1
|
Montoya SA, Mulder CB, Allison KD, Lee MS, Engel SA, Schallmo MP. What does visual snow look like? Quantification by matching a simulation. J Vis 2024; 24:3. [PMID: 38837169 PMCID: PMC11160957 DOI: 10.1167/jov.24.6.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 04/26/2024] [Indexed: 06/06/2024] Open
Abstract
The primary symptom of visual snow syndrome (VSS) is the unremitting perception of small, flickering dots covering the visual field. VSS is a serious but poorly understood condition that can interfere with daily tasks. Several studies have provided qualitative data about the appearance of visual snow, but methods to quantify the symptom are lacking. Here, we developed a task in which participants with VSS adjusted parameters of simulated visual snow on a computer monitor until the simulation matched their internal visual snow. On each trial, participants (n = 31 with VSS) modified the size, density, update speed, and contrast of the simulation. Participants' settings were highly reliable across trials (intraclass correlation coefficients > 0.89), and they reported that the task was effective at stimulating their visual snow. On average, visual snow was very small (less than 2 arcmin in diameter), updated quickly (mean temporal frequency = 18.2 Hz), had low density (mean snow elements vs. background = 2.87%), and had low contrast (average root mean square contrast = 2.56%). Our task provided a quantitative assessment of visual snow percepts, which may help individuals with VSS communicate their experience to others, facilitate assessment of treatment efficacy, and further our understanding of the trajectory of symptoms, as well as the neural origins of VSS.
Collapse
Affiliation(s)
- Samantha A Montoya
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - Carter B Mulder
- Department of Psychiatry and Behavioral Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Karly D Allison
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - Michael S Lee
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, USA
| | - Stephen A Engel
- Department of Psychology, University of Minnesota, Minneapolis, MN, USA
| | - Michael-Paul Schallmo
- Department of Psychiatry and Behavioral Sciences, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
2
|
Wong SH, Pontillo G, Kanber B, Prados F, Wingrove J, Yiannakas M, Davagnanam I, Gandini Wheeler-Kingshott CAM, Toosy AT. Visual Snow Syndrome Improves With Modulation of Resting-State Functional MRI Connectivity After Mindfulness-Based Cognitive Therapy: An Open-Label Feasibility Study. J Neuroophthalmol 2024; 44:112-118. [PMID: 37967050 PMCID: PMC10855987 DOI: 10.1097/wno.0000000000002013] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023]
Abstract
BACKGROUND Visual snow syndrome (VSS) is associated with functional connectivity (FC) dysregulation of visual networks (VNs). We hypothesized that mindfulness-based cognitive therapy, customized for visual symptoms (MBCT-vision), can treat VSS and modulate dysfunctional VNs. METHODS An open-label feasibility study for an 8-week MBCT-vision treatment program was conducted. Primary (symptom severity; impact on daily life) and secondary (WHO-5; CORE-10) outcomes at Week 9 and Week 20 were compared with baseline. Secondary MRI outcomes in a subcohort compared resting-state functional and diffusion MRI between baseline and Week 20. RESULTS Twenty-one participants (14 male participants, median 30 years, range 22-56 years) recruited from January 2020 to October 2021. Two (9.5%) dropped out. Self-rated symptom severity (0-10) improved: baseline (median [interquartile range (IQR)] 7 [6-8]) vs Week 9 (5.5 [3-7], P = 0.015) and Week 20 (4 [3-6], P < 0.001), respectively. Self-rated impact of symptoms on daily life (0-10) improved: baseline (6 [5-8]) vs Week 9 (4 [2-5], P = 0.003) and Week 20 (2 [1-3], P < 0.001), respectively. WHO-5 Wellbeing (0-100) improved: baseline (median [IQR] 52 [36-56]) vs Week 9 (median 64 [47-80], P = 0.001) and Week 20 (68 [48-76], P < 0.001), respectively. CORE-10 Distress (0-40) improved: baseline (15 [12-20]) vs Week 9 (12.5 [11-16.5], P = 0.003) and Week 20 (11 [10-14], P = 0.003), respectively. Within-subject fMRI analysis found reductions between baseline and Week 20, within VN-related FC in the i) left lateral occipital cortex (size = 82 mL, familywise error [FWE]-corrected P value = 0.006) and ii) left cerebellar lobules VIIb/VIII (size = 65 mL, FWE-corrected P value = 0.02), and increases within VN-related FC in the precuneus/posterior cingulate cortex (size = 69 mL, cluster-level FWE-corrected P value = 0.02). CONCLUSIONS MBCT-vision was a feasible treatment for VSS, improved symptoms and modulated FC of VNs. This study also showed proof-of-concept for intensive mindfulness interventions in the treatment of neurological conditions.
