scholarly journals Electrophysiological biomarkers of neuromodulatory strategies to recover motor function after spinal cord injury

2015 ◽  
Vol 113 (9) ◽  
pp. 3386-3396 ◽  
Author(s):  
Parag Gad ◽  
Roland R. Roy ◽  
Jaehoon Choe ◽  
Jack Creagmile ◽  
Hui Zhong ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Motor Control ◽  
Evoked Potentials ◽  
Motor Performance ◽  
Weight Bearing ◽  
Chronic Administration ◽  
Pharmacological Agents ◽  
Extensor Muscles ◽  
Cord Injury ◽  
Complete Paralysis

The spinal cord contains the circuitry to control posture and locomotion after complete paralysis, and this circuitry can be enabled with epidural stimulation [electrical enabling motor control (eEmc)] and/or administration of pharmacological agents [pharmacological enabling motor control (fEmc)] when combined with motor training. We hypothesized that the characteristics of the spinally evoked potentials after chronic administration of both strychnine and quipazine under the influence of eEmc during standing and stepping can be used as biomarkers to predict successful motor performance. To test this hypothesis we trained rats to step bipedally for 7 wk after paralysis and characterized the motor potentials evoked in the soleus and tibialis anterior (TA) muscles with the rats in a non-weight-bearing position, standing and stepping. The middle responses (MRs) to spinally evoked stimuli were suppressed with either or both drugs when the rat was suspended, whereas the addition of either or both drugs resulted in an overall activation of the extensor muscles during stepping and/or standing and reduced the drag duration and cocontraction between the TA and soleus muscles during stepping. The administration of quipazine and strychnine in concert with eEmc and step training after injury resulted in larger-amplitude evoked potentials [MRs and late responses (LRs)] in flexors and extensors, with the LRs consisting of a more normal bursting pattern, i.e., randomly generated action potentials within the bursts. This pattern was linked to more successful standing and stepping. Thus it appears that selected features of the patterns of potentials evoked in specific muscles with stimulation can serve as effective biomarkers and predictors of motor performance.

scholarly journals Neuromodulation of evoked muscle potentials induced by epidural spinal-cord stimulation in paralyzed individuals

2014 ◽  
Vol 111 (5) ◽  
pp. 1088-1099 ◽  
Author(s):  
Dimitry G. Sayenko ◽  
Claudia Angeli ◽  
Susan J. Harkema ◽  
V. Reggie Edgerton ◽  
Yury P. Gerasimenko
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Weight Bearing ◽  
Lower Limbs ◽  
Lumbar Spinal Cord ◽  
Wide Field ◽  
Electrode Arrays ◽  
Lumbosacral Spinal Cord ◽  
Spinal Circuitry ◽  
Cord Injury

Epidural stimulation (ES) of the lumbosacral spinal cord has been used to facilitate standing and voluntary movement after clinically motor-complete spinal-cord injury. It seems of importance to examine how the epidurally evoked potentials are modulated in the spinal circuitry and projected to various motor pools. We hypothesized that chronically implanted electrode arrays over the lumbosacral spinal cord can be used to assess functionally spinal circuitry linked to specific motor pools. The purpose of this study was to investigate the functional and topographic organization of compound evoked potentials induced by the stimulation. Three individuals with complete motor paralysis of the lower limbs participated in the study. The evoked potentials to epidural spinal stimulation were investigated after surgery in a supine position and in one participant, during both supine and standing, with body weight load of 60%. The stimulation was delivered with intensity from 0.5 to 10 V at a frequency of 2 Hz. Recruitment curves of evoked potentials in knee and ankle muscles were collected at three localized and two wide-field stimulation configurations. Epidural electrical stimulation of rostral and caudal areas of lumbar spinal cord resulted in a selective topographical recruitment of proximal and distal leg muscles, as revealed by both magnitude and thresholds of the evoked potentials. ES activated both afferent and efferent pathways. The components of neural pathways that can mediate motor-evoked potentials were highly dependent on the stimulation parameters and sensory conditions, suggesting a weight-bearing-induced reorganization of the spinal circuitries.

Motor Evoked Potentials

2016 ◽  
pp. 592-605
Author(s):  
Jeffrey A. Strommen ◽  
Andrea J. Boon
Keyword(s):  
Spinal Cord ◽  
Evoked Potentials ◽  
Magnetic Stimulation ◽  
Motor Evoked Potentials ◽  
Standard Of Care ◽  
Transcranial Electrical Stimulation ◽  
Pharmacological Agents ◽  
Physiological Variables ◽  
Stimulation Parameters ◽  
Cord Injury

Motor evoked potentials (MEP) may be used in the diagnosis of central and peripheral neurological disorders and have become the standard of care in many operative procedures as a means to monitor the motor pathways.In the awake patient, transcranial magnetic stimulation (TMS) can be utilized with surface or subcutaneous muscle recordings to identify central conduction abnormalities, as well as assist with prognosis, in conditions such as multiple sclerosis, stroke, spinal cord injury, Parkinson’s disease, hereditary spastic paraplegia, or ALS. In the operating theater, transcranial electrical stimulation with recording from the spinal cord, root, peripheral nerve, or muscle can be used to prevent spinal cord damage, determine continuity of roots or peripheral nerves, and assist with surgical planning. MEP are significantly affected by many physiological variables and pharmacological agents. Various techniques in regards to simulation sites, stimulation parameters, and recording techniques and sites need to be modified to enhance the reproducibility and reliability of these responses.

