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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.
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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
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2
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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.
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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
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Chojdak-Łukasiewicz J, Dziadkowiak E. Visual Snow Syndrome in Patient with Migraine: Case Report and Literature Review. J Clin Med 2024; 13:1373. [PMID: 38592219 PMCID: PMC10931930 DOI: 10.3390/jcm13051373] [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: 01/10/2024] [Revised: 02/23/2024] [Accepted: 02/26/2024] [Indexed: 04/10/2024] Open
Abstract
Visual snow syndrome (VSS) is a rarely diagnosed neurological phenomenon. It is a visual disorder characterised by the presence of numerous white, black, or translucent dots in the visual field, resembling the 'snow' of an analogue TV set experiencing reception interference. According to The International Classification of Headache Disorders, 3rd edition, visual snow is defined as a pattern of continuous small dots across the visual field lasting >3 months and accompanied by at least two of the following four additional symptoms: palinopsia, increased entoptic phenomena, photophobia, and nyctalopia. These complaints are not consistent with a typical migraine with visual aura and cannot be better explained by another disorder. The authors present the case of a 39-year-old woman who was diagnosed with VSS. The symptoms appeared after a migraine attack and had not alleviated. The patient reported a sensation of constant 'TV screen snow'. A neurological examination found no signs of focal damage to the nervous system. The results of the ophthalmological examination, MRI of the brain with contrast, MRI of the eye sockets, and EEG were normal. VSS is a phenomenon that is still not fully understood, different from migraine aura and associated with a number of additional symptoms. VSS is very difficult to treat. In this case, a lot of drugs were used without improvement. Further research must be conducted to determine the best treatment options for these patients.
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Affiliation(s)
| | - Edyta Dziadkowiak
- Department of Neurology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw, Poland;
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Stern JI, Robertson CE. Visual Snow: Updates and Narrative Review. Curr Pain Headache Rep 2024; 28:55-63. [PMID: 38079073 DOI: 10.1007/s11916-023-01186-3] [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] [Accepted: 10/25/2023] [Indexed: 02/22/2024]
Abstract
PURPOSE OF REVIEW Visual snow (VS) involves visualization of innumerable dots throughout the visual field, sometimes resembling "TV static." Patients who experience this symptom may also have additional visual symptoms (e.g., photophobia, palinopsia, floaters, and nyctalopia) with a pattern now defined as visual snow syndrome (VSS). This manuscript describes both VS and VSS in detail and provides an updated review on the clinical features, pathophysiology, and optimal management strategies for these symptoms. RECENT FINDINGS VS/VSS may be primary or secondary to a variety of etiologies, including ophthalmologic or brain disorders, systemic disease, and medication/hallucinogen exposure. Evaluation involves ruling out secondary causes and mimics of VS. Increasing evidence suggests that VSS is a widespread process extending beyond the visual system. Pathophysiology may involve cortical hyperexcitability or dysfunctional connectivity of thalamocortical or attention/salience networks. VSS is typically a benign, non-progressive syndrome and can be managed with non-medicine strategies. Though no medication provides complete relief, some may provide partial improvement in severity of VS.
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Affiliation(s)
- Jennifer I Stern
- Neurology Department, Mayo Clinic College of Medicine and Science, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Carrie E Robertson
- Neurology Department, Mayo Clinic College of Medicine and Science, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA.
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Satgunam P, Kannan K, Hathibelagal AR. Understanding visual snow syndrome: A retrospective study from a tertiary eye care center. Indian J Ophthalmol 2024; 72:211-216. [PMID: 38099384 PMCID: PMC10941942 DOI: 10.4103/ijo.ijo_2180_22] [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: 01/19/2023] [Revised: 05/02/2023] [Accepted: 05/16/2023] [Indexed: 12/19/2023] Open
Abstract
PURPOSE Visual snow syndrome is a debilitating neurological condition. A comprehensive eye examination may not detect any abnormalities in this condition. Presently the condition is recognized only through the history elicited. Hence, it becomes important to understand the presenting complaints and profile of these patients. A retrospective study at a tertiary eye care center was undertaken to achieve this goal. METHODS Electronic medical records of patients presenting to a Binocular Vision and Orthoptics clinic were reviewed. Records of the patients containing keywords such as "light sensitivity, shadowing, visual snow, multiple images, and night vision" were retrieved and inspected. Those matching the diagnostic criteria of visual snow syndrome were included in the study. RESULTS A total of 33 patients (average age ± standard deviation: 29.7 ± 9.8 years) were identified. Majority of the patients were males (69%). All the patients had logMAR visual acuity 0 or better in each eye. The most prominent (84.4%) presenting symptom was palinopsia (or afterimage or trailing). About 34.4% complained of floaters (including snow-like appearance). More than half (54.6%) of the patients also had binocular dysfunction. CONCLUSION Visual snow syndrome is a relatively new condition on the rise, with unclear pathology. The symptoms of this condition can easily be confused with regular floaters or black spots seen in vitreous and retinal pathologies. In the absence of such pathology, an elaborate history should be elicited, and the distress of the patient should be acknowledged. The patient should also be reassured that this is not a blinding condition.
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Affiliation(s)
- PremNandhini Satgunam
- Brien Holden Institute of Optometry and Vision Sciences, Hyderabad Eye Research Foundation, Hyderabad, Telangana, India
| | - Kiruthika Kannan
- Srimati Kanuri Santhamma Centre for Vitreoretinal Diseases, Anant Bajaj Retina Institute, L. V. Prasad Eye Institute, Hyderabad, Telangana, India
| | - Amithavikram R Hathibelagal
- Brien Holden Institute of Optometry and Vision Sciences, Hyderabad Eye Research Foundation, Hyderabad, Telangana, India
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Puledda F, Viganò A, Sebastianelli G, Parisi V, Hsiao FJ, Wang SJ, Chen WT, Massimini M, Coppola G. Electrophysiological findings in migraine may reflect abnormal synaptic plasticity mechanisms: A narrative review. Cephalalgia 2023; 43:3331024231195780. [PMID: 37622421 DOI: 10.1177/03331024231195780] [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] [Indexed: 08/26/2023]
Abstract
BACKGROUND The cyclical brain disorder of sensory processing accompanying migraine phases lacks an explanatory unified theory. METHODS We searched Pubmed for non-invasive neurophysiological studies on migraine and related conditions using transcranial magnetic stimulation, electroencephalography, visual and somatosensory evoked potentials. We summarized the literature, reviewed methods, and proposed a unified theory for the pathophysiology of electrophysiological abnormalities underlying migraine recurrence. RESULTS All electrophysiological modalities have determined specific changes in brain dynamics across the different phases of the migraine cycle. Transcranial magnetic stimulation studies show unbalanced recruitment of inhibitory and excitatory circuits, more consistently in aura, which ultimately results in a substantially distorted response to neuromodulation protocols. Electroencephalography investigations highlight a steady pattern of reduced alpha and increased slow rhythms, largely located in posterior brain regions, which tends to normalize closer to the attacks. Finally, non-painful evoked potentials suggest dysfunctions in habituation mechanisms of sensory cortices that revert during ictal phases. CONCLUSION Electrophysiology shows dynamic and recurrent functional alterations within the brainstem-thalamus-cortex loop varies continuously and recurrently in migraineurs. Given the central role of these structures in the selection, elaboration, and learning of sensory information, these functional alterations suggest chronic, probably genetically determined dysfunctions of the synaptic short- and long-term learning mechanisms.
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Affiliation(s)
- Francesca Puledda
- Headache Group, Wolfson CARD, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | | | - Gabriele Sebastianelli
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome Polo Pontino ICOT, Latina, Italy
| | | | - Fu-Jung Hsiao
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Shuu-Jiun Wang
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Wei-Ta Chen
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Marcello Massimini
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Gianluca Coppola
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome Polo Pontino ICOT, Latina, Italy
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Silva EM, Puledda F. Visual snow syndrome and migraine: a review. Eye (Lond) 2023; 37:2374-2378. [PMID: 36788360 PMCID: PMC10397188 DOI: 10.1038/s41433-023-02435-w] [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: 01/14/2023] [Revised: 01/19/2023] [Accepted: 01/30/2023] [Indexed: 02/16/2023] Open
Abstract
Visual snow syndrome is a neurological condition characterized by ongoing prominent phenomena described consistently as tiny dots moving across the entire visual field, often associated with complex visual symptoms. These can take the form of afterimages, entoptic phenomena, nyctalopia and light sensitivity. Although some of these symptoms can be benign, they can nonetheless become significantly impactful for many who experience them, particularly in cases that have a sudden and abrupt start. As visual snow syndrome becomes increasingly recognized in clinical practice we begin to learn about its typical presentation and underlying pathophysiology. Treatment of visual snow, however, still proves quite challenging, and efforts need to be focused on unravelling the biological mechanisms of the syndrome. This endeavour has characterized the most recent research on visual snow, mostly involving neuroimaging, neurophysiological and neurobehavioral studies aimed at understanding its underlying neural signature. Another important aspect of the syndrome, which will likely prove critical in deepening our understanding of visual snow, is represented by the intricate biological and historical connexion with migraine. This narrative review focused on visual snow syndrome will explore its clinical, pathophysiological and treatment aspects in detail.
