To determine biomarkers of cortical connectivity and neuronal metabolism that characterise visual snow syndrome.
By expanding on previous imaging work, this objective focuses on analysing changes in cortical metabolism using proton spectroscopy and assessing the functional response of visual areas through functional spectroscopy. The experiment will be repeated before and after use of lamotrigine to investigate the role of glutamatergic neurotransmission on metabolic reserve in the visual cortex. Together, these complementary techniques will enable a detailed examination of the altered mechanisms of sensory processing and atypical visual perception that are at the basis of VSS.
To provide novel insights concerning the neurophysiological changes pertaining to the visual snow brain, and how these differ from migraine biology.
Non-invasive neurophysiology can help disentangle neural networks at the basis of pathological brain function. Little research has been done to investigate this aspect in VSS. This objective, reached primarily through the use of advanced electrophysiological techniques (TMS/EEG, high-density EEG, and visual evoked potentials), will allow further investigation of cortical excitability in VSS and enable us to distinguish its neurophysiological fingerprint from that of comorbid migraine biology.
To study the pharmacology of VSS and the role of GABA-ergic neurotransmission in cortical disinhibition and symptom onset.
By administering GABAA receptor agonist and antagonist drugs, we will be able to assess the response to receptor-specific stimulation or inhibition in VSS and to observe changes in clinical symptoms and neuropsychological measures. TMS/EEG measurements before and after drug administration will further allow us to underpin the cortical biomarkers for these differences and enable repeated longitudinal neurophysiological assessments.
Collaborating with TwinsUK to obtain epidemiological and genetic data to better understand the genetics behind VSS.
TwinsUK is the largest adult twin registry and the most clinically detailed in the world. It provides a rich resource of data and samples from which scientists can study conditions, including VSS. We are working to incorporate a dedicated visual snow syndrome questionnaire into their cohort. The work is undergoing the necessary regulatory approvals.
Visual Paradigms: “VISION Study” which aims to investigate sensory filtering and perceptual processing in VSS using behavioural visual paradigms.
The study also includes a synaesthesia questionnaire and the use of augmented reality to simulate visual snow symptoms, allowing us to better characterise perceptual phenomena and sensory processing in patients. Pilot work and task optimisation are currently ongoing.
Researchers & Institutions:
- Dr. Francesca Puledda – King’s College London
- Dr. Peter Goadsby – UCLA; King’s College London
- Mark Richardson – Professor, King’s College London
- Viviana Santoro – PhD Student, King’s College London
- Samaksh Gupta – PhD Student, King’s College London
- VSI Global Research Team (collaborative support)
