Detection of anterograde and retrograde degeneration after subcortical infarction with diffusion tensor imaging

Objective To investigate the secondary anterograde and retrograde degeneration after subcortical infarction as well as its potential meaning for clinical practice.Methods Ten patients underwent DTI and evaluation with the NIH Stroke Scale(NIHSS),the Fugl-Meyer motor scale(FM)and the barthel index after an isolated subcortical middle cerebral artery(MCA)infarction in the 1st week(D7),1 month(M1)and 3 months(M3)respectively.Mean diffusivity(MD)and fractional anisotropy(FA)were measured at internal capsule,centrum semiovale,cerebral peduncle and pons,from the first week to the third month after stroke onset in these patients and in the same number of age-and sex-matched controls.Neurological deficit was evaluated with the NIHSS,motor deficit with Fugl-Meyer Scale,life independence with Barthel Index.Results The FA values of patients significantly decreased from D7 to M3 in regions above internal capsule(0.34±0.01 vs 0.28±0.03,P0.01)and below the internal capsule(0.42±0.02 vs 0.37±0.06,P0.01).No significant modification of MD was detected at these regions.Conclusion A subcortical infarct may result in secondary anterograde and retrograde degeneration at remote regions,but its potential meaning remains unrevealed.