Understanding Visual Snow Syndrome: A Functional Imaging Approach
Research type
Research Study
Full title
Understanding the Pathophysiology of Visual Snow Syndrome: A Functional Imaging Approach
IRAS ID
193354
Contact name
P J Goadsby
Contact email
Sponsor organisation
King's College London
Duration of Study in the UK
1 years, 0 months, 1 days
Research summary
Patients with “visual snow” suffer from continuous TV-static-like tiny flickering dots in the entire visual field. Most patients describe additional visual symptoms of the following categories: palinopsia (“afterimages” and “trailing”), entopic phenomena arising from the optic apparatus itself (floaters, blue field entoptic phenomenon, photopsia, self-light of the eye), photophobia, nyctalopia (impaired night vision), as well as the non-visual symptom tinnitus. The high prevalence of migraine and typical migraine aura in this population has led to the assumption that “visual snow” is caused by persistent migraine aura. Due to the lack of objective measures, alternative diagnoses are malingering or a psychogenic disorder.
Previous work by the authors suggests that visual snow (VS) is a unique syndrome clinically distinct from migraine aura, dominated by visual symptoms and highly disabling for patients. Systematic studies of its clinical features, biology and treatment responses need to be commenced to understand what has been an almost completely ignored although highly disabling disorder.
Our group has previously demonstrated the involvement of structures in the posterior occipital cortex in visual snow, most of all the lingual gyrus using Pet imaging and we intend to repeat this investigation using a type of non-invasive functional imaging, in order to expand our knowledge of the underlying neuronal and physiological dysfunction of the visual system visual snow during this condition.
We intend to recruit 24 subjects with visual snow syndrome as assessed by the study team, as well as 24 controls. Subjects will attend upto two visits at the Clinical Research Facility, King’s College Hospital, one visit will be a screening visit, where subjects will provide informed consent. The second visit will be a scanning visit where the subject will undergo an MRI scan for up to an hour. Participants will complete a number of questionnaires to assess their visual snow symptoms and other potential comorbidities.REC name
London - City & East Research Ethics Committee
REC reference
16/LO/0964
Date of REC Opinion
16 Jun 2016
REC opinion
Favourable Opinion