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Affiliation(s)
| | - Francesca Puledda
- Headache Group, Wolfson CARD, Institute of Psychiatry, Psychology and Neuroscience, King's College, London, UK.
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Rusztyn P, Stańska W, Torbus A, Maciejewicz P. Visual Snow: A Review on Pathophysiology and Treatment. J Clin Med 2023; 12:3868. [PMID: 37373563 DOI: 10.3390/jcm12123868] [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: 04/05/2023] [Revised: 05/28/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
OBJECTIVE Visual snow (VS) is a rare clinical entity in neuro-ophthalmology. It is described as the presence of flickering dots affecting the whole visual field, often compared by patients to snow or pixelated television static. Importantly, it can be an alarming symptom for many patients, lowering their quality of life. Our purpose is to increase awareness of this disease, because many healthcare professionals have difficulty identifying symptoms as the nature of the condition is subjective. In this review, we aimed to describe the updates in the etiology and treatment of visual snow. We searched for articles in English, presenting original data and published after December 2019. Different studies show inconsistent data. Neuroimaging studies found, among other things, hypermetabolism of the lingual gyrus, increased gray matter in different brain areas, and altered connectivity in visual pathways. However, these findings were not present in all patients. According to the literature, among the most effective drugs is lamotrigine. Unfortunately, it also carries a risk of worsening the symptoms. It is crucial to remember that VS can be worsened or induced by alcohol, recreational drugs, and certain medication. In terms of treatment, nonpharmacological approaches such as color filters and repetitive Transcranial Magnetic Stimulation were also used. INTERPRETATION Further studies are needed to understand the nature of VS fully. Even though the pathophysiology and effective treatment of the condition remains unknown, expanding the knowledge about visual snow can impact the comfort of patients.
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Affiliation(s)
- Przemysław Rusztyn
- Students' Scientific Club, Department of Ophthalmology, Medical University of Warsaw, 02-005 Warsaw, Poland
| | - Wiktoria Stańska
- Students' Scientific Club, Department of Ophthalmology, Medical University of Warsaw, 02-005 Warsaw, Poland
| | - Anna Torbus
- Students' Scientific Club, Department of Ophthalmology, Medical University of Warsaw, 02-005 Warsaw, Poland
| | - Piotr Maciejewicz
- Department of Ophthalmology, Medical University of Warsaw, 02-005 Warsaw, Poland
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Han MHE, Ciuffreda KJ, Rutner D. Historical, Diagnostic, and Chromatic Treatment in Visual Snow Syndrome: A Retrospective Analysis. Optom Vis Sci 2023; 100:328-333. [PMID: 37071109 DOI: 10.1097/opx.0000000000002019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2023] Open
Abstract
PURPOSE This study aimed to determine the historical, diagnostic, and treatment aspects in patients with documented visual snow syndrome/visual snow in an academic, optometric setting. METHODS A retrospective analysis was performed in patients (N = 40, aged 12 to 55 years) with documented visual snow syndrome/visual snow examined over a 4-year period. Information was collected by a detailed case history and the Visual Snow Syndrome Symptom Survey. Treatment assessment was performed using the Intuitive Colorimeter, and a wide selection of chromatic tints was assessed under the most provocative/exacerbating and other conditions. RESULTS Visual snow was typically constant and monochromatic, with it being present on average 6.43 years. Bright and dark surfaces were the most provocative/exacerbating/revealing conditions, along with the viewing of computer screens. The most common etiology was mild traumatic brain injury. The most common primary and secondary symptoms were photosensitivity and tinnitus, respectively. There was a high frequency of occurrence of oculomotor deficits, especially accommodative and vergence insufficiency (~40 to 50%). Eighty percent of the patients were prescribed a chromatic tint with subjective visual reduction of visual snow ranging from 15 to 100% (mean, 45%). CONCLUSIONS The present information will help in understanding this unusual medicoperceptual condition, especially with respect to simple treatment frequently using readily available chromatic tints.
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Affiliation(s)
| | - Kenneth J Ciuffreda
- Vision Rehabilitation Service, SUNY/College of Optometry, New York, New York
| | - Daniella Rutner
- Vision Rehabilitation Service, SUNY/College of Optometry, New York, New York
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Differential Diagnosis of Visual Phenomena Associated with Migraine: Spotlight on Aura and Visual Snow Syndrome. Diagnostics (Basel) 2023; 13:diagnostics13020252. [PMID: 36673062 PMCID: PMC9857878 DOI: 10.3390/diagnostics13020252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 12/30/2022] [Accepted: 12/30/2022] [Indexed: 01/11/2023] Open
Abstract
Migraine is a severe and common primary headache disorder, characterized by pain as well as a plethora of non-painful symptoms. Among these, visual phenomena have long been known to be associated with migraine, to the point where they can constitute a hallmark of the disease itself. In this review we focus on two key visual disorders that are directly or indirectly connected to migraine: visual aura and visual snow syndrome (VSS). Visual aura is characterized by the transient presence of positive and negative visual symptoms, before, during or outside of a migraine attack. VSS is a novel stand-alone phenomenon which has been shown to be comorbid with migraine. We discuss key clinical features of the two disorders, including pathophysiological mechanisms, their differential diagnoses and best treatment practices. Our aim is to provide an aid for clinicians and researchers in recognizing these common visual phenomena, which can even appear simultaneously in patients with an underlying migraine biology.
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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.
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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
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Tsang T, Shidlofsky C, Mora V. The efficacy of neuro-optometric visual rehabilitation therapy in patients with visual snow syndrome. Front Neurol 2022; 13:999336. [PMID: 36545398 PMCID: PMC9760742 DOI: 10.3389/fneur.2022.999336] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 11/21/2022] [Indexed: 12/12/2022] Open
Abstract
Objective This study intends to evaluate the feasibility of Neuro-Optometric Rehabilitation Therapy (NORT) to treat Visual Snow Syndrome (VSS). This pilot study utilized the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) to assess quality of life (QOL) before and after treatment. Methods Twenty-one participants were recruited as successive intake patients diagnosed with VSS at the clinics of Dr. Terry Tsang Optometry, Inc and Neuro-Vision Associates of North Texas. Participants completed the NEI Visual Function Questionnaire 25-2000 edition and performed NORT, conducted by a neuro-optometrist or a qualified vision therapist. The NEI-VFQ-25 was administered before, at 6 weeks, and at 12 weeks of NORT to evaluate the effects of treatment on patient QOL. Results The participants demonstrated an improvement in QOL composite and subscale scores after 6 and 12 weeks of NORT treatment. The NEI-VFQ-25 composite scores from the pre-test (M = 68, SD = 18) and at 6 weeks of treatment (M = 75, SD = 17) indicate an improvement in QOL [t (20) = 4.0, p = 0.0007]. The NEI-VFQ-25 composite scores from pretest to 12 weeks of treatment showed further improvements. This trend of improvement on NEI-VFQ-25 composite scores continued into the 12th week (M = 77, SD = 17) of treatment [t (20) = 4.5, p = 0.0002]. The subscales of general vision, distance activities, near activities, social functioning, mental health, role difficulties and dependency also showed improvement. Conclusion Our results suggest that patients with VSS experience improvement in QOL in as little as 6 weeks, with further improvement by 12 weeks of NORT. This suggests NORT is an effective treatment option for managing the condition and improving QOL in patients with VSS, although a reduction in specific symptoms has yet to be demonstrated. This study provides justification that NORT warrants further investigation on VSS symptom reduction.
