Improving Visual Field Deficits With Noninvasive Brain Stimulation

Exclusion Criteria20

• No evidence of damage to the primary visual cortex.
• Visual cortex damage as a result of a subsequent stroke (not primary).
• Total cortical blindness, covering both left and right visual fields.
• Unable to fixate visual targets precisely or unable to perform the visual training exercises as directed.
• Complete loss of reading abilities.
• Current or prior history of any neurological disorder other than stroke, such as epilepsy, a progressive neurologic disease (e.g. multiple sclerosis) or intracranial brain lesions other than the qualifying stroke lesion.
• Current history of poorly controlled migraines including chronic medication for migraine prevention.
• History of seizures, diagnosis of epilepsy, history of abnormal (epileptiform) EEG or immediate (1st degree relative) family history of epilepsy; with the exception of a single seizure of benign etiology (e.g. febrile seizure) in the judgment of the investigator.
• History of fainting spells of unknown or undetermined etiology that might constitute seizures.
• Past or current history of major depression, bipolar disorder or psychotic disorders, or any other major psychiatric condition.
• Participants who are suffering from one-sided attentional neglect as determined by standard neuropsychological tests: figure cancellation and line bisection tasks.
• Contraindication for receiving tRNS.
• Chronic (particularly) uncontrolled medical conditions that may cause a medical emergency in case of a provoked seizure (cardiac malformation, cardiac dysrhythmia, asthma, etc.).
• Any complex, uncontrolled/unstable or terminal medical illness.
• Substance abuse or dependence within the past six months.
• Medications will be reviewed by the responsible MD (Drs. Sandeep Kumar or Dan Press) and a decision about inclusion will be made based on the following: The patient's past medical history, drug dose, history of recent medication changes or duration of treatment, and combination of CNS active drugs.
• All female participants that are pre-menopausal will be required to have a pregnancy test; any participant who is pregnant or breastfeeding will not be enrolled in the study.
• Subjects who, in the investigator's opinion, might not be suitable for the study.
• A hair style or head dress that prevents electrode contact with the scalp or would interfere with the stimulation (for example: thick braids, hair weave, afro, wig).
• Additional criteria for Group 1b only: Contraindication for using VR technology, specifically an implanted medical device such as a pacemaker, implanted defibrillator, deep brain or vagal nerve stimulator. Participants with a history of seizures are already excluded per the above criteria.