Shock Therapy Takes on a New Form
"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."