Image of magnet stimulator
Multifocal transcranial rotating permanent magnet stimulator (TRPMS). (Credit: Blessy John)

A noninvasive, wearable, magnetic brain stimulation device could improve motor function in stroke patients. In an initial clinical trial of 30 chronic ischemic stroke survivors, the transcranial, rotating, permanent magnet stimulator, or TRPMS, produced significant increases in physiological brain activity in areas near the injured brain, as measured by functional MRI.

Stroke survivors who had weakness on one side of their body at least three months post-stroke were enrolled in a preliminary study to evaluate safety and efficacy of the device. Half of the patients were treated with brain stimulation administered in twenty 40-minute sessions over four weeks. The rest had sham, or mock, treatment. Researchers analyzed physiologic brain activity before, immediately after and one month after treatment.

Although the study could not prove that the transcranial stimulator improved motor function, numerical improvements were demonstrated in five of six clinical scales of motor function, as measured by a functional MRI test. The scales measured gait velocity, grip strength, pinch strength, and other motor functions of the arm. The treatment effects persisted over a three-month follow-up.

The researchers believe the study results are a signal of possible improved clinical motor function after magnetic brain stimulation for patients after stroke, which will need to be confirmed in a larger, multicenter trial.