BCI With Virtual Reality for Stroke Rehabilitation: A Crossover Study

Inclusion Criteria: * Clinical diagnosis of stroke confirmed by neuroimaging, with resulting upper limb hemiparesis. * Time since stroke between 6 and 24 months at the time of selection. * Sufficient cognitive ability to understand and follow the intervention procedures. * Spasticity score \<3 on the Modified Ashworth Scale in upper limb muscle groups. * Adults aged 18 to 80 years. * Ability to remain seated for approximately 2 hours. * Motivation to participate and capacity to provide informed consent. * Undergoing conventional rehabilitation therapy during the study period. Exclusion Criteria: * Severe communication difficulties preventing comprehension or execution of instructions. * Skin lesions, allergies, or metal implants in the cephalic region, or history of craniectomy, that hinder electrode placement or interfere with EEG signal acquisition. * Concomitant neurological or musculoskeletal conditions affecting upper limb motor function. * Other neurological, musculoskeletal, or psychiatric conditions that may compromise participation or study outcomes (e.g., major depression, severe visual impairment, photosensitive epilepsy, frequent vertigo or dizziness). * Upper limb impairment due to a previous stroke.