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Fay F, Straube A, Ruscheweyh R, Eren OE. [Characterization of a German cohort with visual snow syndrome]. DER NERVENARZT 2024:10.1007/s00115-024-01768-5. [PMID: 39532711 DOI: 10.1007/s00115-024-01768-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/10/2024] [Indexed: 11/16/2024]
Abstract
BACKGROUND Visual snow is a disorder of visual perception that is manifested as a constant flickering or "TV-like" noise in the entire visual field. Visual snow syndrome (VSS) describes a combination with other additional visual symptoms, such as sensitivity to light, afterimages, night blindness and entoptic phenomena. Cases of VS have been described in the literature using a wide variety of terms, often misunderstood as persistent migraine aura. Established diagnostic criteria have existed for more than 10 years now; however, the pathophysiology is still incompletely understood. The exact prevalence also remains unknown and high numbers of unreported cases are suspected. This is the first detailed description of a cohort of VSS patients from Germany. METHODS Patients with VSS from several studies conducted at our center were pooled and retrospectively evaluated with respect to demographic, epidemiological and clinical data. RESULTS In this study 66 patients with VSS were included (age 31.3 ± 8.3 years, 30 women). The most commonly associated visual symptoms were photophobia (67%) and afterimages (65%). Of the patients 36 (54%) had comorbid migraine of whom 25 (70%) had migraine with aura, 26 (39%) reported depressive symptoms and 32 (48%) symptoms of an anxiety disorder. Tinnitus was reported by 32 (48%) patients. CONCLUSION The characteristics of the German cohort described here are similar to other international descriptions. Due to the frequent psychological comorbidity there is still a risk of psychosomatic stigmatization.
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Affiliation(s)
- Felix Fay
- Klinik für Neurologie, Oberbayerisches Kopfschmerzzentrum, Klinikum Großhadern, Ludwig-Maximilians-Universität, München, Deutschland
| | - Andreas Straube
- Klinik für Neurologie, Oberbayerisches Kopfschmerzzentrum, Klinikum Großhadern, Ludwig-Maximilians-Universität, München, Deutschland.
- Neurologische Klinik und Poliklinik, LMU-Klinikum, Standort Großhadern, Marchioninistraße 15, 81377, München, Deutschland.
| | - Ruth Ruscheweyh
- Klinik für Neurologie, Oberbayerisches Kopfschmerzzentrum, Klinikum Großhadern, Ludwig-Maximilians-Universität, München, Deutschland
| | - Ozan Emre Eren
- Klinik für Neurologie, Oberbayerisches Kopfschmerzzentrum, Klinikum Großhadern, Ludwig-Maximilians-Universität, München, Deutschland
- Klinik für Neurologie, München Klinik Bogenhausen, München, Deutschland
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2
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Garobbio S, Mazloum R, Rosio M, Popovova J, Schöpfer R, Fierz FC, Disse LR, Weber KP, Schankin CJ, Michels L, Herzog MH. Understanding visual perception in visual snow syndrome: a battery of psychophysical tests plus the 30-day clinical diary. Brain Commun 2024; 6:fcae341. [PMID: 39411245 PMCID: PMC11474241 DOI: 10.1093/braincomms/fcae341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 08/13/2024] [Accepted: 09/27/2024] [Indexed: 10/19/2024] Open
Abstract
Patients with visual snow syndrome (VSS) experience uncountable flickering tiny dots in the entire visual field. Symptoms often persist over the years. Very little is known about altered perception in VSS. VSS is diagnosed based on subjective reports because there is no manual with objective measures. In this study, 20 patients with VSS and 17 healthy controls performed a battery of tests assessing visual acuity, contrast sensitivity, illusion perception, spatial-temporal vision, motion perception, visual attention, and selective attention. Surprisingly, except for one test, which is the honeycomb illusion, patients performed at the same level as controls. Patients reporting black and white visual snow performed better in the Stroop test compared to patients reporting other visual snow colours. In addition to a clinical visit, the 30-day clinical diary was administered to patients to broadly measure their symptom severity. We found that better performance in the tests, in particular in the contrast and coherent motion tests, was correlated with lower VSS symptoms, weaker VS characteristics (e.g. density and size) and lower VS severity. Our results suggest that, even if visual abilities are not deteriorated by VSS, they can determine how severe symptoms are, and show that VSS is an heterogenous disorder where symptoms and visual abilities vary between patients, for instance depending on the VS colour. The study was primarily designed to identify tests where performance differs between controls and patients. In addition, exploratory analyses were conducted to initiate an understanding of the overall pattern of relationships between patients' visual abilities and symptoms, which is of clinical relevance. Future studies with more power are necessary to validate our findings.
