The Use of Transcranial Direct Current Stimulation (TDCS) to Enhance the Rehabilitative Effect of Vision Restoration Therapy
Hemianopia, Quadrantanopia, Scotoma
About this trial
This is an interventional treatment trial for Hemianopia focused on measuring Hemianopia, Rehabilitation, Transcranial direct current stimulation, Visual field
Eligibility Criteria
Inclusion Criteria:
- Hemianopic field loss is defined as (a) visual field defect on the same side of visual space in both eyes as determined by monocular perimetry and (b) established structural damage of the post-charismatic visual system as documented by standard neuroimaging techniques (CT or MRI), medical reports, or a combination of these
- deep scotoma - defined field loss as confirmed by perimetry
- cognitive, language and motor function sufficient to understand the experiments and follow instructions
- informed written consent to participate in the study
- motivation to participate in the VRT program
Exclusion Criteria:
- any sensory-motor loss other than visual
- ongoing use of CNS-active medications for an active neurological disease
- ongoing use of psychoactive medications, such as stimulants, antidepressants, and anti-psychotic medications for an active psychiatric condition
presence of additional potential TDCS risk factors:
- Damaged skin at the site of stimulation (i.e., skin with ingrown hairs, acne, razor nicks, wounds that have not healed, recent scar tissue, broken skin, etc.)
- Presence of an electrically, magnetically or mechanically activated implant (including cardiac pacemaker), an intracerebral vascular clip, or any other electrically sensitive support system.
- Metal in any part of the body, including metal injury to the eye. (Jewelry must be removed during stimulation.)
- A history of medication-resistant epilepsy in the family
- Past history of seizures or unexplained spells of loss of consciousness
Sites / Locations
Arms of the Study
Arm 1
Arm 2
Active Comparator
Sham Comparator
VRT and active tDCS
VRT combined with sham tDCS
Patients will receive tDCS (noninvasive brain stimulation) concurrently with vision restoration therapy. TDCS is delivered using a small battery-operated device. Electrical leads from the device are connected to saline soaked sponges that are placed at strategic locations on the skull corresponding to areas of the brain that need to be stimulated (in this case, the visual cortex). The dosage will be set to 2 mA/min for 30 minutes, twice a day for 3 days a week for 12 weeks.
Patients will receive sham tDCS concurrently with vision restoration therapy. Electrical leads from the tDCS device will be connected to saline soaked sponges placed at strategic locations on the skull, in a similar maner as in the active tDCS group. Current will be turned on for 30 seconds but will be slowly ramped down and turned off. Treatment will continue for 3 days a week for 12 weeks.