Effects of a Neurorehabilitation Program Based on CIMT and Non-invasive Neuromodulation Through C-tDCS on the Recovery of Paretic Upper Limb Function, Quality of Life, and Therapeutic Alliance in Women From the Araucanía Region Who Suffered a Stroke (CIMT + tDCS).

Effects of a Neurorehabilitation Program Based on Constraint-Induced Movement Therapy (CIMT) and Non-invasive Neuromodulation Through Cerebellar Transcranial Direct Current Stimulation (C-tDCS) on the Recovery of Paretic Upper Limb Function, Quality of Life, and Therapeutic Alliance in Women From the Araucanía Region Who Suffered a Stroke.

General Objective To determine the effects of a neurorehabilitation program based on Constraint-Induced Movement Therapy (CIMT) and non-invasive neuromodulation through cerebellar transcranial direct current stimulation (C-tDCS) on the recovery of paretic upper limb function, quality of life, and therapeutic alliance in women from the Araucanía Region who suffered a stroke. Methodology An experimental design consisting of a single-blind randomized controlled clinical trial is proposed. The study will include two independent groups of women diagnosed with stroke, who will participate in five assessment time points (pre-treatment, intermediate, post-treatment, and two follow-ups). Motor function (Motor Activity Log-30 and ARAT), quality of life (ECVI-38), and therapeutic alliance (CAF-P) will be evaluated. The intervention includes 10 sessions (120 minutes each), delivered daily over a two-week period. The experimental group (EG) will receive CIMT combined with C-tDCS, while the control group (CG) will receive CIMT plus sham C-tDCS (using the standard safety sham protocol commonly known as "FISSFO" [Fade In of Stimulation, Brief Real Stimulation, Fade Out]). In both groups, C-tDCS will be applied during the first 20 minutes of the session simultaneously with the practice of specific upper-limb motor tasks, followed by 100 minutes of CIMT. The CG will receive the same intervention but with sham stimulation, applying current for one minute to generate the initial sensation without producing a physiological effect. Sessions will be conducted in mixed subgroups (two participants from the EG and two from the CG) sharing the same therapeutic space. A proposed sample size of N = 26 (13 patients per group) was calculated considering a statistical power of 80%, assuming a medium effect size of f = 0.25, an error probability α = 0.05, a power (1 - error probability β) = 0.95, and correlations among repeated measures = 0.50. An additional 10% was included to compensate for potential losses during follow-up. Simple random allocation of the sample will be performed using SPSS Statistics 27. Proposed Analysis Plan SPSS Statistics 27 software will be used. Initially, descriptive statistics will be employed to analyze the sample according to sociodemographic and clinical characteristics. Subsequently, Cronbach's alpha reliability coefficient will be calculated to examine the internal consistency of the motor function and quality-of-life variables, both within and between groups and across evaluation time points. The effects of the intervention will be assessed using unifactorial intragroup and intergroup analyses of covariance (ANCOVA). In each ANCOVA, treatment will be considered the independent variable, each motor function and quality-of-life score will be considered the dependent variable, and control variables will be included as covariates. All results with p-values less than or equal to 0.05 in one-tailed tests will be considered statistically significant. Expected Results It is expected that the combination of CIMT and C-tDCS will significantly enhance motor recovery in post-stroke women. The intervention may improve upper-limb function recovery, promote better quality of life, and optimize the therapeutic alliance, resulting in greater participation in daily activities. By modulating cerebellar activity, C-tDCS may facilitate neuronal plasticity and accelerate the response to intensive training. If confirmed, the study will provide evidence for a safe, accessible, and effective neurorehabilitation strategy, opening future low-cost avenues for current rehabilitation practices.

Inclusion Criteria:

• Women aged between 30 and 80 years.
• Who present hemorrhagic or ischemic stroke confirmed by CT with evolution greater than 1 month, corroborated by discharge epicrisis supporting the diagnosis of the patient.
• Who presents trunk control in sitting.
• Score greater than 14 points on the Minimental Examination scale.
• Function of the upper extremity, referring to taking and releasing a small ball with the affected hand and signing or accepting the consent written informed.

Exclusion Criteria:

• Shoulder pain greater than 4 according to the VAS scale and spasticity greater than 2 according to the Modified Ashworth Scale.
• Sensory compromise (visual-auditory).
• Presence of severe aphasia.
• Cochlear implants, aneurysm clips, brain electrodes and cardiac pacemaker.
• Epilepsy or psychiatric disorders (diagnosed in the last 3 months).
• Pregnancy, use of psychotropic medications.