June 1, 2001 -- Transcranial magnetic stimulation has emerged in recent years as an alternative to electroconvulsive therapy, offering a technique for stimulating the brains of people with severe depression without general anesthesia and without causing a seizure. The still-experimental therapy has generated substantial debate, with advocates claiming documented success, and others saying that lasting change is not possible without bringing about a seizure in the patient.
But some researchers are putting a new spin on the new technology, using it to do what electroconvulsive therapy, or ECT, does -- intentionally cause a person to have a seizure -- but in ways that may be better and safer, without the loss of memory that often accompanies ECT.
Now, the first human trial in the U.S. using transcranial magnetic stimulation -- also called magnetic stimulation therapy, or MST -- to bring about a seizure has proven both feasible and safe, with important benefits over ECT, according to researchers at the New York State Psychiatric Institute.
The study looked at 10 people with depression who received courses of both ECT and MST. Seizures were successfully induced in all 10 people using the new technology, and all treatments were well tolerated, says Sarah H. Lisanby, MD.
Importantly, patients were able to recall their names, place, date, and location much faster following MST than they did following ECT. "After ECT it took 13 minutes for patients to become reoriented, Lisanby tells WebMD, "With MST it took less than two minutes."
A test of people's ability to perform a task requiring concentration following the treatments also revealed a benefit over ECT.
"After ECT patients took about four minutes to perform the task, but after MST it took about two minutes," Lisanby says.
Lisanby is director of the Magnetic Stimulation Laboratory at New York State Psychiatric Institute and assistant professor of clinical psychiatry at Columbia University College of Physicians and Surgeons. She presented the findings at annual meeting of the Association for Convulsive Therapy, which met in conjunction with the American Psychiatric Association, in New Orleans last month.
Whether the new procedure successfully treats depression remains to be seen, but the need to find safer alternatives to ECT makes research on the new technology invaluable.
"The significance of this is not yet known," Lisanby tells WebMD. "We know it is feasible in humans, and we have some evidence that seizures induced by MST have fewer side effects. This is extremely important for people who need [this type of] therapy, and who shouldn't have to experience amnesia as a routine part of life."
But if the promise of transcranial magnetic stimulation is its ability to relieve depression without inducing a seizure, what is the purpose of using the device to do the same thing that ECT does?
Lisanby says research is progressing on using transcranial magnetic stimulation that works without producing a seizure -- but adds that there is a group of depressed patients that will need to have a seizure in order to get better. "I hope we get to the point where [transcranial magnetic stimulation without a seizure] will be useful, but it doesn't help all patients," she says.
Lisanby explains that both ECT and transcranial magnetic stimulation produce electricity in the brain, which stimulates brain cells. "The major difference is how you get the electricity to the brain," she tells WebMD. "With ECT [it goes] through the scalp and skull, which causes the energy to be smeared because the scalp and skull act as resistors."
The scattering of energy throughout the scalp, skull, and brain with ECT produces a host of unintended side effects, including amnesia. With MST, in contrast, energy is passed through the scalp and skull as if they were transparent, and can be targeted to specific areas of the brain. "The goal is to peel away the unintended effects by developing a more refined treatment," Lisanby says.
She cautions that transcranial magnetic stimulation, with or without a seizure, requires much more work before it will be available as a treatment. But, she says, "It is exciting the way the field has been evolving on all fronts," she says.
Mark George, MD, hails the study as an important extension of research on the new technology of transcranial magnetic stimulation.
"It shows they can reliably induce a seizure and that the side effects are less," says George, professor of psychiatry, radiology, and neurology at the Medical University of South Carolina, in Charleston. " It's important work."
George believes that transcranial magnetic stimulation -- whether it is used to induce a seizure or not -- is bound to be superior to ECT. "You are much more efficient with your energy delivery with [transcranial magnetic stimulation], instead of spreading it around the skull as with ECT," he tells WebMD. "What remains to be explored is whether it works to treat depression, and if so in whom."
Ultimately, the question researchers need to answer is where in the brain to focus the stimulation, he says.
But like Lisanby, George believes that the new technology can be used without causing a seizure, and that inducing a seizure is not necessary to treat depression. He says that there is a "widespread assumption" that you need to cause the person to have a seizure. "I think there are ways of getting depressed people undepressed without inducing a seizure."