Safety of Transcranial Direct Current Stimulation in the Subacute Phase After Stroke

The investigators main goal is to confirm the safety of transcranial direct current stimulation (tDCS) associated with conventional physical therapy, compared to conventional physical therapy associated with sham tDCS, for upper limb rehabilitation in an early phase (72 hours until 6 weeks) after stroke. Patients will be randomized to receive one of these two treatments, 3 times per week, for 2 weeks. Adverse effects will be monitored during each session. The working hypothesis is that conventional physical therapy associated with active tDCS in the subacute phase of ischemic stroke will be as safe as conventional therapy alone. The investigators will also preliminarily evaluate the efficacy of active tDCS associated with conventional therapy, compared to conventional therapy alone, in improvement of upper limb motor impairment. The investigators secondary goals are: 1) To compare effects of the above mentioned interventions on disability, spasticity and quality of life, in patients at an early stage after stroke ( subacute phase), immediately after treatment and 3 months later. The investigators hypothesis is that the association of conventional physical therapy and active tDCS will lead to better outcomes than conventional therapy alone. Patients will be assessed before the first session and after the last session of treatment, as well as 3 months after the last session of treatment.

Preliminary data about structural and functional connectivity will be collected in order to plan future studies related to mechanisms of tDCS in the subacute phase after stroke.

Inclusion criteria

• Ischemic stroke confirmed by computed tomography or magnetic resonance imaging, with onset between 72 hours and 6 weeks before enrollment.
• Unilateral paresis of upper limb
• National Institute of Health Stroke Scale ( NIHSS) score of at least 1 point in items 5a or 5b .
• Ability to provide written informed consent (patient ou legal representative).

Exclusion criteria

• Lesions affecting the corticomotor pathway in the hemisphere contralateral to the stroke.
• Neurologic diseases except migraine.
• Modified Rankin Scale > 2 prior to stroke.
• Advanced systemic disease such as cancer or advanced chronic renal disease.
• Clinical instability such as uncontrolled cardiac arrhythmia or heart failure.
• Contraindication for physical therapy.
• Pregnancy.
• Absolute or relative contraindications to tDCS: metallic prosthesis in the head or neck; lesions on the scalp, history of neurosurgery, pacemaker.
• Comprehension aphasia
• Dementia
• Cerebellar stroke or ataxia caused by involvement of cerebellar pathways in the brainstem