Visual snow syndrome Nervous System Diseases
Conditions
Interventions
The study design consists of a randomized, double-blind design with two treatment conditions (oral placebo or oral lamotrigine) and neuroimaging with magnetic resonance imaging/spectroscopy. The desig
Sponsors
King's College London
Eligibility
Sex/Gender
All
Age
18 Years to 100 Years
Inclusion criteria
Inclusion criteria: Group 1: VSS patients 1. Diagnosis of visual snow syndrome following the published criteria 2. Aged >18 years 3. Able to provide written informed consent in English 4. Evidence of a personally signed and dated informed consent document indicating that the subject (or a legally acceptable representative) has been informed of all pertinent aspects of the trial detailed in the patient information sheet, informed consent form, and in the protocol 5. Willing and able to comply with scheduled visits, lifestyle guidelines and trial procedures, including using a reliable method of birth control whilst on the medication for female participants 6. No history of worsening of VSS with prior medications Group 2: Migraine patients 1. Diagnosis of migraine with or without aura following the International Classification of Headache Disorders (ICHD-3) beta criteria 2. Aged >18 years 3. Able to provide written informed consent in English 4. Evidence of a personally signed and dated informed consent document indicating that the subject (or a legally acceptable representative) has been informed of all pertinent aspects of the trial detailed in the patient information sheet, informed consent form, and in the protocol 5. Willing and able to comply with scheduled visits, lifestyle guidelines and trial procedures, including using a reliable method of birth control whilst on the medication for female participants 6. No concomitant diagnosis of VSS Group 2: Healthy controls 1. Aged >18 years 2. Able to provide written informed consent in English 3. Evidence of a personally signed and dated informed consent document indicating that the subject (or a legally acceptable representative) has been informed of all pertinent aspects of the trial detailed in the patient information sheet, informed consent form, and in the protocol 4. Willing and able to comply with scheduled visits, lifestyle guidelines (see below) and trial procedures 5. No concomitant diagnosis of VSS or migraine
Exclusion criteria
Exclusion criteria: 1. Pregnancy and breastfeeding 2. Any metal implants in the head or body (except for titanium and dental work) 3. Any other medical and safety contraindications to undergo ultra-high-field MRI (e.g., large tattoos, ongoing dizziness and vertigo) 4. History of epilepsy or of prior lamotrigine use (for VSS and MO groups only) 5. History of adverse or allergic reactions to drugs (for VSS and MO groups only) 6. Family history of Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) (for VSS and MO groups only) 7. Known or suspected carriers of HLA alleles associated with SJS or TEN (e.g., HLA-B15:02, HLA-A24:02, and HLA-B38:01) (for VSS and MO groups only) 8. Regular smoking of >6 cigarettes a day 9. Regular intake of medications acting on the central nervous system 10. Regular use of recreational drugs 11. History of psychosis or psychological disease either (a) requiring ongoing psychoactive drugs, or (b) that the investigator has reason to believe will either affect the patient’s neural pathways or hinder the performance of the patient regarding the ability to successfully complete the tasks required of them according to the protocol 12. Any person unable to understand written or spoken English 13. Subjects unwilling to comply with lifestyle guidelines necessary for the study 14. Subjects who are or have recently (last 30 days) been involved in any interventional clinical trial 15. Any other condition that in the opinion of the investigator would make the subject unsuitable for the study
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Visual cortex glutamate and GABA concentrations measured using proton magnetic resonance spectroscopy at 7 Tesla (7T ¹H-MRS), acquired at rest and during visual stimulation (functional 1H-MRS), at baseline (Visit 1) and at 5 weeks post-randomisation (Visit 2) | — |
Secondary
| Measure | Time frame |
|---|---|
| 1. Change in visual cortex glutamate concentration in response to lamotrigine versus placebo is measured using 7T ¹H-MRS at Visit 1 and Visit 2 (5 weeks) 2. Differences in visual cortex glutamate and GABA concentrations between participants with visual snow syndrome and participants with migraine are measured using 7T ¹H-MRS at Visit 1 and Visit 2 (5 weeks) 3. Resting-state functional connectivity is measured using blood oxygenation level-dependent functional MRI at 7 Tesla (7T BOLD fMRI) at Visit 1 and Visit 2 (5 weeks) 4. Visual snow syndrome symptom severity is measured using the Visual Snow Scale and Diary at Visit 1 and Visit 2 (5 weeks), and at 7-week telephone follow-up 5. Visual sensitivity is measured using the Visual Sensitivity Questionnaire (VSQ) at pre-screening, baseline (Visit 1), at 5 weeks post-randomisation (Visit 2), and at 7 weeks (telephone follow-up) 6. Headache impact is measured using the Headache Impact Test (HIT-6) at pre-screening, baseline (Visit 1), at 5 weeks post-randomisation (Visit 2), and at 7 weeks (telephone follow-up) 7. Migraine-related disability is measured using the Migraine Disability Assessment Test (MIDAS) at pre-screening, baseline (Visit 1), at 5 weeks post-randomisation (Visit 2), and at 7 weeks (telephone follow-up) 8. Depressive symptoms are measured using the Patient Health Questionnaire (PHQ-8) at pre-screening, baseline (Visit 1), at 5 weeks post-randomisation (Visit 2), and at 7 weeks (telephone follow-up) 9. Anxiety symptoms are measured using the Generalised Anxiety Disorder questionnaire (GAD-7) at pre-screening, baseline (Visit 1), at 5 weeks post-randomisation (Visit 2), and at 7 weeks (telephone follow-up) 10. Health-related quality of life is measured using the EuroQol five-dimension five-level questionnaire (EQ-5D-5L) at pre-screening, baseline (Visit 1), at 5 weeks post-randomisation (Visit 2), and at 7 weeks (telephone follow-up) 11. Migraine and visual snow syndrome symptom frequency and severity are me | — |
Countries
England, United Kingdom
Contacts
Public ContactFrancesca Puledda
Outcome results
None listed