Clinical trial NCT06961864: Investigating Brain Function in People With and Without Visual Snow Syndrome Using Adaptation to Visual Stimuli
Official title: Visual Perception in Visual Snow Syndrome
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Visual Snow Syndrome
Migraine
Healthy
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
Lead sponsor: University of Minnesota
Sponsor class: OTHER
Collaborators: name: National Institutes of Health (NIH)
name: Mayo Clinic
name: National Eye Institute (NEI)
First posted: 2025-05-08
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

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:

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.


Eligibility criteria: Inclusion Criteria for People with Visual Snow Syndrome:

* 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

Inclusion Criteria for Non-snow Controls:

* 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 for People with Visual Snow Syndrome:

* 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

Exclusion Criteria for Non-snow Controls:

* 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

Primary outcomes:
measure: Psychophysical Adaptation Task Performance
timeFrame: 1.5-2 hours per session, with experiments divided across multiple (e.g., 3) sessions
measure: Functional Magnetic Resonance Imaging (fMRI) Measures
timeFrame: 1-2 hours per session, with experiments split across multiple (e.g., 3) sessions
measure: Magnetic Resonance Spectroscopy (MRS)
timeFrame: 1-2 hours
Secondary outcomes:
measure: Clinical Symptom Scores
timeFrame: 1-2 hours
Other outcomes:
Locations:
city: Minneapolis
country: United States
facility: University of Minnesota
state: Minnesota
Study officials:
affiliation: University of Minnesota, Department of Psychiatry and Behavioral Sciences
name: Michael-Paul Schallmo, Ph.D.
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Minnesota, Department of Psychology
name: Stephen A Engel, Ph.D.
role: STUDY_CHAIR
affiliation: University of Minnesota, Department of Ophthalmology and Visual Neurosciences
name: Michael S Lee, M.D.
role: STUDY_CHAIR
affiliation: University of Minnesota, Department of Neurology
name: Abby Metzler, M.D.
role: STUDY_CHAIR
affiliation: University of Minnesota, Department of Radiology
name: Malgorzata Marjanska, Ph.D.
role: STUDY_CHAIR
affiliation: Mayo Clinic, Rochester, Department of Neurology
name: Carrie E Robertson, M.D.
role: STUDY_CHAIR
References:
citation: 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.
citation: Montoya, S.A., Hillstrom, A.J., Allison, K.D., Mulder, C.B., Moser, H.R., Lee, M.S., Schallmo, M-P., Engel, S.A. (submitted). Visual snow is susceptible to the motion aftereffect. Preprint available on PsyArXiv, doi: 10.31234/osf.io/u6fcx_v1
citation: 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.