Spinal cord stimulation (SCS) is a method of treating disease by implanting electrodes into the spinal canal and stimulating spinal nerves with pulsed current. The research progress in analgesic mechanism and clinical application in recent years is reviewed as follows. The analgesic mechanism of SCS has several aspects: (1) the retrograde impulse generated by stimulating the posterior spinal cord conflicts with the prograde nociceptive impulse; (2) the retrograde impulse of the posterior spinal cord activates the gate control system in the posterior horn of the spinal cord, so that the pain impulse cannot be uploaded; (3) the upstream impulse of stimulating the posterior spinal cord produces interference in the thalamus and cortex; (4) the activation of the downstream inhibitory pathway in the higher center; (5) the involvement of endogenous analgesic substances. Involvement of endogenous analgesic substances. Studies in recent years have shown that γ-aminobutyric acid (GABA)-ergic neurons are highly involved in the analgesic mechanism of SCS. After ligation of the sciatic nerve in mice, extracellular GABA in the dorsal horn neurons of the spinal cord decreased significantly [(2.3±0.5) nmol/L, compared with (8.1±1.0) nmol/L in normal], and its level increased significantly after SCS stimulation [(5.7±0.5) nmol /The neurons (fibers) stimulated by SCS, the dorsal root of spinal nerve, the posterior horn neurons of spinal cord, and the spinal thalamic tract were related to the analgesic effect of SCS. 2, the analgesic method of SCS Spinal cord electrical stimulation as a mature operation technique, the specific operation is not complicated, the previous is the use of surgical methods, sometimes need to remove the vertebral plate, expand the spinal canal. In recent years, electrodes are more often delivered into the spinal canal by percutaneous puncture, and the corresponding spinal cord segment in the pain area is first detected by somatosensory or motor evoked potentials, and then unipolar or multipolar stimulation electrodes are placed into the epidural cavity of the corresponding segment by endoscopic or surgical techniques, and the precise position of the electrodes is determined under X-ray fluoroscopy or by using evoked potentials, electrical stimulation or a computerized control system. The receiver is buried under the skin of the right subcostal or right anterior abdominal wall for short-term experimental stimulation. During the experimental stimulation period, if the patient responds well, the stimulator is permanently buried under the skin of the abdomen as a permanent stimulus to relieve chronic pain, which is usually intractable. The main indications for SCS include: low back pain that is not treated by other methods and cannot or should not be treated surgically; failed cervical spine surgery; neuralgia syndrome of the extremities; bilateral spinal nerve root pain syndrome; intractable angina pectoris that cannot be operated immediately; ischemic diseases of the limbs, etc. SCS may be effective for ischemic pain secondary to atherosclerosis, vasospasm or vasculitis that cannot be operated. Pain may be effective. In Europe, SCS is used to treat intractable angina pectoris that cannot be operated immediately. 4.Clinical application of SCS for analgesia Many studies have shown that SCS has different degrees of analgesic effects on painful conditions such as low back pain, coronary angina, post-herpetic neuralgia, phantom pain, peripheral nerve injury, trigeminal neuralgia, cancer pain, thrombotic vasculitis, spinal cord injury, reflexive sexual dystrophy, etc. SCS is the best choice for treating neuropathic pain syndromes of the extremities. The most effective conditions are cancer pain and burning neuralgia; followed by pain of diabetic neuropathy, and dual-lead stimulation therapy has been successfully applied to the treatment of diabetic neuropathy; progressive sympathetic-mediated pain syndrome also responds well to SCS. Less effective are postherpetic neuralgia, thrombophlebitis, and intercostal neuralgia syndrome. Phantom pain and chronic spinal cord injury pain have the poorest efficacy. With the development of dual-lead stimulation therapy, the implementation of axonal stimulation has helped in the treatment of patients with bilateral nerve root and mechanical back pain syndromes. Treatment of prosthetic and residual limb pain is limited. 