Managing chronic neuropathic pain: the role of spinal cord stimulation

Epidural electrical stimulation effectively restores locomotion function in rats with complete spinal cord injury

Epidural electrical stimulation can restore limb motor function after spinal cord injury by reactivating the surviving neural circuits. In previous epidural electrical stimulation studies, single electrode sites and continuous tetanic stimulation have often been used. With this stimulation, the body is prone to declines in tolerance and locomotion coordination. In the present study, rat models of complete spinal cord injury were established by vertically cutting the spinal cord at the T8 level to eliminate disturbance from residual nerve fibers, and were then subjected to epidural electrical stimulation. The flexible extradural electrode had good anatomical topology and matched the shape of the spinal canal of the implanted segment. Simultaneously, the electrode stimulation site was able to be accurately applied to the L2–3 and S1 segments of the spinal cord. To evaluate the biocompatibility of the implanted epidural electrical stimulation electrodes, GFAP/Iba-1 double-labeled immunofluorescence staining was performed on the spinal cord below the electrodes at 7 days after the electrode implantation. Immunofluorescence results revealed no significant differences in the numbers or morphologies of microglia and astrocytes in the spinal cord after electrode implantation, and there was no activated Iba-1⁺ cell aggregation, indicating that the implant did not cause an inflammatory response in the spinal cord. Rat gait analysis showed that, at 3 days after surgery, gait became coordinated in rats with spinal cord injury under burst stimulation. The regained locomotion could clearly distinguish the support phase and the swing phase and dynamically adjust with the frequency of stimulus distribution. To evaluate the matching degree between the flexible epidural electrode (including three stimulation contacts), vertebral morphology, and the level of the epidural site of the stimulation electrode, micro-CT was used to scan the thoracolumbar vertebrae of rats before and after electrode implantation. Based on the experimental results of gait recovery using three-site stimulation electrodes at L2–3 and S1 combined with burst stimulation in a rat model of spinal cord injury, epidural electrical stimulation is a promising protocol that needs to be further explored. This study was approved by the Animal Ethics Committee of Chinese PLA General Hospital (approval No. 2019-X15-39) on April 19, 2019.

Experiences with spinal cord stimulator in patients with chronic neuropathic back pain

Neuropathic pain is a complex, chronic, and disabling condition that has physical, functional, and psychosocial repercussions. Although the estimated prevalence of neuropathic pain in the general population ranges from 1.5% to 8%, neuropathic pain is frequently underdiagnosed and undertreated. The aims of this study were to examine the experience of patients treated with spinal cord stimulation as a pain-relieving treatment and how this may influence the patient's ability to participate in everyday life activities. A qualitative approach based on seven telephone interviews was performed. The participants were recruited from a university hospital in Norway, and all used spinal cord stimulation as a pain-relieving treatment. Qualitative content analysis was used. Two thematic findings emerged: (1) pain relief with spinal cord stimulation as a complex and individual experience and (2) challenges in adaptations in everyday life with spinal cord stimulation. Findings indicate that spinal cord stimulation can offer pain relief that can help patients achieve a meaningful life despite chronic pain. Spinal cord stimulation also may have disadvantages that should be considered before offering this treatment. It seems evident that extended information needs about working mechanism of SCS and precautions as well as follow-up are required to meet unexpected challenges in adaptation. Here the nurse has an important role when informing and following this patient group.