Electrophysiological evaluation of sensory and motor pathways after incomplete unilateral spinal cord contusion Laboratory investigation
Electrophysiological evaluation of sensory and motor pathways after incomplete unilateral spinal cord contusion Laboratory investigation
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DOI：
10.3171/2012.1.spine11684
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发表时间：
2012-04-01
影响因子：
2.8
通讯作者：
All, Angelo H.
中科院分区：
文献类型：
--
作者：
Bazley, Faith A.;Hu, Charles;All, Angelo H.
对象。单侧挫伤是研究脊髓损伤通路和恢复机制的一种日益流行的模型。目前的研究严重依赖于运动行为评分和组织学证据来进行评估。电生理学是一种可靠地量化运动通路功能的方法。作者试图通过测量运动和体感诱发电位（分别为MEPs和ssep）来量化单侧脊髓损伤后双侧运动和感觉通路的功能完整性。18只大鼠随机分为3组，分别为轻度单侧挫伤、轻度中线挫伤和仅行椎板切除术（对照组）。使用MASCIS撞击器在T-8处诱导挫伤。然后进行电生理分析、运动行为评分和组织学定量分析，以确定通路电导率、运动功能和组织保存之间的关系。损伤同侧后肢MEPs在损伤后28天恢复，约有61%的皮质脊髓束（CST）组织保留。相比之下，中线损伤组的MEPs没有恢复，相应的，约有90%的CST组织受损。体感诱发电位仅显示出中度幅度的降低，损伤同侧通路的潜伏期没有差异。此外，在相同程度的白质损伤情况下，这些ssep明显优于中线损伤大鼠。在单侧和中线损伤中，运动诱发电位的恢复与CST的剩余量相关，但运动行为的恢复与MEPs无关。这些数据支持了保留对侧神经通路有助于减少损伤的同侧神经通路功能缺陷的观点，并进一步支持了中枢神经系统可塑性的观点。(http: / / thejns.org/doi/abs/10.3171/2012.1.SPINE11684)
Object. Unilateral contusions represent an increasingly popular model for studying the pathways and recovery mechanisms of spinal cord injury (SCI). Current studies rely heavily on motor behavior scoring and histological evidence to make assessments. Electrophysiology represents one way to reliably quantify the functionality of motor pathways. The authors sought to quantify the functional integrity of the bilateral motor and sensory pathways following unilateral SCI by using measurements of motor and somatosensory evoked potentials (MEPs and SSEPs, respectively).Methods. Eighteen rats were randomly divided into 3 groups receiving a mild unilateral contusion, a mild midline contusion, or a laminectomy only (control). Contusions were induced at T-8 using a MASCIS impactor. Electrophysiological analysis, motor behavior scoring, and histological quantifications were then performed to identify relationships among pathway conductivity, motor function, and tissue preservation.Results. Hindlimb MEPs ipsilateral to the injury showed recovery by Day 28 after injury and corresponded to approximately 61% of spared corticospinal tract (CST) tissue. In contrast, MEPs of the midline-injured group did not recover, and correspondingly >90% of the CST tissue was damaged. Somatosensory evoked potentials showed only a moderate reduction in amplitude, with no difference in latency for the pathways ipsilateral to injury. Furthermore, these SSEPs were significantly better than those of the midline-injured rats for the same amount of white matter damage.Conclusions. Motor evoked potential recovery corresponded to the amount of spared CST in unilateral and midline injuries, but motor behavior consistently recovered independent of MEPs. These data support the idea that spared contralateral pathways aid in reducing the functional deficits of injured ipsilateral pathways and further support the ides of CNS plasticity. (http ://thejns.org/doi/abs/10.3171/2012.1.SPINE11684)