache days, less pain, and better quality of life than controls did, according to a study presented at the 15th Annual Meeting of the North American Neuromodulation Society.

Most patients with chronic migraine experience neck pain before and during their headache, and patients who have occipital neuralgia also experience these symptoms, according to Stephen D. Silberstein, MD, Professor of Neurology and Director of the Jefferson Headache Center at Thomas Jefferson University in Philadelphia. A 1999 paper by Weiner and Reed investigated peripheral nerve stimulation as a treatment for intractable occipital neuralgia, and Dr. Silberstein decided to evaluate the technique’s efficacy as a treatment for chronic migraine.

Extrapolating from Occipital Neuralgia to Chronic Migraine
Dr. Silberstein and other investigators conducted a prospective, multicenter, double-blind study involving 157 patients diagnosed with chronic migraine. Eligible patients had to have failed at least two preventive medications for acute migraine. Most patients who were included had had chronic migraine for more than 20 years and experienced headache between 16 and 19 days per month. Most of these headaches were bilateral and lasted more than 12 hours per day.

All patients had a medical neurostimulator implanted and all were assigned randomly to either an active or a control group in a 2:1 ratio. For 12 weeks, patients in the active group received occipital nerve stimulation, and patients in the control group received no stimulation. At the end of this initial period, all patients received stimulation and were followed up for as many as 52 weeks.

The primary endpoint was the number of patients who experienced 50% pain reduction, as measured by visual analog scales (VAS). The study’s outcome measures included headache days (ie, days with a moderately intense headache that lasts for more than four hours), pain intensity (as measured by VAS), and disability, as measured by the migraine disability assessment (MIDAS) test.

Positive Results, Despite a Missed Endpoint
At the end of the 12-week period, the difference between the numbers of patients who experienced 50% pain reduction in the active and control groups was not statistically significant, according to Dr. Silberstein. However, the researchers did see statistically significant group differences for 10%, 20%, and 30% pain reduction. In the active group, 37.1% of patients achieved 30% pain reduction. In contrast, 17.3% of patients in the control group achieved 30% pain reduction. VAS pain scores decreased by 13.6 in the active group and by 6.9 in the control group.

The number of headache days decreased by 7.3 for the active group and by 4.3 for the control group. The difference between the two groups was larger than the one that Dr. Silberstein had observed previously in a trial of Botox as a treatment for chronic migraine. The reduction in the number of headache days indicated that, by definition, many of the patients in the active group went from having chronic migraine to having episodic migraine, he added.

MIDAS headache days (ie, the number of days with headache that a patient has had during the past 90 days) improved by 22.5 for the active group and by 3.4 for the control group. Total MIDAS scores decreased by 64.6 for the active group, which represented a nearly 40% reduction. Total MIDAS scores decreased by 20.4, or about 13%, for the control group.

Evidence suggests that the treatment improved patients’ quality of life. Nearly 67% of patients in the active group reported improved quality of life, as opposed to 17.2% of patients in the control group. Most patients in the active group (ie, 51.4%) were satisfied, while 19.2% in the control group were satisfied.

At the end of the study, the investigators asked patients several questions. When asked whether they would want to have the procedure done again, 83% of patients said “yes.” When asked whether they would recommend the procedure to someone else, almost 90% said “yes.”

Of the 157 patients, 111 experienced one or more adverse events. The researchers observed 209 adverse events, including hardware-related problems, biologic events (ie, infections), and problems resulting from stimulation (ie, painful paresthesia). The investigators resolved 38.3% of the device-related events with little or no risk to the patient. Almost 41% of the adverse events resulted in an additional surgery.

A New Indication for a Previously Studied Treatment
Although the trial failed to reach its primary endpoint, the results were largely positive, according to the researchers. Most patients rated headache relief as excellent or good, would undergo the procedure again, and would recommend it to someone else. “This study clearly supports the safety and effectiveness of occipital nerve block of the peripheral type for the management of chronic migraine,” said Dr. Silberstein.

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