Investigating Brain Function in People With and Without Visual Snow Syndrome Using Adaptation to Visual Stimuli

NCT06961864 | Recruiting

• 2 other identifiers: STUDY00014113R01EY036005
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

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:

• Does VSS arise from spontaneous activity in brain pathways?
• Where in the brain does the activity contributing to VSS arise?
• How does brain activity contribute to VSS? Participants will:
• Undergo assessments and questionnaires to understand visual and mental symptoms, cognitive, and sensory function.
• Make visual judgements based on images presented to them both inside and outside a magnetic resonance imaging (MRI) machine.
• Undergo scanning of their brain while inside of an MRI machine.

Conditions

Migraine; Healthy; Visual Snow Syndrome

Keywords

Visual Snow Syndrome; Visual Snow; Migraine; Floaters; Palinopsia; Photophobia; Nyctalopia; Entoptic phenomena; Visual trailing; Adaptation; Magnetic resonance spectroscopy; MRS; Magnetic resonance imaging; MRI; University of Minnesota; Afterimages; Poor night vision; Light sensitivity; Persistent positive visual phenomena; Static

Outcome Measures

Primary Outcomes (3)

• 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.

  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.

  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.

  1-2 hours

Secondary Outcomes (1)

• Clinical Symptom Scores

  1-2 hours

Study Arms (2)

People with Visual Snow Syndrome

ACTIVE COMPARATOR

Behavioral: Visual Adaptation; Behavioral: Assessments and Questionnaires; Device: Functional Magnetic Resonance Imaging (fMRI); Device: Magnetic Resonance Imaging (MRS)

Non-snow Controls

PLACEBO COMPARATOR

Behavioral: Visual Adaptation; Behavioral: Assessments and Questionnaires; Device: Functional Magnetic Resonance Imaging (fMRI); Device: Magnetic Resonance Imaging (MRS)

Interventions

Visual Adaptation BEHAVIORAL

Presentation of visual stimuli to quantify the appearance of visual snow or its effects in the visual system of the brain.

Non-snow Controls; People with Visual Snow Syndrome

Assessments and Questionnaires BEHAVIORAL

Administration of clinical assessments and questionnaires to gather information about visual and mental symptoms, cognitive, and sensory function.

Non-snow Controls; People with Visual Snow Syndrome

Functional Magnetic Resonance Imaging (fMRI) DEVICE

7 tesla fMRI data will be acquired during visual paradigms designed to measure neural responses with and without adaptation.

Non-snow Controls; People with Visual Snow Syndrome

Magnetic Resonance Imaging (MRS) DEVICE

7 tesla MRS data will be acquired to quantify the concentrations of different brain chemicals in brain regions including visual cortex.

Non-snow Controls; People with Visual Snow Syndrome

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Between the ages of 18 and 60 years old
• Normal (20/25 or better in each eye) or corrected-to-normal vision (MR-compatible glasses will be provided as needed)
• Ability to comply with study instructions
• Individuals who have a current diagnosis of VSS from a neuro-ophthalmologist or meet diagnostic criteria of VSS (experience of dynamic dots across the visual field persisting longer than 3 months and at least 2 of the following additional visual symptoms: palinopsia, entoptic phenomena, trails behind moving objects, photophobia, or nyctalopia)
• Individuals living in Minnesota within 2 hours of the study site
• Between the ages of 18 and 60 years old
• Normal (20/25 or better in each eye) or corrected-to-normal vision (MR-compatible glasses will be provided as needed)
• Ability to comply with study instructions
• Individuals living in Minnesota within 2 hours of the study site

You may not qualify if:

