Non-invasive Current Stimulation for Restoration of Vision

Study Overview
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Brief Summary
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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.

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

Conditions
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Stroke, Electrical Stimulation

Intervention / Treatment
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* Device: repetitive transorbital AC Stimulation
* Device: combination of transcranial direct current stimulaton and rtACS


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: randomized, controlled
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: rtACS<br>repetitive transorbital ACS | Device: repetitive transorbital AC Stimulation<br>* Repetitive transorbital ACS with max 30 Hz, 1,5 mA for 10 days, 20 min/day<br>Device: combination of transcranial direct current stimulaton and rtACS<br>* Sequential tDCS (anodal occipital stimulation with 2 mA for 20 min/day for 10 days) and rtACS<br>|
| Experimental: tDCS/rtACS<br>Sequential tDCS - tACS | Device: repetitive transorbital AC Stimulation<br>* Repetitive transorbital ACS with max 30 Hz, 1,5 mA for 10 days, 20 min/day<br>Device: combination of transcranial direct current stimulaton and rtACS<br>* Sequential tDCS (anodal occipital stimulation with 2 mA for 20 min/day for 10 days) and rtACS<br>|
| Sham Comparator: Sham stimulation<br> | Device: repetitive transorbital AC Stimulation<br>* Repetitive transorbital ACS with max 30 Hz, 1,5 mA for 10 days, 20 min/day<br>Device: combination of transcranial direct current stimulaton and rtACS<br>* Sequential tDCS (anodal occipital stimulation with 2 mA for 20 min/day for 10 days) and rtACS<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Size of the visual field | Mean threshold in standard static perimetry and and detection accuracy in HRP | 2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Resting EEG power spectra | EEG measurement using 128 channel | 2 weeks |