Multi-limb acquisition of motor evoked potentials and its application in spinal cord injury

2010 ◽  
Vol 193 (2) ◽  
pp. 210-216 ◽  
Author(s):  
Shrivats Iyer ◽  
Anil Maybhate ◽  
Alessandro Presacco ◽  
Angelo H. All
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Cord Injury

scholarly journals Treatment of chronic acromioclavicular joint dislocation in a paraplegic patient with the Weaver-Dunn procedure and a hook-plate

2016 ◽  
Vol 8 (2) ◽  
Author(s):  
Holger Godry ◽  
Mustafa Citak ◽  
Matthias Königshausen ◽  
Thomas A. Schildhauer ◽  
Dominik Seybold
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Weight Bearing ◽  
Full Range ◽  
Hook Plate ◽  
Acromioclavicular Joint Dislocation ◽  
Ac Joint ◽  
Joint Dislocation ◽  
Ac Joint Dislocation ◽  
Cord Injury

Abstract In case of patients with spinal cord injury and concomitant acromioclavicular (AC) jointdislocation the treatment is challenging, as in this special patient group the function of the shoulder joint is critical because patients depend on the upper limb for mobilization and wheelchair-locomotion. Therefore the goal of this study was to examine, if the treatment of chronic AC-joint dislocation using the Weaver- Dunn procedure augmented with a hook-plate in patients with a spinal cord injury makes early postoperative wheelchair mobilization and the wheelchair transfer with full weightbearing possible. In this case the Weaver- Dunn procedure with an additive hook-plate was performed in a 34-year-old male patient with a complete paraplegia and a posttraumatic chronic AC-joint dislocation. The patient was allowed to perform his wheelchair transfers with full weight bearing on the first postoperative day. The removal of the hook-plate was performed four months after implantation. At the time of follow-up the patient could use his operated shoulder with full range of motion without restrictions in his activities of daily living or his wheel-chair transfers.

Slope analysis of somatosensory evoked potentials in spinal cord injury for detecting contusion injury and focal demyelination

2010 ◽  
Vol 17 (9) ◽  
pp. 1159-1164 ◽  
Author(s):  
Gracee Agrawal ◽  
David Sherman ◽  
Anil Maybhate ◽  
Michael Gorelik ◽  
Douglas A. Kerr ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Evoked Potentials ◽  
Somatosensory Evoked Potentials ◽  
Slope Analysis ◽  
Cord Injury ◽  
Contusion Injury ◽  
Focal Demyelination

scholarly journals Segmental analysis in cervical spinal cord injury reveals the recovery potential of hand muscles with preserved corticospinal tract: Insights beyond impairment scales

2021 ◽  
Author(s):  
Gustavo Balbinot ◽  
Guijin Li ◽  
Sukhvinder Kalsi-Ryan ◽  
Rainer Abel ◽  
Doris Maier ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Muscle Strength ◽  
Evoked Potentials ◽  
Corticospinal Tract ◽  
Cervical Spinal Cord ◽  
Hand Muscles ◽  
Recovery Potential ◽  
Strength Recovery ◽  
Cord Injury

Cervical spinal cord injury (SCI) severely impacts widespread bodily functions with extensive impairments for individuals, who prioritize regaining hand function. Although prior work has focused on the recovery at the person-level, the factors determining the recovery potential of individual muscles are poorly understood. There is a need for changing this paradigm in the field by moving beyond person-level classification of residual strength and sacral sparing to a muscle-specific analysis with a focus on the role of corticospinal tract (CST) sparing. The most striking part of human evolution involved the development of dextrous hand use with a respective expansion of the sensorimotor cortex controlling hand movements, which, because of the extensive CST projections, may constitute a drawback after SCI. Here, we investigated the muscle-specific natural recovery after cervical SCI in 748 patients from the European Multicenter Study about SCI (EMSCI), one of the largest datasets analysed to date. All participants were assessed within the first 4 weeks after SCI and re-assessed at 12, 24, and 48 weeks. Subsets of individuals underwent electrophysiological multimodal evaluations to discern CST and lower motor neuron (LMN) integrity [motor evoked potentials (MEP): N = 203; somatosensory evoked potentials (SSEP): N = 313; nerve conduction studies (NCS): N = 280]. We show the first evidence of the importance of CST sparing for proportional recovery in SCI, which is known in stroke survivors to represent the biological limits of structural and functional plasticity. In AIS D, baseline strength is a good predictor of segmental muscle strength recovery, while the proportionality in relation to baseline strength is lower for AIS B/C and breaks for AIS A. More severely impaired individuals showed non-linear and more variable recovery profiles, especially for hand muscles, while measures of CST sparing (by means of MEP) improved the prediction of hand muscle strength recovery. Therefore, assessment strategies for muscle-specific motor recovery in acute SCI improve by accounting for CST sparing and complement gross person-level predictions. The latter is of paramount importance for clinical trial outcomes and to target neurorehabilitation of upper limb function, where any single muscle function impacts the outcome of independence in cervical SCI.

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