Hu Junda, Tu Yiji, Ding Zuoyou, Chen Zenggan, Dellon A Lee, Lineaweaver William C, Zhang Feng
Department of Orthopedics, Zhongshan Hospital, Fudan University, Shanghai, China.
Department of Plastic Surgery, Johns Hopkins University, Baltimore, MD.
Ann Plast Surg. 2018 Dec;81(6):682-687. doi: 10.1097/SAP.0000000000001646.
Diabetic rats are more sensitive to nerve entrapment. This study was conducted to evaluate nerve function and histological changes in diabetic rats after nerve compression and subsequent decompression.
A total of 35 Wistar rats were included. The experimental group was divided into diabetic sciatic nerve compression group (DSNC, n = 5) and diabetic sciatic nerve decompression group (DSND, n = 20). The DSNC model was created by wrapping a silicone tube circumferentially around the nerve for 4 weeks, and then the DSND group accepted nerve decompression and was followed up to 12 weeks. The DSND group was equally divided into DSND 3 weeks (DSND3), 6 weeks (DSND6), 9 weeks (DSND9), and 12 weeks (DSND12) groups. Five rats were taken as normoglycemic control group (CR, n = 5), and another 5 rats as diabetic control group (DM, n = 5). The mechanical hyperalgesia of rats was detected by Semmes-Weinstein nylon monofilaments (SWMs) and by motor nerve conduction velocity (MNCV). These 2 physiological indicators and histology of sciatic nerves were compared among different groups.
The SWM measurements improved toward normal values after decompression. The SWM value was significantly lower (more normal) in the DSNC groups than in the DSND group (P < 0.05). The MNCV was 53.7 ± 0.8 m/s in the CR group, whereas it was 28.4 ± 1.0 m/s in the DSNC group (P < 0.001). Six weeks after decompression, the MNCV was significantly faster than that in the DSNC group (P < 0.001). Histological examination demonstrated chronic nerve compression, which responded toward normal after decompression, but with degree of myelination never recovering to normal.
Chronic compression of the diabetic sciatic nerve has measureable negative effects on sciatic nerve motor nerve function, associated with a decline of touch/pressure threshold and degeneration of myelin sheath and axon. Nerve decompression surgery can reverse these effects and partially restore nerve function.
糖尿病大鼠对神经压迫更为敏感。本研究旨在评估糖尿病大鼠神经受压及随后减压后的神经功能和组织学变化。
共纳入35只Wistar大鼠。实验组分为糖尿病坐骨神经压迫组（DSNC，n = 5）和糖尿病坐骨神经减压组（DSND，n = 20）。DSNC模型通过用硅胶管环绕神经4周建立，然后DSND组接受神经减压并随访至12周。DSND组又平均分为DSND 3周（DSND3）、6周（DSND6）、9周（DSND9）和12周（DSND12）组。选取5只大鼠作为血糖正常对照组（CR，n = 5），另5只大鼠作为糖尿病对照组（DM，n = 5）。通过Semmes-Weinstein尼龙单丝（SWMs）和运动神经传导速度（MNCV）检测大鼠的机械性痛觉过敏。比较不同组间这两项生理指标及坐骨神经的组织学情况。
减压后SWM测量值向正常值改善。DSNC组的SWM值显著低于DSND组（更接近正常）（P < 0.05）。CR组的MNCV为53.7 ± 0.8 m/s，而DSNC组为28.4 ± 1.0 m/s（P < 0.001）。减压6周后，MNCV显著快于DSNC组（P < 0.001）。组织学检查显示存在慢性神经压迫，减压后有向正常转变的趋势，但髓鞘化程度从未恢复到正常水平。
糖尿病坐骨神经的慢性压迫对坐骨神经运动神经功能有可测量的负面影响，伴有触觉/压力阈值下降以及髓鞘和轴突退变。神经减压手术可逆转这些影响并部分恢复神经功能。
