Department of Pain Medicine, The Second Affiliated Hospital of Guangzhou Medical University.
Department of Anesthesiology, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong Province.
Neuroreport. 2023 Oct 4;34(14):720-727. doi: 10.1097/WNR.0000000000001946. Epub 2023 Aug 14.
An injury of the peripheral nerve may lead to neuropathic pain, which could be treated with pulsed radiofrequency to the dorsal root ganglion (DRG) or peripheral nerve [the nerve trunk (NT) or proximal to the injury site (NI)]. However, it is not clear whether there is any difference in analgesic effect or maintenance among the three targets. PRF was applied to the ipsilateral L5 DRG, peripheral nerve (NT or NI) 5 days after spared nerve injury (SNI). Triptolide (10 µg/kg) or vehicle was intrathecally administered 5 days after SNI for 3 days. Mechanical withdrawal thresholds were tested after treatment at different time points. Furthermore, microglia and the P2X7 receptor (P2X7R) in the ipsilateral spinal cord were measured with immunofluorescence and western blotting, respectively. PRF + NI exerted a more remarkable analgesic effect than PRF + DRG and PRF + NT at the early stage, but PRF + DRG had a stronger analgesic effect than PRF + NI and PRF + NT at the end of our study. In addition, PRF + DRG showed no significant difference from intrathecal administration of triptolide. Moreover, SNI-induced microglia activation and upregulation of P2X7R in spinal dorsal horn could be markedly inhibited by PRF + DRG. The results suggest that the analgesic effect of PRF + DRG increased with time whereas the other two not and microglia and P2X7R in the ipsilateral spinal dorsal horn may be involved in the process.
外周神经损伤可导致神经病理性疼痛，可采用脉冲射频治疗背根神经节（DRG）或外周神经[神经干（NT）或损伤部位近端（NI）]。然而，尚不清楚这三个靶点的镇痛效果或维持时间是否存在差异。在 spared nerve injury（SNI）后 5 天，对同侧 L5 DRG、外周神经（NT 或 NI）施加 PRF。在 SNI 后 5 天，鞘内给予雷公藤内酯醇（10μg/kg）或载体 3 天。在不同时间点治疗后测试机械性撤回阈值。此外，通过免疫荧光和 Western blot 分别测量同侧脊髓中的小胶质细胞和 P2X7 受体（P2X7R）。PRF + NI 在早期比 PRF + DRG 和 PRF + NT 产生更显著的镇痛效果，但在研究结束时，PRF + DRG 比 PRF + NI 和 PRF + NT 具有更强的镇痛效果。此外，PRF + DRG 与鞘内给予雷公藤内酯醇无显著差异。此外，SNI 诱导的小胶质细胞活化和脊髓背角 P2X7R 的上调可被 PRF + DRG 明显抑制。结果表明，PRF + DRG 的镇痛效果随时间增加，而其他两种则不然，同侧脊髓背角的小胶质细胞和 P2X7R 可能参与了这一过程。
