scholarly journals Posteroanterior Cervical Transcutaneous Spinal Cord Stimulation: Interactions with Cortical and Peripheral Nerve Stimulation

2021 ◽  
Vol 10 (22) ◽  
pp. 5304
Author(s):  
Jaclyn R. Wecht ◽  
William M. Savage ◽  
Grace O. Famodimu ◽  
Gregory A. Mendez ◽  
Jonah M. Levine ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Motor Cortex ◽  
Motor Neurons ◽  
Nerve Stimulation ◽  
Spinal Cord Stimulation ◽  
Cervical Spinal Cord ◽  
Hand Function ◽  
Median Nerve Stimulation ◽  
Cord Injury ◽  
Transcutaneous Spinal Cord Stimulation

Transcutaneous spinal cord stimulation (TSCS) has demonstrated potential to beneficially modulate spinal cord motor and autonomic circuitry. We are interested in pairing cervical TSCS with other forms of nervous system stimulation to enhance synaptic plasticity in circuits serving hand function. We use a novel configuration for cervical TSCS in which the anode is placed anteriorly over ~C4–C5 and the cathode posteriorly over ~T2–T4. We measured the effects of single pulses of TSCS paired with single pulses of motor cortex or median nerve stimulation timed to arrive at the cervical spinal cord at varying intervals. In 13 participants with and 15 participants without chronic cervical spinal cord injury, we observed that subthreshold TSCS facilitates hand muscle responses to motor cortex stimulation, with a tendency toward greater facilitation when TSCS is timed to arrive at cervical synapses simultaneously or up to 10 milliseconds after cortical stimulus arrival. Single pulses of subthreshold TSCS had no effect on the amplitudes of median H-reflex responses or F-wave responses. These findings support a model in which TSCS paired with appropriately timed cortical stimulation has the potential to facilitate convergent transmission between descending motor circuits, segmental afferents, and spinal motor neurons serving the hand. Studies with larger numbers of participants and repetitively paired cortical and spinal stimulation are needed.

scholarly journals Transcutaneous spinal cord stimulation of the cervical cord modulates lumbar networks

2020 ◽  
Vol 123 (1) ◽  
pp. 158-166 ◽  
Author(s):  
Trevor S. Barss ◽  
Behdad Parhizi ◽  
Vivian K. Mushahwar
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Stimulation ◽  
Cervical Spinal Cord ◽  
H Reflex ◽  
Cervical Cord ◽  
Arm Cycling ◽  
Cord Injury ◽  
Walking Capacity ◽  
Transcutaneous Spinal Cord Stimulation ◽  
Lumbar Cord

It has been established that coordinated arm and leg (A&L) cycling facilitates corticospinal drive and modulation of cervico-lumbar connectivity and ultimately improves overground walking in people with incomplete spinal cord injury or stroke. This study examined the effect of noninvasive transcutaneous spinal cord stimulation (tSCS) on the modulation of cervico-lumbar connectivity. Thirteen neurologically intact adults participated in the study. The excitability of the Hoffmann (H) reflex elicited in the soleus muscle was examined under multiple conditions involving either the arms held in a static position or rhythmic arm cycling while tSCS was applied to either the cervical or lumbar cord. As expected, soleus H-reflex amplitude was significantly suppressed by 19.2% during arm cycling (without tSCS) relative to arms static (without tSCS). Interestingly, tSCS of the cervical cord with arms static significantly suppressed the soleus H-reflex (−22.9%), whereas tSCS over the lumbar cord did not suppress the soleus H-reflex (−3.8%). The combination of arm cycling with cervical or lumbar tSCS did not yield additional suppression of the soleus H-reflex beyond that obtained with arm cycling alone or cervical tSCS alone. The results demonstrate that activation of the cervical spinal cord through both rhythmic arm cycling and tonic tSCS significantly modulates the activity of lumbar networks. This highlights the potential for engaging cervical spinal cord networks through tSCS during rehabilitation interventions to enhance cervico-lumbar connectivity. This connectivity is influential in facilitating improvements in walking function after neurological impairment. NEW & NOTEWORTHY This is the first study to investigate the modulatory effects of transcutaneous spinal cord stimulation (tSCS) on cervico-lumbar connectivity. We report that both rhythmic activation of the cervical spinal cord through arm cycling and tonic activation of the cervical cord through tSCS significantly modulate the activity of lumbar networks. This suggests that engaging cervical spinal cord networks through tSCS during locomotor retraining interventions may not only enhance cervico-lumbar connectivity but also further improve walking capacity.

