Recovery of the upper extremity (UE) and hand function is considered the highest priority for people with tetraplegia, because these functions closely integrate with their activities of daily living. ...Spinal cord transcutaneous stimulation (scTS) has great potential to facilitate functional restoration of paralyzed limbs by neuro-modulating the excitability of the spinal network. Recently, this approach has been demonstrated effective in improving UE function in people with motor complete and incomplete cervical SCI. However, the research thus far is limited by the lack of a comprehensive assessment of functional improvement and neurological recovery throughout the intervention. The goal of this study was to investigate whether scTS can also facilitate UE functional restoration in an individual with motor and sensory complete tetraplegia. A 38-year-old male with a C5 level, ASIA Impairment Scale-A SCI (15 years post-injury, left hand dominant pre- and post-injury), received 18 sessions (60 minutes/session) of scTS combined with task-specific hand training over the course of 8 weeks. The total score of the Graded Redefined Assessment of Strength, Sensibility, and Prehension significantly improved from 72/232 to 96/232 at post-intervention, and maintained ranging from 82/232 to 86/232 during the three months follow-up without any further treatment. The bilateral handgrip force improved by 283.4% (left) and 30.7% (right), respectively at post-intervention. These strength gains were sustained at 233.5% -250% (left) and 11.5%-73.1% (right) during the follow-up evaluation visits. Neuromuscular Recovery Scale demonstrated dramatic and long-lasting improvements following the completion of the intervention. Changes of spinal motor evoked potentials from pre- to post-intervention indicated an increased level of spinal network excitability. The present data offer preliminary evidence that the novel scTS intervention combined with hand training can enhance UE functional use in people with motor and sensory complete SCI.
The aims of this study are to characterize the contamination of EMG signals by artifacts generated by the delivery of spinal cord transcutaneous stimulation (scTS) and to evaluate the performance of ...an Artifact Adaptive Ideal Filtering (AA-IF) technique to remove scTS artifacts from EMG signals. Methods : In five participants with spinal cord injury (SCI), scTS was delivered at different combinations of intensity (from 20 to 55 mA) and frequencies (from 30 to 60 Hz) while Biceps Brachii (BB) and Triceps Brachii (TB) muscles were at rest or voluntarily activated. Using a Fast Fourier Transform (FFT), we characterized peak amplitude of scTS artifacts and boundaries of contaminated frequency bands in the EMG signals recorded from BB and TB muscles. Then, we applied the AA-IF technique and the empirical mode decomposition Butterworth filtering method (EMD-BF) to identify and remove scTS artifacts. Finally, we compared the content of the FFT that was preserved and the root mean square of the EMG signals (EMGrms) following application of the AA-IF and EMD-BF techniques. Results : Frequency bands of ~2Hz width were contaminated by scTS artifact at frequencies nearby the main frequency set for the stimulator and its harmonics. The width of the frequency bands contaminated by scTS artifacts increased with current intensity delivered using scTS (p<0.001), was lower when EMG signals were recorded during voluntary contractions compared to rest (p<0.05), and was larger in BB muscle compared to TB muscle (p<0.001). A larger portion of the FFT was preserved using the AA-IF technique compared to the EmD-BF technique (96±5% vs. 75±6%, p<0.001). Conclusion : The AA-IF technique allows for a precise identification of the frequency bands contaminated by scTS artifacts and ultimately preserves a larger amount of uncontaminated content from the EMG signals.
Recovery of function following a complete spinal cord injury (SCI) or an incomplete SCI where recovery has plateaued still eludes us despite extensive research. Epidural spinal cord stimulation (SCS) ...was initially used for managing neuropathic pain. It has subsequently demonstrated improvement in motor function in otherwise non-recovering chronic spinal cord injury in animal and human trials. The mechanisms of how it is precisely effective in doing so will need further research, which would help refine the technology for broader application. Transcutaneous spinal cord stimulation (TSCS) is also emerging as a modality to improve the functional outcome in SCI individuals, especially when coupled with appropriate rehabilitation. Apart from motor recovery, ESCS and TSCS have also shown improvement in autonomic, metabolic, genitourinary, and pulmonary function. Since the literature on this is still in its infancy, with no large-scale randomised trials and different studies using different protocols in a wide range of patients, a review of the present literature is imperative to better understand the latest developments in this field. This article examines the existing literature on the use of SCS for SCI individuals with the purpose of enabling functional recovery. It also examines the voids in the present research, thus providing future directions.
