Home Transcranial Direct Current Stimulation (tDCS) to Enhance Functional Recovery

Inclusion Criteria: * At least 3 months after ischemic/hemorrhagic/anoxic stroke or 3 months after completion of cranial radiation or cranial surgery for treatment of primary or metastatic intracranial tumors or neurodegenerative conditions include, but are not limited to, primary progressive aphasia, corticobasal syndrome, progressive supranuclear palsy, Parkinson's disease, and Alzheimer's disease dementia. * Expected survival \>6 months * Functional impairment in the domains of language and/or cognition affecting quality of life determined by PI. * Have a legally authorized representative who is able to sign on their behalf in unable to consent for themselves (ex., individuals with aphasia). * Have a legally authorized representative who is able to sign on their behalf in unable to consent for themselves (ex., individuals with aphasia). Exclusion Criteria: * Pregnancy * Contraindication to tDCS, including metallic implanted objects. * Medical instability or inability to cooperate during the study as assessed by the treating physician to participate in the study. * Individuals with epilepsy