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Affiliation(s)
- Terry Tsang
- Dr. Terry Tsang Optometry, Inc., Irvine, CA, United States,*Correspondence: Terry Tsang
| | | | - Vanessa Mora
- Department of Research, Visual Snow Initiative, Miami, FL, United States
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Costa RM, Campos P, Wiborg M, Rebôlo C, Wittmann M, Kornmeier J. Prevalence of visual snow and relation to attentional absorption. PLoS One 2022; 17:e0276971. [PMID: 36342911 PMCID: PMC9639836 DOI: 10.1371/journal.pone.0276971] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 10/18/2022] [Indexed: 11/09/2022] Open
Abstract
Visual snow is a condition of unclear prevalence characterized by tiny flickering dots throughout the entire visual field. It appears to result from visual cortex hyperactivity and possibly correlates with propensity to be engrossed in sensory and imaginary experiences (absorption). The prevalence and correlates of visual snow, and emotional reactions to it, were explored in the general Portuguese population with three studies with online surveys. In Study 1, 564 participants were shown an animated graphic simulation of visual snow and asked to rate how frequently they have similar percepts on a scale anchored by 0% and 100% of their waking time. They also reported their degree of distress and fascination resulting from visual snow. Absorption was measured with the Modified Tellegen Absorption Scale. 44% of respondents reported they see visual snow at least 10% of the time, and 20% reported seeing it between 80% and 100% of the time. Similar to findings in clinical samples, the frequency of visual snow correlated with tinnitus frequency and entoptic phenomena, but not with ophthalmologic problems. It was confirmed that visual snow is related to absorption. Although distress caused by visual snow was generally absent or minimal in our samples, a substantial minority (28%) reported moderate to high levels of distress. High fascination with visual snow was reported by 9%. In Studies 2 and 3, visual snow was measured by means of verbal descriptions without graphic simulation (“visual field full of tiny dots of light” and “world seen with many dots of light”, respectively). The results were similar to those in Study 1, but seeing visual snow 80%-100% of the time was less frequent (6.5% in Study 2 and 3.6% in Study 3). Visual snow has been insufficiently investigated. More research is needed to uncover underlying neurophysiological mechanisms and psychological and behavioral correlates.
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Affiliation(s)
- Rui Miguel Costa
- William James Center for Research, Ispa–Instituto Universitário, Lisbon, Portugal
- * E-mail:
| | | | | | | | - Marc Wittmann
- Institute for Frontier Areas of Psychology and Mental Health, Freiburg, Germany
| | - Jürgen Kornmeier
- Institute for Frontier Areas of Psychology and Mental Health, Freiburg, Germany
- Faculty of Medicine, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Freiburg, Germany
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14
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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.
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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
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15
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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
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16
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Kondziella D. Visual snow syndrome and the emperor’s new clothes. Brain Commun 2022; 4:fcac178. [PMID: 35898721 PMCID: PMC9311787 DOI: 10.1093/braincomms/fcac178] [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: 05/08/2022] [Revised: 05/08/2022] [Accepted: 07/05/2022] [Indexed: 11/15/2022] Open
Abstract
This scientific commentary refers to ‘Microstructure in patients with visual snow syndrome: an ultra-high field morphological and quantitative MRI study’, by Strik et al. (https://doi.org/10.1093/braincomms/fcac164)
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Affiliation(s)
- Daniel Kondziella
- Department of Neurology, Rigshospitalet, Copenhagen University Hospital , Copenhagen , Denmark
- Department of Clinical Medicine, University of Copenhagen , Copenhagen , Denmark
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17
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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.
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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
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18
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Puledda F, Villar-Martínez MD, Goadsby PJ. Case Report: Transformation of Visual Snow Syndrome From Episodic to Chronic Associated With Acute Cerebellar Infarct. Front Neurol 2022; 13:811490. [PMID: 35242098 PMCID: PMC8886039 DOI: 10.3389/fneur.2022.811490] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 01/24/2022] [Indexed: 12/23/2022] Open
Abstract
Visual snow syndrome is a novel neurological condition characterized by a panfield visual disturbance associated with several additional symptoms. Although it is usually a continuous and primary disorder, cases of intermittent visual snow have been described in the literature, as well as rare secondary forms. This report is the first description of a case of intermittent visual snow syndrome, which transformed into a persistent form following a posterior circulation stroke due to vertebral artery dissection. At 1 and 2 years after experiencing the acute cerebellar infarct, the patient's only neurological sequalae was visual snow. This case provides a description of how visual snow syndrome may be caused by an underlying brain disorder, and highlights the importance of the cerebellum in the pathophysiology of this relatively unknown condition. It further shows evidence of how existing predispositions might be relevant to the development of visual snow, in certain subjects and following specific circumstances.
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Affiliation(s)
- Francesca Puledda
- Headache Group, Wolfson Centre for Age-Related Diseases (CARD), SLaM Biomedical Research Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, National Institute for Health Research (NIHR)-Wellcome Trust King's Clinical Research Facility, King's College Hospital, London, United Kingdom
| | - María Dolores Villar-Martínez
- Headache Group, Wolfson Centre for Age-Related Diseases (CARD), SLaM Biomedical Research Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, National Institute for Health Research (NIHR)-Wellcome Trust King's Clinical Research Facility, King's College Hospital, London, United Kingdom
| | - Peter J Goadsby
- Headache Group, Wolfson Centre for Age-Related Diseases (CARD), SLaM Biomedical Research Centre, Institute of Psychiatry, Psychology and Neuroscience, King's College London, National Institute for Health Research (NIHR)-Wellcome Trust King's Clinical Research Facility, King's College Hospital, London, United Kingdom.,Department of Neurology, University of California, Los Angeles, Los Angeles, CA, United States
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19
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Abstract
Purpose of Review Until the last 5 years, there was very little in the literature about the phenomenon now known as visual snow syndrome. This review will examine the current thinking on the pathology of visual snow and how that thinking has evolved. Recent Findings While migraine is a common comorbidity to visual snow syndrome, evidence points to these conditions being distinct clinical entities, with some overlapping pathophysiological processes. There is increasing structural and functional evidence that visual snow syndrome is due to a widespread cortical dysfunction. Cortical hyperexcitability coupled with changes in thalamocortical pathways and higher-level salience network controls have all shown differences in patients with visual snow syndrome compared to controls. Summary Further work is needed to clarify the exact mechanisms of visual snow syndrome. Until that time, treatment options will remain limited. Clinicians having a clearer understanding of the basis for visual snow syndrome can appropriately discuss the diagnosis with their patients and steer them towards appropriate management options.
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Affiliation(s)
- Clare L Fraser
- Faculty of Health and Medicine, Save Sight Institute, The University of Sydney, 8 Macquarie Street, Sydney, NSW, 2000, Australia. .,Macquarie Ophthalmology, School of Clinical Medicine, Macquarie University, Sydney, Australia.
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20
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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
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21
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Age- and frequency-dependent changes in dynamic contrast perception in visual snow syndrome. J Headache Pain 2021; 22:148. [PMID: 34895130 PMCID: PMC8903496 DOI: 10.1186/s10194-021-01355-y] [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: 09/03/2021] [Accepted: 11/08/2021] [Indexed: 12/03/2022] Open
Abstract
Objective Patients with visual snow syndrome (VSS) suffer from a debilitating continuous (“TV noise-like”) visual disturbance. They report problems with vision at night and palinopsia despite normal visual acuity. The underlying pathophysiology of VSS is largely unknown. Currently, it is a clinical diagnosis based on the patient’s history, an objective test is not available. Here, we tested the hypothesis that patients with VSS have an increased threshold for detecting visual contrasts at particular temporal frequencies by measuring dynamic contrast detection-thresholds. Methods Twenty patients with VSS were compared to age-, gender-, migraine- and aura-matched controls in this case-control study. Subjects were shown bars randomly tilted to the left or right, flickering at six different frequencies (15 Hz, 20 Hz, 25 Hz, 30 Hz, 35 Hz, 40 Hz). The contrast threshold (CT) for detection of left or right tilt was measured in a two-alternative adaptive forced-choice procedure (QUEST). The threshold was defined as the Michelson contrast necessary to achieve the correct response in 75% of the cases. Results The CT increased for higher flicker frequencies (ANOVA: main effect frequency: F (5,180) = 942; p < 0.001), with an additional significant frequency*diagnosis interaction (ANOVA: F (5,180) = 5.00; p < 0.001). This interaction effect was due to an increased CT at a flicker frequency of 15 Hz in the VSS cohort (VSS: MC = 1.17%; controls: MC = 0.77%). At the other frequencies, group comparisons revealed no differences. Furthermore, in the VSS cohort we observed an increase of CT with higher age (r = 0.69; p < 0.001), which was not seen in controls (r = 0.30; p = 0.20). Conclusions This study demonstrates a lower visual contrast sensitivity exclusively at 15 Hz in VSS patients and demonstrates frequency-dependent differences in dynamic contrast vision. The peak sensitivities of both parvo- and magnocellular visual pathways are close to a frequency of about 10 Hz. Therefore, this frequency seems to be of crucial importance in everyday life. Thus, it seems plausible that the impairment of contrast sensitivity at 15 Hz might be an important pathophysiological correlate of VSS. Furthermore, the overall age-related decrease in contrast sensitivity only in VSS patients underscores the vulnerability of dynamic contrast detection in VSS patients. Dynamic CT detection seems to be a promising neurophysiological test that may contribute to the diagnosis of VSS.