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Affiliation(s)
- Simona Garobbio
- Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Reza Mazloum
- Department of Neuroradiology, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Michael Rosio
- Department of Neuroradiology, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Jeanette Popovova
- Department of Neuroradiology, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Raphaela Schöpfer
- Department of Neuroradiology, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Fabienne C Fierz
- Department of Ophthalmology, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Leah R Disse
- Department of Ophthalmology, University Hospital Zurich, 8091 Zurich, Switzerland
- Department of Neurology, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Konrad Peter Weber
- Department of Ophthalmology, University Hospital Zurich, 8091 Zurich, Switzerland
- Department of Neurology, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Christoph J Schankin
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, 3010 Bern, Switzerland
| | - Lars Michels
- Department of Neuroradiology, University Hospital Zurich, 8091 Zurich, Switzerland
- Clinical Neuroscience Center, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Michael H Herzog
- Laboratory of Psychophysics, Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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3
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González-Ávila C, García-Azorín D, Mínguez-Olaondo A, Rubio-Flores L, Lamas R, Nieves-Castellanos C, López-Bravo A, Muñoz-Vendrell A, Campoy S, Sebastian-Valles F, Quintas S. Visual snow syndrome in patients with migraine: widening the clinical spectrum of the syndrome with permanent and episodic manifestations. Neurol Sci 2024; 45:4437-4444. [PMID: 38536549 DOI: 10.1007/s10072-024-07483-y] [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: 01/22/2024] [Accepted: 03/19/2024] [Indexed: 08/09/2024]
Abstract
PURPOSE Migraine is the comorbidity most frequently associated with visual snow syndrome (VSS), but the prevalence of VSS in patients with migraine (PWM) has not been studied. Our objective was to evaluate the frequency of VSS in PWM and to analyze if symptoms of VSS happened in a permanent or episodic manner (eVSS) in this population. METHODS We conducted a multicenter observational cross-sectional study. PWM was recruited from headache units, and a survey about the presence of visual snow symptoms was administered. The frequency and characteristics of patients that met current VSS criteria were analyzed. Demographic and clinical features of patients with VSS, eVSS, and PWM with no visual snow were compared. RESULTS A total of 217 PWM were included. Seventeen patients (7.8%) met the VSS criteria. VSS patients had visual aura more frequently (58.8% vs. 31%; p = 0.019) and a higher MIDAS score (96.6 vs. 47.7; p = 0.014). Fifty-eight PWM (26.7%) showed visual snow and associated features in an episodic way and were classified as eVSS. Patients with VSS showed a tendency towards a higher frequency of visual symptoms than patients with eVSS (p > 0.05). No statistically significant differences in sociodemographic characteristics and comorbid conditions were found between VSS and eVSS. CONCLUSION The prevalence of VSS in PWM may be higher than that described for the general population. Some PWM may present similar visual symptoms to patients with VSS but in an episodic manner. Our study reinforces the observation that the clinical spectrum of visual snow is likely to be broader than previously described.
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Affiliation(s)
- Carmen González-Ávila
- Headache Unit, Neurology Department, Hospital Universitario de La Princesa, Madrid, Spain.
