Every 40 seconds someone in the U.S. experiences a stroke, according to the Centers for Disease Control and Prevention. And because stroke is the country’s leading cause of long-term disability, the effectiveness of post-stroke rehabilitation is vital to a person’s quality of life.
Researchers at the Medical University of South Carolina (MUSC) have found that when post-stroke survivors wear a wireless wrist band designed to send vibrations through the arm during occupational therapy, they get more value out of their sessions and have improved motor function.
As reported in a recent paper published in OTJR: Occupation, Participation and Health, these researchers found that the extra stimulus increases activity in the brain during grip tasks, which in turn improves a patient’s hand function after therapy has concluded.
A stroke occurs when blood flow to a particular area of the brain is cut off, which can lead to brain damage. Na Jin Seo, Ph.D., the primary investigator on the paper and a professor in the College of Health Professions at MUSC, says that the main outcomes in the aftermath of a stroke are issues with mobility and movement.
Working alongside Amanda Vatinno, Ph.D., first author on the paper and a research assistant at MUSC at the time, Seo assessed the effectiveness of a wearable device called a TheraBracelet on patients over the course of a 6-week therapy session.
Vatinno says it’s easy to take the use of your limbs for granted – she even catches herself doing it sometimes. “But tasks that seem simple can become so difficult following a stroke,” she said. “I see people struggling to open a jar or take a drink.”
She says devices like the TheraBracelet can enhance treatment and provide longer-lasting effects. The device works by sending imperceptible vibrations through a person’s arm and up to their brain while they perform everyday tasks.
The stimulus primes the sensory cortex in the brain and prepares it for the upcoming movement. Increasing the brain’s activity like this helps with motor output and thus helps patients move their arms more freely and effectively.
Vatinno says the activities they perform with patients could be as basic as brushing their teeth or zipping a jacket, both of which are regularly practiced in occupational therapy without wearable technology assistance.
Therapists can also assist patients with practicing more social or sports-driven activities depending on what is important to that patient. “One participant was an avid golfer,” Vatinno said. “So we practiced golf swings in therapy while wearing the bracelet.”
Previous papers have shown that sensory stimulus prior to a therapy session can improve outcomes, but those methods had patients remain still for 2 hours while receiving the stimulus before practicing any movements. That sedentary time was necessary for the treatment plan, and the effects diminished once the stimulation was removed.
Seo and Vatinno’s study was different. “What sets it apart from traditional therapy is adding that particular stimulation,” according to Vatinno. “It’s wireless and can be done during the therapy itself.”
By using the stimulation simultaneously and removing the need for patients to remain sedentary for so long to achieve results, Seo hopes to apply it more easily to clinical practice. Her method has yielded longer-lasting results for stroke survivors, and she hopes to continue to assess its effectiveness. S
he will need to determine if a time limit for treatment is necessary so patients don’t become desensitized to it, and she’d like more information on how long the treatment lasts. Ultimately, she believes that better treatments will help people regain their independence and improve their quality of life.
his study systematically investigated the safety of daily use of TheraBracelet at home over a month in chronic stroke survivors. The extended daily use of TheraBracelet was likely achieved as suggested by the high rates of adherence to the study protocol, except for the two participants with SAE who were instructed to stop wearing the device.
TheraBracelet stimulation did not increase the number of participants experiencing device-related AEs compared with the sham stimulation. Relatively high occurrence of mild AEs regardless of the conditions could be due to extensive tests performed weekly and measurement reliability issues for the 2-point discrimination and monofilament tests that have been shown to have little to moderate reliabilities.29 Participants perceived that the device was safe, as seen by the user feedback. Therefore, it is concluded that long-term use of TheraBracelet stimulation at home (i.e., >4hr/day daily over a month) is safe for chronic stroke survivors.
This study was not designed to test efficacy. Participants were not instructed to perform any hand task practices, exercises, or therapeutic activities during enrollment. Rather, participants were instructed to continue with their routine lifestyle. The reason was to focus the investigation on the safety of the stimulation, in the absence of the confounding effects of upper extremity therapy.
Chronic stroke survivors generally have a reduced amount of affected upper limb movement (mean 5 hours/day of movement46 compared to 9 hours/day for age-matched controls47 detected based on accelerometry). Their daily routine may not involve much movement of the affected upper extremity. Because no upper extremity therapeutic activity was encouraged, the anticipated effects of the TheraBracelet stimulation on hand function was minimal.
Despite having no intervention other than wearing the stimulation device, secondary safety analysis showed that there was a general trend of improvements in the 2-point discrimination test score, NHPT time, and grip strength over weeks. However, changes in the 2-point discrimination and NHPT were small or less than the minimum detectable change. Change in grip strength was not specific to the real stimulation month. Thus, it may represent a placebo or practice effect.
Limitations of this study are as follows. A relatively small size was used (n=25). Perfect covariate balance does not manifest in small trials. However, the differences observed in our study are insignificant and therefore simply due to chance. This study focused on examination of the safety of TheraBracelet in the absence of any therapeutic activities.
Therefore, this study lacks information on the efficacy of using TheraBracelet in conjunction with a standard therapy program with home exercises. This study did not systematically examine whether the device interferes with any therapeutic activities. A cross-over design was used because it was initially anticipated that changes in measures that occurred during the first month would subside during 2 weeks of not wearing the device. However, changes were sustained, resulting in different baselines for the two months (Figure 3).
This trend informs that future trials may use a parallel design rather than crossover. We chose the cross-over design and powered it sufficiently to account for the known variability in the stroke population. However, larger stratified studies considering subpopulations may be warranted to further explore the heterogeneity of the stroke population. Although the vibration intensity was adjusted to be 40% below their sensory threshold at the weekly visit, some participants were able to feel vibration for a brief period during the following week, suggesting changes in the sensory threshold over time.
This study did not use any wear sensor to objectively monitor wear time. We cannot rule out the possibility that participants may inflate their self-reported wear time. Some device function issues such as breakage were observed, suggesting the need to improve the device exterior design.
Daily long-term use of TheraBracelet stimulation at home (i.e., >4hr/day over a month) is safe in chronic stroke survivors. It is a logical step to plan a phase II study investigating the efficacy of pairing TheraBracelet with a standard hand rehabilitation therapy in increasing hand motor outcomes and functional independence while continuing to monitor safety.
reference link : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7035973/
More information: Amanda A. Vatinno et al, Using Subthreshold Vibratory Stimulation During Poststroke Rehabilitation Therapy: A Case Series, OTJR: Occupation, Participation and Health (2021). DOI: 10.1177/15394492211042275