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22
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Puledda F, Vandenbussche N, Moreno-Ajona D, Eren O, Schankin C, Goadsby PJ. Evaluation of treatment response and symptom progression in 400 patients with visual snow syndrome. Br J Ophthalmol 2021; 106:1318-1324. [PMID: 34656983 PMCID: PMC9411880 DOI: 10.1136/bjophthalmol-2020-318653] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/24/2021] [Accepted: 03/26/2021] [Indexed: 11/03/2022]
Abstract
AIMS To gather information on useful medications to treat visual snow syndrome (VSS) as well as to validate an instrument to assess its clinical severity and the course of the disorder over time. METHODS Four hundred patients with VSS were included in this web-based prospective questionnaire study. All subjects completed a treatment questionnaire and a clinical diary. The first allowed evaluation of the effects of previous medications on visual snow, while the second measured VSS symptoms daily over the course of 30 days. RESULTS Patients commonly reported previous use of medications such as antidepressants, antiepileptics, antibiotics and benzodiazepines. However, none of these drug classes was beneficial for the majority of patients. Recreational drugs and alcohol worsened visual snow symptoms in several reports. Vitamins and benzodiazepines had high therapeutic ratios, although in most cases they did not change the course of VSS.The monthly diary confirmed that the static in VSS is a consistent symptom over time. It also showed that indoor and fluorescent lights have a worse effect on symptoms when compared with natural outdoor lighting. CONCLUSIONS The study confirms clinical experience that medications are generally ineffective in VSS, with the exception of vitamins and perhaps benzodiazepines, which could be beneficial in some patients. The 30-day diary represents a useful tool to measure symptom progression over time, which could be used in future trials on VSS.
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Affiliation(s)
- Francesca Puledda
- Headache Group, Wolfson CARD, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK .,NIHR-Wellcome Trust King's Clinical Research Facility, SLaM Biomedical Research Centre, King's College Hospital, NIHR, London, UK
| | | | - David Moreno-Ajona
- Headache Group, Wolfson CARD, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.,NIHR-Wellcome Trust King's Clinical Research Facility, SLaM Biomedical Research Centre, King's College Hospital, NIHR, London, UK
| | - Ozan Eren
- Neurology, University Hospital LMU Munich, Munchen, Germany
| | | | - Peter J Goadsby
- Headache Group, Wolfson CARD, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK.,NIHR-Wellcome Trust King's Clinical Research Facility, SLaM Biomedical Research Centre, King's College Hospital, NIHR, London, UK.,Neurology, University of California Los Angeles, Los Angeles, California, USA
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23
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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.
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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
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24
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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.
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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
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25
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Klein A, Schankin CJ. Visual snow syndrome, the spectrum of perceptual disorders, and migraine as a common risk factor: A narrative review. Headache 2021; 61:1306-1313. [PMID: 34570907 PMCID: PMC9293285 DOI: 10.1111/head.14213] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 08/06/2021] [Accepted: 08/19/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The aim of this narrative review is to explore the relationship between visual snow syndrome (VSS), migraine, and a group of other perceptual disorders. BACKGROUND VSS is characterized by visual snow and additional visual and nonvisual disturbances. The clinical picture suggests a hypersensitivity to internal and external stimuli. Imaging and electrophysiological findings indicate a hyperexcitability of the primary and secondary visual areas of the brain possibly due to an impairment of inhibitory feedback mechanisms. Migraine is the most frequent comorbidity. Epidemiological and clinical studies indicate that other perceptual disorders, such as tinnitus, fibromyalgia, and dizziness, are associated with VSS. Clinical overlaps and parallels in pathophysiology might exist in relation to migraine. METHODS We performed a PubMed and Google Scholar search with the following terms: visual snow syndrome, entoptic phenomenon, fibromyalgia, tinnitus, migraine, dizziness, persistent postural-perceptual dizziness (PPPD), comorbidities, symptoms, pathophysiology, thalamus, thalamocortical dysrhythmia, and salience network. RESULTS VSS, fibromyalgia, tinnitus, and PPPD share evidence of a central disturbance in the processing of different stimuli (visual, somatosensory/pain, acoustic, and vestibular) that might lead to hypersensitivity. Imaging and electrophysiological findings hint toward network disorders involving the sensory networks and other large-scale networks involved in the management of attention and emotional processing. There are clinical and epidemiological overlaps between these disorders. Similarly, migraine exhibits a multisensory hypersensitivity even in the interictal state with fluctuation during the migraine cycle. All the described perceptual disorders are associated with migraine suggesting that having migraine, that is, a disorder of sensory processing, is a common link. CONCLUSION VSS, PPPD, fibromyalgia, and chronic tinnitus might lie on a spectrum of perceptual disorders with similar pathophysiological mechanisms and the common risk factor migraine. Understanding the underlying network disturbances might give insights into how to improve these currently very difficult to treat conditions.
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Affiliation(s)
- Antonia Klein
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Christoph J Schankin
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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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.
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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
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Puledda F, Schankin CJ, O'Daly O, Ffytche D, Eren O, Karsan N, Williams SCR, Zelaya F, Goadsby PJ. Localised increase in regional cerebral perfusion in patients with visual snow syndrome: a pseudo-continuous arterial spin labelling study. J Neurol Neurosurg Psychiatry 2021; 92:918-926. [PMID: 34261750 PMCID: PMC8372400 DOI: 10.1136/jnnp-2020-325881] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 06/09/2021] [Indexed: 12/11/2022]
Abstract
OBJECTIVES We aimed to investigate changes in regional cerebral blood flow (rCBF) using arterial spin labelling (ASL) in patients with visual snow syndrome (VSS), in order to understand more about the underlying neurobiology of the condition, which remains mostly unknown. METHODS We performed an MRI study in which whole-brain maps of rCBF were obtained using pseudo-continuous ASL. Twenty-four patients with VSS and an equal number of gender and age-matched healthy volunteers took part in the study. All subjects were examined with both a visual paradigm consisting of a visual-snow like stimulus, simulating key features of the snow, and a blank screen at rest, randomly presented. RESULTS Patients with VSS had higher rCBF than controls over an extensive brain network, including the bilateral cuneus, precuneus, supplementary motor cortex, premotor cortex and posterior cingulate cortex, as well as the left primary auditory cortex, fusiform gyrus and cerebellum. These areas were largely analogous comparing patients either at rest, or when looking at a 'snow-like' visual stimulus. This widespread, similar pattern of perfusion differences in either condition suggests a neurophysiological signature of visual snow. Furthermore, right insula rCBF was increased in VSS subjects compared with controls during visual stimulation, reflecting a greater task-related change and suggesting a difference in interoceptive processing with constant perception of altered visual input. CONCLUSION The data suggest VSS patients have marked differences in brain processing of visual stimuli, validating its neurobiological basis.
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Affiliation(s)
- Francesca Puledda
- Headache Group, Wolfson CARD, Institute of Psychiatry, Psychology & Neuroscience, King's College London, King's College London, London, UK .,NIHR-Wellcome Trust King's Clinical Research Facility, SLaM NIHR Biomedical Research Centre, King's College Hospital, London, UK
| | - Christoph J Schankin
- Department of Neurology, Inselspital University Hospital Bern, Bern, Switzerland
| | - Owen O'Daly
- Centre for Neuroimaging Sciences, Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Dominic Ffytche
- Old Age Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Ozan Eren
- Department of Neurology, University Hospital Munich Campus Grosshadern, Munchen, Germany
| | - Nazia Karsan
- Headache Group, Wolfson CARD, Institute of Psychiatry, Psychology & Neuroscience, King's College London, King's College London, London, UK
| | - Steve C R Williams
- Centre for Neuroimaging Sciences, Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Fernando Zelaya
- Centre for Neuroimaging Sciences, Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Peter J Goadsby
- Headache Group, Wolfson CARD, Institute of Psychiatry, Psychology & Neuroscience, King's College London, King's College London, London, UK.,NIHR-Wellcome Trust King's Clinical Research Facility, SLaM NIHR Biomedical Research Centre, King's College Hospital, London, UK
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Healy D, Mangin D, Lochhead J. Development and persistence of patient-reported visual problems associated with serotonin reuptake inhibiting antidepressants. INTERNATIONAL JOURNAL OF RISK & SAFETY IN MEDICINE 2021; 33:37-47. [PMID: 34366298 DOI: 10.3233/jrs-210018] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The majority of antidepressants inhibit serotonin reuptake and include the selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and the serotonin reuptake inhibiting tricyclic antidepressants. OBJECTIVE The objective of this study was to investigate and describe the range and impact of reported adverse visual effects linked to serotonin reuptake inhibiting antidepressants. METHODS Using data from a global database of patient spontaneous reports of drug adverse events, we systematically identified eligible reports of visual problems linked to the use of serotonin reuptake inhibiting antidepressants. We analyzed these data using simple descriptive statistics to present the range and impact. RESULTS We identified 124 reports of visual problems. Reports originate from 18 countries and involve 11 different drugs. The most commonly reported symptoms were vision blurred/visual acuity reduced (n = 79, 63.7%), night blindness (n = 22, 17.7%), vitreous floaters (n = 21, 16.9%), photophobia (n = 19, 15.3%), diplopia (n = 15, 12.1%), palinopsia (n = 13, 10.5%), visual field defect (n = 12, 9.7%), photopsia (n = 11, 8.9%) and visual snow syndrome (n = 11, 8.9%). 74 patients indicated that the side effect was bad enough to affect everyday activities, 62 had sought health care, and 50 indicated that their work had been affected. 49 patients reported an enduring vision problem after discontinuation of treatment. CONCLUSIONS The data suggest that serotonin reuptake inhibiting antidepressants can produce a range of adverse effects on vision that in some cases can be long-lasting after discontinuation of the drug. Further efforts are needed to understand the mechanisms involved, the incidence among those prescribed these medications, and identify any risk or mitigation factors.
