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Tannen B, Sample A, Ciuffreda KJ, Tannen NM. Clinical reading-related oculomotor assessment in visual snow syndrome. JOURNAL OF OPTOMETRY 2024; 17:100500. [PMID: 37918058 PMCID: PMC10641535 DOI: 10.1016/j.optom.2023.100500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 10/02/2023] [Accepted: 10/08/2023] [Indexed: 11/04/2023]
Abstract
PURPOSE Visual snow syndrome (VSS) is a complex neurological condition presenting with an array of sensory, motor, and perceptual dysfunctions and related visual and non-visual symptoms. Recent laboratory studies have found subtle, basic, saccadic-based abnormalities in this population. The objective of the present investigation was to determine if saccadic-related problems could be confirmed and extended using three common clinical reading-related eye movement tests having well-developed protocols and normative databases. METHODS This was a retrospective analysis of 32 patients (ages 16-56 years) diagnosed with VSS in the first author's optometric practice. There was a battery of three reading-related tests: the Visagraph Reading Eye Movement Test, the Developmental Eye Movement (DEM) Test, and the RightEye Dynamic Vision Assessment Test, all performed using their standard documented protocols and large normative databases. RESULTS A high frequency of oculomotor deficits was found with all three tests. The greatest percentage was revealed with the Visagraph (56%) and the least with the RightEye (23%). A total of 77% of patients failed at least one of the three tests. CONCLUSION The present findings confirm and extend earlier investigations revealing a high frequency of saccadic-based oculomotor problems in the VSS population, now including reading-related tasks. This is consistent with the more general oculomotor/motor problems found in these individuals.
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Affiliation(s)
- Barry Tannen
- EyeCare Professionals, PC 1777 Kuser Road, Hamilton Square, NJ 08690, USA; SUNY State College of Optometry, New York, NY, USA.
| | - Alina Sample
- Gabrielle Family Vision Care, Kirkland, Washington, USA
| | | | - Noah M Tannen
- EyeCare Professionals, PC 1777 Kuser Road, Hamilton Square, NJ 08690, 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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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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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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8
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Hang C, Yan Y. Case report: Visual snow as the presenting symptom in multiple evanescent white dot syndrome. Two case reports and literature review. Front Neurol 2022; 13:972943. [PMID: 36277919 PMCID: PMC9582439 DOI: 10.3389/fneur.2022.972943] [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: 06/19/2022] [Accepted: 09/12/2022] [Indexed: 11/17/2022] Open
Abstract
Purpose Multiple evanescent white dot syndrome (MEWDS) usually manifests as photopsia, enlarged blind spots, scotomas, and blurred vision, which can be classified into positive and negative visual phenomena. Visual snow and chromatopsia were rarely reported in these patients. Herein, we described two Chinese female patients with MEWDS who initially presented with visual snow, and one of them also had yellow-tinged vision. Methods First, we performed the chart review of two patients. Second, we reviewed the English literature for all cases of MEWDS through PubMed until December 2021, using the terms “MEWDS” or “multiple evanescent white dot syndrome.” We concluded on all the reported patients' demographic features and symptoms. The visual acuity of patients with/without positive or negative visual phenomena was compared through one-way ANOVA. Results Patient 1: A 27-year-old Chinese woman experienced continuous visual snow and yellow-tinged vision in the right eye for a week. She noticed tiny white and black dots involving the entire visual field and shimmering light inferiorly. Patient 2: A 22-year-old Chinese woman complained of a gray area with continuous visual snow in the temporal visual field of the left eye for 5 days. The ocular examinations, including fundus autofluorescence (FAF), optical coherence tomography (OCT), and indocyanine green angiography (ICGA), confirmed the diagnosis of MEWDS. Their symptoms resolved spontaneously without treatment. We found 60 MEWDS case reports (147 cases) in PubMed. The mean age was 31.2 years old. The mean LogMAR best-corrected visual acuity was 0.35 ± 0.39 at the first visit and 0.01 ± 0.16 at the last visit. The most common symptoms included blurred vision (72.8%), enlarged blind spot (42.2%), photopsia (37.4%), and scotoma (33.3%). We found the patients with only positive visual phenomena had significantly worse visual acuity at the first and last visit than patients with only negative visual phenomena (p = 0.008) or the patients with both positive and negative visual phenomena (p = 0.026). Four cases similar to visual snow were discovered. Compared to the MEWDS patients without visual snow, the patients with visual snow tend to have a larger proportion of females (p = 0.005) and a better visual acuity at the first visit (p = 0.007). Conclusion Herein, we expand upon the clinical manifestations of MEWDS with visual snow, and the symptoms attributable to visual snow could precede the onset of MEWDS. Neurologists and ophthalmologists should carefully rule out occult chorioretinopathy before diagnosing visual snow syndrome.
