1. Posteroanterior cervical transcutaneous spinal stimulation targets ventral and dorsal nerve roots
- Author
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Jonah M. Levine, Jaclyn R. Wecht, Sana Saeed, Joseph P. Weir, Yu-Kuang Wu, Matthew T. Maher, James M. LiMonta, Kenneth S. Guber, Eric Bailey, Shivani Kastuar, Noam Y. Harel, Tiffany M. Santiago, Jason B. Carmel, and Lok Yung more...
- Subjects
Adult ,Male ,Sensory Receptor Cells ,Efferent ,Stimulation ,Stimulus (physiology) ,050105 experimental psychology ,03 medical and health sciences ,0302 clinical medicine ,Physiology (medical) ,medicine ,Biological neural network ,Humans ,0501 psychology and cognitive sciences ,Amyotrophic lateral sclerosis ,Spinal cord injury ,Spinal Cord Injuries ,Aged ,Motor Neurons ,Spinal Cord Stimulation ,Abductor pollicis brevis muscle ,business.industry ,Amyotrophic Lateral Sclerosis ,05 social sciences ,Spinal stimulation ,Anatomy ,Middle Aged ,Hand ,medicine.disease ,Sensory Systems ,Neurology ,Female ,Neurology (clinical) ,Spinal Nerve Roots ,business ,Neck ,030217 neurology & neurosurgery - Abstract
Objective We aim to non-invasively facilitate activation of spared neural circuits after cervical spinal cord injury (SCI) and amyotrophic lateral sclerosis (ALS). We developed and tested a novel configuration for cervical transcutaneous spinal stimulation (cTSS). Methods cTSS was delivered via electrodes placed over the midline at ~T2-T4 levels posteriorly and ~C4-C5 levels anteriorly. Electromyographic responses were measured in arm and hand muscles across a range of stimulus intensities. Double-pulse experiments were performed to assess homosynaptic post-activation depression (PAD). Safety was closely monitored. Results More than 170 cTSS sessions were conducted without major safety or tolerability issues. A cathode-posterior, 2 ms biphasic waveform provided optimal stimulation characteristics. Bilateral upper extremity muscle responses were easily obtained in subjects with SCI and ALS. Resting motor threshold at the abductor pollicis brevis muscle ranged from 5.5 to 51.0 mA. As stimulus intensity increased, response latencies to all muscles decreased. PAD was incomplete at lower stimulus intensities, and decreased at higher stimulus intensities. Conclusions Posteroanterior cTSS has the capability to target motor neurons both trans-synaptically via large-diameter afferents and non-synaptically via efferent motor axons. Significance Posteroanterior cTSS is well tolerated and easily activates upper extremity muscles in individuals with SCI and ALS. more...
- Published
- 2020
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