CHICAGO, Feb 01, 2002 (United Press International via COMTEX) -- Researchers believe magnetic pulses fired into the brain might fight severe depression as effectively as shock therapy with fewer harmful side effects.

Medical scientists believe the technique may prove a far more inexpensive alternative therapy "particularly for the many severely depressed patients who do not benefit from or tolerate current established treatments," said lead researcher Philip Janicak, medical director of the Psychiatric Clinical Research Center at the University of Illinois at Chicago.

The technique, known as transcranial magnetic stimulation, delivers brief, intense magnetic pulses to the brain at a rate of 10 per second. These pulses, delivered by a hand-held wire coil over the forehead, are roughly as powerful as the magnetic fields used in magnetic resonance imaging but are much more focused.

The magnetic field passes through the body unimpeded, unlike electricity, which can experience resistance from skin, muscle and bone. The pulses generate a small amount of electrical discharge in brain tissue in the left prefrontal cortex, an area of the brain that in depressed patients typically shows abnormal electrical activity and decreased blood flow.

"This is an intense magnetic field that is highly localized -- you don't see that simply by putting magnets on your wrist or on your head," Janicak explained. "This is something completely different. The only similarity is they both use the word magnet."

The treatment appears relatively benign when compared with traditional electroconvulsive therapy -- better known as shock treatment, or ECT -- which works by inducing a seizure. Sedation is not required, and patients do not appear to experience memory problems or deterioration in cognition, which are common side effects of shock treatment.

"The cost is therefore strikingly less -- a typical ECT treatment costs $1,000 because of anesthesiology, operating room time and nurses to monitor vital signs," Janicak told United Press International.

Janicak cautioned there is an extremely small risk of seizure with magnetic stimulation, but it is much less than 1 percent.

"Patients might feel their facial muscles contract at time of treatment and may have a mild headache afterward, but that's all," he said.

The medical scientists held a clinical trial with 25 patients who either had severe depression or bipolar disorder, also known as manic depression. The volunteers were randomly assigned to undergo a course of either 10 to 20 magnetic stimulation sessions or 4 to 12 shock treatments. Afterwards, the patients were assessed using widely used psychological tests for depression symptoms such as sleep problems, agitation and feelings of guilt.

Both groups of patients showed significant improvement in their depression at statistically similar levels.

"We were very surprised," Janicak said. "I was somewhat skeptical myself. If someone were to ask me before the clinical trial began, I would have said ECT would have been far superior, but that's not how the data came out."

Magnetic brain stimulation technology is not approved in the United States for therapy, although it is available in Europe, Israel and Canada. Medical investigators are skeptical as to whether depressed patients are experiencing a placebo effect, which in other depression therapies may result in up to 60 percent of "successes."

"This study is helpful in that it compares the technique to ECT, our most effective and most powerful treatment for depression," said neurologist and psychiatrist Mark George at the Medical University of South Carolina in Charleston, a leading proponent of magnetic brain stimulation. "The failure to find significant differences in this sample is encouraging but not definitive."

The scientists say a lot more work needs to be done, including examining a larger group of patients under more rigorous experimental conditions. "But our preliminary results are very positive and exciting," Janicak said.

The researchers reported their findings in Biological Psychiatry.

　　From Healthy.net