A surgically implanted neuroprosthesis improved the walking speed and distance of a patient with limited mobility due to stroke, according to results recently published in the American Journal of Physical Medicine & Rehabilitation.
According to a press release from Wolters Kluwer Health, the neuroprosthesis is programmed to stimulate coordinated activity in the hip, knee and ankle muscles.
Nathaniel S. Makowski, PhD, an investigator at Cleveland FES Center and research scientist at Louis Stokes Cleveland VA Medical Center, and colleagues implanted a neuroprosthesis in a 64-year-old man with impaired motion and sensation in his left leg and foot caused by hemorrhagic stroke. The researchers placed a pulse generator and intramuscular stimulating electrodes in seven muscles in the man’s hip, knee and ankle. They created a customized electrical stimulation program to activate the patient’s muscles to restore a more natural gait pattern. The patient underwent several months of extensive training after placement of the neuroprosthesis.
Results showed the patient made significant gains in walking speed and distance. Without muscle stimulation, change in gait speed was not significant, increasing from 0.29 meters per second before surgery to 0.35 meters per second after training. With muscle stimulation, gait speed increased to 0.72 meters per second. The patient showed “more symmetrical and dynamic gait,” according to the release.
He also was able to walk farther. Before surgery, the patient could walk 76 meters before becoming fatigued. After surgery — but without stimulation — he could walk 300 meters in 16 minutes. With stimulation, he was able to walk 1,400 meters in 41 minutes — a 370% increase in distance at nearly double the speed.
According to the release, the patient’s walking ability in daily life improved significantly and he was able to move from “household-only” walking to increased walking outside in his neighborhood. Although the stimulation was only used inside the laboratory, Makowski and colleagues reported the stimulated exercise and gait training may have a therapeutic effect.
Large-scale studies are needed to show wider applicability of a neuroprosthesis for multi-joint control, according to the study results. Makowski and colleagues said an implanted system could have “significant clinical relevance” to patients with stroke, according to the release.
Makowski NS, et al. Am J Phys Med Rehabil. [published online ahead of print May 26, 2016].