scholarly journals Restoration of breathing after opioid overdose and spinal cord injury using temporal interference stimulation

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Michael D. Sunshine ◽  
Antonino M. Cassarà ◽  
Esra Neufeld ◽  
Nir Grossman ◽  
Thomas H. Mareci ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Neurons ◽  
Drug Overdose ◽  
Cervical Spinal Cord ◽  
Opioid Overdose ◽  
Electrode Position ◽  
Spinal Motor Neurons ◽  
Cord Injury ◽  
Low Amplitude

AbstractRespiratory insufficiency is a leading cause of death due to drug overdose or neuromuscular disease. We hypothesized that a stimulation paradigm using temporal interference (TI) could restore breathing in such conditions. Following opioid overdose in rats, two high frequency (5000 Hz and 5001 Hz), low amplitude waveforms delivered via intramuscular wires in the neck immediately activated the diaphragm and restored ventilation in phase with waveform offset (1 Hz or 60 breaths/min). Following cervical spinal cord injury (SCI), TI stimulation via dorsally placed epidural electrodes uni- or bilaterally activated the diaphragm depending on current and electrode position. In silico modeling indicated that an interferential signal in the ventral spinal cord predicted the evoked response (left versus right diaphragm) and current-ratio-based steering. We conclude that TI stimulation can activate spinal motor neurons after SCI and prevent fatal apnea during drug overdose by restoring ventilation with minimally invasive electrodes.

A critical reappraisal of corticospinal tract somatotopy and its role in traumatic cervical spinal cord syndromes

2021 ◽  
pp. 1-7
Author(s):  
Allan D. Levi ◽  
Jan M. Schwab
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Upper Extremity ◽  
Corticospinal Tract ◽  
Cervical Spinal Cord ◽  
Hand Function ◽  
Cervical Spinal Cord Injury ◽  
Pathophysiological Mechanism ◽  
Cord Injury ◽  
Central Cord Syndrome

The corticospinal tract (CST) is the preeminent voluntary motor pathway that controls human movements. Consequently, long-standing interest has focused on CST location and function in order to understand both loss and recovery of neurological function after incomplete cervical spinal cord injury, such as traumatic central cord syndrome. The hallmark clinical finding is paresis of the hands and upper-extremity function with retention of lower-extremity movements, which has been attributed to injury and the sparing of specific CST fibers. In contrast to historical concepts that proposed somatotopic (laminar) CST organization, the current narrative summarizes the accumulated evidence that 1) there is no somatotopic organization of the corticospinal tract within the spinal cord in humans and 2) the CST is critically important for hand function. The evidence includes data from 1) tract-tracing studies of the central nervous system and in vivo MRI studies of both humans and nonhuman primates, 2) selective ablative studies of the CST in primates, 3) evolutionary assessments of the CST in mammals, and 4) neuropathological examinations of patients after incomplete cervical spinal cord injury involving the CST and prominent arm and hand dysfunction. Acute traumatic central cord syndrome is characterized by prominent upper-extremity dysfunction, which has been falsely predicated on pinpoint injury to an assumed CST layer that specifically innervates the hand muscles. Given the evidence surveyed herein, the pathophysiological mechanism is most likely related to diffuse injury to the CST that plays a critically important role in hand function.

scholarly journals Modification of spasticity by transcutaneous spinal cord stimulation in individuals with incomplete spinal cord injury

2013 ◽  
Vol 37 (2) ◽  
pp. 202-211 ◽  
Author(s):  
Ursula S. Hofstoetter ◽  
William B. McKay ◽  
Keith E. Tansey ◽  
Winfried Mayr ◽  
Helmut Kern ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Spinal Cord Stimulation ◽  
Incomplete Spinal Cord Injury ◽  
Cord Injury ◽  
Transcutaneous Spinal Cord Stimulation

