Changes in Resting State Effective Connectivity in the Motor Network Following Rehabilitation of Upper

Background: A promising paradigm in human neuroimaging is the study of slow (<0.1 Hz) spontaneous fl uctuations in the hemodynamic response measured by functional magnetic resonance imaging (fMRI). Spontaneous activity (i.e., resting state) refers to activity that cannot be attributed to specifi c inputs or outputs, that is, activity intrinsically generated by the brain. Method: This article presents pilot data examining neural connectivity in patients with poststroke hemiparesis before and after 3 weeks of upper extremity rehabilitation in the Accelerated Skill Acquisition Program (ASAP). Resting-state fMRI data acquired pre and post therapy were analyzed using an exploratory adaptation of structural equation modeling (SEM) to evaluate therapy-related changes in motor network effective connectivity. Results: Each ASAP patient showed behavioral improvement. ASAP patients also showed increased infl uence of the affected hemisphere premotor cortex (a-PM) upo