Collapse
|
3
|
Barrachina-Esteve O, Hidalgo-Torrico I, Acero C, Aranceta S, Cánovas-Vergé D, Ribera G. Visual snow syndrome and its relationship with migraine. Neurologia 2024; 39:190-195. [PMID: 37442427 DOI: 10.1016/j.nrleng.2021.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 05/01/2021] [Indexed: 07/15/2023] Open
Abstract
INTRODUCTION Visual snow syndrome (VSS) is a central nervous system disorder that consists of the constant perception of small black and white dots throughout the entire visual field. DEVELOPMENT VSS can present from infancy to old age, with greater prevalence in the young population, and shows no difference between sexes. The diagnostic criteria include the presence of visual snow and such other visual phenomena as palinopsia, photophobia, nyctalopia, and other persistent visual phenomena. The pathophysiology of VSS is unknown, but hyperexcitability of the visual cortex and a dysfunction in higher-order visual processing are postulated as potential mechanisms. The prevalence of migraine among patients with VSS is high, compared to the general population, and symptoms are more severe in patients presenting both conditions. No effective treatment is available, but the drug with the best results is lamotrigine, which is recommended only in selected cases with severe functional limitation. CONCLUSIONS VSS is a little-known and underdiagnosed entity, but the increasing number of studies in recent years has made it possible to establish diagnostic criteria and begin studying its pathophysiology. This entity is closely related to migraine, with overlapping symptoms and probably shared pathophysiological mechanisms.
Collapse
Affiliation(s)
- O Barrachina-Esteve
- Servicio de Neurología, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, Spain.
| | - I Hidalgo-Torrico
- Servicio de Cirugía Cardiaca, Hospital Universitario Son Espases, Palma de Mallorca, Spain
| | - C Acero
- Servicio de Oftalmología, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, Spain
| | - S Aranceta
- Servicio de Neurología, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, Spain
| | - D Cánovas-Vergé
- Servicio de Neurología, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, Spain
| | - G Ribera
- Servicio de Neurología, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, Spain
| |
Collapse
|
4
|
Vaphiades MS. Delta-8 gummies causing visual snow: a case report. FRONTIERS IN OPHTHALMOLOGY 2024; 3:1349525. [PMID: 38983002 PMCID: PMC11182212 DOI: 10.3389/fopht.2023.1349525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 12/27/2023] [Indexed: 07/11/2024]
Abstract
A 26-year-old man developed visual snow syndrome (VSS) after consuming a little less than half of a delta-8 gummy (estimated at 4 mg of delta-8 tetrahydrocannabinol). Secondary VSS and hallucinogen-persisting perception disorder (HPPD) are discussed, and clinicians who evaluate patients with VS and VSS should ask about delta-8 gummies as an etiology of secondary VSS.
Collapse
Affiliation(s)
- Michael S Vaphiades
- Department of Ophthalmology, University of Alabama, Birmingham, AL, United States
| |
Collapse
|
5
|
Zaroban NJ, Kedar S, Anderson D, Vuppala AAD. Analysis of Retinal Structure and Electrophysiological Function in Visual Snow Syndrome: An Exploratory Case Series. J Neuroophthalmol 2023; 43:227-231. [PMID: 36503963 DOI: 10.1097/wno.0000000000001757] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Visual snow (VS) is a rare but distressing phenomenon of persistent granular or pixelated visual distortions that may occur in isolation or as a component of visual snow syndrome (VSS). The current understanding of VS pathogenesis, including the role of retinal involvement structurally and functionally, is limited. The objective of this study is to investigate retinal structural and electrophysiological abnormalities in VS. METHODS This retrospective case series included 8 subjects (7 with VSS and 1 with isolated VS). Patients with other ocular and neurologic diseases were excluded. Data were assessed from automated perimetry, optical coherence tomography (OCT), visual evoked potential (VEP), and full-field electroretinography (ffERG) testing. The VEP and ffERG data of visual snow subjects were compared with age- and sex-matched control subjects for statistical significance. RESULTS The mean age of the cohort was 29.4 years (SD = ±5.3) with 50% gender split. The mean age of VS onset was 24.2 years (SD = ±3.8). All subjects had normal visual acuity, color vision, brain MRI, automated perimetry, OCT parameters (peripapillary retinal nerve fiber layer and macular ganglion cell layer thickness), and P100 and N135 wave pattern on VEP. Compared with controls, VS subjects had a greater mean b-wave amplitude in response to light-adapted 3.0 stimuli ( t test; P = 0.035 right eye and P = 0.072 left eye), greater mean light-adapted 3.0 flicker amplitude ( t test; P = 0.028 right eye P = 0.166 left eye) and greater b-wave amplitude in response to dark-adapted 10.0 stimuli ( t test; P = 0.102 right eye; P = 0.017 left eye) on ERG. CONCLUSIONS Patients with VS and VSS have normal retinal structure, but abnormal electrophysiology compared with control subjects. The increased b-wave and flicker amplitudes observed with ffERG suggest increased responsiveness of the rod and cone photoreceptors and may contribute to VS pathophysiology.
