A study on the correlation between excitability of the M1 hand area and activities of daily living and neuropathic pain after spinal cord injury
LIU Xinyu
DAI Chunqiu
GAO Ming
LIN Xiaodong
CHENG Guiqing
LU Yixing
SUN Xiaolong
YUAN Hua
Abstract：Objective To investigate the changes in excitability of the bilateral primary motor cortex(M1)hand area after spinal cord injury(SCI)and its correlation with activities of daily living(ADL)and neuropathic pain(NP).Methods This study included 67 SCI patients(SCI group)who were admitted to the Department of Rehabilitation Medicine,Xijing Hospital,Air Force Medical University from March 2022 to March 2024.Single-pulse transcranial magnetic stimulation was used to detect motor evoked potentials(MEP)in the bilateral M1 hand area to evaluate excitability.The patients'ADL function was evaluated using the modified Barthel Index and the Spinal Cord Independence Measure(SCIM),while the severity of NP was assessed using the simplified Short-Form McGill Pain Questionnaire-2(SF-MPQ-2).The natural logarithm(LN)of the ratio of MEP amplitudes in the M1 hand area from the dominant to the non-dominant side was calculated to analyze its correlation with ADL and NP.Results Compared with the healthy group,SCI group showed significantly reduced MEP amplitudes(P＜0.01)and prolonged latencies in the bilateral M1 hand area(P＜0.01).Additionally,the LN(dominant side amplitude/non-dominant side amplitude)was reduced(P＜0.05).In SCI patients,LN values showed a significant positive correlation with the modified Barthel Index(r=0.250,P=0.041),SCIM score(r=0.263,P=0.033),and the SCIM indoor activity score(r=0.273,P=0.027).In NP patients,LN values were significantly higher and showed a positive correlation with SF-MPQ-2 pain score(r=0.276,P=0.047).Conclusion The excitability in the bilateral M1 hand area is significantly reduced in SCI patients.Furthermore,the degree of excitability asymmetry is closely related to ADL function and the severity of NP.Therefore,the degree of excitability asymmetry in the bilateral M1 hand area may serve as a potential marker for assessing ADL function and the severity of NP after SCI,and provide new targets for future intervention strategies.
Keywords：spinal cord injurycortical excitabilitymotor evoked potentialsactivities of daily livingneuropathic pain
Publication Date：2025-03-31
Online Publishing Date：2026-08-26(First online date of this platform, not the publication date of the document)
Pages：7( 305-311 )