Severely impaired stroke survivors may be able to regain function, sometimes after years of immobility, with a novel video game–led training device, preliminary research suggests. Results from a small randomized control trial showed that the device, known as the myoelectric computer interface (MyoCI), reduced impairment and spasticity and improved stroke survivors' arm function. "This myoelectric computer interface training enables chronic stroke patients to reduce abnormal coactivation in their arms, leading to some improvement in their ability to reach," study coauthor Marc Slutzky, MD, PhD, associate professor of neurology at Northwestern University Feinberg School of Medicine in Chicago, Illinois, told Medscape Medical News. The study was published online March 19 in Neurorehabilitation and Neural Repair. Unique Approach The investigators developed the MyoCI training method to reduce abnormal muscle pair coactivation. This coactivation, in which two muscles around a joint contract at the same time, contributes to poststroke disability. In contrast to traditional occupational therapy, which aims to improve specific functional tasks, MyoCI training focuses on reducing the underlying cause of impairment, Slutzky said. The approach "is unique in that it could potentially help patients benefit more from other therapies as well." The current research builds on a pilot study that demonstrated that MyoCI training of bicep and anterior deltoid muscle pairs cut abnormal coactivation by 99%. The earlier research, however, did not feature a blinded occupational therapist to assess functional outcomes. For the study, the investigators screened 42 adult chronic stroke survivors who had moderate to severe arm impairment after a period of at least 6 months from stroke onset. Of the participants, 15 were women; the mean period since stroke was 6.5 years. The candidates each scored from 8 to 40 on the Fugel Meyer Upper Extremity (FMA-UE) assessment. After exclusions and discontinuations, 32 patients were included in the analysis. Twelve patients were randomly assigned to undergo 60 minutes of isometric therapy; 11 patients were assigned to undergo 90 minutes of isometric therapy; and nine patients completed 90 minutes of unrestrained movements during the training. The researchers placed wireless electromyography electrodes along the affected arms to measure muscle activity. They selected the muscle pairs with the largest abnormal coactivation disparities, compared to the contralateral healthy arm, for MyoCI training. Improved Function The approach significantly reduced impairment in all participants, as reflected by FMA-UE scores, which increased a mean of 3.3 points at 6 weeks and 3.1 points at 10 weeks. These outcomes were statistically significant (P < .0001 at both assessment points) compared to baseline. "This is roughly around the minimum clinically important difference for FMA in severely impaired patients," Slutzky said. Improvements occurred rapidly. For example, abnormal coactivation decreased during the first 2 weeks by 54% compared to coactivation during a baseline free-reaching task. Participants also demonstrated improved performance on the Wolf Motor Function Test at 6 weeks and at the 10-week follow-up. This test assesses upper arm weakness of stroke survivors during timed- and function-based tasks. Scores ranged from a 0.6-point increase to a 7.3-point decrease in isometric and unrestrained movement groups in which patients were stratified on the basis of moderate or severe disability. "The improvement in Wolf Motor Test is probably more translatable than FMA-UE results, since it is a functional measure," said Slutzky. Participants "clearly improved in ability to use the arm more quickly in some functional tasks." The participants who completed isometric or unrestrained movements all improved; there were no significant differences in outcomes among them. Gamification Gains Slutzky said "gamifying" chronic stroke rehabilitation has several benefits. "First, there are socioeconomic barriers to getting everyone to therapists, and this may turn out to be more cost-effective. Second, the more repetitions patients do, the more they can recover, and gamifying it should make it more motivating for patients to practice more." Although the findings were positive, the research is preliminary. "This is an early-phase trial with in-lab testing," said Slutzky. Nevertheless, "the beauty of this paradigm is that it could be made into an inexpensive, wearable version for use at home, which we are now testing," he said. A third advantage would be the greater ease of use of such home-based training, he added. A home-based, first-generation wearable version that is in development communicates wirelessly with a tablet or laptop. Investigators will compare the results between chronic stroke survivors and a control group. They also plan to assess the new version's role in treating acute stroke patients who are still in the hospital. "We hope that intervening earlier after stroke will enable us to prevent the abnormal coactivation patterns before they develop and thus translate to greater benefits," Slutzky said. More Evidence Needed Commenting on the findings for Medscape Medical News, Nick S. Ward, MD, professor of clinical neurology and neurorehabilitation at University College London, United Kingdom, noted that the number of participants in each group in the study was "very small." Ward added that the effect size on the FMA-UE was likewise small, with a mean 3-point improvement. For moderately disabled stroke survivors, a minimum clinically important difference requires a 6- to 7-point improvement, he said. Further study is warranted, because "what we need is big effects," added Ward, who was the lead investigator on a 2019 study that reported positive outcomes following a 6-month intensive neurorehabilitation program to improve upper limb impairment and activity among 224 chronic stroke survivors. The study was supported by grants from the National Institutes of Health. Slutzky and Ward have disclosed no relevant financial relatioships. Neurorehabil Neural Rep. Published online March 19, 2019. Abstract Source