Collapse
Affiliation(s)
- Nathaniel J Zaroban
- University of Nebraska Medical Center (NZ), University of Nebraska College of Medicine, Omaha, Nebraska; Department of Ophthalmology (SK), Emory University School of Medicine, Atlanta, Georgia; University of Nebraska Medical Center (DA), Truhlsen Eye Institute, Omaha, Nebraska; and Department of Ophthalmology and Visual Sciences (A-AV), Medical College of Wisconsin, Milwaukee, Wisconsin
| | | | | | | |
Collapse
|
6
|
Evers S, Tassorelli C. Migraine with aura. HANDBOOK OF CLINICAL NEUROLOGY 2023; 198:169-186. [PMID: 38043960 DOI: 10.1016/b978-0-12-823356-6.00009-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
This chapter describes the different types of aura including rare aura subtypes such as retinal aura. In addition, aura manifestations not classified in the International Classification of Headache Disorders and auras in headache disorders others than migraine are also described. The differential diagnosis of migraine aura comprises several neurological disorders which should be known to specialists. Migraine aura also has impact on the choice of migraine treatment; recommendations for the treatment of the migraine aura itself are also presented in this chapter.
Collapse
Affiliation(s)
- Stefan Evers
- Faculty of Medicine, University of Münster, Münster, Germany; Department of Neurology, Lindenbrunn Hospital, Coppenbrügge, Germany.
| | - Cristina Tassorelli
- Headache Science and Neurorehabilitation Center, IRCCS Mondino Foundation, Pavia, Italy; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| |
Collapse
|
7
|
Van Laere K, Ceccarini J, Gebruers J, Goffin K, Boon E. Simultaneous 18F-FDG PET/MR metabolic and structural changes in visual snow syndrome and diagnostic use. EJNMMI Res 2022; 12:77. [PMID: 36583806 PMCID: PMC9803799 DOI: 10.1186/s13550-022-00949-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 12/21/2022] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Visual snow syndrome (VSS) is a recently recognized chronic neurologic condition characterized by the constant perceiving of tiny flickering dots throughout the entire visual field. Metabolic overactivity and grey matter volume increase in the lingual gyrus has been reported. We investigated this by 18F-FDG PET/MR in comparison to healthy controls. Aside from voxel-based characterization, the classification accuracy of volume-of-interest (VOI)-based multimodal assessment was evaluated, also in comparison with visual analysis. METHODS Simultaneous 18F-FDG PET and MR imaging was performed in 7 patients with VSS (24.6 ± 5.7 years; 5 M/2F) and 15 age-matched healthy controls (CON) (28.0 ± 5.3 years; 8 M/7F). SPM12 and voxel-based morphometric analysis was performed. A VOI-based discriminant analysis was performed with relative 18F-FDG uptake, MR grey matter (GM) volumes and their combination. A visual analysis was done by two blinded experienced readers. RESULTS Relative increased hypermetabolism was found in VSS patients in the lingual gyrus and cuneus (pFWE < 0.05, peak change + 24%), and hypometabolism in the mesiotemporal cortex (pheight,uncorr < 0.001, peak change - 14%). VSS patients also had increased GM volume in the limbic system and frontotemporal cortex bilaterally (pFWE < 0.05), and in the left secondary and associative visual cortex and in the left lingual gyrus (pheight,uncorr < 0.001). Discriminant analysis resulted in 100% correct classification accuracy for 18F-FDG with lingual gyrus, cuneus and lateral occipital lobe (BA 17 and BA 18) as main discriminators. Unimodal MR- and combined 18F-FDG + MR classification resulted in an accuracy of 91% and 95%, respectively. Visual analysis of 18F-FDG was highly observer dependent. CONCLUSION Patients with VSS have highly significant structural and metabolic abnormalities in the visual and limbic system. VOI-based discriminant analysis of 18F-FDG PET allows reliable individual classification versus controls, whereas visual analysis of experienced observers was highly variable. Further investigation in larger series, also in comparison to VSS mimicking disorders such as migraine, is warranted. TRAIL REGISTRATION Retrospectively registered at clinicaltrials.gov under NCT05569733 on Oct 5, 2022.