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Affiliation(s)
- Chenyue Hang
- Ottawa-Shanghai Joint School of Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yan Yan
- Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Yan Yan
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9
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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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10
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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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11
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White OB, Fielding J, Pelak VS, Schankin CJ. Editorial: Visual Snow: Old Problem, New Understanding. Front Neurol 2022; 13:884752. [PMID: 35493832 PMCID: PMC9051336 DOI: 10.3389/fneur.2022.884752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 03/14/2022] [Indexed: 12/04/2022] Open
Affiliation(s)
- Owen B. White
- Central Clinical School, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia
- *Correspondence: Owen B. White
| | - Joanne Fielding
- Central Clinical School, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia
| | | | - Christoph J. Schankin
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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12
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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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13
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Waterston J, Chen L, Mahony K, Gencarelli J, Stuart G. Persistent Postural-Perceptual Dizziness: Precipitating Conditions, Co-morbidities and Treatment With Cognitive Behavioral Therapy. Front Neurol 2022; 12:795516. [PMID: 35027907 PMCID: PMC8749949 DOI: 10.3389/fneur.2021.795516] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/01/2021] [Indexed: 11/13/2022] Open
Abstract
Persistent postural perceptual dizziness (PPPD) is a common chronic vestibular disorder characterized by persistent vestibular symptoms, including postural instability and non-spinning vertigo, which is aggravated by motion, upright posture and moving or complex visual stimuli. In our review of 198 cases seen over a 5 year period, we have confirmed a number of common precipitating conditions for PPPD, including anxiety disorders and vestibular migraine. Vestibular abnormalities, including a unilateral loss of vestibular hypofunction and isolated otolith abnormalities, were found on investigation in just under half the cases. The use of cognitive behavioral therapy (CBT) as a treatment for PPPD resulted in impressive reductions in anxiety and measures of dizziness over follow up periods of up to 6 months.
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Affiliation(s)
- John Waterston
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Oto-Neurology Department, Alfred Hospital, Melbourne, VIC, Australia
| | - Luke Chen
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Oto-Neurology Department, Alfred Hospital, Melbourne, VIC, Australia
| | - Kate Mahony
- Private Practice, Lyttleton Street Medical Clinic, Castlemaine, VIC, Australia
| | - Jamila Gencarelli
- Oto-Neurology Department, Alfred Hospital, Melbourne, VIC, Australia
| | - Geoff Stuart
- Department of Cognitive Science, Macquarie University, Sydney, NSW, Australia.,School of Psychological Sciences, University of Melbourne, Parkville, VIC, Australia
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14
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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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Hepschke JL, Seymour RA, He W, Etchell A, Sowman PF, Fraser CL. Cortical oscillatory dysrhythmias in visual snow syndrome: a magnetoencephalography study. Brain Commun 2021; 4:fcab296. [PMID: 35169699 PMCID: PMC8833316 DOI: 10.1093/braincomms/fcab296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 09/15/2021] [Accepted: 12/15/2021] [Indexed: 12/30/2022] Open
Abstract
Visual snow refers to the persistent visual experience of static in the whole visual field of both eyes. It is often reported by patients with migraine and co-occurs with conditions such as tinnitus and tremor. The underlying pathophysiology of the condition is poorly understood. Previously, we hypothesized that visual snow syndrome may be characterized by disruptions to rhythmical activity within the visual system. To test this, data from 18 patients diagnosed with visual snow syndrome, and 16 matched controls, were acquired using magnetoencephalography. Participants were presented with visual grating stimuli, known to elicit decreases in alpha-band (8–13 Hz) power and increases in gamma-band power (40–70 Hz). Data were mapped to source-space using a beamformer. Across both groups, decreased alpha power and increased gamma power localized to early visual cortex. Data from the primary visual cortex were compared between groups. No differences were found in either alpha or gamma peak frequency or the magnitude of alpha power, p > 0.05. However, compared with controls, our visual snow syndrome cohort displayed significantly increased primary visual cortex gamma power, p = 0.035. This new electromagnetic finding concurs with previous functional MRI and PET findings, suggesting that in visual snow syndrome, the visual cortex is hyperexcitable. The coupling of alpha-phase to gamma amplitude within the primary visual cortex was also quantified. Compared with controls, the visual snow syndrome group had significantly reduced alpha–gamma phase–amplitude coupling, p < 0.05, indicating a potential excitation–inhibition imbalance in visual snow syndrome, as well as a potential disruption to top-down ‘noise-cancellation’ mechanisms. Overall, these results suggest that rhythmical brain activity in the primary visual cortex is both hyperexcitable and disorganized in visual snow syndrome, consistent with this being a condition of thalamocortical dysrhythmia.