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Affiliation(s)
- David Healy
- Department of Family Medicine, McMaster University, Hamilton, ON, Canada
| | - Dee Mangin
- Department of Family Medicine, McMaster University, Hamilton, ON, Canada
| | - Jonathan Lochhead
- Department of Ophthalmology, St Mary's Hospital, Newport, Isle of Wight, UK
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Mehta DG, Garza I, Robertson CE. Two hundred and forty-eight cases of visual snow: A review of potential inciting events and contributing comorbidities. Cephalalgia 2021; 41:1015-1026. [PMID: 33615842 DOI: 10.1177/0333102421996355] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE To review characteristics and outcomes of all cases of visual snow seen at our institution, with attention to possible triggering events or comorbidities. METHODS This is a retrospective case series of patients seen at our tertiary care center from January 1994 to January 2020. Charts were reviewed if they contained the term "visual snow". RESULTS Of the 449 charts reviewed, 248 patients described seeing visual snow in part or all of their vision. Thirty-eight reported transient visual snow as their typical migraine aura. Of the remaining 210 patients, 89 were reported to have either an inciting event or contributing comorbidity for their visual snow symptoms, including: Post-concussion (n = 15), dramatic change in migraine or aura (n = 14), post-infection (n = 13), hallucinogen persisting perception disorder (n = 10), ocular abnormalities (n = 7), idiopathic intracranial hypertension (n = 4), neoplastic (n = 1), and posterior cortical atrophy (n = 1). Some patients had partial improvement with benzodiazepines (n = 6), lamotrigine (n = 5), topiramate (n = 3) and acetazolamide (n = 3). Presenting characteristics were similar, but patients with visual snow attributed to an inciting event or contributing comorbidity were more likely to have some improvement in their symptoms by last follow-up compared to spontaneous visual snow (p < .001). CONCLUSIONS Though most cases of visual snow are spontaneous, potential secondary causes should be recognized by clinicians. Patients who develop visual snow after an inciting event or related to an underlying comorbidity may have a better prognosis than those in whom it develops spontaneously. In select cases, treatment of the suspected underlying cause may significantly alleviate the otherwise typical intractable visual disturbances associated with visual snow.
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Affiliation(s)
- Dev G Mehta
- Department of Neurology, 6915Mayo Clinic, Rochester, MN, USA
| | - Ivan Garza
- Department of Neurology, 6915Mayo Clinic, Rochester, MN, USA
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Eren OE, Ruscheweyh R, Rauschel V, Eggert T, Schankin CJ, Straube A. Magnetic Suppression of Perceptual Accuracy Is Not Reduced in Visual Snow Syndrome. Front Neurol 2021; 12:658857. [PMID: 34017304 PMCID: PMC8129492 DOI: 10.3389/fneur.2021.658857] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/15/2021] [Indexed: 11/22/2022] Open
Abstract
Objective: Patients with visual snow syndrome (VSS) suffer from continuous (“TV snow-like”) visual disturbance of unknown pathoetiology. In VSS, changes in cortical excitability in the primary visual cortex and the visual association cortex are discussed, with recent imaging studies tending to point to higher-order visual areas. Migraine, especially migraine with aura, is a common comorbidity. In chronic migraine and episodic migraine with aura but not in episodic migraine without aura, a reduced magnetic suppression of perceptual accuracy (MSPA) reflects a probably reduced inhibition of the primary visual cortex. Here we investigated the inhibition of the primary visual cortex using MSPA in patients with VSS, comparing that with MSPA in controls matched for episodic migraine. Methods: Seventeen patients with VSS were compared to 17 age- and migraine-matched controls. Visual accuracy was assessed by letter recognition and modulated by transcranial magnetic stimulation delivered to the occipital cortex at different intervals with respect to the letter presentation (40, 100, and 190 ms). Results: Suppression of visual accuracy at the 100-ms interval was present without significant differences between VSS patients and age- and migraine-matched controls (percentage of correctly recognized trigrams, control: 46.4 ± 34.3; VSS: 52.5 ± 25.4, p = 0.56). Conclusions: In contrast to migraine with aura, occipital cortex inhibition, as assessed with MSPA, may not be affected in VSS.
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Affiliation(s)
- Ozan E Eren
- Department of Neurology, Ludwig Maximilians University of Munich, University Hospital - Großhadern, Munich, Germany
| | - Ruth Ruscheweyh
- Department of Neurology, Ludwig Maximilians University of Munich, University Hospital - Großhadern, Munich, Germany
| | - Veronika Rauschel
- Department of Neurology, Ludwig Maximilians University of Munich, University Hospital - Großhadern, Munich, Germany
| | - Thomas Eggert
- Department of Neurology, Ludwig Maximilians University of Munich, University Hospital - Großhadern, Munich, Germany
| | - Christoph J Schankin
- Department of Neurology, Ludwig Maximilians University of Munich, University Hospital - Großhadern, Munich, Germany.,Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Andreas Straube
- Department of Neurology, Ludwig Maximilians University of Munich, University Hospital - Großhadern, Munich, Germany
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Ciuffreda KJ, Han ME, Tannen B, Rutner D. Visual snow syndrome: evolving neuro-optometric considerations in concussion/mild traumatic brain injury. Concussion 2021; 6:CNC89. [PMID: 34084555 PMCID: PMC8162163 DOI: 10.2217/cnc-2021-0003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Kenneth J Ciuffreda
- SUNY/College of Optometry, University Eye Center, Vision Rehabilitation Service, New York, NY 10036, USA
| | - Mh Esther Han
- SUNY/College of Optometry, University Eye Center, Vision Rehabilitation Service, New York, NY 10036, USA
| | - Barry Tannen
- SUNY/College of Optometry, University Eye Center, Vision Rehabilitation Service, New York, NY 10036, USA
| | - Daniella Rutner
- SUNY/College of Optometry, University Eye Center, Vision Rehabilitation Service, New York, NY 10036, USA
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Abstract
PURPOSE OF REVIEW Visual snow is considered a disorder of central visual processing resulting in a perturbed perception of constant bilateral whole-visual field flickering or pixelation. When associated with additional visual symptoms, it is referred to as visual snow syndrome. Its pathophysiology remains elusive. This review highlights the visual snow literature focusing on recent clinical studies that add to our understanding of its clinical picture, pathophysiology, and treatment. RECENT FINDINGS Clinical characterization of visual snow syndrome is evolving, including a suggested modification of diagnostic criteria. Regarding pathophysiology, two recent studies tested the hypothesis of dysfunctional visual processing and occipital cortex hyperexcitability using electrophysiology. Likewise, advanced functional imaging shows promise to allow further insights into disease mechanisms. A retrospective study now provides Class IV evidence for a possible benefit of lamotrigine in a minority of patients. SUMMARY Scientific understanding of visual snow syndrome is growing. Major challenges remain the subjective nature of the disease, its overlap with migraine, and the lack of quantifiable outcome measures, which are necessary for clinical trials. In that context, refined perceptual assessment, objective electrophysiological parameters, as well as advanced functional brain imaging studies, are promising tools in the pipeline.