Adaptation in the motor cortex following cervical spinal cord injury

Neurology ◽  
2002 ◽  
Vol 58 (5) ◽  
pp. 794-801 ◽  
Author(s):  
D. J. Mikulis ◽  
M. T. Jurkiewicz ◽  
W. E. McIlroy ◽  
W. R. Staines ◽  
L. Rickards ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Motor Cortex ◽  
Cervical Spinal Cord ◽  
Cervical Spinal Cord Injury ◽  
Cord Injury

scholarly journals Hand function recovery using nerve segment insert grafting in patients with chronic incomplete lower cervical spinal cord injury: a preliminary clinical report

2019 ◽  
Vol 7 (3) ◽  
pp. 129-135 ◽  
Author(s):  
Wenbin Ding ◽  
Shaocheng Zhang ◽  
Dajiang Wu ◽  
Yanpeng Zhang ◽  
Hualong Ye
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Upper Limb ◽  
Cervical Spinal Cord ◽  
Hand Function ◽  
Cervical Spinal Cord Injury ◽  
Clinical Report ◽  
Hand Functions ◽  
Nerve Segment ◽  
Cord Injury

Objective:The objective of this study was to show that hand functions could be recovered using nerve segment insert grafting in quadriplegic patients with chronic incomplete lower cervical spinal cord injury (CSCI) (C5/6/7/8).Methods:A retrospective analysis was performed in 18 quadriplegic patients (12 male and 6 female patients; mean age, 27 years; age range, 17–55 years) with chronic incomplete lower CSCI who had undergone nerve segment insert grafting from January 2001 to June 2015. Among the 18 patients, the right upper limb was involved in 7, left upper limb in 4, and bilateral upper limbs in 7 patients.Results:The mean follow-up period was 16 months (range, 3 months–3 years), and all patients exhibited obvious relief of limb spasm. Among all patients, 15 patients experienced no obvious spasm attacks and exhibited recovery of living abilities, i.e., recovery of the hand functions of grasping, holding, and pinching, and recovery of pain and temperature sensation in the fingers and palms; furthermore, they were able to steer an ordinary wheelchair independently postoperatively. The remaining three patients exhibited a significant and continuous improvement in hand functions over time, without any significant donor nerve dysfunction.Conclusions:Nerve segment insert grafting is an effective method that helps recover hand functions in quadriplegic patients with chronic incomplete lower CSCI. Moreover, spasticity can be relieved and partial normal innervation can be obtained in the spastic muscles postoperatively.

scholarly journals Fully Characterized Mature Human iPS- and NMP-Derived Motor Neurons Thrive Without Neuroprotection in the Spinal Contusion Cavity

2022 ◽  
Vol 15 ◽  
Author(s):  
Zachary T. Olmsted ◽  
Cinzia Stigliano ◽  
Brandon Marzullo ◽  
Jose Cibelli ◽  
Philip J. Horner ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Progenitor Cells ◽  
Motor Neurons ◽  
Ex Vivo ◽  
Cervical Spinal Cord ◽  
Neural Cell ◽  
Oligodendrocyte Progenitor Cells ◽  
Limited Information ◽  
Cord Injury

Neural cell interventions in spinal cord injury (SCI) have focused predominantly on transplanted multipotent neural stem/progenitor cells (NSPCs) for animal research and clinical use due to limited information on survival of spinal neurons. However, transplanted NSPC fate is unpredictable and largely governed by injury-derived matrix and cytokine factors that are often gliogenic and inflammatory. Here, using a rat cervical hemicontusion model, we evaluate the survival and integration of hiPSC-derived spinal motor neurons (SMNs) and oligodendrocyte progenitor cells (OPCs). SMNs and OPCs were differentiated in vitro through a neuromesodermal progenitor stage to mimic the natural origin of the spinal cord. We demonstrate robust survival and engraftment without additional injury site modifiers or neuroprotective biomaterials. Ex vivo differentiated neurons achieve cervical spinal cord matched transcriptomic and proteomic profiles, meeting functional electrophysiology parameters prior to transplantation. These data establish an approach for ex vivo developmentally accurate neuronal fate specification and subsequent transplantation for a more streamlined and predictable outcome in neural cell-based therapies of SCI.

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