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Affiliation(s)
- Jenny L. Hepschke
- Save Sight Institute, Faculty of Health and Medicine, The University of Sydney, Sydney, NSW, Australia
- Department of Ophthalmology, Prince of Wales Hospital, High Street, Randwick, NSW, Australia
| | - Robert A. Seymour
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London WC1N 3AR, UK
- Department of Cognitive Science, Macquarie University, Sydney, NSW, Australia
| | - Wei He
- Department of Cognitive Science, Macquarie University, Sydney, NSW, Australia
| | - Andrew Etchell
- Department of Cognitive Science, Macquarie University, Sydney, NSW, Australia
| | - Paul F. Sowman
- Department of Cognitive Science, Macquarie University, Sydney, NSW, Australia
| | - Clare L. Fraser
- Save Sight Institute, Faculty of Health and Medicine, The University of Sydney, Sydney, NSW, Australia
- Macquarie Ophthalmology, Macquarie University, Sydney, NSW, Australia
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Brooks CJ, Chan YM, Fielding J, White OB, Badcock DR, McKendrick AM. Visual contrast perception in visual snow syndrome reveals abnormal neural gain but not neural noise. Brain 2021; 145:1486-1498. [PMID: 34633444 DOI: 10.1093/brain/awab383] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 09/17/2021] [Accepted: 09/21/2021] [Indexed: 11/14/2022] Open
Abstract
Visual snow syndrome is a neurological condition characterised by a persistent visual disturbance, visual snow, in conjunction with additional visual symptoms. Cortical hyperexcitability is a potential pathophysiological mechanism, which could be explained by increased gain in neural responses to visual input. Alternatively, neural noise in the visual pathway could be abnormally elevated. We assessed these two potential competing neural mechanisms in our studies of visual contrast perception. Cortical hyperexcitation also occurs in migraine, which commonly co-occurs with visual snow syndrome. Therefore, to determine whether the effect of visual snow syndrome can be distinguished from interictal migraine, we recruited four participant groups: controls, migraine alone, visual snow syndrome alone, visual snow syndrome with migraine. In the first experiment, we estimated internal noise in 20 controls, 21 migraine participants, 32 visual snow syndrome participants (16 with migraine) using a luminance increment detection task. In the second experiment, we estimated neural contrast gain in 21 controls, 22 migraine participants, 35 visual snow syndrome participants (16 with migraine) using tasks assessing sensitivity to changes in contrast from a reference. Contrast gain and sensitivity were measured for the putative parvocellular and ON and OFF magnocellular pathways, respectively. We found that luminance increment thresholds and internal noise estimates were normal in both visual snow syndrome and migraine. Contrast gain measures for putative parvocellular processing and contrast sensitivity for putative OFF magnocellular processing were abnormally increased in visual snow syndrome, regardless of migraine status. Therefore, our results indicate that visual snow syndrome is characterised by increased neural contrast gain but not abnormal neural noise within the targeted pathways.
