Late LTP-like Plasticity Effects of tDCS in Subacute Stroke Patients

Rationale: About 80% of stroke patients suffer motor impairments, but current therapies have limited effects on motor recovery. Therefore, investigating new potential therapeutic approaches is crucial. Transcranial Direct Current Stimulation (tDCS) is a form of non-invasive electrical stimulation where a weak current is applied through electrodes over the scalp. This stimulation is known to (1) induce changes in neuronal excitability -which can last up to one day with late LTP-like plasticity protocols in a polarity and site-specific manner, and (2) facilitate motor learning and stroke recovery. So far, several pilot studies have reported beneficial results from tDCS in both subacute and chronic stroke patients, but it's still unclear how tDCS should be repeated over multiple days to optimally enhance recovery and training effects. Using a late LTP-like plasticity protocol could increase effectiveness of standard clinical care rehabilitation sessions and thus enhance the effects of rehabilitation. Therefore, the investigators want to investigate how late LTP-like plasticity tDCS affects rehabilitation in subacute stroke patients. The outcome of this study can provide important guidelines on effective motor therapy during stroke rehabilitation. Objective: Identify the effect of late LTP-like plasticity on motor rehabilitation during the subacute phase after stroke. Study design: Double-blinded, randomized between-subjects trials. Study population: Subacute stroke patients. Main study parameters/endpoints: The primary outcome measure is the upper limb motor function during the subacute phase after stroke.

Motor training of the affected upper extremity combined with dual transcranial direct current stimulation (tDCS).

Inclusion Criteria: Subacute stroke (within 1-4 weeks post stroke) Acute hemiparesis (Fugl-Meyer Stage < IV) with single thromboembolic non-hemorrhagic infarction documented by a neurologist Aged 18-79 Exclusion Criteria: Absence of voluntary movement (Fugl-Meyer Stage < III) Head injury or the presence of intracranial metal or intracranial lesions History of cranial irradiation History of epilepsy Presence of a pacemaker Taking anticonvulsant or neuroleptic medication Substance abuse Inability to understand instructions

Elsner B, Kugler J, Pohl M, Mehrholz J. Transcranial direct current stimulation (tDCS) for improving activities of daily living, and physical and cognitive functioning, in people after stroke. Cochrane Database Syst Rev. 2020 Nov 11;11(11):CD009645. doi: 10.1002/14651858.CD009645.pub4.