The Value Of Diffusion Tensor Imaging Combined With Motor Evoked Potentials In The Prognostic Assessment Of Hemiplegic Patients With Cerebral Infarction

Objective:The objective of this study was to analyze the changes of diffusion tensor imaging（DTI）,transcranial magnetic stimulation motor evoked potential（TMS-MEP）in patients with acute ischemic stroke,to evaluate the correlation between DTI,TMS-MEP and prognosis of motor function,and determined their application value in assessing the recovery of limb function in patients with cerebral infarction.Methods:Strictly according to the inclusion and exclusion criteria,a total of 62 patients with acute cerebral infarction for the first time from March 2020 to December 2022 who were admitted to the Department of Neurology,Shanxi Provincial People’s Hospital were included,and the general data of the patients were collected.After admission,DTI and TMS-MEP was performed on all patients after admission,and data on fractional anisotropy（FA）and apparent diffusion coefficient（ADC）were collected in the region of basal ganglia of the DTI.Patients were divided into MEP waveform prolongation group and MEP waveform disappearance group according to the status of the MEP waveform on the affected side,and MRC scores and modified Rankin Scale（m RS）scores were recorded 3 months after admission.The difference between the different prognostic groups was observed,and the correlation between each indicator and the m RS score after90 days of follow-up was analysed to understand the value of each indicator in the prognostic assessment.All data were collated and analysed using SPSS22.0 software.Results:After 90 days of onset,62 patients with cerebral infarction completed follow-up,of which 37 patients recovered well and 25 patients recovered poorly.The FA、r FA、ADC and r ADC value at the lesion were found to be decreased to different degrees compared with the healthy side（P<0.05）.The FA and r FA values on the lesion side were statistically significantly different between the good prognosis group and the poor prognosis group（P<0.05）,and the ADC and r ADC values on the lesion side were not statistically different between the two groups.The lesion-side FA value and r FA value were negatively correlated with the patients’long-term functional prognostic score（m RS score）after 90days,respectively（r₁=-0.513 and r₂=-0.553,P<0.001）.The ROC curve for assessing good recovery of limb function in patients with r FA values was established,the area under the curve was 0.82,a sensitivity of 81.6%and a specificity of 83.3%,and the optimal diagnostic cut-off value for r FA value to assess good recovery of limb function was 0.476.For patients with evoked potentials,the values of Lat（ms）,cortex Amp（m V）,and CMCT（ms）on the affected side were longer than those on the affected side and Lat（ms）and CMCT（ms）on the affected side than those on the affected side,and the Amp（m V）of the affected cortex was lower than that on the unaffected side（P<0.05）.There was a significant difference between the prolongation and disappearance of MEP waveform（P<0.05）between the good prognosis group and the poor prognosis group,and after Spearman correlation analysis,the MEP waveform state was negatively correlated with the patient’s long-term functional prognostic score（m RS score）after 90 days（r=-0.441,P<0.001）.The prolongation of MEP waveform was used as an index to evaluate the good recovery of limb motor function,and its sensitivity was 40.54%,specificity was 92%,positive predictive value was 88.24%,and negative predictive value was 51.11%.Taking r FA>0.476 and MEP waveform prolongation results as the best evaluation indicators for patients with good prognosis and functional recovery,it was found that the sensitivity and specificity of DTI combined with TMS-MEP in assessing good limb functional recovery were 83.8%and 84.0%respectively.Conclusion:DTI and TMS-related indicators can be a good means of assessing patients’long-term functional prognosis,and combining the two methods can accurately predict the potential for recovery of limb dysfunction in post-stroke patients.