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Puledda F, O'Daly O, Schankin C, Ffytche D, Williams SC, Goadsby PJ. Disrupted connectivity within visual, attentional and salience networks in the visual snow syndrome. Hum Brain Mapp 2021; 42:2032-2044. [PMID: 33448525 PMCID: PMC8046036 DOI: 10.1002/hbm.25343] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 12/11/2020] [Accepted: 01/04/2021] [Indexed: 01/22/2023] Open
Abstract
Here we investigate brain functional connectivity in patients with visual snow syndrome (VSS). Our main objective was to understand more about the underlying pathophysiology of this neurological syndrome. Twenty‐four patients with VSS and an equal number of gender and age‐matched healthy volunteers attended MRI sessions in which whole‐brain maps of functional connectivity were acquired under two conditions: at rest while watching a blank screen and during a visual paradigm consisting of a visual‐snow like stimulus. Eight unilateral seed regions were selected a priori based on previous observations and hypotheses; four seeds were placed in key anatomical areas of the visual pathways and the remaining were derived from a pre‐existing functional analysis. The between‐group analysis showed that patients with VSS had hyper and hypoconnectivity between key visual areas and the rest of the brain, both in the resting state and during a visual stimulation, compared with controls. We found altered connectivity internally within the visual network; between the thalamus/basal ganglia and the lingual gyrus; between the visual motion network and both the default mode and attentional networks. Further, patients with VSS presented decreased connectivity during external sensory input within the salience network, and between V5 and precuneus. Our results suggest that VSS is characterised by a widespread disturbance in the functional connectivity of several brain systems. This dysfunction involves the pre‐cortical and cortical visual pathways, the visual motion network, the attentional networks and finally the salience network; further, it represents evidence of ongoing alterations both at rest and during visual stimulus processing.
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Affiliation(s)
- Francesca Puledda
- Headache Group, Department of Basic and Clinical Neuroscience, King's College London, London, United Kingdom.,NIHR-Wellcome Trust King's Clinical Research Facility, SLaM NIHR Biomedical Research Centre, King's College Hospital, London, United Kingdom
| | - Owen O'Daly
- Centre for Neuroimaging Sciences, Department of Neuroimaging, King's College London, London, United Kingdom
| | - Christoph Schankin
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Dominic Ffytche
- Department of Old Age Psychiatry, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Steven Cr Williams
- Centre for Neuroimaging Sciences, Department of Neuroimaging, King's College London, London, United Kingdom
| | - Peter J Goadsby
- Headache Group, Department of Basic and Clinical Neuroscience, King's College London, London, United Kingdom.,NIHR-Wellcome Trust King's Clinical Research Facility, SLaM NIHR Biomedical Research Centre, King's College Hospital, London, United Kingdom
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Abstract
Illusions and hallucinations are commonly encountered in both daily life and clinical practice. In this chapter, we review definitions and possible underlying mechanisms of these phenomena and then review what is known about specific conditions that are associated with them, including ophthalmic causes, migraine, epilepsy, Parkinson's disease, and schizophrenia. We then discuss specific syndromes including the Charles Bonnet syndrome, visual snow syndrome, Alice in Wonderland syndrome, and peduncular hallucinosis. The scientific study of illusions and hallucinations has contributed significantly to our understanding of how eye and brain process vision and contribute to perception. Important concepts are the distinction between topologic and hodologic mechanisms underlying hallucinations and the involvement of attentional networks. This chapter examines the various ways in which pathological illusions and hallucinations might arise in relation to the phenomenology and known pathology of the various conditions associated with them.
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Affiliation(s)
- Clare L Fraser
- Department of Ophthalmology, Save Sight Institute, Faculty of Health and Medicine, University of Sydney, Sydney, Australia.
| | - Christian J Lueck
- Department of Neurology, Canberra Hospital, and Australian National University Medical School, Canberra, Australia
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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: 25] [Impact Index Per Article: 6.3] [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.
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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
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Puledda F, Bruchhage M, O'Daly O, Ffytche D, Williams SCR, Goadsby PJ. Occipital cortex and cerebellum gray matter changes in visual snow syndrome. Neurology 2020; 95:e1792-e1799. [PMID: 32759201 PMCID: PMC7682819 DOI: 10.1212/wnl.0000000000010530] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 05/11/2020] [Indexed: 12/16/2022] Open
Abstract
Objective To determine whether regional gray and white matter differences characterize the brain of patients with visual snow syndrome, a newly defined neurologic condition, we used a voxel-based morphometry approach. Methods In order to investigate whole brain morphology directly, we performed an MRI study on patients with visual snow syndrome (n = 24) and on age- and sex-matched healthy volunteers (n = 24). Voxel-based morphometry was used to determine volumetric differences in patients with visual snow. We further analyzed cerebellar anatomy directly using the high-resolution spatially unbiased atlas template of the cerebellum. Results Compared to healthy controls, patients with visual snow syndrome had increased gray matter volume in the left primary and secondary visual cortices, the left visual motion area V5, and the left cerebellar crus I/lobule VI area. These anatomical alterations could not be explained by clinical features of the condition. Conclusion Patients with visual snow syndrome have subtle, significant neuroanatomical differences in key visual and lateral cerebellar areas, which may in part explain the pathophysiologic basis of the disorder.
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Affiliation(s)
- Francesca Puledda
- From the Headache Group, Department of Basic and Clinical Neuroscience (F.P., P.J.G.), Centre for Neuroimaging Sciences, Department of Neuroimaging (M.B., O.O., S.C.R.W.), and Department of Old Age Psychiatry, Institute of Psychiatry, Psychology & Neuroscience (D.F.), King's College London; NIHR-Wellcome Trust King's Clinical Research Facility, SLaM Biomedical Research Centre (F.P., P.J.G.), King's College Hospital, London, UK; and Advanced Baby Imaging Laboratory (M.B.), Warren Alpert School of Medicine at Brown University, Providence, RI.
| | - Muriel Bruchhage
- From the Headache Group, Department of Basic and Clinical Neuroscience (F.P., P.J.G.), Centre for Neuroimaging Sciences, Department of Neuroimaging (M.B., O.O., S.C.R.W.), and Department of Old Age Psychiatry, Institute of Psychiatry, Psychology & Neuroscience (D.F.), King's College London; NIHR-Wellcome Trust King's Clinical Research Facility, SLaM Biomedical Research Centre (F.P., P.J.G.), King's College Hospital, London, UK; and Advanced Baby Imaging Laboratory (M.B.), Warren Alpert School of Medicine at Brown University, Providence, RI
| | - Owen O'Daly
- From the Headache Group, Department of Basic and Clinical Neuroscience (F.P., P.J.G.), Centre for Neuroimaging Sciences, Department of Neuroimaging (M.B., O.O., S.C.R.W.), and Department of Old Age Psychiatry, Institute of Psychiatry, Psychology & Neuroscience (D.F.), King's College London; NIHR-Wellcome Trust King's Clinical Research Facility, SLaM Biomedical Research Centre (F.P., P.J.G.), King's College Hospital, London, UK; and Advanced Baby Imaging Laboratory (M.B.), Warren Alpert School of Medicine at Brown University, Providence, RI
| | - Dominic Ffytche
- From the Headache Group, Department of Basic and Clinical Neuroscience (F.P., P.J.G.), Centre for Neuroimaging Sciences, Department of Neuroimaging (M.B., O.O., S.C.R.W.), and Department of Old Age Psychiatry, Institute of Psychiatry, Psychology & Neuroscience (D.F.), King's College London; NIHR-Wellcome Trust King's Clinical Research Facility, SLaM Biomedical Research Centre (F.P., P.J.G.), King's College Hospital, London, UK; and Advanced Baby Imaging Laboratory (M.B.), Warren Alpert School of Medicine at Brown University, Providence, RI
| | - Steven C R Williams
- From the Headache Group, Department of Basic and Clinical Neuroscience (F.P., P.J.G.), Centre for Neuroimaging Sciences, Department of Neuroimaging (M.B., O.O., S.C.R.W.), and Department of Old Age Psychiatry, Institute of Psychiatry, Psychology & Neuroscience (D.F.), King's College London; NIHR-Wellcome Trust King's Clinical Research Facility, SLaM Biomedical Research Centre (F.P., P.J.G.), King's College Hospital, London, UK; and Advanced Baby Imaging Laboratory (M.B.), Warren Alpert School of Medicine at Brown University, Providence, RI
| | - Peter J Goadsby
- From the Headache Group, Department of Basic and Clinical Neuroscience (F.P., P.J.G.), Centre for Neuroimaging Sciences, Department of Neuroimaging (M.B., O.O., S.C.R.W.), and Department of Old Age Psychiatry, Institute of Psychiatry, Psychology & Neuroscience (D.F.), King's College London; NIHR-Wellcome Trust King's Clinical Research Facility, SLaM Biomedical Research Centre (F.P., P.J.G.), King's College Hospital, London, UK; and Advanced Baby Imaging Laboratory (M.B.), Warren Alpert School of Medicine at Brown University, Providence, RI
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Viana M, Puledda F, Goadsby PJ. Visual snow syndrome: a comparison between an Italian and British population. Eur J Neurol 2020; 27:2099-2101. [PMID: 32478974 DOI: 10.1111/ene.14369] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE Visual snow manifests as a pan-field, dynamic visual disturbance described as continuous television static-like tiny flickering dots. Current diagnostic criteria further require at least two additional symptoms for visual snow syndrome (VSS) from: palinopsia (afterimages and trailing); entoptic phenomena (floaters, blue field entoptic phenomenon, photopsia, self-light of the eye); photophobia and nyctalopia. Our objective was to compare the phenotype of VSS in an Italian and British population. METHODS Patients with VSS were characterized clinically using the current criteria. An online survey was prepared in collaboration with the patient group Eye-on-Vision. Patients were directed to the site if they contacted us by email asking to be involved in research. After data collection, we compared the phenotypic characteristics of a subgroup of British versus Italian patients taking part in the survey. As we expected more responses from the UK, we matched 100 UK patients for gender and age with our Italian cohort. RESULTS Patients were enrolled from the UK (n = 100) and Italy (n = 100). The populations had similar demography. After multiple correction testing there were no differences in VSS features between the two groups. The same was true for the prevalence of migraine and previous use of recreational drugs. CONCLUSION This is the first study comparing the phenotype of VSS between two distinct populations. Our findings suggest that the visual snow phenotype, as well as migraine comorbidity, is similar across the two groups.