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Affiliation(s)
- Cassandra J Brooks
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Australia
| | - Yu Man Chan
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Australia
| | - Joanne Fielding
- Department of Neurosciences, Central Clinical School, Monash University, Melbourne, Australia
| | - Owen B White
- Department of Neurosciences, Central Clinical School, Monash University, Melbourne, Australia
| | - David R Badcock
- School of Psychological Science, The University of Western Australia, Crawley, Western Australia
| | - Allison M McKendrick
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Australia
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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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18
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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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20
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Hepschke JL, Martin PR, Fraser CL. Short-Wave Sensitive ("Blue") Cone Activation Is an Aggravating Factor for Visual Snow Symptoms. Front Neurol 2021; 12:697923. [PMID: 34489849 PMCID: PMC8418220 DOI: 10.3389/fneur.2021.697923] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/29/2021] [Indexed: 11/13/2022] Open
Abstract
Background and Purpose: Visual Snow (VS) is a disorder characterised by the subjective perception of black-and-white visual static. The aetiology of this condition is not known. In our previous work we suggested that there is a link between short-wave (S or “blue” cone) signals and severity of visual snow symptoms. Therefore we aimed to further characterise this potential link. Methods: Patients (n = 22) with classic VS based on the diagnostic criteria and healthy controls (n = 12), underwent Intuitive Colorimetry (IC) testing (Cerium Visual Technologies). Twelve hue directions (expressed as angle in CIE 1976 LUV space relative to D65) were rated on a five-point scale from preferred (relieving, positive score) to non-preferred (exacerbating, negative score), and overall preferred and non-preferred angles were chosen. Results: A non-preferred violet region near the tritanopic confusion line / S-cone axis (267 deg.) was strongly associated with exacerbation of VS symptoms (range 250–310 deg, mean 276 ± 16, n = 20, Rayleigh p < 0.001). Two subjects with non-preferred region > 90 deg from mean were considered as outliers. Median rank at hue angle 270 deg was significantly lower than at angle 90 (−1.5 vs. 0.0, p < 0.001, Wilcoxon non-parametric rank-sum test). Patients showed preference for one of two spectral regions which relieved VS symptoms: orange-yellow (range 50–110 deg., mean 79 ± 24, n = 14) and turquoise-blue (range (210–250 deg., mean 234 ± 27, n = 8). Conclusion: Our results show that visual snow symptoms are exacerbated by colour modulation that selectively increased levels of S-cone excitation. Because S-cone signals travel on primordial brain pathways that regulate cortical rhythms (koniocellular pathways) we hypothesis that these pathways contribute to the pathogenesis of this disorder.
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Affiliation(s)
- Jenny L Hepschke
- Faculty of Health and Medicine, Save Sight Institute, The University of Sydney, Sydney, NSW, Australia
| | - Paul R Martin
- Faculty of Health and Medicine, Save Sight Institute, The University of Sydney, Sydney, NSW, Australia
| | - Clare L Fraser
- Faculty of Health and Medicine, Save Sight Institute, The University of Sydney, Sydney, NSW, Australia
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21
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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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22
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Solly EJ, Clough M, Foletta P, White OB, Fielding J. The Psychiatric Symptomology of Visual Snow Syndrome. Front Neurol 2021; 12:703006. [PMID: 34393980 PMCID: PMC8362098 DOI: 10.3389/fneur.2021.703006] [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: 04/30/2021] [Accepted: 06/28/2021] [Indexed: 12/25/2022] Open
Abstract
Objective: To characterise the psychiatric symptoms of visual snow syndrome (VSS), and determine their relationship to quality of life and severity of visual symptoms. Methods: One hundred twenty-five patients with VSS completed a battery of questionnaires assessing depression/anxiety, dissociative experiences (depersonalisation), sleep quality, fatigue, and quality of life, as well as a structured clinical interview about their visual and sensory symptoms. Results: VSS patients showed high rates of anxiety and depression, depersonalisation, fatigue, and poor sleep, which significantly impacted quality of life. Further, psychiatric symptoms, particularly depersonalisation, were related to increased severity of visual symptoms. The severity/frequency of psychiatric symptoms did not differ significantly due to the presence of migraine, patient sex, or timing of VSS onset (lifelong vs. later onset). Conclusion: Psychiatric symptoms are highly prevalent in patients with VSS and are associated with increased visual symptom severity and reduced quality of life. Importantly, patients with lifelong VSS reported lower levels of distress and milder self-ratings of visual symptoms compared to patients with a later onset, while being equally likely to experience psychiatric symptoms. This suggests that the psychiatric symptoms of VSS are not solely due to distress caused by visual symptoms. While no consistently effective treatments are available for the visual symptomology of VSS, psychiatric symptoms offer an avenue of treatment that is likely to significantly improve patient quality of life and ability to cope with visual symptoms.