Collapse
Affiliation(s)
- Koen Van Laere
- grid.410569.f0000 0004 0626 3338Nuclear Medicine, University Hospitals Leuven, UZ Leuven, Campus Gasthuisberg, Nucleaire Geneeskunde, E901, Herestraat 49, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Leuven Brain Institute (LBI), KU Leuven, Leuven, Belgium
| | - Jenny Ceccarini
- grid.5596.f0000 0001 0668 7884Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Leuven Brain Institute (LBI), KU Leuven, Leuven, Belgium
| | - Juanito Gebruers
- grid.410569.f0000 0004 0626 3338Nuclear Medicine, University Hospitals Leuven, UZ Leuven, Campus Gasthuisberg, Nucleaire Geneeskunde, E901, Herestraat 49, 3000 Leuven, Belgium
| | - Karolien Goffin
- grid.410569.f0000 0004 0626 3338Nuclear Medicine, University Hospitals Leuven, UZ Leuven, Campus Gasthuisberg, Nucleaire Geneeskunde, E901, Herestraat 49, 3000 Leuven, Belgium ,grid.5596.f0000 0001 0668 7884Nuclear Medicine and Molecular Imaging, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Elizabet Boon
- grid.410569.f0000 0004 0626 3338Division of Neurology and Psychiatry, University Hospitals Leuven and UPC Kortenberg, Leuven, Belgium
| |
Collapse
|
8
|
Strik M, Clough M, Solly EJ, Glarin R, White OB, Kolbe SC, Fielding J. Brain network dynamics in people with visual snow syndrome. Hum Brain Mapp 2022; 44:1868-1875. [PMID: 36478470 PMCID: PMC9980880 DOI: 10.1002/hbm.26176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/10/2022] [Accepted: 11/29/2022] [Indexed: 12/13/2022] Open
Abstract
Visual snow syndrome (VSS) is a neurological disorder characterized by a range of continuous visual disturbances. Little is known about the functional pathological mechanisms underlying VSS and their effect on brain network topology, studied using high-resolution resting-state (RS) 7 T MRI. Forty VSS patients and 60 healthy controls underwent RS MRI. Functional connectivity matrices were calculated, and global efficiency (network integration), modularity (network segregation), local efficiency (LE, connectedness neighbors) and eigenvector centrality (significance node in network) were derived using a dynamic approach (temporal fluctuations during acquisition). Network measures were compared between groups, with regions of significant difference correlated with known aberrant ocular motor VSS metrics (shortened latencies and higher number of inhibitory errors) in VSS patients. Lastly, nodal co-modularity, a binary measure of node pairs belonging to the same module, was studied. VSS patients had lower modularity, supramarginal centrality and LE dynamics of multiple (sub)cortical regions, centered around occipital and parietal lobules. In VSS patients, lateral occipital cortex LE dynamics correlated positively with shortened prosaccade latencies (p = .041, r = .353). In VSS patients, occipital, parietal, and motor nodes belonged more often to the same module and demonstrated lower nodal co-modularity with temporal and frontal regions. This study revealed reduced dynamic variation in modularity and local efficiency strength in the VSS brain, suggesting that brain network dynamics are less variable in terms of segregation and local clustering. Further investigation of these changes could inform our understanding of the pathogenesis of the disorder and potentially lead to treatment strategies.
Collapse
Affiliation(s)
- Myrte Strik
- Melbourne Brain Centre Imaging Unit, Department of Radiology, Melbourne Medical SchoolUniversity of MelbourneMelbourneVictoriaAustralia
| | - Meaghan Clough
- Department of Neuroscience, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - Emma J. Solly
- Department of Neuroscience, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - Rebecca Glarin
- Melbourne Brain Centre Imaging Unit, Department of Radiology, Melbourne Medical SchoolUniversity of MelbourneMelbourneVictoriaAustralia
| | - Owen B. White
- Department of Neuroscience, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - Scott C. Kolbe
- Department of Neuroscience, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - Joanne Fielding
- Department of Neuroscience, Central Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| |
Collapse
|
9
|
Sampatakakis SN, Lymperopoulos L, Mavridis T, Karagiorgis G, Papadopoulos C, Deligianni CI, Mitsikostas DD. Visual snow: A systematic review and a case series. Cephalalgia 2022; 42:1409-1419. [PMID: 35945691 DOI: 10.1177/03331024221118917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Visual Snow Syndrome is a recently recognized neurological condition presenting, continuous, tiny dots across the entire visual field, accompanied by nyctalopia, photophobia and palinopsia that persist for months. It may be part of migraine aura spectrum, yet its definition is still questionable. Diagnostic criteria for Visual Snow Syndrome are included in the supplemental material of ICHD-3. We aimed to summarize recent data to improve the understanding of Visual Snow Syndrome. METHODS After presenting four new cases, we conducted a PRISMA systematic search in PubMed/MEDLINE and Embase databases using the keyword "visual snow" with specific inclusion and exclusion criteria. RESULTS From the 855 articles identified 30 were included for the qualitative analysis. These reports covered five aspects related to Visual Snow Syndrome: epidemiology, clinical features, comorbidities, pathophysiology, and treatment. We found limited data concerning Visual Snow Syndrome's epidemiology (one study). Clinical presentation (22 articles) and the comorbidities (migraine with aura and tinnitus most often, five reports) are described in detail. The pathophysiology of Visual Snow Syndrome is only approached with hypotheses, but several neuroimaging studies have been identified (seven articles). Treatment is based on single case reports only. CONCLUSION Data for Visual Snow Syndrome are few and not strong enough to support Visual Snow Syndrome as a medical identity. Further investigation is needed.
