Magnetic Stimulation of the Brain May Aid Working Memory in MS Patients

Repeated magnetic stimulation of the brain may help to rebuild the brain’s network in patients with multiple sclerosis (MS), leading to improved working memory, researchers reported. But more studies are necessary to confirm the procedure’s safety and efficacy as a treatment for MS.

Results were published in a study titled “rTMS Affects Working Memory Performance, Brain Activation And Functional Connectivity In Patients With Multiple Sclerosis” in the Journal of Neurology, Neurosurgery, and Psychiatry.

Repetitive Transcranial Magnet Stimulation (rTMS) is approved by the U.S. Food and Drug Administration (FDA) as a treatment for major depression. In this procedure, doctors place a device on the patient’s scalp that sends electromagnet impulses to a specific area of the brain, thereby stimulating its activity. Previous studies have shown that rTMS significantly eases depression in MS patients.

Working memory refers to memory required for day-to-day tasks, such as making mental calculations.

The study included 17 MS patients and 11 healthy individuals, with no signs of impaired memory, to test whether rTMS, or a “sham” lower intensity version of this procedure, could also improve the working memory in MS patients. Participants considered at risk of seizures or with brain lesions in particular areas due to MS were excluded from the study.

Before and after the procedure, all participants were extensively analyzed with imaging and neuropsychological tests to assess their memory status. Each then received three sessions (baseline, real-rTMS and sham-rTMS). Activity in the stimulated area (a region in the prefrontal cortex, at the front of the brain) was assessed by a magnetic resonance (MR) scanner while participants completed a working memory task, so that researchers could measure activity during the task.

Results indicated that, while at baseline there were no differences between the groups, treatment with real-rTMS (but not sham-rTMS) improved working memory, brain activity and connectivity between the prefrontal cortex and other brain areas in MS patients, but not in healthy individuals.

Together, the findings suggest that rTMS induces changes in the efficiency of brain network in patients with MS, “shifting patients’ brain function towards the healthy situation,” the researchers wrote.

According to the authors, the results obtained imply that rTMS has a potential role in cognitive rehabilitation in MS patients, but they recognize that their study is limited by the small number of participants and the absence of clear cognitive problems between groups. Further studies are necessary to confirm these preliminary results and investigate whether rTMS is a safe and efficient way to improve day-to-day life for MS patients.