Department of Orthopedic Surgery, The First Affiliated Hospital of Chongqing Medical University, No.1 Youyi Road, Yuzhong District, Chongqing 400016, China; Department of Orthopaedics, The Affiliated Hospital of Southwest Medical University, No.25 Taiping Street, Jiangyang District, Sichuan 646000, China; Orthopedic Laboratory of Chongqing Medical University, No.1 Youyi Road, Yuzhong District, Chongqing 400016, China.
Department of Orthopedic Surgery, The First Affiliated Hospital of Chongqing Medical University, No.1 Youyi Road, Yuzhong District, Chongqing 400016, China; Orthopedic Laboratory of Chongqing Medical University, No.1 Youyi Road, Yuzhong District, Chongqing 400016, China; Department of Orthopaedic Trauma, Chongqing General Hospital, No.118 Xingguang Avenue, Liangjiang New District, Chongqing 40114, China.
Exp Neurol. 2022 Nov;357:114206. doi: 10.1016/j.expneurol.2022.114206. Epub 2022 Aug 19.
Elevated intraspinal pressure (ISP) following traumatic spinal cord injury (tSCI) can be an important factor for secondary SCI that may result in greater tissue damage and functional deficits. Our present study aimed to investigate the dynamic changes in ISP after different degrees of acute compression SCI in rabbits with closed canals and explore its influence on spinal cord pathophysiology. Closed balloon compression injuries were induced with different inflated volumes (40 μl, 50 μl or no inflation) at the T7/8 level in rabbits. ISP was monitored by a SOPHYSA probe at the epicenter within 7 days post-SCI. Edema progression, spinal cord perfusion and damage severity were evaluated by serial multisequence MRI scans, somatosensory evoked potentials (SEPs) and behavioral scores. Histological and blood spinal cord barrier (BSCB) permeability results were subsequently analyzed. The results showed that the ISP waveforms comprised three peaks, significantly increased after tSCI, peaked at 72 h (21.86 ± 3.13 mmHg) in the moderate group or 48 h (31.71 ± 6.02 mmHg) in the severe group and exhibited "slow elevated and fast decreased" or "fast elevated and slow decreased" dynamic changes in both injured groups. Elevated ISP after injury was correlated with spinal cord perfusion and edema progression, leading to secondary lesion enlargement. The secondary damage aggravation can be visualized by diffusion tensor tractography (DTT). Moreover, the BSCB permeability was significantly increased at the epicenter and rostrocaudal segments at 72 h after SCI; by 14 days, notable permeability was still observed at the caudal segment in the severely injured rabbits. Our results suggest that the ISP of rabbits with closed canals increased after acute compression SCI and exhibited different dynamic change patterns in moderately and severely injured rabbits. Elevated ISP exacerbated spinal cord perfusion, drove edema progression and led to secondary lesion enlargement that was strongly associated with BSCB disruption. For severe tSCI, early intervention targeting elevated ISP may be an indispensable choice to rescue spinal cord function.
脊髓损伤（SCI）后椎管内压力升高（ISP）可能是继发性 SCI 的一个重要因素，可导致更严重的组织损伤和功能障碍。本研究旨在探讨闭合性椎管内 SCI 后不同程度急性压迫伤兔 ISP 的动态变化，并探讨其对脊髓病理生理学的影响。在兔 T7/8 水平用不同膨胀体积（40 μl、50 μl 或不膨胀）诱导封闭球囊压迫伤。通过 SOPHYSA 探头在 SCI 后 7 天内于损伤中心监测 ISP。通过连续多序列 MRI 扫描、体感诱发电位（SEP）和行为评分评估水肿进展、脊髓灌注和损伤严重程度。随后分析组织学和血脊髓屏障（BSCB）通透性结果。结果显示，ISP 波形包括三个峰值，tSCI 后明显升高，中度组在 72 h（21.86±3.13 mmHg）或重度组在 48 h（31.71±6.02 mmHg）达峰值，伤后两组均呈“慢升快降”或“快升慢降”的动态变化。损伤后 ISP 升高与脊髓灌注和水肿进展相关，导致继发性损伤扩大。弥散张量轨迹（DTT）可观察到继发性损伤加重。此外，SCI 后 72 h 损伤中心和头尾部节段的 BSCB 通透性显著增加；14 天时，严重损伤兔的尾部仍有明显的通透性。我们的结果表明，兔闭合性椎管内 SCI 后 ISP 升高，中度和重度损伤兔 ISP 呈不同的动态变化模式。ISP 升高加重脊髓灌注，驱动水肿进展，导致继发性损伤扩大，与 BSCB 破坏密切相关。对于严重的 tSCI，针对升高的 ISP 进行早期干预可能是挽救脊髓功能不可或缺的选择。
