Diffusion Tensor Imaging With Variety Of Cortical Thickness Predict Long-term Outcome In Patients With Stroke

Objective:Most stroke patients have dyskinesia.If we can predict the recovery of motor function in the early stage,it will help to set reasonable goals and improve the corresponding rehabilitation strategies to promote function recovery.This article intends to study the dynamic changes of neuroimaging and motor function within 3 months and about 1 year after onset.And we analyze the possible relationship with the recovery of long-term motor function within 3 months so as to provide the basis for clinical treatment.Methods: Forty patients with stroke were randomly enrolled and evaluated for clinical function at an subaute phase of stroke recovery(within 3 months after stroke)and chronic phase of recovery(approximately 1 year after stroke).Motor function was assessed using the National Institutes of Health stroke scale(NIHSS)as a basis for paresis grading(PG).We use the Brunel balance assessment(BBA)to assess the balance of patients.And the functional outcome with a modified Rankin scale(m RS)and functional independence measures(FIMs)were assessed.MRI scan was performed within 3 months(first time)and 1 year(2nd time)respectively.The region of interest(ROI)was used to determine the fractional anisotropy(FA)of the corticospinal tract.The regions of interest include the posterior limb of internal capsule(PLIC),cerebral peduncle(CP)and middle cerebellar peduncles(MCP).The ratio of fractional anisotropy(rFA,lesion-side FA value / lesion contralateral FA value)was measured and calculated.The corpus callosum FA values were measured using a template method.We use the Free Surfer software to calculate the changes in cortical thickness of primary motor cortex(M1),insula and praecuneus.The relationship between rFA value and motor function in each region of interest was compared.The relationship between cortical thickness changes and motor function was analyzed.The relationship between FA value and cortical thickness of corpus callosum was analyzed.Results:There were differences in FA values of hemispheres between the three ROI within 3 months and 1 year after stroke.The rFA of CP in 3 months was negatively correlated with NIHSS score,m RS,upper and lower extremity total PG,upper extremity PG and lower extremity PG in one year(r =-0.626,P = 0.000;r =-0.693,P = 0.000;r =-0.669,P = 0.000;r =-0.694,P = 0.000;r =-0.525,P = 0.001)and was positively correlated with FIM and balance function(r=0.732,P=0.000;r=0.611,P=0.000);The rFA value of the PLIC within 3 months was negatively correlated with the NIHSS score of 1 year,m RS,PG of the lower extremity,PG of the upper extremity and PG of the upper and lower limbs(r=-0.406,P=0.025;r=-0.485,P=0.041;r=-0.630,P=0.016;r=-0.529,P=0.020;r=-0.432,P=0.014)and was positively correlated with FIM and balance function(r=0.346,P=0.034;r=0.514,P=0.029);The rFA value of MCP in 3 months was negatively correlated with NIHSS score,m RS,upper and lower extremity PG total score,upper extremity PG and lower extremity PG in one year(r=-0.401,P=0.015;r=-0.346,P=0.002;r=-0.546;P=0.006;r=-0.637,P=0.012;r=-0.644,P=0.044)and positively correlated with FIM score r=0.701,P=0.018).It had no significant correlation with balance function(P=0.069).The second cortical thickness of ipsilesional M1(2.37 ± 0.24)was less than the thickness of first(2.45±0.23,P=0.004).The second cortical thickness of the praecuneus(2.53 ± 0.19)less than the thickness of first(2.71±0.21,P=0.041).The thickness of the cortex on the contralateral insula was(3.00 ± 0.24)greater than that of the 3 months(2.94±0.26,P=0.048).The difference of FA value between the corpus callosum was positively correlated with the difference between the ipsilesional M1 area and the praecuneus of the lesion(r=0.624,P=0.049;r=0.697,P=0.025).There was no significant correlation between the difference of contralateral M1,the lesion side and the contralateral insula,and the difference of the contralateral praecuneus(P=0.907,P=0.244,P=0.403,P=0.347,P>0.05).ROC curve analysis showed that the ratio of area underFA curve was 0.80 ± 0.18,the area under rFA curve was 0.78 ± 0.15 and the area under rFA curve was 0.47 ± 0.12.The cutoff point for the rFA of the CP was 0.80(sensitivity 66%,specificity 98%).The cutoff point for the rFA of the MCP was 0.79(sensitivity 59%,specificity 98%).The cutoff point for the rFA of PLIC was 0.76(sensitivity 40%,specificity 90%).Conclusion:Within 3 months,the rFA value of the CP,the MCP and PLIC can predict the motor function outcome of 1 year or so.After onset of stroke,the cortical thickness of the ipsilesional M1 and praecuneus were decreased.The cortical thickness of the contralateral insula was increased.This cortical structure change has no significant correlation with the motor outcome but is related to daily living ability.Compensation for other areas outside of the motor cortex may be a possible replastic mechanism for relative retention of self-care capabilities.The corpus callosum plays an important role in neural remodeling between cerebral hemispheres after stroke.