Prospective Investigations On The Lateral Pyramidal Tract Remodeling And Motor Cortex Activation Following A Subcortical Cerebral Infarct With Diffusion Kurtosis Imaging

Objective To investigate the time course of lateral pyramidal tract remodeling and motor cortex activation,as we ll as its potential significance for motor recovery following focal infarction.Methods Tweenty patients with a recently isolated MCA subcortical infarct underwent diffusion kurtosis imaging(DKI)examinations and evaluations at the first week(W1),the end of the fourth week(W4)and the twelfth week(W12)respectively.Tweenty the age and gender matched volunteers underwent DKI one time as controls.Mean kurtosis(MK),anisotropy(Ka),fractional anisotropy(FA)and other parameters were measured and analyzed on a total of 6 regions of interesting(ROI)including subcortical peri-lesion,centrum semiovale,precentral gyrus and the axial symmetry of the healthy sides.The DKI parameters of ROI in experimental group were compared with the mean of the corresponding parameters of the controls.The relationship between DKI parameter changes and the clinical score changes were then examined in experimental group.Result The percent increase of subcortical Ka value and FA value at peri-lesion,as well as Ka value at lateral centrum semiovale correlated to the percent reduction of NIHSS and to the percent increase of FM.In addiction,the percent increase of MK value at precentral gyrus correlated to the percent reduction of NIHSS and to the percent increase of FM.Conclusion After a focal cerebral infarct,the fiber remodeling of subcortical peri-lesion and super-lesion,as well as affected motor cortex activation may reconstructed the fiber links beteen descending pathway and motor neurons in the cortex.This phenomenon may contribute to the spontaneous motor recovery after stroke.