| | - David García-Azorín
- Headache Unit, Neurology Department, Hospital Clínico Universitario, Valladolid, Spain
| | - Ane Mínguez-Olaondo
- Neurology Department, Hospital Universitario Donostia, San Sebastián, Spain
- Athenea Neuroclinics (Donostia), San Sebastián, Spain
- Neuroscience Area, Biodonostia Research Institute (Donostia), San Sebastián, Spain
- Departamento de Medicina, Facultad de Ciencias de La Salud, Universidad de Deusto (Bilbao), San Sebastián, Spain
| | - Laura Rubio-Flores
- Neurology Department, Hospital Universitario General de Villalba, Madrid, Spain
- Neuroscience Institute, La Milagrosa University Hospital and Vithas Madrid, Aravaca University Hospital, Vithas Hospital Group, Madrid, Spain
| | - Raquel Lamas
- Headache Unit, Neurology Department, Hospital Virgen del Rocío, Seville, Spain
| | | | - Alba López-Bravo
- Headache Unit, Department of Neurology, Hospital Reina Sofía, Tudela, Navarra, Spain
- Instituto de Investigación Sanitaria de Aragón, Zaragoza, Spain
| | - Albert Muñoz-Vendrell
- Headache Unit, Neurology Department, Hospital Universitari de Bellvitge-IDIBELL, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Sergio Campoy
- Headache Unit, Neurology Department, Hospital Universitari de Bellvitge-IDIBELL, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
| | - Fernando Sebastian-Valles
- Endocrinology and Nutrition Department, Hospital Universitario de La Princesa, Instituto de Investigación Sanitaria de La Princesa, Madrid, Spain
| | - Sonia Quintas
- Headache Unit, Neurology Department, Hospital Universitario de La Princesa, Madrid, Spain
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4
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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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5
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Aeschlimann SA, Klein A, Schankin CJ. Visual snow syndrome: recent advances in understanding the pathophysiology and potential treatment approaches. Curr Opin Neurol 2024; 37:283-288. [PMID: 38465699 PMCID: PMC11064904 DOI: 10.1097/wco.0000000000001258] [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: 03/12/2024]
Abstract
PURPOSE OF REVIEW Visual snow syndrome (VSS) is a disorder characterized by persistent visual disturbances, including the visual snow phenomenon, palinopsia, heightened perception of entoptic phenomena, impaired night vision, and photophobia. The purpose of this review is to provide an update on recent findings over the past 18 months in VSS research and to summarize the current state of treatment approaches. RECENT FINDINGS Electrophysiological studies have revealed cortical hyperresponsivity in visual brain areas, imaging studies demonstrated microstructural and functional connectivity alterations in multiple cortical and thalamic regions and investigated glutamatergic and serotoninergic neurotransmission. These findings suggest that VSS might be a network disorder.Only few treatment studies are currently available demonstrating limited response to medication and even worsening or triggering of visual symptoms by certain antidepressants. Promising nonpharmacological treatments include mindfulness-based cognitive therapy, the use of chromatic filters, and research on visual noise adaption and neuro-optometric visual rehabilitation therapy (NORT). However, the level of evidence is still low and further research is needed including larger trials and involving objective measures of individual dysfunction. SUMMARY Although there has been recent progress, we still have not fully understood the nature of VSS. Further research is needed on a clinical and pathophysiological level to successfully treat the condition.
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Affiliation(s)
- Sarah A Aeschlimann
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
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Brooks CJ, Chan YM, Fielding J, White OB, Badcock DR, McKendrick AM. Improving Understanding of Visual Snow by Quantifying its Appearance and Effect on Vision. Invest Ophthalmol Vis Sci 2024; 65:38. [PMID: 38787547 PMCID: PMC11129720 DOI: 10.1167/iovs.65.5.38] [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: 10/18/2023] [Accepted: 04/27/2024] [Indexed: 05/25/2024] Open
Abstract
Purpose Visual snow is the hallmark of the neurological condition visual snow syndrome (VSS) but the characteristics of the visual snow percept remain poorly defined. This study aimed to quantify its appearance, interobserver variability, and effect on measured visual performance and self-reported visual quality. Methods Twenty-three participants with VSS estimated their visual snow dot size, separation, luminance, and flicker rate by matching to a simulation. To assess whether visual snow masks vision, we compared pattern discrimination thresholds for textures that were similar in spatial scale to visual snow as well as more coarse than visual snow, in participants with VSS, and with and without external noise simulating visual snow in 23 controls. Results Mean and 95% confidence intervals for visual snow appearance were: size (6.0, 5.8-6.3 arcseconds), separation (2.0, 1.7-2.3 arcmin), luminance (72.4, 58.1-86.8 cd/m2), and flicker rate (25.8, 18.9-32.8 frames per image at 120 hertz [Hz]). Participants with finer dot spacing estimates also reported greater visibility of their visual snow (τb = -0.41, 95% confidence interval [CI] = -0.62 to -0.13, P = 0.01). In controls, adding simulated fine-scale visual snow to textures increased thresholds for fine but not coarse textures (F(1, 22) = 4.98, P = 0.036, ηp2 = 0.19). In VSS, thresholds for fine and coarse textures were similar (t(22) = 0.54, P = 0.60), suggesting that inherent visual snow does not act like external noise in controls. Conclusions Our quantitative estimates of visual snow constrain its likely neural origins, may aid differential diagnosis, and inform future investigations of how it affects vision. Methods to quantify visual snow are needed for evaluation of potential treatments.
