tDCS Combined With Constraint-Induced Therapy in Post-Stroke Upper Limb Rehabilitation

The objective of this clinical trial is to evaluate the effects of transcranial direct current stimulation (tDCS) combined with constraint-induced therapy (CIT) on upper limb motor recovery in individuals after stroke. The main questions it aims to answer are: Does the combination of tDCS and CIT improve upper limb motor function compared to CIT alone? Does the combined intervention promote changes in muscle morphology and electromyographic activity? Researchers will compare the group receiving tDCS combined with constraint-induced therapy to the group receiving constraint-induced therapy alone to determine whether the addition of cortical neuromodulation enhances motor recovery outcomes. This is a randomized, controlled, and blinded clinical trial in which participants will be divided into two groups: one group will receive tDCS combined with CIMT, and the other will undergo only CIMT. The protocol will include 18 sessions over six weeks, three times a week. Clinical and instrumental assessments will be performed before, during, and after the intervention, including the Fugl-Meyer scale for the upper limb, musculoskeletal ultrasound for morphological analysis, and surface electromyography for muscle activity assessment.

Inclusion Criteria: * present a clinical diagnosis of stroke confirmed by imaging examination and/or report issued by a neurologist; - are in the chronic phase of the lesion with an occurrence time greater than six months; - hemiparesis with brachial predominance, mild to moderate motor deficit in the affected upper limb defined by a score between 19 and 55 points on the FMA-UE; - have minimum joint integrity to perform the movements required in the protocol with an active range of motion of at least 20° of wrist extension, 10° of extension of the metacarpophalangeal and interphalangeal joints and 20° of elbow extension considering the standard position of 90° elbow flexion, measured with a Carci® goniometer; - demonstrate the ability to understand and follow simple commands on the Mini Mental State Examination (MMSE) (ANNEX II) with a score higher than 23 points for literate persons and lower than 15 points for illiterate persons. Exclusion Criteria: - diagnosis of epilepsy; - intracranial metallic implants or implantable electronic devices; - contraindications to transcranial direct current stimulation (tDCS), including skin lesions on the scalp; - severe musculoskeletal limitations that prevent the execution of tasks; - history of recurrent stroke; - associated disabling musculoskeletal and neurological pathologies; (7) use of botulinum toxin in the previous three months; - uncontrolled systemic arterial hypertension or diabetes mellitus; - clinically relevant heart disease; - apraxia and aphasia of comprehension; - fracture and pain during movement or displacement of the affected limb, or pain related to shoulder subluxation. Those who feel uncomfortable, drop out of the research, do not respect the rules established in the Informed Consent Form (APPENDIX C), or do not attend the stages of the study will also be excluded.