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Affiliation(s)
- Emma J 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
| | - Paige Foletta
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Owen B White
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Neurology, Alfred Health, Melbourne, VIC, Australia
| | - Joanne Fielding
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Department of Neurology, Alfred Health, Melbourne, VIC, Australia
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23
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Latini F, Fahlström M, Marklund N, Feresiadou A. White matter abnormalities in a patient with visual snow syndrome: New evidence from a diffusion tensor imaging study. Eur J Neurol 2021; 28:2789-2793. [PMID: 33960084 DOI: 10.1111/ene.14903] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/02/2021] [Accepted: 05/03/2021] [Indexed: 12/17/2022]
Abstract
BACKGROUND Visual snow syndrome (VSS) is a neurological condition characterized by flickering dots throughout the entire visual field. Both the pathophysiology and possible location of VSS are still under debate. White matter abnormalities were investigated using diffusion tensor imaging (DTI) in a patient with VSS. METHODS A 28-year-old patient with VSS and 10 healthy controls were investigated with DTI. Diffusion parametric maps were calculated and reconstructed using q-space diffeomorphic reconstruction. White matter pathways of the dorsal, ventral, integrative visual streams and thalamic connectivity were tracked. Then, they were applied to each subject's parameter map, stretched to the same length, and sampled along the tracts for regional analyses of DTI parameters. RESULTS Compared with healthy controls, our patient displayed higher axial diffusivity (AD) and radial diffusivity (RD) in the dorsal visual stream (cingulum, arcuate fasciculus, horizontal indirect anterior segment of the superior longitudinal fasciculus), in the ventral visual stream (fronto-occipital fasciculus, inferior longitudinal fasciculus) and in the integrative visual stream (indirect posterior component of the superior longitudinal fasciculus, vertical occipital fasciculus). Higher AD and RD were also detected in acoustic and optic radiations, and in thalamic radiations distal to the thalamus. CONCLUSION This VSS patient displayed multiple, bilateral white matter changes in the temporo-parieto-occipital junction in white matter pathways related to vision. We encourage the study of white matter pathology using DTI in complex neurological syndromes including VSS.
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Affiliation(s)
- Francesco Latini
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden
| | - Markus Fahlström
- Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden
| | - Niklas Marklund
- Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala, Sweden.,Department of Clinical Sciences Lund, Neurosurgery, Skåne University Hospital, Lund University, Lund, Sweden
| | - Amalia Feresiadou
- Department of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden
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24
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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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25
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Tauscher RG, Simon SS, Volpe NJ. Retinal disease in the neurology clinic. Curr Opin Neurol 2021; 34:122-132. [PMID: 33278143 DOI: 10.1097/wco.0000000000000883] [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: 11/26/2022]
Abstract
PURPOSE OF REVIEW Retinal disease can manifest with visual symptoms similar to those which result from central nervous system disorders. We provide a framework for considering retinal causes of common visual complaints presenting to a neurology clinic. RECENT FINDINGS Technological advances have afforded quicker detection and a more thorough understanding of these retinal entities and are crucial to consider when evaluating visual complaints in the neurology clinic. SUMMARY It is essential to maintain a working knowledge of common retinal conditions that symptomatically overlap with common neurologic conditions. Furthermore, the ophthalmoscopic exam and retinal imaging modalities can both aid in the diagnosis and workup of visual complaints and neurologic disease.
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Affiliation(s)
| | - Shira S Simon
- Department of Ophthalmology
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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26
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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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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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28
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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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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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30
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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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31
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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 is a common headache disorder characterized by often-severe headaches that may be preceded or accompanied by a variety of visual symptoms. Although a typical migraine aura is not difficult to diagnose, patients with migraine may report several other visual symptoms, such as prolonged or otherwise atypical auras, "visual blurring", "retinal migraine", "ophthalmoplegic migraine", photophobia, palinopsia, and "visual snow". Here, we provide a short overview of these symptoms and what is known about the relationship with migraine pathophysiology. For some symptoms, the association with migraine is still debated; for other symptoms, recent studies indicate that migraine mechanisms play a role.
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Affiliation(s)
- Robin M. van Dongen
- Department of Neurology, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Joost Haan
- Department of Neurology, Leiden University Medical Centre, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
- Department of Neurology, Alrijne Ziekenhuis, Simon Smitweg 1, 2353 GA, Leiderdorp, 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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