Researchers at Shepherd Center in Atlanta are studying whether stimulating the brain before rehabilitation could yield greater gains in motor function for people recovering from stroke.
Shepherd Center is one of 12 U.S. centers participating in a clinical trial that is evaluating whether coupling navigated transcranial magnetic stimulation (TMS) of the brain with standard occupational therapy can measurably improve hand and arm function following a stroke. Experts say this approach could unlock a totally new, non-invasive treatment to promote recovery and function.
“It’s really a seminal study in neurorehabilitation that, if successful, will change common practices for how we take care of certain stroke patients,” said Ford Vox, M.D., a physical medicine and rehabilitation physician at Shepherd Center and primary investigator for this study. “We have this golden opportunity right after someone has a stroke when we know people are most likely to improve or recover function, and this therapy may offer patients the best potential.”
Shepherd Center is testing a navigated brain stimulation system developed by a Finnish medical technology company called Nexstim. It uses TMS therapy to apply a mild electromagnetic current to excite the brain, a technique that can be used to both investigate the brain’s functions and change them. The technique is growing in popularity as a way to map the brain before surgery and as a treatment for depression. Nexstim’s device provides visual guidance to the operator, who uploads and correlates MRI pictures of the patient’s brain with the device’s infrared guidance system. Then, the device creates a 3-D model of the patient’s brain, pinpointing the target site for stimulation in real time (called stereotactic guidance).
In this new trial, clinicians believe TMS works by slowing activity in the healthy area of the brain, which can become overly active following a stroke, causing detriment to the injured side.
The technology is akin to a more advanced version of constraint-induced therapy in which clinicians physically tie down a patient’s good arm, which forces the patient to use the injured side. With Nexstim’s non-invasive device, researchers are using electromagnetism to slow activity in portions of the healthy brain hemisphere that control the uninjured arm, similarly forcing the brain to use its injured half.
Eligible clinical trial participants receive either the navigated brain stimulation or a sham (simulated) treatment in conjunction with six weeks of hand and arm therapy provided by an occupational therapist. Researchers and study participants do not know whether they are in the treatment or simulation group. Visits start with 20 minutes of standardized, task-oriented activity followed by the treatment or simulated therapy and then an hour of upper-limb rehabilitation therapy.
The goal is to improve a patient’s range of motion, coordination, flexibility, strength, and use of the weak arm and hand. Specifically, researchers are interested to see whether – at the end of the study – patients are better able to perform daily activities, such as dressing, grooming, cooking, doing laundry, writing, typing and leisure activities.