IMPULSE - StIMulation of Brain Plasticity to Improve Upper Limb Recovery After StrokE

Stroke is a leading cause of adult long-term disability worldwide. Recovery of arm and hand function after stroke is limited to about 50% of patients and full recovery is achieved in only 12% of stroke survivors by 6 months after stroke. Within the first 8-12 weeks post-stroke, a proportional recovery of 70%, corresponding to good recovery, may be achieved, but at later stages no major gain is observed with current therapy practices. Accordingly, there is a need to find new potential therapeutic tools to enhance post-stroke motor recovery. Rehabilitation supported by neuroplastic intervention is a new and pragmatic therapeutic approach in the treatment of stroke, giving way to a concept of 'recovery enhancers'. The objective of this study is to assess whether an additional therapy with Cerebrolysin and anodal transcranial direct current stimulation (atDCS) increases the success of conventional rehabilitation therapy in subacute and chronic stroke patients with unexploited potential for functional recovery despite intact structural and functional pathways in the brain. Hypothesis: The hypothesis is that the combination of Cerebrolysin and atDCS facilitates motor learning in subacute and chronic stroke patients. Accordingly, motor function recovery at day 21 post-baseline is expected to be higher in the verum group (conventional rehabilitation + task-specific motor training + Cerebrolysin + atDCS) as compared to the control group (conventional rehabilitation + task-specific motor training + placebo + sham-transcranial direct current stimulation). The primary objective is to show a significantly higher proportional recovery rate in the Action Research Arm Test (ARAT) at day 21 post-baseline in the verum group as compared to the control group. The secondary objective is to assess the impact of this neuroplastic intervention on finger dexterity (Nine-hole peg test - 9HPT), hand grip strength, and neurological deficits (National Institutes of Healths Stroke Scale - NIHSS) at the end of therapy (day 21 post-baseline). Safety data are collected throughout the study and thereafter in case of ongoing serious adverse events (SAEs) at study endpoint. Optional secondary parameters include electroencephalography (EEG) parameters and Brain Derived Neurotrophic Factor (BDNF) status analyses to document plastic changes in the brain, in particular changes of the cortical network functionality during neurorehabilitation, and to assess the impact of neuroplastic intervention on the BDNF synthesis rate as well as the influence of different BDNF polymorphisms.