Migraine Relief From Unexpected Source

(CBS)  The epilepsy drug topiramate appears to prevent migraine headaches — and unlike some other migraine medications that seem to attract pounds, its main side effect is weight loss, said a study released Monday.

The drug may help patients who do not respond to more traditional migraine drugs, said Dr. Stephen Silberstein, director of the Jefferson Headache Center at Thomas Jefferson University in Philadelphia.

"Migraine is due to a more sensitive brain," said Silberstein, who was scheduled to present his findings to a meeting in Britain Monday of the Migraine Trust.

Some 28 million Americans suffer from migraines - an intense, pulsing headache that can last hours, even days. There are a number of drugs sold to prevent migraines, but they don't work for everyone, so scientists are seeking new medications.

In recent years that search has included epilepsy drugs — after scientists discovered that migraines are not caused by the abnormal blood vessels once blamed but by a unique electrical disorder of brain cells.

Somewhat like epilepsy patient do, migraine sufferers have abnormally excitable brain nerve cells that, when triggered, fire across important pain centers to awaken nerve pain and inflame blood vessels.

Several migraine experts have described a process known as sensitization, during which pain starts in the nerves on the outside of the brain. If the pain is not stopped right away, the effect moves to nerves that normally do not perceive pain.

Non-painful stimuli are perceived as painful by the patient, who may say things like "my hair hurts." This strange sensation is called cutaneous allodynia.

Triptan drugs used to treat migraines can prevent this from happening, but cannot reverse it once it starts. Beta-blockers, narcotics and ergot derivatives, each with a different mechanism of action, are also used to treat migraine.

"Different types of migraine respond to different types of medication," Silberstein told a seminar organized by the American Medical Association.

Migraine patients often know they can stop a migraine if they take drugs right away, but the specialized drugs are expensive and can have severe side-effects. Sometimes a simple aspirin will work in very early migraine in some patients, but there is the risk of overuse.

In a study of more than 400 migraine sufferers given varying doses of topiramate or dummy pills for four months, about half found their number and duration of migraines cut in half.

The best-treated patients took 100 or 200 milligrams of topiramate a day, a lower dose than is used for epilepsy. But like in epilepsy patients, the migraine users experienced a side effect that would cause few to complain: weight loss.

"What was amazing in this trial was the effect on weight," said Silberstein. The patients who got topiramine lost, on average, 3.8 percent of their body weight.

For a skinny person that could be a problem, he acknowledged, but most patients in the study were overweight.

In February Ortho-McNeil said it was halting clinical trials testing Topamax to treat obesity while it reformulated the drug because of its side-effects, including memory problems, fatigue, sleepiness, difficulty in concentration and tingling in the fingers and toes.

Earlier this month it stopped a test of the drug against bipolar disorder because it did not work well enough.

Topiramate is sold under the name Topamax by Ortho-McNeil, a subsidiary of Johnson & Johnson. Johnson & Johnson helped sponsor the AMA seminar where Silberstein spoke.