Collapse
Affiliation(s)
- Stefanos N Sampatakakis
- 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Loukas Lymperopoulos
- 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Theodoros Mavridis
- 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Georgios Karagiorgis
- 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Constantinos Papadopoulos
- 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Christina I Deligianni
- Danish Headache Center, Rigshospitalet Glostrup, Faculty of Medicine, Universtiy of Copenhagen, Copenhagen, Denmark
| | - Dimos D Mitsikostas
- 1st Department of Neurology, Eginition Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| |
Collapse
|
10
|
Fraser CE, Vaphiades MS, Van Stavern GP, Lee AG. Should Visual Snow and Visual Snow Syndrome Be Evaluated Outside of Standard In-clinic Ophthalmologic Testing? J Neuroophthalmol 2022; 42:384-389. [PMID: 35921623 DOI: 10.1097/wno.0000000000001675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Clare E Fraser
- Faculty of Health and Medicine (CF), Department of Ophthalmology, Save Sight Institute, University of Sydney, Sydney, Australia; Departments of Ophthalmology, Neurology and Neurosurgery (MV), University of Alabama, Birmingham, Alabama; Department of Ophthalmology and Visual Sciences (GPV), Washington University in St. Louis School of Medicine, St Louis, Missouri; and Department of Ophthalmology, Blanton Eye Institute (AGL), Houston Methodist Hospital, Houston, Texas
| | | | | | | |
Collapse
|
11
|
Strik M, Clough M, Solly EJ, Glarin R, White OB, Kolbe SC, Fielding J. Microstructure in patients with visual snow syndrome: an ultra-high field morphological and quantitative MRI study. Brain Commun 2022; 4:fcac164. [PMID: 35974797 PMCID: PMC9373960 DOI: 10.1093/braincomms/fcac164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/02/2022] [Accepted: 06/21/2022] [Indexed: 12/03/2022] Open
Abstract
Visual snow syndrome is a neurological condition characterized by continuous visual disturbance and a range of non-visual symptoms, including tinnitus and migraine. Little is known about the pathological mechanisms underlying visual snow syndrome. Here, we assessed brain morphometry and microstructure in visual snow syndrome patients using high-resolution structural and quantitative MRI. Forty visual snow syndrome patients (22 with migraine) and 43 controls underwent 7-Tesla MRI (MP2RAGE, 0.75 mm isotropic resolution). Volumetric and quantitative T1 values were extracted for white and grey matter regions and compared between groups. Where regions were significantly different between groups (false discovery rate corrected for multiple comparisons), post hoc comparisons were examined between patients with and without migraine. For visual snow syndrome patients, significant MRI variables were correlated with clinical severity (number of visual symptoms, perceived visual snow intensity, disruptiveness, fatigue and quality of life) and psychiatric symptoms prevalent in visual snow syndrome (depression, anxiety and depersonalization). Finally, cortical regions and individual thalamic nuclei were studied. Compared with controls, visual snow syndrome patients demonstrated a trend towards larger brain and white matter volumes and significantly lower T1 values for the entire cortex (P < 0.001), thalamus (P = 0.001) and pallidum (P = 0.001). For the patient group, thalamic T1 correlated with number of visual symptoms (P = 0.019, r = 0.390) and perceived disruptiveness of visual snow (P = 0.010, r = 0.424). These correlations did not survive multiple comparison corrections. As for specificity in visual snow syndrome group, T1 changes were most evident in caudal regions (occipital cortices) followed by parietal, temporal and prefrontal cortices. T1 values differed between groups for most individual thalamic nuclei. No differences were revealed between patients with and without migraine. In visual snow syndrome patients, we observed no changes in morphometry, instead widespread changes in grey matter microstructure, which followed a caudal-rostral pattern and affected the occipital cortices most profoundly. Migraine did not appear to independently affect these changes. Lower T1 values may potentially result from higher neurite density, myelination or increased iron levels in the visual snow syndrome brain. Further investigation of these changes may enhance our understanding of the pathogenesis of visual snow syndrome, ultimately leading to new treatment strategies.
