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.

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.

Objective assessment of cervical spinal cord injury levels by transcranial magnetic motor-evoked potentials

2006 ◽  
Vol 66 (5) ◽  
pp. 475-483 ◽  
Author(s):  
Christopher B. Shields ◽  
Yi Ping Zhang ◽  
Lisa B.E. Shields ◽  
Darlene A. Burke ◽  
Steven D. Glassman
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Evoked Potentials ◽  
Motor Evoked Potentials ◽  
Cervical Spinal Cord ◽  
Objective Assessment ◽  
Cervical Spinal Cord Injury ◽  
Cord Injury

scholarly journals Improvement of Tetraplegia and Respiratory Symptoms with Complex Korean Medicine Treatment After Traumatic Cervical Spinal Cord Injury: A Case Report

2020 ◽  
Vol 37 (4) ◽  
pp. 275-280
Author(s):  
Eunbyul Cho ◽  
Hyeonjun Woo ◽  
Nam geun Cho
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Muscle Strength ◽  
Barthel Index ◽  
Respiratory Symptoms ◽  
Cervical Spinal Cord ◽  
Cervical Spinal Cord Injury ◽  
Korean Medicine ◽  
Independent Measure ◽  
Cord Injury

This study reports the effectiveness of traditional Korean medicine in treating tetraplegia and respiratory symptoms (including dyspnea) after traumatic cervical spinal cord injury surgery. The patient was treated with complex Korean medical treatment including electroacupuncture, pharmacopuncture, and herbal medicine. The manual muscle test (expanded Medical Research Council system) was used to measure the patient’s muscle strength. The Korean version of the modified Barthel index and the functional independent measure were used to evaluate the patient’s independence in performing daily activities. Following 2 hospitalizations and treatments, the patient’s muscle strength improved > 4+ score for all joints, and the Korean version of the modified Barthel index and functional independent measure scores increased from 26 to 79 and 56 to 95, respectively. Symptoms of dyspnea, coughing, and sputum gradually improved and finally disappeared during hospitalization. This study suggests complex Korean medicine treatment may be effective in the rehabilitation of post-surgical cervical spinal cord injury patients.

scholarly journals Wallerian degeneration in cervical spinal cord tracts is commonly seen in routine T2-weighted MRI after traumatic spinal cord injury and is associated with impairment in a retrospective study

2020 ◽  
Author(s):  
Tim Fischer ◽  
Christoph Stern ◽  
Patrick Freund ◽  
Martin Schubert ◽  
Reto Sutter
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Wallerian Degeneration ◽  
Evoked Potential ◽  
Corticospinal Tract ◽  
Cervical Spinal Cord ◽  
Dorsal Column ◽  
Traumatic Spinal Cord Injury ◽  
Spinothalamic Tract ◽  
Cord Injury

Abstract Objectives Wallerian degeneration (WD) is a well-known process after nerve injury. In this study, occurrence of remote intramedullary signal changes, consistent with WD, and its correlation with clinical and neurophysiological impairment were assessed after traumatic spinal cord injury (tSCI). Methods In 35 patients with tSCI, WD was evaluated by two radiologists on T2-weighted images of serial routine MRI examinations of the cervical spine. Dorsal column (DC), lateral corticospinal tract (CS), and lateral spinothalamic tract (ST) were the analyzed anatomical regions. Impairment scoring according to the American Spinal Injury Association Impairment Scale (AIS, A–D) as well as a scoring system (0–4 points) for motor evoked potential (MEP) and sensory evoked potential (SEP) was included. Mann-Whitney U test was used to test for differences. Results WD in the DC occurred in 71.4% (n = 25), in the CS in 57.1% (n = 20), and in 37.1% (n = 13) in the ST. With WD present, AIS grades were worse for all tracts. DC: median AIS B vs D, p < 0.001; CS: B vs D, p = 0.016; and ST: B vs D, p = 0.015. More pathological MEP scores correlated with WD in the DC (median score 0 vs 3, p < 0.001) and in the CS (0 vs 2, p = 0.032). SEP scores were lower with WD in the DC only (1 vs 2, p = 0.031). Conclusions WD can be detected on T2-weighted scans in the majority of cervical spinal cord injury patients and should be considered as a direct effect of the trauma. When observed, it is associated with higher degree of impairment. Key Points • Wallerian degeneration is commonly seen in routine MRI after traumatic spinal cord injury. • Wallerian degeneration is visible in the anatomical regions of the dorsal column, the lateral corticospinal tract, and the lateral spinothalamic tract. • Presence of Wallerian degeneration is associated with higher degree of impairment.

scholarly journals Trihydroxyethyl Rutin Provides Neuroprotection in Rats With Cervical Spinal Cord Hemi-Contusion

