[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-study-detail:100590011":3},{"organization":4,"armGroups":7,"interventions":21,"overallOfficials":40,"centralContacts":61,"locations":68,"responsibleParty":86,"collaborators":88,"id":96,"slug":97,"hasResults":98,"nctId":99,"briefTitle":100,"officialTitle":101,"acronym":102,"eligibilityCriteria":103,"healthyVolunteers":104,"sex":105,"minAge":106,"maxAge":107,"enrollmentInfo":108,"targetDuration":11,"studyType":111,"phases":112,"briefSummary":114,"conditions":115,"keywords":119,"overallStatus":70,"whyStopped":11,"lastUpdateSubmitDate":137,"lastUpdatePostDateStruct":138,"startDateStruct":141,"completionDateStruct":143,"leadSponsor":145,"locationsCount":146},{"fullName":5,"class":6},"University of Minnesota","OTHER",[8,17],{"label":9,"type":10,"description":11,"interventionNames":12},"People with Visual Snow Syndrome","ACTIVE_COMPARATOR",null,[13,14,15,16],"Behavioral: Visual Adaptation","Behavioral: Assessments and Questionnaires","Device: Functional Magnetic Resonance Imaging (fMRI)","Device: Magnetic Resonance Imaging (MRS)",{"label":18,"type":19,"description":11,"interventionNames":20},"Non-snow Controls","PLACEBO_COMPARATOR",[13,14,15,16],[22,27,31,36],{"type":23,"name":24,"description":25,"armGroupLabels":26,"otherNames":11},"BEHAVIORAL","Visual Adaptation","Presentation of visual stimuli to quantify the appearance of visual snow or its effects in the visual system of the brain.",[18,9],{"type":23,"name":28,"description":29,"armGroupLabels":30,"otherNames":11},"Assessments and Questionnaires","Administration of clinical assessments and questionnaires to gather information about visual and mental symptoms, cognitive, and sensory function.",[18,9],{"type":32,"name":33,"description":34,"armGroupLabels":35,"otherNames":11},"DEVICE","Functional Magnetic Resonance Imaging (fMRI)","7 tesla fMRI data will be acquired during visual paradigms designed to measure neural responses with and without adaptation.",[18,9],{"type":32,"name":37,"description":38,"armGroupLabels":39,"otherNames":11},"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.",[18,9],[41,45,49,52,55,58],{"name":42,"affiliation":43,"role":44},"Michael-Paul Schallmo, Ph.D.","University of Minnesota, Department of Psychiatry and Behavioral Sciences","PRINCIPAL_INVESTIGATOR",{"name":46,"affiliation":47,"role":48},"Stephen A Engel, Ph.D.","University of Minnesota, Department of Psychology","STUDY_CHAIR",{"name":50,"affiliation":51,"role":48},"Michael S Lee, M.D.","University of Minnesota, Department of Ophthalmology and Visual Neurosciences",{"name":53,"affiliation":54,"role":48},"Abby Metzler, M.D.","University of Minnesota, Department of Neurology",{"name":56,"affiliation":57,"role":48},"Malgorzata Marjanska, Ph.D.","University of Minnesota, Department of Radiology",{"name":59,"affiliation":60,"role":48},"Carrie E Robertson, M.D.","Mayo Clinic, Rochester, Department of Neurology",[62,66],{"name":42,"role":63,"phone":64,"phoneExt":11,"email":65},"CONTACT","(612) 273-9130","schallmolab@umn.edu",{"name":67,"role":63,"phone":11,"phoneExt":11,"email":65},"Hannah Moser, Ph.D.",[69],{"facility":5,"status":70,"city":71,"state":72,"zip":73,"country":74,"countryCode":75,"cosmosGeoPoint":76,"geoPoint":81,"contacts":82},"RECRUITING","Minneapolis","Minnesota","55455","United States","US",{"type":77,"coordinates":78},"Point",[79,80],-93.26384,44.97997,{"lat":80,"lon":79},[83],{"name":84,"role":63,"phone":85,"phoneExt":11,"email":65},"Michael-Paul Schallmo, Ph.D., Assistant Professor","612-273-9130",{"type":87,"investigatorFullName":11,"investigatorTitle":11,"investigatorAffiliation":11,"oldNameTitle":11,"oldOrganization":11},"SPONSOR",[89,92,94],{"name":90,"class":91},"National Institutes of Health (NIH)","NIH",{"name":93,"class":6},"Mayo Clinic",{"name":95,"class":91},"National Eye Institute (NEI)","100590011","investigating-brain-function-in-people-with-and-without-visual-snow-syndrome-using-adaptation-to-visual-stimuli-100590011",false,"NCT06961864","Investigating Brain Function in People With and Without Visual Snow Syndrome Using Adaptation to Visual Stimuli","Visual Perception in Visual Snow Syndrome","VPVSS","Inclusion Criteria for People with Visual Snow Syndrome:\n\n* Between the ages of 18 and 60 years old\n* Normal (20\u002F25 or better in each eye) or corrected-to-normal vision (MR-compatible glasses will be provided as