posted June 22, 2006 12:46 PM         

Magnetic device can head off migraines, neurologists say
UNNATI GANDHI

From Thursday's Globe and Mail

It's like something out of a video game.

Flashing lights, vertigo, a visual shower of “shooting stars”— the early warning signs of an impending migraine attack. But before it has a chance to strike, you whip out a special gun and zap it dead with a high-powered magnetic pulse.

That surreal chain of events may very soon become a reality.

A team of Canadian and American neurologists have developed a hand-held transcranial magnetic stimulator (TMS) device that they have found to be effective in eliminating headaches when administered during the onset of a migraine.

“This research is very important because at least one-third of [migraine] patients don't respond to current treatments. There is a need for an alternative,” said Yousef Mohammad, a neurologist at Ohio State University Medical Centre who is presenting the findings at the annual American Headache Society meeting in Los Angeles Thursday.The device will go through one more clinical study involving 200 patients next month before it is submitted to the U.S. Food and Drug Administration for approval at the end of the year.

The TMS, which looks like a modified hair dryer, is held against the back of the head after a person experiences the aura phase often preceding a migraine. The aura, as Dr. Mohammad describes it, is the “electrical storm” that migraine sufferers feel about an hour before the severe headache, often associated with flashing lights and blurred vision.

The stimulator then sends a strong electric current through a metal coil, which creates an intense magnetic field for about one millisecond. This magnetic pulse generates an electric current in the neurons of the brain and is thought to interrupt the aura before it results in a severe headache.

Canadian Adrian Upton, head of neurology at McMaster University Medical Centre in Hamilton, said studies he conducted four years ago showed the device works just as well even after the headache has begun.

“Not only that, but with repeated stimulations we got better results, with many patients saying they experienced fewer headaches. There was a cumulative benefit, although we're still not quite sure why that is,” said Dr. Upton, who came up with the original idea of using a machine to disrupt the electrical activity as it travels through the brain during a migraine.

Currently, the most common treatment for this powerful type of headache is either over-the-counter analgesics or, for more severe sufferers, a group of drugs called triptans, which mimic the effect of serotonin. But these drugs often come with side effects, Dr. Upton said.

However, in his study, he saw up to an 87-per-cent reduction in pain among migraine patients, which is slightly better than the 74 per cent the U.S. clinical trial saw, and there have been no noted side effects. But he used an inconvenient 27-kilogram version of the device, with patients having to come in to his medical clinic to be treated, often after the headache had already begun.

He says he's awaiting the arrival of the smaller hand-held device so that many more migraine sufferers can reap the benefits of his original research.

Even so, a Vancouver neurologist who treats migraine patients is wary of some of the claims the researchers are presenting.

“It's sort of like, ‘Wow, if it's that good then why isn't everyone doing it?'” said Gordon Robinson of the Vancouver Hospital and Health Sciences Centre.

“I think there will be a real show-me attitude [at the annual meeting]. You've taken some scientific hypotheses for migraines, but how much of a stretch is it that transcranial magnetic stimulation will abort [the headache]?” Dr. Robinson added. “It would be great if it worked, but I'm dubious.”

Allan Gordon of the Wasser Pain Management Clinic at Mount Sinai Hospital in Toronto said he's open to the study, calling it a “fascinating concept that if it does work [it] could have future implications for treating other kinds of pain.”

Migraine headaches affect more than 3.3 million Canadians, and are the leading cause of absenteeism in the workplace, costing the Canadian economy roughly $500-million annually, according the World Headache Alliance.
http://www.theglobeandmail.com/servlet/story/RTGAM.20060621.whmigraine22/BNStory/specialScienceandHealth/home

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If you spend your whole life waiting for the storm, you’ll never enjoy the sunshine.~Morris West