Collapse
Affiliation(s)
- Myrte Strik
- Melbourne Brain Centre Imaging Unit, Department of Radiology, Melbourne Medical School, University of Melbourne , Melbourne, VIC 3010 , Australia
| | - Meaghan Clough
- Department of Neuroscience, Central Clinical School, Monash University , Melbourne, VIC 3004 , Australia
| | - Emma J Solly
- Department of Neuroscience, Central Clinical School, Monash University , Melbourne, VIC 3004 , Australia
| | - Rebecca Glarin
- Melbourne Brain Centre Imaging Unit, Department of Radiology, Melbourne Medical School, University of Melbourne , Melbourne, VIC 3010 , Australia
| | - Owen B White
- Department of Neuroscience, Central Clinical School, Monash University , Melbourne, VIC 3004 , Australia
| | - Scott C Kolbe
- Department of Neuroscience, Central Clinical School, Monash University , Melbourne, VIC 3004 , Australia
| | - Joanne Fielding
- Department of Neuroscience, Central Clinical School, Monash University , Melbourne, VIC 3004 , Australia
| |
Collapse
|
12
|
Abstract
OBJECTIVES Visual snow syndrome is relatively a recently recognized neurological entity presenting primarily with positive visual disturbance. Etiology is largely speculative. METHODS Authors report here on a child case of ADHD that developed a probable visual snow syndrome related to methylphenidate. RESULTS AND CONCLUSIONS Although remaining rare, prescribers ought to be cognizant of such unusual methylphenidate-related perceptual alterations.
Collapse
|
13
|
Ford H, Fraser CL, Solly E, Clough M, Fielding J, White O, Van Der Walt A. Hallucinogenic Persisting Perception Disorder: A Case Series and Review of the Literature. Front Neurol 2022; 13:878609. [PMID: 35599738 PMCID: PMC9120359 DOI: 10.3389/fneur.2022.878609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/11/2022] [Indexed: 11/18/2022] Open
Abstract
Background Hallucinogen persisting perception disorder (HPPD) is characterized by the re-emergence of perceptual symptoms experienced during acute hallucinogen intoxication following drug cessation. The underlying pathophysiology is poorly understood. We report the clinical characteristics and investigation findings of a series of HPPD cases with a literature review of previous case reports. We draw parallels between the features of HPPD and Visual Snow Syndrome (VSS). Methods Retrospective case series of 13 patients referred from neuro-ophthalmologists. Literature review with 24 HPPD case reports were identified through database search using the terms “hallucinogenic persisting perception disorder” OR “hallucinogen persisting perception disorder.” Results Lysergic acid diethylamide (LSD), 3,4-Methyl enedioxy methamphetamine (MDMA) and cannabinoid use was common. Cannabinoids and MDMA were mostly used in association with classical hallucinogens. The most frequent symptoms in our patients were visual snow, floaters, palinopsia, photophobia and nyctalopia. In the literature other symptoms included visual hallucinations altered motion perception, palinopsia, tracers and color enhancement. Ophthalmic and neurologic investigations were mostly normal. The majority of patients had ongoing symptoms. Two of our patients fully recovered—one after treatment with benzodiazepine and one without treatment. Twenty-five percent of cases from the literature fully recovered. Conclusions HPPD presents with heterogeneous visual phenomena on a background of previous classic and non-classic hallucinogen use. Ophthalmic investigations are typically normal. The symptoms of HPPD in our case series overlap with the typical features of Visual Snow Syndrome (VSS). Patients presenting with VSS should be screened for past recreational drug use. The DSM-5 description of HPPD does not include visual snow, nyctalopia, photophobia or floaters. A revision of the diagnostic criteria to include these symptoms may better reflect the typical clinical phenotype. Increased awareness of HPPD as a secondary cause of VSS can avoid extensive investigations. Controlled trials comparing primary and secondary VSS patients are needed to understand the pathophysiology better and optimize treatment for HPPD.
Collapse
Affiliation(s)
- Hannah Ford
- Department of Neurology, Alfred Health, Melbourne, VIC, Australia
| | - Clare L. Fraser
- Faculty of Health and Medicine, Save Sight Institute, The University of Sydney, Sydney, NSW, Australia
| | - Emma Solly
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Meaghan Clough
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Joanne Fielding
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Owen White
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Anneke Van Der Walt
- Department of Neurology, Alfred Health, Melbourne, VIC, Australia
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
- Department of Neuro-Ophthalmology, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
- *Correspondence: Anneke Van Der Walt
| |
Collapse
|
14
|
Unal-Cevik I. The role of occipital cortex hyperexcitability in visual snow syndrome. NEUROL SCI NEUROPHYS 2022. [DOI: 10.4103/nsn.nsn_193_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
|
15
|
Michels L, Stämpfli P, Aldusary N, Piccirelli M, Freund P, Weber KP, Fierz FC, Kollias S, Traber G. Widespread White Matter Alterations in Patients With Visual Snow Syndrome. Front Neurol 2021; 12:723805. [PMID: 34621237 PMCID: PMC8490630 DOI: 10.3389/fneur.2021.723805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 08/04/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Visual snow is considered a disorder of central visual processing resulting in a perturbed perception of constant binocular flickering or pixilation of the whole visual field. The underlying neurophysiological and structural alterations remain elusive. Methods: In this study, we included patients (final n = 14, five dropouts; five females, mean age: 32 years) with visual snow syndrome (VSS) and age- and sex-matched controls (final n = 20, 6 dropouts, 13 females, mean age: 28.2 years). We applied diffusion tensor imaging to examine possible white matter (WM) alterations in patients with VSS. Results: The patient group demonstrated higher (p-corrected < 0.05, adjusted for age and sex) fractional anisotropy (FA) and lower mean diffusivity (MD) and radial diffusivity (RD) compared to controls. These changes were seen in the prefrontal WM (including the inferior fronto-occipital fascicle), temporal and occipital WM, superior and middle longitudinal fascicle, and sagittal stratum. When additionally corrected for migraine or tinnitus-dominant comorbidities in VSS-similar group differences were seen for FA and RD, but less pronounced. Conclusions: Our results indicate that patients with VSS present WM alterations in parts of the visual cortex and outside the visual cortex. As parts of the inferior fronto-occipital fascicle and sagittal stratum are associated with visual processing and visual conceptualisation, our results suggest that the WM alterations in these regions may indicate atypical visual processing in patients with VSS. Yet, the frequent presence of migraine and other comorbidities such as tinnitus in VSS makes it difficult to attribute WM disruptions solely to VSS.
