Non-Invasive Mapping of Corticofugal Fibers from Multiple Motor Areas: useful tool for assessing disconnection after sub-cortical stroke?
Newton J, Parker G, Deichmann R, Alexander D, Friston K, Ward N, Frackowiak R
University College London, UCLA
Here we describe the trajectories of the corticofugal connections from each major component of the motor system using probabilistic tractography in normal subjects. We then infer damage to corticofugal pathways in patients with sub-cortical stroke by comparing the overlap between significant regions of reduced anisotropy with the trajectories of corticofugal fibers to each motor area in the normal subjects. We found that these inferred disconnections could explain enhanced handgrip related responses, as assessed with functional MRI, in the ipsilesional motor system. These results confirm that selective disruption of motor corticofugal fibers influences functional reorganization in individual patients.