CAJ | 학술논문

目的建立新型大鼠脊髓慢性压迫模型,进一步探讨体感诱发电位(somatosensory evoked potential,SEP)对慢性压迫性脊髓症的诊断价值及其对应的病理生理改变.方法 15只大鼠经后路手术于颈椎管内植入吸水性聚氨酯胶片,植入体内会逐渐吸水胀大,形成对脊髓的慢性持续压迫.术后6个月,对慢性压迫脊髓进行SEP、影像学、组织学和组织化学检测.结果 15只造模大鼠脊髓均出现侧后方明显压迫性形态学改变,微焦点计算机断层扫描显示脊髓灰质和白质扭曲变形.9只表现为潜伏期延长和(或)波幅F降等SEP异常,SEP反应分为Ⅰ型6只、Ⅱa型5只、Ⅱ b型2只、Ⅲ型2只.正常和异常SEP的脊髓压迫率差异无统计学意义(P>0.05).SEP反应异常的大鼠与反应正常者脊髓的组织学、组织化学比较,脊髓后索髓鞘染色显著减少(Ⅱ a:106±12,Ⅰ:121±8,P=0.038),脊髓后索的对比剂密度差异有统计学意义(Ⅱ a:95±5,Ⅰ:87±6,P=0.042),而且后角内神经元也明显较少[Ⅱ a:(25±8)/mm~2,Ⅰ:(29± 6)/mm~2 P>0.05];Ⅱ b型和Ⅲ型不仅脊髓后索髓鞘着色减少,灰质后角神经元密度只有(16±5)/mm~2和(14±5)/mm~2;均出现基质海绵样变和静脉扩张.结论在慢性压迫性脊髓症发展过程中,SEP出现异常迟于形态学改变,但是反映了脊髓后索和后角神经元损伤的严重程度.为深入研究脊髓型颈椎病的病理生理机制和疗效评估提供了良好的动物模型.
목적 건립신형대서척수만성압박모형,진일보탐토체감유발전위(somatosensory evoked potential,SEP)대만성압박성척수증적진단개치급기대응적병리생리개변.방법 15지대서경후로수술우경추관내식입흡수성취안지효편,식입체내회축점흡수창대,형성대척수적만성지속압박.술후6개월,대만성압박척수진행SEP、영상학、조직학화조직화학검측.결과 15지조모대서척수균출현측후방명현압박성형태학개변,미초점계산궤단층소묘현시척수회질화백질뉴곡변형.9지표현위잠복기연장화(혹)파폭F강등SEP이상,SEP반응분위Ⅰ형6지、Ⅱa형5지、Ⅱ b형2지、Ⅲ형2지.정상화이상SEP적척수압박솔차이무통계학의의(P>0.05).SEP반응이상적대서여반응정상자척수적조직학、조직화학비교,척수후색수초염색현저감소(Ⅱ a:106±12,Ⅰ:121±8,P=0.038),척수후색적대비제밀도차이유통계학의의(Ⅱ a:95±5,Ⅰ:87±6,P=0.042),이차후각내신경원야명현교소[Ⅱ a:(25±8)/mm~2,Ⅰ:(29± 6)/mm~2 P>0.05];Ⅱ b형화Ⅲ형불부척수후색수초착색감소,회질후각신경원밀도지유(16±5)/mm~2화(14±5)/mm~2;균출현기질해면양변화정맥확장.결론 재만성압박성척수증발전과정중,SEP출현이상지우형태학개변,단시반영료척수후색화후각신경원손상적엄중정도.위심입연구척수형경추병적병리생리궤제화료효평고제공료량호적동물모형.
Objective To explore the pathophysiological changes behind somatosensory evoked po-tential (SEP) defect and its diagnostic value in an established model of spinal cord chronic compression. Methods Total 15 rats were operated with implantation of a water-absorbing polymer sheet in cervical spinal canal, which expanded gradually to induce chronic compression to the spinal cord. At 6 months after surgery, SEP, radioiogical and pathohistological/istochemistry evaluations were done. Results Spinal cord in 15 rats showed significant morphological compressed deformity after chronic compression. It was also characterized by higher contrast intensity and distortion of gray matter and whiter matter under micro-CT e-valuations. SEP revealed that nine rats had prolonged latency and/or decreased amplitude. Based on their different SEP response, they were categorized into: type Ⅰ (n=6), type Ⅱa (n=5), type Ⅱb (n=2), type Ⅲ (n=2), and type Ⅳ (n=0). Compression ratio was not different between normal and abnormal SEP responses in the rats. Compared with the rats with normal SEP responses, the spinal cord of rats with normal SEP responses showed less myelin staining in white matter(Ⅱa: 106±12 vs.Ⅰ: 121±8; P=0.038), less contrast medium density in posterior dorsal column (Ⅱa: 95±5 vs. Ⅰ: 87±6; P=0.042), lower neuron density and cavitation in gray mat-ter[Ⅱa: (25±8)/mm~2 vs. Ⅰ: (29±6)/mm~2, P>0.05]. Less myelin staining in posterior column whiter matter could be seen in type Ⅱb and Ⅲ. Neuron density in posterior horn of gray matter were (16±5)/mm~2 and (14± 5)/mm~2 respectively. Histological cystic cavitations and sinusoidal dilation of veins were noted in spinal cord with significant distortion after compression. Conclusion SEP responses reflected the severity of spinal cord posterior tract and horn damage in chronic compressive injuries after gross appearance changes.