Novel wearable device for hand motor recovery in stroke survivors

This study investigated whether combining clicks with muscle stimulation could improve hand treatment in stroke survivors. Researchers suggested that this treatment can produce a small but significant treatment improvement.

Stroke is a serious condition that more than doubled in low- and middle- income countries in the past 30 years. It consists of a decrease of blood flow to the brain due to obstruction by a blood clot or a burst blood vessel. Brain cells stop receiving oxygen and begin to die. The body abilities controlled by these cells are lost causing effects such as arm paralysis. 30 to 66% of stroke survivors lose arm functions that are necessary for daily living.  

Standard arm therapy is recommended, but access to such therapy in low-income countries is limited. New treatment solutions that reduce the contact time required from therapists are needed.   

In humans, hand function is controlled by the reticulospinal tract (RST; area of the brain connected to the spinal cord). Non-invasive methods to activate the RST are limited. Prior studies in monkeys showed that loud auditory clicks activate the RST. A medical device was developed to continually deliver clicks paired with electrical stimulation on muscles. In healthy humans, this device induced long-term changes in recovery. However, the effectiveness of this method in the hand recovery of stroke survivors is not known.

This study included information about 95 patients 6 months after surviving a stroke. Clicks and electrical stimulation were delivered through a small earpiece. A wearable medical device allowed patients to receive stimulation at home while performing daily activities.

These patients were assigned to 3 different groups. Group 1 wore a device with electrical shock paired with a click. Group 2 wore a device with clicks and shocks delivered separately and group 3 received standard care (no stimulation). Group 1 and 2 wore the device for at least 4 hours per day, every day for 4 weeks. Participants were followed-up at the start of the study and at weeks 2, 4, and 8.

Only group 1 showed significant improvement in hand movements such as grasp, grip, pinch, and gross. Participants reported that the device and clicks did not interfere with their normal activities of daily living. One participant reported a skin reaction because of the device. This improved with steroid creams.

This study concluded that a wearable medical device that delivers paired clicks and electrical shocks improves hand recovery in stroke survivors.

Patients in this study did not receive the same physical therapy. This might have changed the results.