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Affiliation(s)
- M Viana
- Headache Group, Department of Basic and Clinical Neurosciences, King's College London, London, UK.,Headache Centre, Neurocentre of Southern Switzerland (NSI), Regional Hospital Lugano, Switzerland
| | - F Puledda
- Headache Group, Department of Basic and Clinical Neurosciences, King's College London, London, UK.,NIHR-Wellcome Trust King's Clinical Research Facility, SLaM Biomedical Research Centre, King's College Hospital, London, UK
| | - P J Goadsby
- Headache Group, Department of Basic and Clinical Neurosciences, King's College London, London, UK.,NIHR-Wellcome Trust King's Clinical Research Facility, SLaM Biomedical Research Centre, King's College Hospital, London, UK
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Neuro-Ophthalmic Symptoms of Primary Headache Disorders: Why the Patient With Headache May Present to Neuro-Ophthalmology. J Neuroophthalmol 2020; 39:200-207. [PMID: 31022065 DOI: 10.1097/wno.0000000000000790] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Primary headache disorders can cause many ophthalmic symptoms that lead many patients to present for neuro-ophthalmic evaluation. Neuro-ophthalmologists frequently encounter these patients in clinical practice. EVIDENCE ACQUISITION A literature review was completed in PubMed using the following terms paired with "migraine" and "headache:" dry eye, eye pain, monocular diplopia, binocular diplopia, photophobia, visual field defect, tunnel vision, floaters, amaurosis fugax, transient visual obscuration, autonomic symptoms, anisocoria, visual snow, Alice in Wonderland syndrome, and palinopsia. RESULTS Patients with migraine experience a wide range of visual disturbances including aura and more complex perceptual abnormalities such as Alice in Wonderland syndrome and visual snow. Visual disturbances may consist of positive and/or negative phenomena and may be binocular or monocular. Migraine and other primary headache disorders can be associated with photophobia, eye pain, dry eye, autonomic features, and anisocoria. CONCLUSIONS Patients with primary headache disorders may experience a wide range of visual and ophthalmic symptoms. An understanding of the typical features of these disorders allows providers to help patients find appropriate treatment without unnecessary testing and to recognize when atypical presentations require additional evaluation.
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Puledda F, Ffytche D, Lythgoe DJ, O'Daly O, Schankin C, Williams SCR, Goadsby PJ. Insular and occipital changes in visual snow syndrome: a BOLD fMRI and MRS study. Ann Clin Transl Neurol 2020; 7:296-306. [PMID: 32154676 PMCID: PMC7086005 DOI: 10.1002/acn3.50986] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 01/13/2020] [Indexed: 12/24/2022] Open
Abstract
Objective To investigate the pathophysiology of visual snow (VS), through a combined functional neuroimaging and magnetic resonance spectroscopy (1H‐MRS) approach. Methods We applied a functional MRI block‐design protocol studying the responses to a visual stimulation mimicking VS, in combination with 1H‐MRS over the right lingual gyrus, in 24 patients with VS compared to an equal number of age‐ and gender‐matched healthy controls. Results We found reduced BOLD responses to the visual stimulus with respect to baseline in VS patients compared to controls, in the left (k = 291; P = 0.025; peak MNI coordinate [‐34 12 ‐6]) and right (k = 100; P = 0.003; peak MNI coordinate [44 14 ‐2]) anterior insula. Our spectroscopy analysis revealed a significant increase in lactate concentrations in patients with respect to controls (0.66 ± 0.9 mmol/L vs. 0.07 ± 0.2 mmol/L; P < 0.001) in the right lingual gyrus. In this area, there was a significant negative correlation between lactate concentrations and BOLD responses to visual stimulation (P = 0.004; r = −0.42), which was dependent on belonging to the patient group. Interpretation As shown by our BOLD analysis, VS is characterized by a difference in bilateral insular responses to a visual stimulus mimicking VS itself, which could be due to disruptions within the salience network. Our results also suggest that patients with VS have a localized disturbance in extrastriate anaerobic metabolism, which may in turn cause a decreased metabolic reserve for the regular processing of visual stimuli.
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Affiliation(s)
- Francesca Puledda
- Headache Group, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom.,NIHR-Wellcome Trust King's Clinical Research Facility, King's College Hospital, London, United Kingdom
| | - Dominic Ffytche
- Department of Old Age Psychiatry, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - David J Lythgoe
- Centre for Neuroimaging Sciences, Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Owen O'Daly
- Centre for Neuroimaging Sciences, Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Christoph Schankin
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Steven C R Williams
- Centre for Neuroimaging Sciences, Department of Neuroimaging, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Peter J Goadsby
- Headache Group, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, United Kingdom.,NIHR-Wellcome Trust King's Clinical Research Facility, King's College Hospital, London, United Kingdom
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Kondziella D, Olsen MH, Dreier JP. Prevalence of visual snow syndrome in the UK. Eur J Neurol 2020; 27:764-772. [DOI: 10.1111/ene.14150] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 01/22/2020] [Indexed: 12/20/2022]
Affiliation(s)
- D. Kondziella
- Department of Neurology Rigshospitalet Copenhagen University Hospital Copenhagen Denmark
- Department of Clinical Medicine University of Copenhagen Copenhagen Denmark
| | - M. H. Olsen
- Department of Neuroanesthesiology Rigshospitalet Copenhagen University Hospital Copenhagen Denmark
| | - J. P. Dreier
- Department of Neurology Charité – Universitätsmedizin Berlin Freie Universität Berlin Humboldt‐Universität zu Berlin Berlin Institute of Health Berlin
- Center for Stroke Research Berlin Charité – Universitätsmedizin Berlin Freie Universität Berlin Humboldt‐Universität zu Berlin Berlin Institute of Health Berlin
- Department of Experimental Neurology Charité – Universitätsmedizin Berlin Freie Universität Berlin Humboldt‐Universität zu Berlin Berlin Institute of Health Berlin
- Bernstein Center for Computational Neuroscience Berlin Berlin
- Einstein Center for Neurosciences Berlin Berlin Germany
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Costello FE, Bisdorff AR, Robbins MS. Visual snow: Are we beginning to see the light? Neurology 2020; 94:241-242. [PMID: 31949088 DOI: 10.1212/wnl.0000000000008913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Fiona E Costello
- From the Departments of Clinical Neurosciences and Surgery (F.E.C.), University of Calgary, Alberta, Canada; Department of Neurology (A.R.B.), Centre Hospitalier Emile Mayrisch, Esch-sur-Alzette, Luxembourg; and Department of Neurology (M.S.R.), Weill Cornell Medical College, New York, NY.
| | - Alexander R Bisdorff
- From the Departments of Clinical Neurosciences and Surgery (F.E.C.), University of Calgary, Alberta, Canada; Department of Neurology (A.R.B.), Centre Hospitalier Emile Mayrisch, Esch-sur-Alzette, Luxembourg; and Department of Neurology (M.S.R.), Weill Cornell Medical College, New York, NY
| | - Matthew S Robbins
- From the Departments of Clinical Neurosciences and Surgery (F.E.C.), University of Calgary, Alberta, Canada; Department of Neurology (A.R.B.), Centre Hospitalier Emile Mayrisch, Esch-sur-Alzette, Luxembourg; and Department of Neurology (M.S.R.), Weill Cornell Medical College, New York, NY
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Puledda F, Schankin C, Goadsby PJ. Visual snow syndrome: A clinical and phenotypical description of 1,100 cases. Neurology 2020; 94:e564-e574. [PMID: 31941797 PMCID: PMC7136068 DOI: 10.1212/wnl.0000000000008909] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 08/28/2019] [Indexed: 12/23/2022] Open
Abstract
Objective To validate the current criteria of visual snow and to describe its common phenotype using a substantial clinical database. Methods We performed a web-based survey of patients with self-assessed visual snow (n = 1,104), with either the complete visual snow syndrome (n = 1,061) or visual snow without the syndrome (n = 43). We also describe a population of patients (n = 70) with possible hallucinogen persisting perception disorder who presented clinically with visual snow syndrome. Results The visual snow population had an average age of 29 years and had no sex prevalence. The disorder usually started in early life, and ≈40% of patients had symptoms for as long as they could remember. The most commonly experienced static was black and white. Floaters, afterimages, and photophobia were the most reported additional visual symptoms. A latent class analysis showed that visual snow does not present with specific clinical endophenotypes. Severity can be classified by the amount of visual symptoms experienced. Migraine and tinnitus had a very high prevalence and were independently associated with a more severe presentation of the syndrome. Conclusions Clinical characteristics of visual snow did not differ from the previous cohort in the literature, supporting validity of the current criteria. Visual snow likely represents a clinical continuum, with different degrees of severity. On the severe end of the spectrum, it is more likely to present with its common comorbid conditions, migraine and tinnitus. Visual snow does not depend on the effect of psychotropic substances on the brain.
