Characteristics of Brain fMRI Responses to Motor Loads in Patients with Mild Posttraumatic Hemiparesis

Motor fMRI responses analyzed in 10 patients with mild posttraumatic hemiparesis displayed high variability in deviations from normal on movement not only of the afflicted but also the intact hand. Changes in fMRI rearrangements, most marked on use of the afflicted hand, were apparent as weakening of the main components of the response and increases in activation of cortical and subcortical brain structures not specific for the movement. Comparison of fMRI responses on motor loading of the afflicted and intact hands showed that the clearest marker of mild hemiparesis was weakening of the cerebellar component of the response. Comparison with normative data (15 healthy subjects) showed more marked features in the reorganization of the sensorimotor motor fMRI response in patients with right-sided hemiparesis.