Brain energy: by altering or repairing brain circuitry, transcranial magnetic stimulation may help you enhance performance and resist depression and disease

Natural Health, May, 2004 by Peter Jaret

It's a scene straight out of a low-budget sci-fi movie:

In the Brain Stimulation Laboratory at the Medical University of South Carolina in Charleston, scientists position a powerful magnetic coil shaped like a figure eight on the scalp of a volunteer. When everything is ready, the lab's director. neurologist Mark S. George, M.D., throws a switch.

With a popping sound, the magnet begins generating high-energy magnetic pulses, each lasting only milliseconds. The volunteer feels a sensation like a pencil eraser being tapped repeatedly against the skull. Most of the magnetic energy, however, passes through flesh and bone and into the brain, where it is converted into electrical energy, triggering discrete areas of the brain. Depending on the magnet's position, it can make fingers twitch or cause volunteers to see bright flashes of light. Placed over the part of the brain that controls language, it can render subjects temporarily speechless.

Transcranial magnetic stimulation, or TMS, offers a noninvasive way to manipulate parts of the brain. For more than a decade, it's been used to map how brain functions are organized and to watch the way the brain changes as it learns new skills. But researchers hope it will ultimately do much more. Neurologists see TMS as a promising new way to treat brain disorders by repairing circuitry that has gone awry in conditions such as epilepsy, depression or Parkinson's disease. And a maverick band of investigators thinks that magnetic stimulation could enhance normal performance--potentially making it easier to learn a new language or solve the Sunday crossword puzzle.

a different magnetic beast

Magnets are hardly new to the field of alternative medicine. For years, claims have been made for the healing powers of magnetic mattresses and magnetic bandages, most of them unsubstantiated. Transcranial magnetic stimulation is a different beast. The magnetic fields generated by the coils are far more powerful than what a simple magnet can produce. And by tinkering with the pulse and direction of magnetic energy, researchers can vary the effect on specific brain cells.

Different frequencies of magnetic waves have different effects, explains George, one of the pioneers of TMS research. "Low-frequency magnetic pulses tend to relax an area of the brain, a kind of mental yoga. High-frequency magnetic waves tend to excite them, like a localized jolt of caffeine." The hope is that by activating dormant areas or quieting down overactive ones, doctors can fix abnormal brain function associated with a wide range of maladies.

One condition currently under investigation is depression. Psychiatrists have long known that electroconvulsive shock therapy, which delivers a serious dose of electricity to the brain--enough to cause a generalized seizure--can ease major depression in patients. Could the much smaller and more controlled amount delivered by TMS do the same thing? In one recent study, researchers at Australia's Monash University enlisted 60 patients suffering from depression and gave some of them repetitive TMS treatments daily while others received a placebo treatment that looked like TMS but didn't generate magnetic waves. Patients getting the real thing showed significant improvement in scores for depression after just four weeks of treatment. Also, researchers at the University of Illinois at Chicago reported that patients suffering from depression improved their scores after being given 10 to 20 TMS treatments.

Magnetic stimulation may also provide hope for those suffering from Parkinson's disease. At Egypt's Assiut University Hospital, researchers tested the therapy on 36 patients with the disorder, which interferes with normal motor movement. One group was given daily treatments that consisted of 2,000 pulses of TMS; the others received a look-alike treatment with no magnetic stimulation. In a paper published last year in the European Journal of Neurology, the investigators reported that the treatment group showed significant improvement in tests that measure motor movements.

Additionally, recent findings suggest that TMS may prove useful for quitting smoking. When researchers at Germany's University of Regensburg used TMS on smokers who wanted to kick the habit, volunteers smoked significantly fewer cigarettes during the six hours after their magnetic stimulation compared with subjects who were given a sham magnetic treatment.

boosting brainpower

If magnetic stimulation can repair abnormal brain function, could it a]so boost a healthy brain's thinking power? In 2001, scientists at the National Institute for Neurological Disorders and Stroke in Bethesda, Md., administered TMS to volunteers who were then asked to solve difficult geometric puzzles that required identifying similar shapes. "Subjects given TMS were able to solve the problems significantly faster," says Jordan Grafman, Ph.D., the senior investigator who led the study. "The improvement was small, but it showed up again and again."

Allan Snyder, Ph.D., director of the Centre for the Mind, part of the University of Sydney and Australian National University, has made the boldest suppositions, arguing that TMS can unlock mathematical wizardry or artistic powers that lie dormant. He has offered evidence in the form of drawings that become remarkably more sophisticated when the volunteers making them are given magnetic stimulation. However, many neuroscientists dismiss Snyder's claims. "We've been testing TMS on hundreds of research subjects for years," says Eric Wassermann, M.D., a neurologist at the National Institutes of Health's Neurology Institute, "and no one has suddenly revealed a sudden genius for anything."