We studied the effects of transcutaneous electrical stimulation at the tragus, the anterior protuberance of the outer ear, for inhibiting atrial fibrillation (AF).
To develop a noninvasive ...transcutaneous approach to deliver low-level vagal nerve stimulation to the tragus in order to treat cardiac arrhythmias such as AF.
In 16 pentobarbital anesthetized dogs, multielectrode catheters were attached to pulmonary veins and atria. Three tungsten-coated microelectrodes were inserted into the anterior right ganglionated plexi to record neural activity. Tragus stimulation (20 Hz) in the right ear was accomplished by attaching 2 alligator clips onto the tragus. The voltage slowing the sinus rate or atrioventricular conduction was used as the threshold for setting the low-level tragus stimulation (LL-TS) at 80% below the threshold. At baseline, programmed stimulation determined the effective refractory period (ERP) and the window of vulnerability (WOV), a measure of AF inducibility. For hours 1-3, rapid atrial pacing (RAP) was applied alone, followed by concomitant RAP+LL-TS for hours 4-6 (N = 6). The same parameters were measured during sinus rhythm when RAP stopped after each hour. In 4 other animals, bivagal transection was performed before LL-TS.
During hours 1-3 of RAP, there was a progressive and significant decrease in ERP, increase in WOV, and increase in neural activity vs baseline (all P < .05). With RAP+LL-TS during hours 4-6, there was a linear return of ERP, WOV, and neural activity toward baseline levels (all P < .05, compared to the third-hour values). In 4 dogs, bivagal transection prevented the reversal of ERP and WOV despite 3 hours of RAP+LL-TS.
LL-TS can reverse RAP-induced atrial remodeling and inhibit AF inducibility, suggesting a potential noninvasive treatment of AF.
Spinal cord injury (SCI) leads to severe impairment in cardiovascular control, commonly manifested as a rapid, uncontrolled rise in blood pressure triggered by peripheral stimuli—a condition called ...autonomic dysreflexia. The objective was to demonstrate the translational potential of noninvasive transcutaneous stimulation (TCS) in mitigating autonomic dysreflexia following SCI, using pre-clinical evidence and a clinical case report. In rats with SCI, we show that TCS not only prevents the instigation of autonomic dysreflexia, but also mitigates its severity when delivered during an already-triggered episode. Furthermore, when TCS was delivered as a multisession therapy for 6 weeks post-SCI, the severity of autonomic dysreflexia was significantly reduced when tested in the absence of concurrent TCS. This treatment effect persisted for at least 1 week after the end of therapy. More importantly, we demonstrate the clinical applicability of TCS in treatment of autonomic dysreflexia in an individual with cervical, motor-complete, chronic SCI. We anticipate that TCS will offer significant therapeutic advantages, such as obviating the need for surgery resulting in reduced risk and medical expenses. Furthermore, this study provides a framework for testing the potential of TCS in improving recovery of other autonomic functions such lower urinary tract, bowel, and sexual dysfunction following SCI.
Widespread pain and headache are common in Gulf War Illness with suboptimal treatments available. We tested the efficacy of non-invasive, transcutaneous vagal nerve stimulation (nVNS) for relief of ...widespread pain and migraine in Gulf War Veterans with GWI.
A 10-week double-blind, randomized controlled trial of nVNS used the gammaCore (ElectroCore, Inc.) compared to sham stimulation with the same device followed by a 10-week open-label follow up with active nVNS. The primary outcome was a numerical pain rating at the end of the blinded period. Secondary outcomes included physical function, migraine frequency and severity, and impression of change during the blinded and open-label periods. Two-factor MANOVA models tested for significant differences between groups from baseline to end of the blinded period and during the open-label period.
Among 27 participants enrolled and issued a nVNS device, there was a slight improvement in pain ratings from baseline to the end of the blinded phase 6.18 (±0.82) vs. 5.05 (±2.3); p = 0.040 which did not differ between active and sham nVNS. Physical function was also slightly improved overall without group differences. There were no significant changes in migraine frequency or severity during the blinded period. Twenty participants started in the open-label phase; no statistically significant changes in pain, physical function, migraine measures, or impression of change were noted during this phase.
Veterans with GWI actively treated with nVNS reported no improvement in either widespread pain or migraine frequency or severity relative to Veterans with GWI who received sham nVNS.
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