Rehabilitating (Stroke-induced) Apraxia With Direct Current Stimulation

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