2021 ◽  
Vol 15 ◽  
Author(s):  
Yapu Liu ◽  
Qi Liu ◽  
Zhou Yang ◽  
Rong Li ◽  
Zhiping Huang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Evoked Potentials ◽  
Grip Strength ◽  
Cervical Spinal Cord ◽  
Microvascular Density ◽  
Post Injury ◽  
Neuroprotective Effects ◽  
Injury Group ◽  
Cord Injury

Objective: To investigate the neuroprotective effects of trihydroxyethyl rutin in rats with cervical spinal cord hemi-contusion.Methods: Adult male Sprague–Dawley rats were subjected to hemi-contusion at a stroke depth of 1.2 mm, and then intraperitoneally injected with 50 or 100 mg/kg trihydroxyethyl rutin per day for 12 weeks (T50 and T100 groups, respectively). Changes in somatosensory evoked potentials (SEPs), motor evoked potentials (MEPs), and behavior were continuously monitored. At 12 weeks post-injury, immunohistochemical staining was performed to assess changes in cervical spinal cord microvascular morphology. Magnetic resonance imaging (MRI) scans were performed to examine end-stage injury in the cervical spinal cord, and Eriochrome cyanine-stained slices of spinal cord tissue were evaluated for injury.Results: There were no significant differences in biomechanical parameters among the spinal cord injury, T50 and T100 rat groups. At 3 days-post-injury, there was a significant decrease in grip strength. At 12 weeks post-injury, grip strength recovery was significantly better in the T50 and T100 groups than in the injury group. Compared with the injury group, the total limb placement frequency was significantly higher in the T50 group at 2, 4, 6, 10, and 12 weeks post-injury and in the T100 group at 2, 6, 8, and 10 weeks post-injury. Ipsilateral SEPs and MEPs were dynamic, increasing in latency and decreasing in amplitude in the injury compared with sham group. MRI scanning demonstrated that the coronal, sagittal, and transversal lesion areas were smaller in the T50 and T100 groups than in the injury group. Microvascular density showed a greater reduction in the injury group compared with the T50 and T100 groups. Eriochrome cyanine staining showed that the ipsilateral side, residual parenchyma, and gray matter areas were larger in the T50 and T100 groups than in the injury group.Conclusion: Trihydroxyethyl rutin exhibits robust neuroprotective effects, improving limb motor function and nerve electrophysiological parameters after spinal cord injury, maintaining microvascular density, and reducing the area of injury and degree of demyelination.

scholarly journals Motor unit number index detects the effectiveness of surgical treatment in improving distal motor neuron loss in patients with incomplete cervical spinal cord injury

2020 ◽  
Author(s):  
Jun Li ◽  
Yancheng Zhu ◽  
Yang Li ◽  
ShiSheng He ◽  
Deguo Wang
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Surgical Treatment ◽  
Muscle Strength ◽  
Motor Neurons ◽  
Surgical Intervention ◽  
Cervical Spinal Cord ◽  
Injury Site ◽  
Cord Injury ◽  
Motor Neuron Loss

Abstract Background Recovery of motor dysfunction is important for patients with incomplete cervical spinal cord injury (SCI). To enhance the recovery of muscle strength, both research and treatments mainly focus on injury of upper motor neurons at the direct injury site. However, accumulating evidences have suggested that SCI has a downstream effect on the peripheral nervous system, which may contribute to the poor improvement of the muscle strength after operation. The aim of this study is to investigate the impact of early vs. delayed surgical intervention on the lower motor neurons (LMNs) distal to the injury site in patients with incomplete cervical SCI. Methods Motor unit number index (MUNIX) was performed on the tibialis anterior (TA), extensor digitorum brevis (EDB) and abductor hallucis (AH) in 47 patients with incomplete cervical SCI (early vs. delayed surgical-treatment: 17 vs. 30) and 34 healthy subjects approximately 12 months after operation. All patients were further assessed by American spinal injury association (ASIA) motor scales and Medical Research Council (MRC) scales. Results There are no difference of both ASIA motor scores and MRC scales between the patients who accepted early and delayed surgical treatment (P > 0.05). In contrast, the patients undergoing early surgical treatment showed lower MUSIX values in both bilateral EDB and bilateral TA, along with greater MUNIX values in both right-side EDB and right-side TA, compared to the patients who accepted delayed surgical treatment (P < 0.05). Conclusions Cervical SCI has a negative effect on the LMNs distal to the injury site. Early surgical intervention in Cervical SCI patients may improve the dysfunction of LMNs distal to the injury site, reducing secondary motor neuron loss, and eventually improving clinical prognosis.

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