ARTICLE IN BRIEF
When used regularly (87 percent of the time), CPAP not only reduced apnea episodes and improved overall sleep quality, but also resulted in fewer migraines over the study period, In another study, investigators reported that six months after bariatric surgery, the mean number of headache days per month fell from 11 to 6.7, pain severity was reduced, and the number of patients reporting moderate-to-severe disability decreased from 50 percent before surgery to 12.5 percent after surgery.
Two new studies offer preliminary evidence supporting interventional approaches for migraine. In one, continuous positive airway pressure therapy, an increasingly common treatment for sleep apnea, appeared to reduce migraine symptoms in some patients, Swiss researchers reported. In another, a US research team found that severely obese patients with migraines who underwent gastric bypass or banding surgery had fewer and less severe episodes.
Although encouraging, both studies, which were published in the Mar. 29 issue of Neurology, involved small groups of patients. Larger trials are needed to corroborate the findings, the researchers said.
Ulf Kallweit, MD, a research neurologist at the University Hospital Zurich in Switzerland, and colleagues prospectively studied 107 patients with obstructive sleep apnea syndrome (OSAS) using continuous positive airway pressure (CPAP) for one year; 11 patients had been diagnosed with migraine.
When used regularly (87 percent of the time), CPAP reduced apnea episodes and improved overall sleep quality, but also resulted in fewer migraines over the study period, Dr. Kallweit told Neurology Today in an e-mail.
Slow wave sleep doubled in patients, from 12 to 24 percent, and total sleep time was less fragmented, with better oxygenation time, and all of the migraine patients reported improvement in symptoms.
In the 11 patients with migraine, the mean attack frequency decreased from 5.8 to 0.1 episodes per month, and 10 patients were free of headaches for the last three months of treatment. Moreover, one patient with chronic migraine experienced a decrease to two daily episodes per month during the last six months, while acute medication intake decreased, from 6.5 to 0 units per month in the CPAP group.
The improvement was considerable, and more pronounced than with the typical dose given to migraine sufferers of 100mg/d of topiramate, which was approved for prophylactic migraine treatment in 2004, he added.
“It remained unclear whether the improvement in migraine was due to improved oxygen supply or better slow wave sleep and sleep efficiency,” Dr. Kallweit noted.
The frequency of obstructive sleep apnea in migraine patients is comparable to that in the general population, while individuals with sleep apnea have a 60 percent to 80 percent prevalence of cluster headaches.
A number of studies have suggested that inflammatory neuropeptides might play an important role in migraine and cluster headache, and that activation of inflammatory pathways could be caused or exacerbated by intermittent hypoxia caused by apnea. However, to date the association remains hypothetical, noted Dr. Kallweit.
In the second paper, a team at the Miriam Hospital Weight Control and Diabetes Research Center in Providence, RI, reported that bariatric surgery also appeared to greatly reduce migraine frequency, pain severity, and disability in severely obese patients within six months.
The trial involved 24 obese migraine patients who were evaluated before and six months after having bariatric surgery. Assessments included weight and body mass measurement, frequency of headache days, average pain severity, and headache-related disability over the past 90 days.
Six months after surgery, the mean number of headache days per month fell from 11 to 6.7, pain severity was reduced, and the number of patients reporting moderate-to-severe disability decreased from 50 percent before surgery to 12.5 percent after surgery, according to the lead study author Dale S. Bond, PhD, assistant professor of psychiatry and human behavior at the Warren Alpert Medical School of Brown University.
Dr. Bond told Neurology Today in a telephone interview that patients lost a mean 49 percent of their excess weight after surgery, and the odds of experiencing a 50 percent or higher reduction in headache days was greater in those who experienced greater weight losses, regardless of whether they underwent the Roux-en-Y gastric bypass or laparoscopic adjustable gastric banding operation.
“This is the first prospective, observational study in this specific group of patients,” he said.
According to recent population studies, migraine prevalence among obese individuals ranges from 11 percent to 28 percent, he said, noting that the variation is likely due to differences in methods of migraine diagnosis, measurement of body weight, and the age and gender composition of the samples.
“Many factors may underlie the link between migraine and obesity — for example, common inflammatory processes, psychological factors such as stress and depression, as well as sleep disturbances, high-fat diet, and low physical activity,” he told Neurology Today.
“While it appears that dramatic weight losses achieved through bariatric surgery positively impact migraine, the next step is to see whether more modest weight losses achieved through behavioral treatments can produce similar improvements,” said Dr. Bond. “It is important that neurologists treating migraines in obese patients inform them that losing weight can also help to alleviate their headaches.”
‘LARGER STUDIES NEEDED’
There are strengths and weaknesses in both studies, Richard B. Lipton, MD, professor of neurology at the Albert Einstein College of Medicine in New York City, told Neurology Today in a telephone interview.
“The major strength with the CPAP study is that it showed a dramatic, almost miraculous decrease in headaches, consistent with the view that good quality of sleep improves migraines,” said Dr. Lipton, who was not involved with the studies. The CPAP study's shortcoming is that there were so few patients, and no control group.
“Nonetheless, it provides very suggestive evidence that CPAP helps, a result compatible with my experience.”
CPAP may improve migraine either by restoring the brain's oxygen supply or by preventing the disruption of sleep, he continued, adding that he does not think it is possible to determine which of these processes is specifically involved in relieving migraine.
The study of weight loss surgery in obese migraine patients had similar shortcomings, he continued; although epidemiological studies, many performed by Dr. Lipton over the last five years, link obesity and depression with worse symptoms in migraine patients.
“This is a very important study which demands our attention. I am personally thrilled by the findings,” he told Neurology Today.
“Obesity is directly linked to more severe and frequent headache episodes in persons with migraine, but this is the first study that I know about to investigate whether significant weight loss might also reduce migraines,” he said. “The results are striking, but again, there was no control group.”
The next step, according to Dr. Lipton, is to explore whether milder weight loss in obese patients might reduce the number and severity of migraine episodes, and if there is a dose-response relationship — whether greater weight loss results in greater improvement.