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Affiliation(s)
- Francesca Puledda
- From the Headache Group (F.P., P.J.G.), Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London; NIHR-Wellcome Trust King's Clinical Research Facility (F.P., P.J.G.), SLaM Biomedical Research Centre, King's College Hospital, London, UK; and Department of Neurology (C.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland.
| | - Christoph Schankin
- From the Headache Group (F.P., P.J.G.), Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London; NIHR-Wellcome Trust King's Clinical Research Facility (F.P., P.J.G.), SLaM Biomedical Research Centre, King's College Hospital, London, UK; and Department of Neurology (C.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Peter J Goadsby
- From the Headache Group (F.P., P.J.G.), Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, King's College London; NIHR-Wellcome Trust King's Clinical Research Facility (F.P., P.J.G.), SLaM Biomedical Research Centre, King's College Hospital, London, UK; and Department of Neurology (C.S.), Inselspital, Bern University Hospital, University of Bern, Switzerland
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Eren O, Schankin CJ. Mirtazapine for treatment of visual snow syndrome: A case series with insights into pathophysiology and therapy. CLINICAL AND TRANSLATIONAL NEUROSCIENCE 2020. [DOI: 10.1177/2514183x20925695] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: Patients with visual snow syndrome (VSS) describe tiny flickering dots in the entire visual field resembling the noise of a poorly adjusted channel of analogue television with additional symptoms. Little is known about the pathophysiology and therapeutic options for this debilitating condition. Objectives: We present a case series of three patients with VSS taking mirtazapine, one of the most often prescribed antidepressants, and discuss the utility of antidepressants by reviewing our current understanding of pathophysiology and therapy. Results: Mirtazapine has no effect on VSS, neither positive nor negative. This is in line with the reports from the literature suggested only some beneficial effects from lamotrigine. Conclusions: Since the pathophysiology of VSS is not fully understood, we still rely on the reports of individual cases or patient series. This includes not only the positive, but also the negative results to avoid unnecessary treatment trials. Looking into the literature, antidepressants do not seem to be a solution for the visual symptoms. So far, best data exists for the anticonvulsant lamotrigine.
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Affiliation(s)
- Ozan Eren
- Department of Neurology, Ludwig Maximilians University Munich, University Hospital - Großhadern, Munich, Germany
| | - Christoph J Schankin
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse, Bern, Switzerland
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Puledda F, Ffytche D, O'Daly O, Goadsby PJ. Imaging the Visual Network in the Migraine Spectrum. Front Neurol 2019; 10:1325. [PMID: 31920945 PMCID: PMC6923266 DOI: 10.3389/fneur.2019.01325] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 11/29/2019] [Indexed: 01/13/2023] Open
Abstract
The involvement of the visual network in migraine pathophysiology has been well-known for more than a century. Not only is the aura phenomenon linked to cortical alterations primarily localized in the visual cortex; but also migraine without aura has shown distinct dysfunction of visual processing in several studies in the past. Further, the study of photophobia, a hallmark migraine symptom, has allowed unraveling of distinct connections that link retinal pathways to the trigeminovascular system. Finally, visual snow, a recently recognized neurological disorder characterized by a continuous visual disturbance, is highly comorbid with migraine and possibly shares with it some common pathophysiological mechanisms. Here, we review the most relevant neuroimaging literature to date, considering studies that have either attempted to investigate the visual network or have indirectly shown visual processing dysfunctions in migraine. We do this by taking into account the broader spectrum of migrainous biology, thus analyzing migraine both with and without aura, focusing on light sensitivity as the most relevant visual symptom in migraine, and finally analyzing the visual snow syndrome. We also present possible hypotheses on the underlying pathophysiology of visual snow, for which very little is currently known.
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Affiliation(s)
- Francesca Puledda
- Headache Group, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- NIHR-Wellcome Trust King's Clinical Research Facility, SLaM NIHR Biomedical Research Centre, King's College Hospital, London, United Kingdom
| | - Dominic Ffytche
- Department of Old Age Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Owen O'Daly
- Department of Neuroimaging, Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Peter J. Goadsby
- Headache Group, Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- NIHR-Wellcome Trust King's Clinical Research Facility, SLaM NIHR Biomedical Research Centre, King's College Hospital, London, United Kingdom
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Abstract
Transient disturbances in neurologic function are disturbing features of migraine attacks. Aura types include binocular visual, hemi-sensory, language and unilateral motor symptoms. Because of the gradual spreading quality of visual and sensory symptoms, they were thought to arise from the cerebral cortex. Motor symptoms previously included as a type of migraine aura were reclassified as a component of hemiplegic migraine. ICHD-3 criteria of the International Headache Society, added brainstem aura and retinal aura as separate subtypes. The susceptibility to all types of aura is likely to be included by complex and perhaps epigenetic factors.
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Affiliation(s)
- Rod Foroozan
- Baylor College of Medicine, 6565 Fannin NC-205, Houston, TX 77030, USA.
| | - F Michael Cutrer
- Mayo Clinic, 200 First Street, Southwest, Rochester, MN 55905, USA
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Abstract
Migraine has long been associated with disturbances of vision, especially migraine with aura. However, the eye plays an important role in sensory processing as well. We have found that the visual quality of life is reduced in migraine. In this review, we discuss how the migraine and eye pain pathways are similar and affect many of the common complaints which are seen in ophthalmology and neuro-ophthalmology offices, such as dry eye and postoperative eye pain. We also review other related phenomena, including visual snow and photophobia, which also are related to altered sensory processing in migraine.
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van Dongen RM, Waaijer LC, Onderwater GLJ, Ferrari MD, Terwindt GM. Treatment effects and comorbid diseases in 58 patients with visual snow. Neurology 2019; 93:e398-e403. [PMID: 31213497 PMCID: PMC6669936 DOI: 10.1212/wnl.0000000000007825] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/11/2019] [Indexed: 11/30/2022] Open
Abstract
Objective To evaluate pharmacologic treatment options for visual snow and to report prevalence of comorbid diseases. Methods Medical charts of patients with a diagnosis of visual snow at the neurology outpatient clinic were reviewed on prescribed medication, and comorbid migraine, tinnitus, and psychiatric conditions including depression and anxiety. Results From 2007 to 2018, 58 patients were diagnosed with visual snow. Comorbid migraine was present in 51.7% of patients, lifetime depression in 41.4%, and lifetime anxiety in 44.8%. Lamotrigine was prescribed most frequently (26/58) and resulted in partial remission of symptoms in 5/26 (19.2%). No patients reported complete remission. Adverse events occurred in 13/26 (50.0%) patients. None of the other prescribed drugs (valproate [n = 7], topiramate [n = 4], acetazolamide [n = 2], flunarizine [n = 1]) led to improvement except for topiramate in one patient, who discontinued, however, because of adverse events. Conclusions Of medication prescribed (lamotrigine, valproate, acetazolamide, flunarizine), only lamotrigine afforded some improvement in a small minority of patients. Migraine, depression, anxiety, and tinnitus were common comorbid diseases. Classification of evidence This study provides Class IV evidence that for some patients with visual snow, lamotrigine resulted in partial remission of symptoms.
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Affiliation(s)
- Robin M van Dongen
- From the Department of Neurology, Leiden University Medical Centre, the Netherlands
| | - Lindy C Waaijer
- From the Department of Neurology, Leiden University Medical Centre, the Netherlands
| | | | - Michel D Ferrari
- From the Department of Neurology, Leiden University Medical Centre, the Netherlands
| | - Gisela M Terwindt
- From the Department of Neurology, Leiden University Medical Centre, the Netherlands.
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Chen BS, Lance S, Lallu B, Anderson NE. Visual snow: Not so benign. J Clin Neurosci 2019; 64:37-39. [DOI: 10.1016/j.jocn.2019.03.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 03/11/2019] [Indexed: 11/25/2022]
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