Clinical Research On The Effect Of Repetitive Transcranial Magnetic Stimulation Of Different Targets On Neuropathic Pain After Spinal Cord Injury

Objective: Neuropathic pain is one of the common complications of spinal cord injury.It is an important reason that affects the rehabilitation treatment of patients with spinal cord injury and hinders the functional recovery of patients.Since neuropathic pain is not sensitive to conventional analgesics,new treatments are urgently needed to relieve the pain of patients.Transcranial magnetic stimulation(TMS)as a neuroregulatory technique,has been found to be able to alleviate neuropathic pain.However,no effective stimulus target has been found to relieve neuropathic pain in patients with spinal cord injury.The primary motor cortex(M1)and the left dorsolateral prefrontal cortex(LDLPFC)were identified as potential therapeutic targets.Therefore,this study aims to compare the analgesic effects of M1 and LDLPFC region on neuropathic pain in patients with spinal cord injury,further identify the best stimulus target and stimulus parameter,provide empirical support for clinical application,reduce the pain of patients to the greatest extent,and thus improve their quality of life.Methods: A total of 34 subjects qualifying for inclusion at Department of Rehabilitation Medicine,the Second Affiliated Hospital and Haikou Courtyard district of Kunming Medical University from November 2021 to December 2022 underwent rTMS treatment for 2 weeks.The stimulation targets were M1 region and LDLPFC region.The stimulation frequency was10 Hz,4s was stimulated,and the interval was 20 s.The re were 2000 pulses per treatment.After the patients signed the informed consent,the patients were divided into M1 group(n=13),DLPFC group(n=11)and conventional treatment group(n=10)by random number table method.Assessment was conducted before and after treatment,including patients’ pain intensity was assessed using the Numerical Rating Scale(NRS),Patients’ anxiety and depression were evaluated by Self-rating Anxiety Scale(SAS)and Self-rating Depression Scale(SDS),The Pittsburgh Sl eep Quality Index(PSQI)measures patients’ sleep quality,The Brief Pain Inventory(BPI)measures the extent to which pain interferes with daily activities,Patient’s Global Impression of Change(PGIC)scale assesses patients’ overall changes during treatment,Resting MotorThreshold(RMT)and Motor Evoked Potentials(MEP)to evoked the excitability of the cerebral cortex of patients.Results: After 2 weeks of treatment,NRS,SAS,PGIC,BPI emotional disturbance and activity disturbance scores were signifi cantly reduced in the two rTMS intervention groups compared with the conventional treatment group(P<0.05).Only SDS scores were significantly different between the two rTMS groups(P<0.05),which showed that DLPFC group were significantly lower than M1 group.A comparison between the three groups of PSQI found a significant difference between the DLPFC group and the conventional treatment group(P<0.05).MEP and RMT values were measured in 8 subjects in M1 group,and the maximum amplitude of MEP was significantly increased and RMT was significantly decreased after treatment compared with before treatment(P<0.05).There were no significant difference in BPI sleep disturbance scores among the three groups(P>0.05).Conclusions:1.The primary motor cortex area(M1)and the left dorsolateral prefrontal cortex area(LDLPFC)can be used as effective stimulation targets for high-frequency rTMS in the treatment of neuropathic pain after spinal cord injury,and the LDLPFC area is better than the M1 region in improving depression.2.High-frequency rTMS stimulation of the M1 region can reduce the RMT value,increase the maximum amplitude of MEP,increase the excitability of the nearby cerebral cortex,and may reduce the pain of patients by activating the brainstem pain downward control system.