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Affiliation(s)
- Cassandra J. Brooks
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
| | - Yu Man Chan
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, 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, Australia
| | - Allison M. McKendrick
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
- Lions Eye Institute, Nedlands, Australia
- School of Allied Health, The University of Western Australia, Crawley, Australia
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7
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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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8
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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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9
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Berman G, Mollan SP. The Pressure of Headache at the United Kingdom CSF Disorders Day 2023. Neuroophthalmology 2024; 48:204-209. [PMID: 38756340 PMCID: PMC11095568 DOI: 10.1080/01658107.2023.2290539] [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: 11/09/2023] [Accepted: 11/18/2023] [Indexed: 05/18/2024] Open
Abstract
Headache in intracranial disorders drives significant disability in our patients. Management principles for secondary headaches require a multidisciplinary approach with expertise from the neurological, neuro-ophthalmological, neuroradiological, and neurosurgical specialities. The Pressure of Headache was the theme of the annual United Kingdom CSF Disorders Day and saw speakers and panellists from Australia, Europe, and the United States. Among the topics presented were the newest concepts underpinning idiopathic intracranial hypertension management and spontaneous intracranial hypotension. Advances in our knowledge of cerebrospinal fluid secretion and the visual snow syndrome debate were particular highlights. This review provides a summary of the research on headache disorders that overlap the neuro-ophthalmological axis of care for patients.
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Affiliation(s)
- Gabriele Berman
- Birmingham Neuro-Ophthalmology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Susan P. Mollan
- Birmingham Neuro-Ophthalmology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
- Translational Brain Science, Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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10
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Montoya SA, Mulder CB, Lee MS, Schallmo MP, Engel SA. Adapting to Visual Noise Alleviates Visual Snow. Invest Ophthalmol Vis Sci 2023; 64:23. [PMID: 38117246 PMCID: PMC10741153 DOI: 10.1167/iovs.64.15.23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/17/2023] [Indexed: 12/21/2023] Open
Abstract
Purpose Visual snow syndrome-characterized by flickering specks throughout the visual field and accompanied by other symptoms-can disrupt daily life and affects roughly 2% of the population. However, its neural bases remain mysterious, and treatments are lacking. Here, we report the first intervention that can temporarily eliminate the visual snow symptom, allowing many observers to see the world without snow for the first time since symptom onset. Prolonged viewing of a visual stimulus strongly reduces the responsiveness of the visual pathways to subsequent stimuli, and we tested whether such adaptation could affect visual snow. Methods Participants with visual snow (total n = 27) viewed high-contrast dynamic noise patterns, resembling television static, and then judged the strength of the symptom. Results Visual snow was temporarily reduced in strength to the point that it was invisible at longer adaptation durations for most observers. The effect followed typical trends of adaptation for physical stimuli in normally sighted observers: Effect duration increased monotonically with duration of exposure to the adapter and was specific to dynamic noise. Conclusions These results establish that spontaneous neural activity in the visual system is causally related to the visual snow percept. Because they perceive this activity, people with visual snow may provide a unique window into the generation and suppression of noise in the visual system. Adaptation allows reliable experimental control over visual snow, and so is a strong candidate for diagnostic testing and a promising tool for further understanding its neural origins, which could in turn aid the development of treatments.
