Prospective cohort studies show that about 80% of all stroke survivors have an upper limb paresis immediately after stroke. Only one third of all stroke patients will regain some dexterity, whereas well-researched evidence based therapies for an effective treatment of the upper limb are lacking. However, the main claim of the literature is that functional recovery of the upper paretic limb is mainly defined within the first month post stroke and that rehabilitation services should be applied preferably within this time window of recovery. Furthermore, it is known that exercise-related interventions are most effective when they are applied intensively in a task-oriented way.
Explicit-stroke builds on the existing knowledge about functional prognosis and effectiveness of exercise therapy in patients with a first-ever MCA stroke. The first RCT of EXPLICIT is aimed to investigate the effects of early applied Constraint Induced Movement Therapy (CIMT) in patients with a known favourable prognosis for functional recovery. The second RCT of Explicit-stroke will focus on the effects of an early started sensorimotor stimulation program by EMG-triggered Neuromuscular Electrical Stimulation (EMG-NMS) in patients with a poor probability for functional recovery of the upper limb. In both single-blinded RCTs, interventions will be compared to a dose-matched control treatment based on usual practice. To improve our knowledge on what patients learn when they show functional recovery, Explicit-stroke will explore the underlying mechanisms that are involved in regaining dexterity. For this latter purpose, the impact of intactness of the primary motor system as revealed with TMS will be related to: 1) changes in cortical activation patterns of ipsi- and contralateral brain by fMRI; 2) adaptive motor control of the upper limb (kinematics) and 3) changed stiffness of the upper paretic limb by haptic robotics in a repeated measurement design. By this, Explicit-stroke will provide an answer to the key question whether therapy induced improvements are due to either a reduction of basic motor impairment by neural repair (i.e., restitution of function) and/or the use of behavioural compensation strategies (i.e., substitution of function).