Collapse
Affiliation(s)
- Lars Michels
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Philipp Stämpfli
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Njoud Aldusary
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich and University of Zurich, Zurich, Switzerland.,Department of Diagnostic Radiology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Marco Piccirelli
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | | | - Konrad P Weber
- Department of Neurology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Fabienne C Fierz
- Department of Ophthalmology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Spyros Kollias
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Ghislaine Traber
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland.,Department of Ophthalmology, University of Basel, Basel, Switzerland
| |
Collapse
|
16
|
Vaphiades MS, Grondines B, Cooper K, Gratton S, Doyle J. Diagnostic Evaluation of Visual Snow. Front Neurol 2021; 12:743608. [PMID: 34603194 PMCID: PMC8481612 DOI: 10.3389/fneur.2021.743608] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 08/17/2021] [Indexed: 01/24/2023] Open
Abstract
Introduction: To determine which patients with visual snow (VS) and VS syndrome (VSS) require standard ophthalmologic testing including automated visual field and which patients require further testing such as macular spectral domain optical coherence tomography (SD-OCT), electrophysiology, and neuroimaging. Materials and Methods: We retrospectively reviewed 52 consecutive patients at three institutions with VS and VSS including the University of Alabama, Callahan Eye Hospital, the University of Missouri-Kansas City School of Medicine, and the Little Rock Eye Clinic from the years 2015 to 2021. We collected historical information, examination findings, ophthalmic testing, electrophysiology, and neuroimaging. Results: Of the 52 patients with VS and VSS, eight of the 52 cases met the clinical criteria for VSS. The ages ranged from 7 to 79 years, with a mean age of 25 years (SD = 14.0). There were 22 males and 30 females. Color vision was tested in 51 cases and was normal in 47 cases (92%). A funduscopic exam was performed in all 52 cases and was normal in 46 cases (88%). The macular SD-OCT was normal in all of the 19 cases that it was performed (100%). A Humphrey visual field was performed in 50 cases and was normal in 43 (86%). A visually evoked potential (VEP) was normal in 18 of the 19 cases where it was obtained (95%). The full-field electroretinography (ffERG) was obtained in 28 cases and was normal in 25 (89%). The multifocal electroretinography (mfERG) was normal in 11 of 12 cases (92%). Only four patients accounted for all of the abnormal electrophysiological tests. In the 37 cases that had an MRI, 29 were normal (78%). Only one patient revealed a lesion in the visual pathway (right optic nerve enhancement in an optic neuritis patient). Conclusions: Patients with VS and VSS, if typical in presentation and with normal testing, do not require a workup beyond a thorough history, neuro-ophthalmologic examination, and automated perimetry. If this testing is abnormal, then ancillary testing is required.
Collapse
Affiliation(s)
- Michael S Vaphiades
- Department of Ophthalmology, University of Alabama, Birmingham, AL, United States
| | - Brendan Grondines
- Department of Ophthalmology, University of Alabama, Birmingham, AL, United States
| | - Kasey Cooper
- Department of Ophthalmology, University of Alabama, Birmingham, AL, United States
| | - Sean Gratton
- Department of Ophthalmology, University of Missouri-Kansas City School of Medicine, Kansas City, MO, United States
| | - Jennifer Doyle
- Department of Ophthalmology, Little Rock Eye Clinic, Little Rock, AK, United States
| |
Collapse
|
17
|
Barrachina-Esteve O, Hidalgo-Torrico I, Acero C, Aranceta S, Cánovas-Vergé D, Ribera G. Visual snow syndrome and its relationship with migraine. Neurologia 2021:S0213-4853(21)00112-2. [PMID: 34521544 DOI: 10.1016/j.nrl.2021.05.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 04/24/2021] [Accepted: 05/01/2021] [Indexed: 10/20/2022] Open
Abstract
INTRODUCTION Visual snow syndrome (VSS) is a central nervous system disorder that consists of the constant perception of small black and white dots throughout the entire visual field. DEVELOPMENT VSS can present from infancy to old age, with greater prevalence in the young population, and shows no difference between sexes. The diagnostic criteria include the presence of visual snow and such other visual phenomena as palinopsia, photophobia, nyctalopia, and other persistent visual phenomena. The pathophysiology of VSS is unknown, but hyperexcitability of the visual cortex and a dysfunction in higher-order visual processing are postulated as potential mechanisms. The prevalence of migraine among patients with VSS is high, compared to the general population, and symptoms are more severe in patients presenting both conditions. No effective treatment is available, but the drug with the best results is lamotrigine, which is recommended only in selected cases with severe functional limitation. CONCLUSIONS VSS is a little-known and underdiagnosed entity, but the increasing number of studies in recent years has made it possible to establish diagnostic criteria and begin studying its pathophysiology. This entity is closely related to migraine, with overlapping symptoms and probably shared pathophysiological mechanisms.