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Affiliation(s)
- Samantha A. Montoya
- Graduate Program in Neuroscience, University of Minnesota, Minnesota, United States
| | - Carter B. Mulder
- Department of Psychiatry and Behavioral Sciences, University of Minnesota, Minnesota, United States
| | - Michael S. Lee
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minnesota, United States
| | - Michael-Paul Schallmo
- Department of Psychiatry and Behavioral Sciences, University of Minnesota, Minnesota, United States
| | - Stephen A. Engel
- Department of Psychology, University of Minnesota, Minnesota, United States
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11
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Puledda F, Dipasquale O, Gooddy BJM, Karsan N, Bose R, Mehta MA, Williams SCR, Goadsby PJ. Abnormal Glutamatergic and Serotonergic Connectivity in Visual Snow Syndrome and Migraine with Aura. Ann Neurol 2023; 94:873-884. [PMID: 37466404 DOI: 10.1002/ana.26745] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 06/22/2023] [Accepted: 07/15/2023] [Indexed: 07/20/2023]
Abstract
OBJECTIVE Neuropharmacological changes in visual snow syndrome (VSS) are poorly understood. We aimed to use receptor target maps combined with resting functional magnetic resonance imaging (fMRI) data to identify which neurotransmitters might modulate brain circuits involved in VSS. METHODS We used Receptor-Enriched Analysis of Functional Connectivity by Targets (REACT) to estimate and compare the molecular-enriched functional networks related to 5 neurotransmitter systems of patients with VSS (n = 24), healthy controls (HCs; n = 24), and migraine patients ([MIG], n = 25, 15 of whom had migraine with aura [MwA]). For REACT we used receptor density templates for the transporters of noradrenaline, dopamine, and serotonin, GABA-A and NMDA receptors, as well as 5HT1B and 5HT2A receptors, and estimated the subject-specific voxel-wise maps of functional connectivity (FC). We then performed voxel-wise comparisons of these maps among HCs, MIG, and VSS. RESULTS Patients with VSS had reduced FC in glutamatergic networks localized in the anterior cingulate cortex (ACC) compared to HCs and patients with migraine, and reduced FC in serotoninergic networks localized in the insula, temporal pole, and orbitofrontal cortex compared to controls, similar to patients with migraine with aura. Patients with VSS also showed reduced FC in 5HT2A -enriched networks, largely localized in occipito-temporo-parietal association cortices. As revealed by subgroup analyses, these changes were independent of, and analogous to, those found in patients with migraine with aura. INTERPRETATION Our results show that glutamate and serotonin are involved in brain connectivity alterations in areas of the visual, salience, and limbic systems in VSS. Importantly, altered serotonergic connectivity is independent of migraine in VSS, and simultaneously comparable to that of migraine with aura, highlighting a shared biology between the disorders. ANN NEUROL 2023;94:873-884.
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Affiliation(s)
- Francesca Puledda
- Headache Group, Wolfson SPaRRC, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- National Institute for Health Research (NIHR) King's Clinical Research Facility, King's College London, London, UK
| | - Ottavia Dipasquale
- National Institute for Health Research (NIHR) King's Clinical Research Facility, King's College London, London, UK
| | - Benjamin J M Gooddy
- Department of Neuroimaging, Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Nazia Karsan
- Headache Group, Wolfson SPaRRC, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- National Institute for Health Research (NIHR) King's Clinical Research Facility, King's College London, London, UK
| | - Ray Bose
- Headache Group, Wolfson SPaRRC, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- National Institute for Health Research (NIHR) King's Clinical Research Facility, King's College London, London, UK
| | - Mitul A Mehta
- Department of Neuroimaging, Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Steven C R Williams
- Department of Neuroimaging, Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Peter J Goadsby
- Headache Group, Wolfson SPaRRC, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
- National Institute for Health Research (NIHR) King's Clinical Research Facility, King's College London, London, UK
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA
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12
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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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13
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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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14
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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: 5] [Impact Index Per Article: 5.0] [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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15
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Eren OE, Straube A. [Temporary and persistent visual phenomena in neurology]. DER NERVENARZT 2023; 94:344-352. [PMID: 37039876 DOI: 10.1007/s00115-023-01466-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Accepted: 02/21/2023] [Indexed: 04/12/2023]
Abstract
Temporary and persistent visual phenomena are a frequent reason for a neurological presentation. The diagnosis can usually be made with the help of a structured anamnesis with determination of the time of onset, the course and symptoms as well as the monocular vs. binocular manifestation. The visual aura in migraine is certainly the most frequent entity to be differentiated. In particular, persistent visual phenomena such as visual snow syndrome, hallucinogen persisting perception disorder and the Charles Bonnet syndrome (CBS) seem to be underdiagnosed in clinical practice for various reasons and are probably not that rare. Instrumental diagnostics are mostly used for exclusion diagnostics and are a component of a complete patient education, but can be indicative for certain questions (CBS, epilepsy). This article presents the most frequent visual phenomena from the neurological practice and their differential diagnoses, guided by a case history.
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Affiliation(s)
- Ozan E Eren
- Neurologie, München Klinik Bogenhausen, München, Deutschland
- Neurologie, Klinikum der Universität München, Marchioninistraße 15, 81377, München, Deutschland
| | - Andreas Straube
- Neurologie, Klinikum der Universität München, Marchioninistraße 15, 81377, München, Deutschland.
