Constraint-induced movement therapy alters cerebral blood flow in subacute post-stroke patients

We attempted to evaluate patterns of hemispheric activation, according to cerebral blood flow changes, in post-stroke patients during motor tasks with and without arm restriction. Bilateral continuous middle cerebral artery monitoring of 6 healthy subjects (control group) and 28 post-stroke patients by transcranial Doppler sonography was executed while performing three simple motor tasks using the paretic or nondominant (in controls) hand: ball grasping, pegs insertion, and "eating" with a spoon. The nonaffected or dominant (in controls) arm was free and thereafter restricted. Mean blood flow velocity and flow velocity changes during the tests were estimated. No significant mean blood flow velocity changes were found in the healthy subjects. Significant elevation of mean blood flow velocity in damaged middle cerebral artery was recorded in post-stroke patients after restricting the undamaged hand. This may explain the positive effect of constraint-induced movement therapy on upper limb function.