动态体感诱发电位评估脊髓型颈椎病手术干预时机的病理机理

Cervical spondylotic myelopathy (CSM) is a degenerative spinal disorder, which is commonly found in elderly population. It may induce severe and irreversible spinal cord functional deficit. The pathological progress of CSM is variable and concealed, with variable and difficult prognosis of surgical treatment. It is a lack of reliable objective and precise assessment to help the treatment decision making and to predict the timing of surgical intervention. Currently, there is no researches on the point of no return to indicate the pathological process from reversible stage to irreversible stage. In particular, there is no any physiological test can indicate the pathological process. This project employs chronic cervical cord compression goat model using balloon. The compression is produced by controlled injection to expand balloon volume, confirmed by MRI. New measurement of dynamic somatosensory evoked potentials (SEP), in terms of trial-to-trial SEP variability of latency, will be investigated along the progress after compression. With the changes in SEP, histology study is to observe the pathological changes. The compression balloon can be deflated to simulate the decompression procedure. This is to evaluate the usefulness of SEP latency variability criterion for indicating the irreversible spinal cord injury during chronic compression. The result can provide a new indication of surgical intervention. This research is to explore the pathological mechanism behind the change in SEP dynamic properties along with chronic spinal cord degeneration, which provide a fundamental basis for using SEP as an indication of CSM surgery.

脊髓型颈椎病是一种退化性脊柱疾病，是老年人群的一种常见病，可能造成严重的脊髓功能不可逆损害。脊髓型颈椎病的病理进程具有多样性和隐匿性，治疗预后变异性大，难于预测，临床治疗方案以及手术时机的选择缺乏可靠、客观、准确的评估指标。目前，尚不清楚慢性压迫下脊髓神经病理发展到什么程度是可逆性向不可逆转变的“转折点”，特别是缺乏判断这种病理过程的生理指标。本课题将对山羊颈椎植入硅胶球囊制造慢性脊髓压迫的动物模型，通过MRI监控下控制球囊体积的充盈来模拟慢性压迫，探究新型的基于动态体感诱发电位潜伏期变异率的随病理进程的变化规律，结合组织学检查脊髓病理变化。以球囊缩瘪模拟神经减压，研究慢性压迫后脊髓损伤达到不可逆的诱发电位潜伏期变异率临界域值，成为选择手术干预的新指征。本研究将揭示慢性脊髓功能退变后体感诱发电位动态变化规律的病理机理，为脊髓型颈椎病的诱发电位手术指征提供理论基础。

脊髓型颈椎病（CSM）的病理进程复杂，其手术时机选择存在较大争议。体感诱发电位（SEP）可反映颈髓感觉传导束的病理变化，但传统SEP测量采用平均叠加方法，丧失动态信息。本项目基于单次SEP潜伏期变异率分析技术，建立山羊和大鼠CSM动物模型，研究SEP潜伏期变异率与CSM病理进程的相关性，及其病理生理学意义，以模拟手术减压，寻找不可逆神经损伤的SEP指征。研究提出并验证了SEP潜伏期变异率与脊髓脱髓鞘病理状态的直接相关性，创新性地提出SEP潜伏期变异率作为在体颈髓脱髓鞘程度的特异指征。对轻度CSM，SEP潜伏期变异率随CSM病理发展而逐渐增高，对重度CSM，出现SEP消失、潜伏期变异率不可测。不可逆神经损伤没有在轻中度CSM模型中出现，说明SEP消失或潜伏期变异率不可测是不可逆神经损伤的SEP特征。另外，SEP时频分析可准确判定脊髓压迫的损伤病灶，可成为为多节段CSM的精准诊断新方法。我们还建立了CSM评估临床研究平台, 为转化医学研究打下基础。总之，单次SEP潜伏期变异率新技术，为在体研究脊髓脱髓鞘病变提供了新方法，可用于临床中脊髓病的早期诊断，有助于临床治疗方案的选择。