TY - JOUR

T1 - Dynamic changes in corticospinal tracts after stroke detected by fibretracking

AU - Møller, M

AU - Frandsen, J

AU - Andersen, G

AU - Gjedde, A

AU - Vestergaard-Poulsen, P

AU - Østergaard, L

N1 - Keywords: Aged; Anisotropy; Axons; Cerebral Infarction; Diagnostic Techniques, Neurological; Diffusion Magnetic Resonance Imaging; Feasibility Studies; Female; Humans; Longitudinal Studies; Male; Middle Aged; Nerve Degeneration; Pyramidal Tracts; Time Factors; Wallerian Degeneration

PY - 2007

Y1 - 2007

N2 - BACKGROUND AND AIMS: The integrity of motor pathways and functional connectivity patterns are important in assessing plastic changes related to successful recovery, to obtain prognostic information and to monitor future therapeutic strategies of stroke patients. We tested the following hypotheses: (1) that changes in axonal integrity along the corticospinal tract after stroke can be detected as a reduction in fractional anisotropy; and (2) that sustained low fractional anisotropy is indicative of axonal loss and therefore is correlated with poor motor outcome, as measured by specific neurological motor scores. METHODS: We developed a segmentation tool based on magnetic resonance diffusion tensor imaging in conjunction with three dimensional fibretracking for longitudinal studies of the corticospinal tract, and used specific neurological motor scores to test the hypotheses in five stroke patients within the first week and 30 and 90 days after the stroke. RESULTS: Reduction in fractional anisotropy within the first weeks after stroke reflected a decline in axonal integrity, leading to Wallerian degeneration, and demonstrated a correlation between the temporal evolution of fractional anisotropy and motor function in patients with poor motor outcome. CONCLUSION: The study demonstrated the feasibility of fibretracking as a segmentation tool for mapping distal parts of the corticospinal motor pathways and showed that fractional anisotropy in the segmented corticospinal tract is a sensitive measure of structural changes after stroke.

AB - BACKGROUND AND AIMS: The integrity of motor pathways and functional connectivity patterns are important in assessing plastic changes related to successful recovery, to obtain prognostic information and to monitor future therapeutic strategies of stroke patients. We tested the following hypotheses: (1) that changes in axonal integrity along the corticospinal tract after stroke can be detected as a reduction in fractional anisotropy; and (2) that sustained low fractional anisotropy is indicative of axonal loss and therefore is correlated with poor motor outcome, as measured by specific neurological motor scores. METHODS: We developed a segmentation tool based on magnetic resonance diffusion tensor imaging in conjunction with three dimensional fibretracking for longitudinal studies of the corticospinal tract, and used specific neurological motor scores to test the hypotheses in five stroke patients within the first week and 30 and 90 days after the stroke. RESULTS: Reduction in fractional anisotropy within the first weeks after stroke reflected a decline in axonal integrity, leading to Wallerian degeneration, and demonstrated a correlation between the temporal evolution of fractional anisotropy and motor function in patients with poor motor outcome. CONCLUSION: The study demonstrated the feasibility of fibretracking as a segmentation tool for mapping distal parts of the corticospinal motor pathways and showed that fractional anisotropy in the segmented corticospinal tract is a sensitive measure of structural changes after stroke.

U2 - 10.1136/jnnp.2006.100248

DO - 10.1136/jnnp.2006.100248

M3 - Journal article

C2 - 17210628

VL - 78

SP - 587

EP - 592

JO - Journal of Neurology, Neurosurgery and Psychiatry

JF - Journal of Neurology, Neurosurgery and Psychiatry

SN - 0022-3050

IS - 6

ER -