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Matthew S. Robbins - One of the best experts on this subject based on the ideXlab platform.

  • Visual snow: Are we beginning to see the light?
    Neurology, 2020
    Co-Authors: Fiona E. Costello, Alexander R. Bisdorff, Matthew S. Robbins
    Abstract:

    Visual snow is a long-recognized clinical phenomenon, first described by Liu et al.1 in 1995. In this case series, persistent Positive Visual Phenomena were depicted as being “extremely similar in their simplicity, quality, and involvement of the entire Visual field.”1 Patients reported seeing “diffuse small particles, such as TV static, snow, lines of ants, dots, and rain, that lasted for months to years.”1 No underlying structural, drug-related, psychiatric, or epileptic cause for the Visual perceptions was identified in this seminal publication; moreover, treatments were unhelpful.

  • Comment: Time for neurologists to see Visual snow.
    Neurology, 2019
    Co-Authors: Matthew S. Robbins
    Abstract:

    A syndrome of continuous, enveloping Positive Visual Phenomena, Visual snow (VS), afflicts patients who have perennially sought care from ophthalmologists and neurologists without broad recognition of their having a distinct clinical syndrome. Early characterizations of VS predominated in cohorts enriched with high rates of migraine, particularly with Visual aura, leading to innumerable treatment trials of migraine preventive therapies for VS that have largely been ineffective.1

Gordon T. Plant - One of the best experts on this subject based on the ideXlab platform.

  • Should ‘Visual snow’ and persistence of after-images be recognised as a new Visual syndrome?
    Journal of neurology neurosurgery and psychiatry, 2014
    Co-Authors: Anne-caroline Bessero, Gordon T. Plant
    Abstract:

    Although seldom recorded in the medical literature, the ‘Visual snow’ phenomenon, as described by patients, leads to a distressing Visual condition and often to multiple unnecessary investigations and inappropriate treatments. It impairs daily life, especially through difficulty in reading, focussing and other Visual tasks. Medical records of 27 patients were reviewed. They were referred to our neuro-ophthalmic clinic between 2005 and 2010 with unclassified Positive Visual Phenomena. All patients underwent a careful history and complete clinical ophthalmic examination. Most of them had electrophysiology assessment and neuroimaging. Three of the patients had suffered post-traumatic Visual discomfort especially when exposed to bright light, one experienced a phosphene in the central Visual field and 23 patients complained of Visual snow and/or intrusive after-images without any known precipitant. Among the latter, 20 experienced Visual snow, 3 persistent after-images only: 1. Twenty patients were classified as suffering ‘Visual snow’ with or without persistence of after-images. These patients consistently described ‘grainy’, ‘dotty’ or ‘pixelated’ vision affecting the entire Visual field of both eyes equally (table 1). The Visual experience is likened to ‘television (TV) snow’ or ‘TV noise’ which is the random dot pattern of static displayed when there is no signal on an analoguei TV monitor, hence, the term ‘Visual snow’. The symptoms were continuous with some fluctuation, frequently varying with changes in ambient illumination. The …

Jean-marc Olivot - One of the best experts on this subject based on the ideXlab platform.

  • Spectrum of Transient Visual Symptoms in a Transient Ischemic Attack Cohort
    Stroke, 2013
    Co-Authors: Philippa C. Lavallée, Lucie Cabrejo, Julien Labreuche, Mikael Mazighi, Elena Meseguer, Céline Guidoux, Halim Abboud, Bertrand Lapergue, Isabelle F. Klein, Jean-marc Olivot
    Abstract:

    Background and Purpose—Transient Visual symptoms (TVS) are common complaints. They can be related to transient ischemic attacks, but the nature of the symptoms often remains uncertain, and data on prognosis are scarce. We studied the prevalence, presentation, and effect of different types of TVS, paying particular attention to the association with high-risk pathology of embolism. Methods—A total of 2398 patients with suspected transient ischemic attack admitted to the SOS-TIA clinic between January 2003 and December 2008 underwent immediate evaluation and treatment. Results—Eight hundred twenty-six (34.5%) patients had TVS, including 422 (17.6%) patients with isolated TVS. Transient monocular blindness was the most frequent TVS (36.3%), followed by diplopia (13.4%), homonymous lateral hemianopia (12.3%), bilateral Positive Visual Phenomena (10.8%), and lone bilateral blindness (4.5%). Positive diffusion-weighted imaging was found in 11.8%, 8.1%, 8.1%, and 5.0% of patients with homonymous lateral hemianopi...

