Objective To investigate the secondary degeneration of corticospinal tracts in cervical spinal cord following a recently cerebral infarct with diffusion tensor imaging(DTI) and its potential impact on neurological recovery.Methods Twenty-six patients with a focal cerebral infract underwent DTI at the first week, the fourth and twelfth week after stroke onset, respectively.The NIH Stroke Scale (NIHSS), the Fugl-Meyer motor scale (FM) and the barthel index (BI) were used to evaluate the neurological function before every DTI.Twenty-six gender and age match healthy volunteers underwent DTI three times at same time points.The DTI parameters of mean diffusivity (MD) and fractional anisotropy (FA value) were measured at the cervical spinal cord and initial lesion.Results Compared to the controls, the FA values of the contralateral side corticospinal tracts in the cervical spinal cord in patients significantly decreased at every observed time point (P<0.01).In patients group, the FA values of the contralateral side corticospinal tracts in the cervical spinal cord decreased progressively from 1~(st) week to 12~(th) week (P<0.01), but MD remained unchange.The absolute value of the percent reduction of FA value of the contralateral side corticospinal tracts in the cervical spinal cord in patients associated negatively with the absolute value of the percent change of NIHSS and FM (P<0.05), but not with the absolute value of the percent change of BI(P>0.05).Conclusions Conclusions: The secondary degeneration of the corticospinal tracts resulted from cerebral infarction may extend to the cervical spinal cord.Which may last at lest three months and thus hamper the process of neurological recovery.