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

NCT ID: NCT06961864

Last Updated: 2026-01-14

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

100 participants

Study Classification

INTERVENTIONAL

Study Start Date

2025-04-11

Study Completion Date

2030-03-31

Brief Summary

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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:

1. Undergo assessments and questionnaires to understand visual and mental symptoms, cognitive, and sensory function.
2. Make visual judgements based on images presented to them both inside and outside a magnetic resonance imaging (MRI) machine.
3. Undergo scanning of their brain while inside of an MRI machine.

Detailed Description

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Conditions

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Visual Snow Syndrome Migraine Healthy

Study Design

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Allocation Method

NON_RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

NONE

Study Groups

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People with Visual Snow Syndrome

Group Type ACTIVE_COMPARATOR

Visual Adaptation

Intervention Type BEHAVIORAL

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

Assessments and Questionnaires

Intervention Type BEHAVIORAL

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

Functional Magnetic Resonance Imaging (fMRI)

Intervention Type DEVICE

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

Magnetic Resonance Imaging (MRS)

Intervention Type 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

Group Type PLACEBO_COMPARATOR

Visual Adaptation

Intervention Type BEHAVIORAL

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

Assessments and Questionnaires

Intervention Type BEHAVIORAL

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

Functional Magnetic Resonance Imaging (fMRI)

Intervention Type DEVICE

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

Magnetic Resonance Imaging (MRS)

Intervention Type DEVICE

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

Interventions

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Visual Adaptation

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

Intervention Type BEHAVIORAL

Assessments and Questionnaires

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

Intervention Type BEHAVIORAL

Functional Magnetic Resonance Imaging (fMRI)

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

Intervention Type DEVICE

Magnetic Resonance Imaging (MRS)

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

Intervention Type DEVICE

Eligibility Criteria

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Inclusion Criteria

* 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

Exclusion Criteria

* 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
* MRI exclusions (for MR visits only):

* 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
* CT scan exclusion only: Research-related radiation exposure within the last 12 months
* Any vision anomaly aside from VS or refractive error (e.g., strabismus/ crossed eyes, lazy eyes, color blindness)
* Current psychotic episode


* 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
* 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
* MRI exclusions (for MR visits only):

* 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
* CT scan exclusion only: Research-related radiation exposure within the last 12 months
* Any vision anomaly or refractive error (e.g. strabismus/ crossed eyes, lazy eyes, color blind)
* A personal history of VSS symptoms or a diagnosis with VSS
* Current psychotic episode
Minimum Eligible Age

18 Years

Maximum Eligible Age

60 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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National Institutes of Health (NIH)

NIH

Sponsor Role collaborator

Mayo Clinic

OTHER

Sponsor Role collaborator

National Eye Institute (NEI)

NIH

Sponsor Role collaborator

University of Minnesota

OTHER

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Michael-Paul Schallmo, Ph.D.

Role: PRINCIPAL_INVESTIGATOR

University of Minnesota, Department of Psychiatry and Behavioral Sciences

Stephen A Engel, Ph.D.

Role: STUDY_CHAIR

University of Minnesota, Department of Psychology

Michael S Lee, M.D.

Role: STUDY_CHAIR

University of Minnesota, Department of Ophthalmology and Visual Neurosciences

Abby Metzler, M.D.

Role: STUDY_CHAIR

University of Minnesota, Department of Neurology

Malgorzata Marjanska, Ph.D.

Role: STUDY_CHAIR

University of Minnesota, Department of Radiology

Carrie E Robertson, M.D.

Role: STUDY_CHAIR

Mayo Clinic, Rochester, Department of Neurology

Locations

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University of Minnesota

Minneapolis, Minnesota, United States

Site Status RECRUITING

Countries

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United States

Central Contacts

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Michael-Paul Schallmo, Ph.D.

Role: CONTACT

(612) 273-9130

Hannah Moser, Ph.D.

Role: CONTACT

Facility Contacts

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Michael-Paul Schallmo, Ph.D., Assistant Professor

Role: primary

612-273-9130

References

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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.

Reference Type BACKGROUND
PMID: 38837169 (View on PubMed)

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.

Reference Type BACKGROUND
PMID: 41085357 (View on PubMed)

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.

Reference Type BACKGROUND
PMID: 38117246 (View on PubMed)

Related Links

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Other Identifiers

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R01EY036005

Identifier Type: NIH

Identifier Source: secondary_id

View Link

STUDY00014113

Identifier Type: -

Identifier Source: org_study_id

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