Restoration of Vision After Stroke

Electrical Stimulation for Restoration of Vision After Stroke in the Damaged Visual Field of Patients With Unilateral Stroke (REVIS Helsinki)

Occipital stroke is associated with homonymous visual field defects (occurring on one side of the visual field). Despite spontaneous recovery, some degree of defect is often permanent. Currently, no treatment exists for such visual field defects.The purpose of this study is to test the efficacy of a type of electrical brain stimulation method, transcranial alternating current stimulation, in reducing these type of visual field defects in their chronic stage.

Inclusion Criteria:

• Occipital ischemic or hemorrhagic stroke 6 months or older
• Hemianopia or quadrantanopia demonstrated by standard automated perimetry
• Visual field defect is stable across baseline
• Presence of residual vision and detectable gradual transition between the the intact and absolutely blind parts of the visual field
• Best corrected visual acuity for at least one eye better or equal to 0.4

Exclusion Criteria:

• Eye or central nervous system disease that interferes with the study
• Cardiac pacemaker
• Other metallic devices or implants precluding participation in MRI scans
• Pregnancy or lactation period
• Epileptic seizures in the past 10 years
• Use of antiepileptic or sedative drugs
• Expected low compliance due to substance abuse
• Known active malignancy