Visual Field Defect, Stroke, Hemianopia, Quadrantanopia, Cortical Blindness, Brain Tumor, Traumatic Brain Injury, Visual Field Defect, Peripheral
Conditions
Brief summary
The VIBRANT (Vision Improvement through Behavioral Rehabilitation And Neuroplasticity Training) study is a prospective, double-blind, crossover design (within-subject) in participants with homonymous hemianopia-a type of visual field loss resulting from damage to the post-chiasmatic visual pathways. It aims to investigate whether transcranial random noise stimulation (tRNS) combined with perceptual learning-based training has potential for improving visual impairments.
Interventions
Stimulation location: bilateral human middle temporal complex (hMT+). Stimulation parameters: 1 mA current intensity, with a frequency range of 101-640 Hz.
DEVICESham Stimulation
Stimulation location: bilateral human middle temporal complex (hMT+). Stimulation parameters: Ramp up stimulation at 1mA with a frequency range of 101-640Hz for the first 30 seconds followed by no current for the remainder of the duration.
BEHAVIORALPerceptual learning-based training
A motion discrimination task, judging the global direction of moving dot stimuli with two different coherence levels.
Sponsors
Georgetown University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)
Masking description
This study is double-blind, meaning that both the participants and the researchers will be blinded to the treatment conditions.
Intervention model description
1. Initial 2-Day Sessions: Participants receive either real or sham transcranial random noise stimulation (tRNS) combined with perceptual learning-based training. 2. Washout Period: A minimum 1-week washout period (typically around 2 weeks) is included to minimize potential carry-over effects. 3. Final 2-Day Sessions: Participants complete the alternate stimulation condition (sham or real) paired with perceptual learning-based training.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
A. Stroke, brain tumor, or traumatic brain injury patients Inclusion Criteria: 1. At least 18 years of age. 2. Capable of providing informed consent and complying with study procedures. 3. Unilateral or bilateral focal brain damage causing loss of vision. 4. At least three months post-stroke or traumatic brain injury, or a stable brain tumor within the past year.
Exclusion criteria
1. Severe CNS diseases or disorders unrelated to the focal lesion, which could interfere with study results. 2. Severe mental health challenges that could interfere with study results, or current or recent (within the past 6 months) drug or alcohol abuse or addiction as defined by DSM-5. 3. Vision loss resulting from ocular disease or disorder. B. Healthy volunteers (age-matched controls): Inclusion Criteria: 1. At least 18 years of age. 2. Capable of providing informed consent and complying with study procedures.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Motion Discrimination Performance | Study visit 1 to 2 (within a week), and study visit 3 to 4 (within a week) | Change in accuracy on a computerized motion direction discrimination task programmed in the lab. The task assesses participants' ability to discriminate the direction of the peripherally presented moving dots at two locations (one within the blind field and the other at a mirror-symmetric location in the intact visual field). Accuracy is defined as the proportion of correct responses out of the total number of trials completed. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Visual Field Change | Baseline (pre-intervention) to post-intervention follow-up (approximately 3 months, up to 6 months) | Change in visual field function, assessed by perimetric mean deviation (PMD) measured using Humphrey perimetry. PMD is a global index representing the average deviation of visual field sensitivity compared to age-matched norms, measured in decibels (dB). More negative PMD values indicate greater visual field loss. |
| Visual Perception Change | Baseline (pre-intervention) to post-intervention follow-up (approximately 3 months, up to 6 months) | Change in visual perception in the following two task: 1. Face/Object Recognition: identify whether a peripherally presented stimulus is a face or an object. 2. Motion Discrimination: discriminate the direction of the peripherally presented moving dots. Performance on both tasks will be measured at visual field locations targeted by brain stimulation and at control visual field locations not targeted by brain stimulation. |
| Quality of Life Change | Baseline (pre-intervention) to post-intervention follow-up (approximately 3 months, up to 6 months) | Change in quality of life evaluated using the National Eye Institute 25 Item Visual Function Questionnaire (NEI-VFQ 25). Scores range from 0 to 100, with higher scores indicating better vision-related quality of life. |
Countries
United States
Contacts
Primary ContactTina Liu, PhD
Backup ContactKyungji Moon, MS
Outcome results
None listed