MONDAY, March 28 (HealthDay News) -- Severely obese men and women who have bariatric surgery may shed more than just excess pounds: They may also reduce much of their pre-surgery risk for experiencing disabling migraines, researchers say.

The finding is based on the results of a small study of obese patients with a history of migraines. The patients went on to lose an average of roughly 66 pounds by the half-year point following either laparoscopic gastric banding surgery or Roux-en-Y gastric bypass. And within that same timeframe, about half of the patients cut the frequency of their migraines in half or more.

The study is published in the March 29 issue of the journal Neurology.

"Obesity is thought to contribute to worsening of migraine, particularly for severely obese individuals, yet no study has examined whether weight loss can actually improve migraine headaches in these patients," study author Dale Bond, a researcher with the Miriam Hospital's Weight Loss and Diabetes Research Center, said in a journal news release.

"Our study provides evidence that weight loss may be an important part of a migraine treatment plan for obese patients," Bond noted.

About 28 million Americans struggle with migraines, the study authors pointed out. The problem primarily affects women, and is characterized by throbbing pain, typically confined to one side of the head, lasting anywhere from four hours to three days, they noted. Often recurring between one and four times a month, these headaches are accompanied by nausea, vomiting and sensitivity to light.

Although the exact mechanism driving migraines is not fully understood, they are believed to be triggered by abnormal brain activity that itself is set in motion by stress, particular foods and a range of environmental factors. To date, there is no known cure, though medications can sometimes help control severity and frequency of attacks.

To explore the potential benefit of bariatric surgery on migraines, Bond and his associates focused on 24 severely obese patients with a history of migraines.

Most of the patients were women (88 percent), with an average age of about 39, and more than 70 percent were white. All were severely obese, with an average pre-surgery body-mass index (BMI, a measurement that is based on height and weight) of 46.6. More than half underwent the banding surgical option, according to the report.

Although 70 percent of the patients were still characterized as "obese" six months post-surgery, by that time point, patient BMI had plummeted to an average of 34.6.

Questionnaires completed before and after the procedure revealed that whereas the patients had experienced an average of 11 migraine headaches over the prior three months leading up to surgery, that figure dropped to less than seven by the six-month post-surgery mark.

Specifically, 58 percent of the patients said they had fewer headaches post-surgery. Another 17 percent experienced no change, while a quarter said they actually had more frequent headaches, the investigators found.

Overall, the greater the weight loss post-surgery, the greater the apparent drop in migraine risk, the researchers reported.

Aside from frequency, migraine severity and the disabling consequences that can result also seemed to dissipate post-surgery. While half of the patients said their migraines were either moderately or severely disabling pre-surgery (requiring medical care), only 12.5 percent said the same was true six months following surgery.

Commenting on the study, Dr. Frederick J. de la Vega, a neurologist at the Scripps Memorial Hospital La Jolla in San Diego, said that the observations raise a lot of as-yet unanswered questions.

"It seems to be good news for these types of obese patients, of course," he said. "It's a win-win. But this kind of surgery involves some risks. And so I don't think people who suffer from migraines who are just a little chubby are going to go get bariatric surgery just to reduce their migraine risk."

"And secondly, there's probably a lot of factors interacting here to influence on migraines related to the benefits of shedding all those pounds," he noted. "Blood pressure changes, other metabolic changes, mood changes resulting from people feeling better about themselves, increased exercise participation after weight loss. And whether the lost weight has a secondary effect on the hormone levels of women, and how all of that might impact on migraines. All of these factors would have to be looked at."

More information

For more on migraine and obesity, visit the American Headache Society.