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16
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Frattale I, Papetti L, Ursitti F, Sforza G, Monte G, Voci A, Proietti Checchi M, Mazzone L, Valeriani M. Visual Disturbances Spectrum in Pediatric Migraine. J Clin Med 2023; 12:jcm12082780. [PMID: 37109116 PMCID: PMC10143789 DOI: 10.3390/jcm12082780] [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: 02/25/2023] [Revised: 04/04/2023] [Accepted: 04/07/2023] [Indexed: 04/29/2023] Open
Abstract
Migraine is a complex neurological disorder with partially unknown pathophysiological mechanisms. The prevalence in childhood ranges from 7.7% to 17.8%, thus representing the most frequent primary headache. In half of the cases, migraine is accompanied or preceded by various neurological disturbances, among which the visual aura is the best known. In literature, other conditions, such as Alice in Wonderland Syndrome and Visual Snow syndrome, are characterized by visual manifestations and are often associated with migraine. The aim of this narrative review is to describe the spectrum of visual disturbances in pediatric migraine and their pathophysiological mechanisms.
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Affiliation(s)
- Ilaria Frattale
- Child Neurology and Psychiatry Unit, Systems Medicine Department, Hospital of Rome, Tor Vergata University, 00165 Rome, Italy
| | - Laura Papetti
- Developmental Neurology, Bambino Gesù Children Hospital, IRCCS, 00165 Rome, Italy
| | - Fabiana Ursitti
- Developmental Neurology, Bambino Gesù Children Hospital, IRCCS, 00165 Rome, Italy
| | - Giorgia Sforza
- Developmental Neurology, Bambino Gesù Children Hospital, IRCCS, 00165 Rome, Italy
| | - Gabriele Monte
- Developmental Neurology, Bambino Gesù Children Hospital, IRCCS, 00165 Rome, Italy
| | - Alessandra Voci
- Developmental Neurology, Bambino Gesù Children Hospital, IRCCS, 00165 Rome, Italy
| | | | - Luigi Mazzone
- Child Neurology and Psychiatry Unit, Systems Medicine Department, Hospital of Rome, Tor Vergata University, 00165 Rome, Italy
| | - Massimiliano Valeriani
- Developmental Neurology, Bambino Gesù Children Hospital, IRCCS, 00165 Rome, Italy
- Center for Sensory Motor Interaction, Aalborg University, 9220 Aalborg, Denmark
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17
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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: 8] [Impact Index Per Article: 8.0] [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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18
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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: 6] [Impact Index Per Article: 3.0] [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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19
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Graber M, Scutelnic A, Klein A, Puledda F, Goadsby PJ, Schankin CJ. Natural course of visual snow syndrome: a long-term follow-up study. Brain Commun 2022; 4:fcac230. [PMID: 36147453 PMCID: PMC9487631 DOI: 10.1093/braincomms/fcac230] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/18/2022] [Accepted: 09/08/2022] [Indexed: 11/13/2022] Open
Abstract
Visual snow syndrome is characterized by a continuous visual disturbance resembling a badly tuned analogue television and additional visual and non-visual symptoms causing significant disability. The natural course of visual snow syndrome has not hitherto been studied. In this prospective longitudinal study, 78 patients with the diagnosis of visual snow syndrome made in 2011 were re-contacted in 2019 to assess symptom evolution using a semi-structured questionnaire. Forty patients (51% of 78) were interviewed after 84 ± 5 months (mean ± SD). In all patients, symptoms had persisted. Visual snow itself was less frequently rated as the most disturbing symptom (72 versus 42%, P = 0.007), whereas a higher proportion of patients suffered primarily from entopic phenomena (2 versus 17%, P = 0.024). New treatment was commenced in 14 (35%) patients, of whom in seven, visual snow syndrome was ameliorated somewhat. Three (7%) experienced new visual migraine aura without headache, and one (2%) had new migraine headache. There were no differences in the levels of anxiety and depression measured by the Patient Health Questionnaire 8 and the Generalized Anxiety Disorder Scale 7. Thirty-eight patients (49%) were lost to follow-up. In visual snow syndrome, symptoms can persist over 8 years without spontaneous resolution, although visual snow itself might become less bothersome.
