Non-invasive Current Stimulation for Restoration of Vision

Non-invasive Current Stimulation for Restoration of Vision (REVIS) After Unilateral Occipital Stroke

The aim of the study is to evaluate effects of current stimulation of the brain on vision parameters, vision-related quality of life, and physiological parameters to uncover mechanisms of vision restoration. These include EEG-spectra and coherence measures, and visual evoked potentials. The design of stimulation protocols involves an appropriate sham-stimulation condition and sufficient follow-up periods to test whether the effects are stable. This is the first application of non-invasive current stimulation for vision rehabilitation in stroke-related visual field deficits.

Inclusion Criteria:

• HH due to ischemic or hemorrhagic stroke
• age between 18 and 75 years
• lesion age at least 6 months
• stable visual field defect across baseline measurement (subjects with spontaneous fluctuations and recovery of vision excluded)
• presence of residual vision and detectable gradual transition between the intact and the absolutely blind part of the visual field according to evaluation of the clinician
• best corrected visual acuity at least 0.4 (20/50 Snellen) or better

Exclusion Criteria:

• known active malignancy
• eye or central nervous system diseases that interfere with the study (including poorly controlled glaucoma)
• electric or electronic implants (e.g. heart pacemaker)
• metal artifacts in the eyes or head (with the exception of dental prosthesis or shunts)
• expected low compliance (e.g. in case of known psychiatric disease, known drug abuse, and dementing syndromes)
• epileptic seizure within the last 10 years
• use of antiepileptic or sedative drugs