Science - Magnet as therapy

WASHINGTON: The U.S. government has approved the first non-invasive brain stimulator to treat depression — a device that beams magnetic pulses through the skull.

If it sounds like science-fiction, well, those woodpecker-like pulses trigger small electrical charges that spark brain cells to fire. Yet it does not cause the risks of surgically implanted electrodes or the treatment of last resort, shock therapy.

Called transcranial magnetic stimulation or TMS, this gentler approach is not for everyone. The Food and Drug Administration approved Neuronetics’ NeuroStar therapy only for patients who had no relief from their first antidepressant, offering them a different option than trying pill after pill.

“We’re opening up a whole new area of medicine,” says Mark George of the Medical University of South Carolina in Charleston, who helped pioneer use of TMS in depression. “There’s a whole field now that’s moving forward of non-invasive electrical stimulation of the brain.”

While there is a big need for innovative approaches — at least one in five depression patients is treatment-resistant — the question is just how much benefit TMS offers. The FDA cleared the prescription-only NeuroStar based on data that found patients did modestly better when treated with TMS than when they unknowingly received a sham treatment that mimicked the magnet. It was a study fraught with statistical questions that concerned the agency’s own advisers.

For a clearer answer, the National Institutes of Health has an independent study under way now that tracks 260 patients and may have the initial results by next year.

Quantifying the benefit is key, considering the price tag. TMS is expected to cost $6,000 to $10,000, depending on how many treatments a patient needs, says Philip Janicak of Rush University Medical Centre in Chicago, who helped lead the study. That is far more expensive than medication yet thousands of dollars cheaper than invasive depression devices.

Neuroscientists have been using TMS for years as a research tool in brain studies. Zap a powerful magnet over a certain spot on the head — where motion is controlled — and someone’s arm can suddenly, involuntarily, lash out. Beyond the “wow” factor, magnetized pulses were triggering brain activity.

The question was how to harness that activity in a way that might improve disease. TMS also is being studied in stroke rehabilitation and other brain disorders. — AP