Neurofeedback in Visual Snow

Not Applicable

Active, not recruiting

• Conditions: Visual Snow Syndrome; Neuro-Ophthalmology
• Interventions: Other: neurofeedback

• Registration Number: NCT04902365
• Lead Sponsor: University of Zurich

Brief Summary

Visual snow (VS) is a distressing, life-impacting condition with unrelenting and persistent disturbing visual phenomena. Disease onset is usually around age 20 and is characterized by continuous perception of innumerable flickering dots (like a 'broken television'). The disease is often accompanied by comorbidities such as migraine, tinnitus, depression and anxiety.

Neuronally, VS patients show cerebral hypermetabolism, resulting in altered neuronal excitability, as well as increased grey matter volume in parts of the visual cortex.

For this pilot study, the investigators aim to recruit VS patients. In a double-blind, randomized and placebo-controlled longitudinal experiment, the investigators will use real-time functional magnetic resonance imaging (rtfMRI) neurofeedback to teach patients to downregulate activity in different regions of the visual cortex.

The investigators hypothesize that neurofeedback will allow patients to learn to downregulate their abnormal visual cortex activity. Moreover, the investigators predict that a stronger downregulation of activity from the lingual gyrus will correlate with a more pronounced decrease in VS symptoms.

Detailed Description

Currently, there is no pharmacological or non-pharmacological treatment available that significantly reduces the high disease burden produced by VS. Thus, there is an unmet need for an appropriate intervention to treat patients with VS. In this study, the investigators will:

1. Test if rtfMRI-based neurofeedback could serve as therapeutic option for patients with VS.

Here, the investigators will examine correlations of neurofeedback regulation success with clinical scores 3 after neurofeedback

2. Examine brain function and structure in patients with VS

Primary and secondary endpoint/outcome(s)

* Primary outcome variable: VS symptom severity before and after rtfMRI, using standardized clinical assessment.

* Secondary outcome variables: fMRI and structural MRI, clinical questionnaires (visual function, anxiety, depression, tinnitus, and migraine), parameters from psychophysical data (assessed before and after neurofeedback).

* Linear Mixed model analysis will be performed (using clinical and imaging data) to estimate the impact of rtfMRI on clinical progression and brain function/structure.

Study Timeline

• Study First Submitted: 2021-05-20
• Study First Submitted QC: 2021-05-20
• Study First Posted: 2021-05-26
• Study Start: 2022-01-14
• Status Verified: 2023-06
• Last Update Submitted: 2023-06-12
• Last Update Posted: 2023-06-15
• Primary Completion: 2023-08-30
• Study Completion: 2023-12-30

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 70

Inclusion Criteria

• Patients with VS (≥ 18 to ≤ 60 years), which can read and sign the informed consent form.
• Male and female
• Healthy controls (≥ 18 to ≤ 60 years), which can read and sign the informed consent form.

Exclusion Criteria

• MR exclusion criteria (patients only): metallic items in the body (i.e. eye splinter, MR incompatible implants), pacemaker, claustrophobia).
• pregnant participants
• participants suffering from a degenerative disorder of the Central Nervous System, such as Stroke, Multiple Sclerosis, Parkinson's Disease, Alzheimer's Disease and Huntington's Disease and with major psychiatric disorders such as schizophrenia, depression, or anxiety disorder requiring pharmacological treatment (psycho-pharmaca).

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Patients group 1	neurofeedback	This group will regulate a brain region by real-time functional magnetic resonance imaging that is centrally involved in the visual snow syndrome
Patients group 2	neurofeedback	This group will regulate a brain region by real-time functional magnetic resonance imaging that is not centrally involved in the visual snow syndrome

Primary Outcome Measures

Name	Time	Method
symptom severity	Acute after neurofeedback and 3 months after neurofeedback	Changes in symptom severity before and after real-time fMRI neurofeedback

Secondary Outcome Measures

Name	Time	Method
Magnetic resonance imaging	before and immediately after the neurofeedback sessions	Assessment of Magnetic resonance imaging parameters related to brain function and structure

Trial Locations

Locations (1)

University Hospital Zurich; 🇨🇭 Zurich, Switzerland