The objective of the clinical trial is to investigate whether weak transcranial direct current stimulation (tDCS) can ameliorate the motor cognitive deficit apraxia during stroke rehabilitation. Stroke patients with apraxia will either receive a real stimulation or a sham stimulation (placebo) for 10 minutes at a time on 5 consecutive days during their in-patient stay in a rehabilitation center. Additionally, motor tasks are performed before and after the stimulation. The effect of the weak current stimulation on motor function is assessed 3-4 days after the last stimulation and 3 months after enrollment.

Despite the high incidence of the motor cognitive deficit apraxia after left-hemispheric stroke, evidence-based therapies do not exist. This randomized controlled clinical trial (RCT) investigates whether anodal transcranial direct current stimulation (tDCS) as an add-on therapy during neuro-rehabilitation can ameliorate apraxic deficits in patients with left hemisphere stroke. Therefore, anodal tDCS is applied over the parietal cortex of the left, lesioned hemisphere with an intensity of 2 mA for 10 minutes at a time on 5 consecutive days in combination with motor tasks before and after the stimulation. The effect of the stimulation is compared to a sham stimulation. Moreover, application of a pre-programmed study mode ensures a double-blind study design (patient and investigator). The performance in the apraxia test KAS (Cologne Apraxia Screening) 3-4 days after the last stimulation, compared to baseline, serves as primary endpoint of the study. Secondary endpoints are evaluated using various apraxia tests, motor tests and neuropsychological tests 3-4 days after the last stimulation and 3 months after enrollment.

Inclusion Criteria:

• left hemispheric ischemic stroke in the subacute/ chronic phase (>10 days and <180 days post-stroke)
• clinical confirmation of apraxia by KAS (Cologne Apraxia Screening), Cut-off ≤ 76/ 80 points;
• age 18 - 90 years;
• written Informed Consent

Exclusion Criteria:

• pregnancy, breastfeeding and women without exclusion of pregnancy
• patients with clinical manifestation of a stroke prior to the index-stroke
• malignant disease with affection of central nervous system
• life expectancy <12 months
• current addiction to alcohol or drugs or other addictive disease (exception: nicotine)
• current clinically manifest psychiatric disorders, such as schizophrenia or severe depressive episode
• epileptic seizure within the past two years
• continuous medication during the intervention phase with benzodiazepine, antipsychotics of high potential and anti-epileptic drugs taken for prophylaxis of epileptic seizures
• enrollment in other studies with brain stimulation in the time period after the index stroke
• heart pacemaker
• electrodes for deep brain stimulation or other metal implants in the head (expected are dental fillings and inlays)
• craniectomy or trepanation
• vulnerable skin lesions at electrode positions
• poor motivation/ cooperation