Updated: Nov 4
Study Shows Groundbreaking Stroke Recovery Facilitated by Digitimer’s DS8R Peripheral Stimulator & D188 Remote Electrode Selector
Stroke patients with hand and arm issues now have another reason for hope regarding the improvement of chronic symptoms, including paresis. According to recent findings published in Nature Medicine, epidural spinal cord stimulation has been shown to return mobility to the arm and hand muscles inpatients who have suffered a stroke. This restoration of function allows stroke survivors to regain their ability to partake in activities of daily living that were previously thought impossible. This research, which resulted from a multicenter collaborative study including the University of Pittsburgh and Carnegie Mellon, has not only sparked vast media attention worldwide, but it may also lead to a gold standard treatment approach for patients who have suffered a stroke.
In the study, researchers posited that by reinvigorating a damaged corticospinal tract (CST) via spinal cord stimulation, stroke survivors could regain voluntary motor control. Their hypothesis was informed by previous research conducted by numerous international groups and commercial organizations that have shown the therapeutic potency of spinal cord stimulation in patients who have suffered spinal cord injury. Given the positive trajectory of this body of advanced research, the study authors undertook an examination of how electrically stimulating the damaged CST (using Digitimer technology) could enhance the capabilities of the viable neurons that remained, increasing their excitability and responsiveness.
Synthesizing the Study’s Abstract
When a patient suffers a stroke that affects the cerebrum, it can result in permanent motor deficits in their arms and hands, as the efferent signals from the motor cortical areas of the brain to the spinal cord are disrupted. Despite this disruption, the spinal circuits distal to the lesion that are responsible for motor activities remain intact. Researchers posited that neurotechnologies could stimulate these circuits to help patients regain movement. In their abstract covering this first-in-human study, researchers describe how electrical stimulation of cervical spinal circuits helped improve motor control of the hand and arm in two patients suffering from chronic post-stroke hemiparesis (NCT04512690).
For 29 days, the study’s participants had two linear leads implanted into their dorsolateral epidural space targeting spinal roots C3 toT1, to increase the excitation of the arm and hand motor neurons. Researchers discovered that this continuous stimulation through selected contacts helped to improve their strength, kinematics, and functional movements. This allowed the two patients to perform motor movements that they could not previously perform without spinal cord stimulation. Both participants were able to retain some of these improvements once the stimulation was removed, and both were free from serious adverse events. Given the study’s scale, it’s not possible to conclusively evaluate the safety and efficacy of the electrical stimulation of the CST, but this preliminary data provides positive evidence that this method could be both a therapeutic and curative approach for regaining motor function of the hand and arm after a patient has suffered a stroke.
Stimulation Methods Used in the Study
To assess the potential of electrical stimulation of the CST to restore motor control following a stroke, the Digitimer DS8R stimulator and D188 Remote Electrode Selector were used to direct stimuli to arrays of epidural electrodes that were located in the cervical spine. The study authors employed a MATLAB-based GUI to allow them to precisely control the DS8R and D188 via an Arduino microcontroller that was connected via a virtual serial port to the PC. This GUI allowed the authors to tightly coordinate pulse amplitude, timing, and electrode selection.
The parameters that were controlled by the software included pulse duration, inter-pulse interval, amplitude, and waveform shape. More specifically, the Digitimer DS8R stimulator was programmed to deliver a cathodic first, biphasic waveform with 200 µs or 400 µs phase duration and 10µs interphase interval. Despite the Digitimer DS8R stimulator being a single-channel device, the study authors used the D188 Remote Electrode Selector as a multiplexer to facilitate the delivery of semi-synchronous stimulation to multiple channels.
More About Post-Paralysis Motor Control Recovery Research
Unfortunately, 25% of adults over 25 years old are likely to suffer from a stroke in their lifetime, and 75% of those strokes will leave survivors with motor control deficits. This is why post-paralysis motor control recovery research of this nature is a critical global health need. In this video below, Marco Capogrosso, director of the University of Pittsburgh Spinal Cord Stimulation Laboratory and co-senior author of the study, provides his insight into the groundbreaking research involving spinal cord stimulation via Digitimer for the recovery of motor control after paralysis.
Study Conclusions and Further Research Aims
Despite the study being limited in its scale, it was able to clearly show that electrical stimulation of the CST may certainly benefit stroke patients who have suffered debilitating motor restrictions involving their upper extremities. The continuous electrical stimulation of the CST, facilitated by Digitimer, saw a marked improvement in motor function that patients had previously been unable to capture via other therapy methods for years. Of note, these positive effects on motor function persisted once the stimulation was removed, which signals that this technology may represent a groundbreaking therapy that could assist stroke patients during their recovery and potentially restore their function.
On the heels of these positive study results, the author shave noted their plan to expand their trial to more participants and investigate whether their electrical stimulation protocols can be further enhanced to optimize patient outcomes. In order to potentially translate this groundbreaking research into a clinical treatment, the University of Pittsburgh and Carnegie Mellon University have formed the start-up company Reach Neuro.
At Digitimer, we find it immensely rewarding that our most advanced electrical research stimulator, the Digitimer DS8Rstimulator, which is pictured opposite, is now being harnessed for innovative human neuroscience research targeted at drastically enhancing the quality of life and functionality of millions of stroke patients across the globe.
Find Out More
For medical scientists looking to learn more about the Digitimer DS8R Stimulator or D188 Remote Electrode Selector used in this study, please do not hesitate to contact us or our local representative. Of note, the Digitimer DS8R and D188 are not medical devices and are marketed and intended for human research applications.
Powell, M.P., Verma, N., Sorensen, E. et al. Epidural stimulation of the cervical spinal cord for post-stroke upper-limb paresis. Nat Med(2023).