Peter J. Goadsby - One of the best experts on this subject based on the ideXlab platform.

  • Persistent and Repetitive Visual Disturbances in Migraine: A Review
    Headache, 2016
    Co-Authors: Christoph J. Schankin, Michele Viana, Peter J. Goadsby
    Abstract:

    Visual disturbances in migraineurs, such as Visual aura, are typically episodic, that is, associated with the headache attack, and overlaid by head pain and other symptoms that impact the patient. In some patients, however, Visual symptoms are dominant due to frequency (migraine aura status), duration (persistent migraine aura and other persistent Positive Visual Phenomena), or complexity (Visual snow syndrome). These syndromes are more rare and challenging to classify in clinical practice resulting in a lack of systematic studies on pathophysiology and treatment. We aim at describing clinical features and pathophysiological concepts of typical migraine aura with a focus on cortical spreading depression and differentiation from non-typical migraine aura. Additionally, we discuss nomenclature and the specifics of migraine aura status, persistent migraine aura, persistent Positive Visual Phenomena, Visual snow, and other migrainous Visual disturbances. The term migraine with prolonged aura might be a useful bridge between typical aura and persistent aura. Further studies would be necessary to assess whether a return of the classification category eventually helps diagnosing or treating patients more effectively. A practical approach is presented to help the treating physician to assign the correct diagnosis and to choose a medication for treatment that has been successful in case reports of these rare but disabling conditions.

Jorge C. Kattah - One of the best experts on this subject based on the ideXlab platform.

  • Neurosurgical Cases with Cortical Vision Loss Followed by Improvement (P6.296)
    Neurology, 2014
    Co-Authors: Bonnie Keung, Julian Lin, Jeffrey D. Klopfenstein, Jorge C. Kattah
    Abstract:

    Background/Objective: Cortical vision loss (CVL) is commonly caused by cerebral infarction from arterial occlusion. Usually, the vision loss is permanent. We describe three neurosurgical cases involving CVL with improvement in Visual function. Methods: Case reports. Results: Case 1: 76-year-old man presented with papilledema due to thrombosis of the torcular herophili. One year later, he became acutely encephalopathic. Neuroimaging showed small bilateral occipital infarcts and a torcular dural arterial venous fistula. He underwent embolization of the feeding arteries followed by resection of the torcula. Post-operatively, he developed cortical blindness. Within two weeks, his vision improved but he had dyslexia. One month later, his Visual acuity improved to 20/20 OU. Perimetry testing showed a residual homonymous quadrantopia. Case 2: 27-year-old man was hit in the back of head. He had a posterior skull fracture and bilateral epidural hematomas. During evacuation of hematomas it was noted that there was increased pressure on the superior sagittal sinus (SSS). Post-operatively his vision was light perception only. MRI showed weak diffusion restriction in the occipital lobes. PET scan showed marked decrease in occipital lobe glycolytic activity. Continuous EEG did not show seizures. Two months post-operatively his vision improved to 20/400 OU. Case 3: 65-year-old man was found to have incidental bi-parietal, parasagittal mass. A resection of the mass and the posterior SSS was performed. The diagnosis was meningioma invasion of the inferior part of the SSS. Post-operatively, he was unable to see inferiorly and was having constant Positive Visual Phenomena. Perimetry testing showed bilateral inferior altitudinal Visual field defects. EEG demonstrated focal occipital status. After treatment with anti-epileptics his Visual fields improved markedly. Conclusions: In cases of CVL attributed to transient increased pressure of the SSS there may be marked improvement of Visual function over time. It is important to rule out a concurrent ictal etiology. Disclosure: Dr. Keung has nothing to disclose. Dr. Lin has nothing to disclose. Dr. Klopfenstein has nothing to disclose. Dr. Kattah has received personal compensation for activities with Pfizer, Inc. as a consultant.