An interventional study of Visual Adaptation and Assessments and Questionnaires in Visual Snow Syndrome, Migraine and Healthy, sponsored by University of Minnesota. Recruiting at 1 site in United States. Open to participants aged 18 Years to 60 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-01-14.
Sponsored by University of Minnesota · Not applicable, Interventional, and Basic science
The goal of this study is to learn more about the brain pathways and activity involved in creating Visual Snow Syndrome (VSS). The main questions it aims to answer are:
Participants will:
1,657 studies on the registry are indexed under Migraine Disorders; 339 are open to participants now.
This study's planned enrollment of 100 is above the median of 80 across 1,269 interventional studies indexed under Migraine Disorders.
Browse Migraine Disorders studies →University of Minnesota is the lead sponsor of 1,216 studies on the registry; 197 are open to participants now.
Of its 136 completed or terminated interventional studies of FDA-regulated products, 95 (70%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Inclusion Criteria for People with Visual Snow Syndrome:
Inclusion Criteria for Non-snow Controls:
Exclusion Criteria for People with Visual Snow Syndrome:
MRI exclusions (for MR visits only):
Exclusion Criteria for Non-snow Controls:
MRI exclusions (for MR visits only):
Behavioral: Visual Adaptation · Behavioral: Assessments and Questionnaires · Device: Functional Magnetic Resonance Imaging (fMRI) · Device: Magnetic Resonance Imaging (MRS)
Behavioral: Visual Adaptation · Behavioral: Assessments and Questionnaires · Device: Functional Magnetic Resonance Imaging (fMRI) · Device: Magnetic Resonance Imaging (MRS)
Presentation of visual stimuli to quantify the appearance of visual snow or its effects in the visual system of the brain.
Administration of clinical assessments and questionnaires to gather information about visual and mental symptoms, cognitive, and sensory function.
7 tesla fMRI data will be acquired during visual paradigms designed to measure neural responses with and without adaptation.
7 tesla MRS data will be acquired to quantify the concentrations of different brain chemicals in brain regions including visual cortex.
Psychophysical Adaptation Task Performance
Visual tasks will consist of perceptual judgments following adaptation (e.g., subject will report when internal or external / simulated visual snow appears the same on the left or right side of the screen). Measures will be compared for visual target stimuli in different task conditions and experiments, with the goal of understanding the neural basis of visual snow.
Time frame: 1.5-2 hours per session, with experiments divided across multiple (e.g., 3) sessions
Functional Magnetic Resonance Imaging (fMRI) Measures
7 tesla fMRI data will be acquired during visual paradigms designed to measure neural responses with and without adaptation. FMRI data will be processed and analyzed to quantify the effect of adaptation across different regions in visual cortex.
Time frame: 1-2 hours per session, with experiments split across multiple (e.g., 3) sessions
Magnetic Resonance Spectroscopy (MRS)
7 telsa MRS data will be acquired to quantify the concentration of different brain chemicals in brain areas including visual cortex.
Time frame: 1-2 hours
Clinical Symptom Scores
Measures of visual and mental symptoms, cognitive, and sensory function (e.g., Visual Snow Questionnaire), will be collected using self-report and interview methods. Scores will be compared across groups to differences in visual and mental symptoms in people with and without visual snow syndrome (VSS).
Time frame: 1-2 hours
Plan to share: Yes — De-identified data will be shared to a public repository at the end of the study. Data that will be shared include the study protocol, informed consent form, analytic code, behavioral data, and brain imaging data. OpenNuero.org will be used for data and Github.com will be used to share code.
Supporting information: Study protocol, Informed consent form, Analytic code
Time frame: Data will be shared within 12 months of the completion of our study or publication of a relevant manuscript, whichever comes first.
Access criteria: Everyone will be able to access the data shared to the repositories.
Started Apr 2025 (actual). Primary completion is estimated for Mar 2030, 59 months after the start.
Of 309 non-industry interventional studies with no phase under Migraine Disorders, half reached primary completion within 17 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 36. This study's planned 59 months is above that.
Counting every sponsor, half of 358 studies reached it within 15 months; a quarter within 7 and three quarters within 34.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
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