• Not being fluent in English or another language for which interpretation/translation services are available
• A diagnosed or self-reported intellectual disability
• Current substance dependence (besides nicotine), or drug dependence with tolerance or withdrawal within past 12 months
• Hallucinogenic substance use within the past 12 months or hallucinogenic substance use within 12 months prior to onset of VSS symptoms
• Severe central nervous system disease
• Head injury with skull fracture or loss of consciousness for more than thirty minutes
• Presence of a physical problem that would render study measures difficult or impossible to administer or interpret (e.g., visual field loss)
• Age less than 18 years or greater than 60 years
• Metal in the body that cannot be approved by the CMRR safety committee
• Pregnancy
• Conditions that affect neuro-hemodynamic coupling
• Claustrophobia
• Inability to lie still for at least an hour
• Weight in excess of 440 lbs
• Any vision anomaly aside from VS or refractive error (e.g., strabismus/ crossed eyes, lazy eyes, color blindness)

Sponsors & Collaborators

• University of Minnesota: lead
• National Institutes of Health (NIH): collaborator
• Mayo Clinic: collaborator
• National Eye Institute (NEI): collaborator

Study Sites (1)

University of Minnesota

Minneapolis, Minnesota, 55455, United States

RECRUITING

Related Publications (3)

• Montoya SA, Mulder CB, Allison KD, Lee MS, Engel SA, Schallmo MP. What does visual snow look like? Quantification by matching a simulation. J Vis. 2024 Jun 3;24(6):3. doi: 10.1167/jov.24.6.3.

  PMID: 38837169 BACKGROUND

• Montoya SA, Hillstrom AJ, Allison KD, Mulder CB, Moser HR, Lee MS, Schallmo MP, Engel SA. Visual Snow Is Susceptible to the Motion Aftereffect. Invest Ophthalmol Vis Sci. 2025 Oct 1;66(13):23. doi: 10.1167/iovs.66.13.23.

  PMID: 41085357 BACKGROUND

• Montoya SA, Mulder CB, Lee MS, Schallmo MP, Engel SA. Adapting to Visual Noise Alleviates Visual Snow. Invest Ophthalmol Vis Sci. 2023 Dec 1;64(15):23. doi: 10.1167/iovs.64.15.23.

  PMID: 38117246 BACKGROUND

Related Links

• Related Info

MeSH Terms

Conditions

visual snow syndrome; Migraine Disorders; vitreous floaters; palinopsia; Photophobia; Night Blindness; Vitamin A Deficiency

Interventions

Surveys and Questionnaires; Magnetic Resonance Imaging

Condition Hierarchy (Ancestors)

Headache Disorders, Primary; Headache Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vision Disorders; Sensation Disorders; Neurologic Manifestations; Eye Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Avitaminosis; Deficiency Diseases; Malnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases

Intervention Hierarchy (Ancestors)

Data Collection; Epidemiologic Methods; Investigative Techniques; Health Care Evaluation Mechanisms; Quality of Health Care; Health Care Quality, Access, and Evaluation; Public Health; Environment and Public Health; Tomography; Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis

Study Officials

• Michael-Paul Schallmo, Ph.D.

  University of Minnesota, Department of Psychiatry and Behavioral Sciences

  PRINCIPAL INVESTIGATOR

• Stephen A Engel, Ph.D.

  University of Minnesota, Department of Psychology

  STUDY CHAIR

• Michael S Lee, M.D.

  University of Minnesota, Department of Ophthalmology and Visual Neurosciences

  STUDY CHAIR

• Abby Metzler, M.D.

  University of Minnesota, Department of Neurology

  STUDY CHAIR

• Malgorzata Marjanska, Ph.D.

  University of Minnesota, Department of Radiology

  STUDY CHAIR

• Carrie E Robertson, M.D.

  Mayo Clinic, Rochester, Department of Neurology

  STUDY CHAIR

Central Study Contacts

Michael-Paul Schallmo, Ph.D.

CONTACT

(612) 273-9130; schallmolab@umn.edu

Hannah Moser, Ph.D.

CONTACT

schallmolab@umn.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 29, 2025
• First Posted: May 8, 2025
• Study Start: April 11, 2025
• Primary Completion (Estimated): March 31, 2030
• Study Completion (Estimated): March 31, 2030
• Last Updated: January 14, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ICF, 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.

Locations

US (1)