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Affiliation(s)
- Michael Graber
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern 3010, Switzerland
| | - Adrian Scutelnic
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern 3010, Switzerland
| | - Antonia Klein
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern 3010, Switzerland
| | - Francesca Puledda
- Headache Group, Wolfson CARD, Institute of Psychiatry, Psychology and Neuroscience, King’s College LondonSE1 1YR, London, UK
- NIHR-Wellcome Trust King’s Clinical Research Facility, SLaM Biomedical Research Center, King’s College LondonSE5 9PJ, London, UK
| | - Peter J Goadsby
- Headache Group, Wolfson CARD, Institute of Psychiatry, Psychology and Neuroscience, King’s College LondonSE1 1YR, London, UK
- NIHR-Wellcome Trust King’s Clinical Research Facility, SLaM Biomedical Research Center, King’s College LondonSE5 9PJ, London, UK
| | - Christoph J Schankin
- Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern 3010, Switzerland
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20
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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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21
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Noseda R. Cerebro-Cerebellar Networks in Migraine Symptoms and Headache. FRONTIERS IN PAIN RESEARCH 2022; 3:940923. [PMID: 35910262 PMCID: PMC9326053 DOI: 10.3389/fpain.2022.940923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
The cerebellum is associated with the biology of migraine in a variety of ways. Clinically, symptoms such as fatigue, motor weakness, vertigo, dizziness, difficulty concentrating and finding words, nausea, and visual disturbances are common in different types of migraine. The neural basis of these symptoms is complex, not completely known, and likely involve activation of both specific and shared circuits throughout the brain. Posterior circulation stroke, or neurosurgical removal of posterior fossa tumors, as well as anatomical tract tracing in animals, provided the first insights to theorize about cerebellar functions. Nowadays, with the addition of functional imaging, much progress has been done on cerebellar structure and function in health and disease, and, as a consequence, the theories refined. Accordingly, the cerebellum may be useful but not necessary for the execution of motor, sensory or cognitive tasks, but, rather, would participate as an efficiency facilitator of neurologic functions by improving speed and skill in performance of tasks produced by the cerebral area to which it is reciprocally connected. At the subcortical level, critical regions in these processes are the basal ganglia and thalamic nuclei. Altogether, a modulatory role of the cerebellum over multiple brain regions appears compelling, mainly by considering the complexity of its reciprocal connections to common neural networks involved in motor, vestibular, cognitive, affective, sensory, and autonomic processing—all functions affected at different phases and degrees across the migraine spectrum. Despite the many associations between cerebellum and migraine, it is not known whether this structure contributes to migraine initiation, symptoms generation or headache. Specific cerebellar dysfunction via genetically driven excitatory/inhibitory imbalances, oligemia and/or increased risk to white matter lesions has been proposed as a critical contributor to migraine pathogenesis. Therefore, given that neural projections and functions of many brainstem, midbrain and forebrain areas are shared between the cerebellum and migraine trigeminovascular pathways, this review will provide a synopsis on cerebellar structure and function, its role in trigeminal pain, and an updated overview of relevant clinical and preclinical literature on the potential role of cerebellar networks in migraine pathophysiology.
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Affiliation(s)
- Rodrigo Noseda
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- *Correspondence: Rodrigo Noseda
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22
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Cycling multisensory changes in migraine: more than a headache. Curr Opin Neurol 2022; 35:367-372. [PMID: 35674081 DOI: 10.1097/wco.0000000000001059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Research on migraine usually focuses on the headache; however, accumulating evidence suggests that migraine not only changes the somatosensory system for nociception (pain), but also the other modalities of perception, such as visual, auditory or tactile sense. More importantly, the multisensory changes exist beyond the headache (ictal) phase of migraine and show cyclic changes, suggesting a central generator driving the multiple sensory changes across different migraine phases. This review summarizes the latest studies that explored the cyclic sensory changes of migraine. RECENT FINDINGS Considerable evidence from recent neurophysiological and functional imaging studies suggests that alterations in brain activation start at least 48 h before the migraine headache and outlast the pain itself for 24 h. Several sensory modalities are involved with cyclic changes in sensitivity that peak during the ictal phase. SUMMARY In many ways, migraine represents more than just vascular-mediated headaches. Migraine alters the propagation of sensory information long before the headache attack starts.
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23
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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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24
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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: 8] [Impact Index Per Article: 4.0] [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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