needed)\n* Ability to comply with study instructions\n* 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)\n* Individuals living in Minnesota within 2 hours of the study site\n\nInclusion Criteria for Non-snow Controls:\n\n* Between the ages of 18 and 60 years old\n* Normal (20\u002F25 or better in each eye) or corrected-to-normal vision (MR-compatible glasses will be provided as needed)\n* Ability to comply with study instructions\n* Individuals living in Minnesota within 2 hours of the study site\n\nExclusion Criteria for People with Visual Snow Syndrome:\n\n* Not being fluent in English or another language for which interpretation\u002Ftranslation services are available\n* A diagnosed or self-reported intellectual disability\n* Current substance dependence (besides nicotine), or drug dependence with tolerance or withdrawal within past 12 months\n* Hallucinogenic substance use within the past 12 months or hallucinogenic substance use within 12 months prior to onset of VSS symptoms\n* Severe central nervous system disease\n* Head injury with skull fracture or loss of consciousness for more than thirty minutes\n* Presence of a physical problem that would render study measures difficult or impossible to administer or interpret (e.g., visual field loss)\n* Age less than 18 years or greater than 60 years\n* MRI exclusions (for MR visits only):\n\n  * Metal in the body that cannot be approved by the CMRR safety committee\n  * Pregnancy\n  * Conditions that affect neuro-hemodynamic coupling\n  * Claustrophobia\n  * Inability to lie still for at least an hour\n  * Weight in excess of 440 lbs\n  * CT scan exclusion only: Research-related radiation exposure within the last 12 months\n* Any vision anomaly aside from VS or refractive error (e.g., strabismus\u002F crossed eyes, lazy eyes, color blindness)\n* Current psychotic episode\n\nExclusion Criteria for Non-snow Controls:\n\n* Not being fluent in English or another language for which interpretation\u002Ftranslation services are available\n* A diagnosed or self-reported intellectual disability\n* Current substance dependence (besides nicotine), or drug dependence with tolerance or withdrawal within past 12 months\n* Hallucinogenic substance use within the past 12 months\n* Severe central nervous system disease\n* Head injury with skull fracture or loss of consciousness for more than thirty minutes\n* Presence of a physical problem that would render study measures difficult or impossible to administer or interpret (e.g., visual field loss)\n* Age less than 18 years or greater than 60 years\n* MRI exclusions (for MR visits only):\n\n  * Metal in the body that cannot be approved by the CMRR safety committee\n  * Pregnancy\n  * Conditions that affect neuro-hemodynamic coupling\n  * Claustrophobia\n  * Inability to lie still for at least an hour\n  * Weight in excess of 440 lbs\n  * CT scan exclusion only: Research-related radiation exposure within the last 12 months\n* Any vision anomaly or refractive error (e.g. strabismus\u002F crossed eyes, lazy eyes, color blind)\n* A personal history of VSS symptoms or a diagnosis with VSS\n* Current psychotic episode",true,"ALL","18 Years","60 Years",{"count":109,"type":110},100,"ESTIMATED","INTERVENTIONAL",[113],"NA","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:\n\n* Does VSS arise from spontaneous activity in brain pathways?\n* Where in the brain does the activity contributing to VSS arise?\n* How does brain activity contribute to VSS?\n\nParticipants will:\n\n1. Undergo assessments and questionnaires to understand visual and mental symptoms, cognitive, and sensory function.\n2. Make visual judgements based on images presented to them both inside and outside a magnetic resonance imaging (MRI) machine.\n3. Undergo scanning of their brain while inside of an MRI machine.",[116,117,118],"Visual Snow Syndrome","Migraine","Healthy",[116,120,117,121,122,123,124,125,126,127,128,129,130,131,5,132,133,134,135,136],"Visual Snow","Floaters","Palinopsia","Photophobia","Nyctalopia","Entoptic phenomena","Visual trailing","Adaptation","Magnetic resonance spectroscopy","MRS","Magnetic resonance imaging","MRI","Afterimages","Poor night vision","Light sensitivity","Persistent positive visual phenomena","Static","2026-01-12",{"date":139,"type":140},"2026-01-14","ACTUAL",{"date":142,"type":140},"2025-04-11",{"date":144,"type":110},"2030-03-31",{"name":5,"class":6},1]