Collapse
Affiliation(s)
- O Barrachina-Esteve
- Servicio de Neurología, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, España.
| | - I Hidalgo-Torrico
- Servicio de Cirugía Cardiaca, Hospital Universitario Son Espases, Palma de Mallorca, España
| | - C Acero
- Servicio de Oftalmología, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT. Universitat Autònoma de Barcelona, Sabadell, España
| | - S Aranceta
- Servicio de Neurología, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, España
| | - D Cánovas-Vergé
- Servicio de Neurología, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, España
| | - G Ribera
- Servicio de Neurología, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, España
| |
Collapse
|
18
|
Aldusary N, Traber GL, Freund P, Fierz FC, Weber KP, Baeshen A, Alghamdi J, Saliju B, Pazahr S, Mazloum R, Alshehri F, Landau K, Kollias S, Piccirelli M, Michels L. Abnormal Connectivity and Brain Structure in Patients With Visual Snow. Front Hum Neurosci 2020; 14:582031. [PMID: 33328934 PMCID: PMC7710971 DOI: 10.3389/fnhum.2020.582031] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 10/14/2020] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE Visual snow (VS) is a distressing, life-impacting condition with persistent visual phenomena. VS patients show cerebral hypermetabolism within the visual cortex, resulting in altered neuronal excitability. We hypothesized to see disease-dependent alterations in functional connectivity and gray matter volume (GMV) in regions associated with visual perception. METHODS Nineteen patients with VS and 16 sex- and age-matched controls were recruited. Functional magnetic resonance imaging (fMRI) was applied to examine resting-state functional connectivity (rsFC). Volume changes were assessed by means of voxel-based morphometry (VBM). Finally, we assessed associations between MRI indices and clinical parameters. RESULTS Patients with VS showed hyperconnectivity between extrastriate visual and inferior temporal brain regions and also between prefrontal and parietal (angular cortex) brain regions (p < 0.05, corrected for age and migraine occurrence). In addition, patients showed increased GMV in the right lingual gyrus (p < 0.05 corrected). Symptom duration positively correlated with GMV in both lingual gyri (p < 0.01 corrected). CONCLUSION This study found VS to be associated with both functional and structural changes in the early and higher visual cortex, as well as the temporal cortex. These brain regions are involved in visual processing, memory, spatial attention, and cognitive control. We conclude that VS is not just confined to the visual system and that both functional and structural changes arise in VS patients, be it as an epiphenomenon or a direct contributor to the pathomechanism of VS. These in vivo neuroimaging biomarkers may hold potential as objective outcome measures of this so far purely subjective condition.
Collapse
Affiliation(s)
- Njoud Aldusary
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, Zurich, Switzerland
- Department of Diagnostic Radiology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ghislaine L. Traber
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
- Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland
| | - Patrick Freund
- Spinal Cord Injury Center Balgrist, University of Zurich, Zurich, Switzerland
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Fabienne C. Fierz
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Konrad P. Weber
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
- Department of Neurology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Arwa Baeshen
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, Zurich, Switzerland
- Department of Radiological Sciences, Faculty of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Jamaan Alghamdi
- Department of Diagnostic Radiology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Bujar Saliju
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Shila Pazahr
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, Zurich, Switzerland
| | - Reza Mazloum
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, Zurich, Switzerland
- Institute of Robotics and Intelligent Systems, D-HEST, ETH Zurich, Zurich, Switzerland
| | - Fahad Alshehri
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, Zurich, Switzerland
- Radiology, College of Medicine, Qassim University, Al Qassim, Saudi Arabia
| | - Klara Landau
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Spyros Kollias
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, Zurich, Switzerland
| | - Marco Piccirelli
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, Zurich, Switzerland
| | - Lars Michels
- Department of Neuroradiology, Clinical Neuroscience Center, University Hospital Zurich, Zurich, Switzerland
| |
Collapse
|