4.1 Low back pain is the main indication for SCS, of which the failed lumbar spine surgery syndrome is the main one. In recent years, it has been reported abroad that low back pain accounts for 45%-61.4% of painful disorders treated with SCS. the early effect of SCS on chronic refractory low back pain is positive, but the long-term effect is not satisfactory. leDoux [9] reported that the efficiency (pain reduction of more than 50%) of SCS for low back pain was 90% after 1 month and decreased to 76% after 1 year. devulder J [10] studied 69 cases of FBSS patients for up to 13 years of follow-up, resulting in 26 cases (37.7%) discontinued SCS treatment due to ineffective treatment and electrode breakage, and 43 cases (62.3%) continued treatment with good results, 11 of which returned to work. 4.2. Coronary angina The treatment of coronary angina has been the focus of SCS research, and its mechanism is related to the following factors: first, direct analgesic effect; second, increasing myocardial blood perfusion; third, similar to the effect of β-blockade, which can reduce myocardial oxygen consumption. The short-term efficacy of SCS in the treatment of angina is very good, the efficiency often reaches 100%, and SCS does not mask and increase the risk of myocardial ischemia, the number of episodes of chest pain, the degree of pain, the intake of nitroglycerin, the degree of ST-segment reduction in the electrocardiogram of patients significantly reduced, the exercise tolerance and exercise end time of the exercise test increased, cardiac function improved, and the quality of life improved, Jessurun reported SCS treatment The effect of long-term treatment of angina pectoris is satisfactory. 4.3. Post-coronary spinal cord injury pain Partial or complete spinal cord injury is accompanied by annoying post-spinal cord injury pain in addition to paraplegia or quadriplegia. Post-spinal cord injury pain is divided into injury pain, neurogenic pain and central pain, among which central tactile nociceptive hypersensitivity is common and the most serious. Better results were obtained using SCS. However, the analgesic effect is better in those with partial injury than in those with complete injury. The pain caused by spinal cord cavitation is mostly central pain, and treatment with SCS is also effective. The mechanism is that electrical stimulation inhibits axonal conduction of nociception or activates axonal inhibition of pain. In addition, successful medical records have been reported for multiple sclerosis, trigeminal neuralgia secondary to multiple sclerosis via high cervical SCS with spastic bladder. In addition, in recent years, it has been reported in the literature that SCS may promote functional recovery after spinal cord injury. Fehlings et al. suggested that the possible mechanisms are: (i) DC electric field promotes the regeneration of damaged but not transected axons; (ii) promotes the regeneration of transected nerve fibers; and (iii) the combination of the first two. the study of SCS to promote functional recovery after spinal cord injury has become a research hotspot in the field of spinal cord injury research. 5, SCS complications and prevention The incidence of SCS complications is <10%. Infection: The most common complication of SCS is local infection, with an incidence of about 3%. Infection usually involves the pulse generator and radiofrequency receiver and the wires of the coupling electrodes, and occasionally the epidural space. Infection can occur within days to years after insertion. Treatment for this persistent infection is removal of the insertion device and 6 weeks of intravenous antibiotics. Electrode displacement: usually occurs within a few days after insertion. The incidence of displacement of percutaneous electrodes is significantly higher than that of plate electrodes. ③Secondary spinal cord compression injury: The most fatal complication of SCS is nerve root or spinal cord injury during insertion or secondary spinal cord compression injury caused by intradural hematoma. (4) Intractable cerebrospinal fluid leak: This can occur after percutaneous or incisional plate electrode placement and is clinically manifested by headache and accumulation of cerebrospinal fluid at the site of pulse generator placement. Treatment is to have the patient use a lap band with adequate tension for 2 to 3 weeks to compress the pulse generator and the path through which the lead passes. If this is ineffective, a small amount of autologous blood may be injected into the epidural space of the spinal canal to promote adhesions to occur, or early surgical exploration and repair of the leak may be performed. ⑤ Interference with pacemakers. ⑥Other: Soft spondylitis is very rare. Neuropneumonia can occur after prolonged irritation of the posterior spinal nerve roots. In addition, electrode rupture and fibrosis of the stimulated tissue may occur. In conclusion, SCS has been developed rapidly in the last 10 years, and it has been widely used in chronic pain treatment abroad, and its application has been extended beyond painful diseases, so the broad prospect of promoting the application of SCS in China is worth looking forward to.