Síndrome de nieve visual y su relación con la migraña / Visual snow syndrome and its relationship with migraine

Introducción El síndrome de nieve visual (SNV) es un trastorno del sistema nervioso central que implica la visión de forma constante de pequeños puntos blancos y negros en la totalidad del campo visual. Desarrollo El SNV puede presentarse desde la infancia hasta la tercera edad, siendo más frecuente en jóvenes y sin diferencia entre géneros. En sus criterios diagnósticos se incluye la presencia de nieve visual, pero también otros fenómenos visuales como palinopsia, fotofobia, nictalopía y otros fenómenos visuales persistentes. La fisiopatología del SNV es desconocida, pero se postulan como mecanismos la hiperexcitabilidad del córtex visual y una disfunción en el procesamiento visual de orden superior. La prevalencia de migraña en los pacientes con SNV es alta en comparación con la población general y cuando se presentan conjuntamente los síntomas son más severos. No se dispone de un tratamiento eficaz, pero el fármaco con mejores resultados es la lamotrigina, recomendándose únicamente en casos seleccionados con alta limitación funcional. Conclusiones El síndrome de nieve visual es una entidad poco conocida e infradiagnosticada, pero el creciente número de investigaciones durante los últimos años ha permitido definir unos criterios diagnósticos y acercarnos a su fisiopatología. Es una entidad íntimamente relacionada con la migraña, con solapamiento de síntomas y probablemente mecanismos fisiopatológicos comunes. (AU)

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. (AU)

Visual snow syndrome and its relationship with migraine.

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.

Eating-induced seizures: A semiological sign of the right temporal pole.

OBJECTIVE: Eating-induced seizures (EIS) are a rare form of reflex seizures. The objective of this study was to report a series of cases of EIS involving patients admitted to our epilepsy unit, and to analyze the clinical characteristics, etiology, and treatment response of this type of infrequent seizure. METHODS: We performed a single-center retrospective analysis of all consecutive patients diagnosed with epilepsy with eating-induced seizures between 2008 and 2020. RESULTS: We included eight patients (six women) with mean age 54.75 years (range: 40-79), and mean age at epilepsy onset 30.75 years (range: 9-58 years). EIS were triggered during a meal in 5/8 (at dinner 1/8, at breakfast in 1/8, and without time preference in 3/8), by a certain flavor in 1/8, by eating different textures or drinking soft drinks in 1/8, and by slicing food in 1/8. All patients suffered nonreflex seizures and 3/8 other types of reflex seizures. In 6/8 of patients, EIS originated in the right hemisphere. In 5/8, the EIS progressed to impaired awareness with oromandibular automatisms. In 6/8, the epilepsy was drug-resistant. Temporopolar encephalocele was the most frequent etiology, in 4/8. Three of the eight underwent surgical treatment, with Engel IA 1 year in 3/3. Three of the eight were treated with vagal stimulation therapy, with McHugh A 1 year in 2/3. SIGNIFICANCE: In our series, eating-induced seizures were observed in patients with focal epilepsy. It was frequently drug-resistant and started predominantly in the right hemisphere, due to temporal pole involvement in half of the patients.

[Temporary and persistent visual phenomena in neurology]. / Passagere und anhaltende visuelle Phänomene in der Neurologie.

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.

Visual snow syndrome and its relationship with migraine. / Síndrome de nieve visual y su relación con la migraña.

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.

Aura-like features and photophobia in sightless migraine patients / Características de fenômenos aura-relacionados e da fotofobia em enxaquecosos deficientes visuais

Migraine is a central nervous system disorder frequently expressed with paroxysmal visual dysfunctions. Objective To test the hypothesis that normal visual input is vital for the migrainous aura and photophobia. Method We studied the migraine-related visual disturbances in 8 sightless migraineurs identified among 200 visually impaired subjects. Results The main findings were the visual aura and photophobia disappearance along with blindness development, the oddness of aura – too short, colourful (e.g. blue or fire-like), auditory in nature or different in shape (round forms) – and the lack of photophobia. Conclusion We propose that the aura duration should be accepted as shorter in visually impaired subjects. The changes in aura phenotype observed in our patients may be the result of both cerebral plasticity induced by the visual impairment and/or the lack of visual input per se. Integrity of visual pathways plays a key role in migraine visual aura and photophobia. .

A enxaqueca é doença neurológica frequentemente associada a anormalidades visuais transitórias. Objetivo Testar a hipótese de que a visão normal é importante para o fenótipo da aura e da fonofobia. Método Estudamos 8 enxaquecosos deficientes visuais identificados em uma população de 200 indivíduos com visão subnormal. Resultados Os principais achados foram: o desaparecimento da aura visual e da fotofobia com o início da cegueira; a ocorrência de aura atípica – muito curta, colorida (p. ex. azul ou cor de fogo) auditiva ou diferente na forma (arredondadas); e a ausência de fotofobia. Conclusão Propomos que a duração da aura possa ser admitida como mais curta em pessoas com deficiência visual. As mudanças no fenótipo da aura observadas nos nossos pacientes pode ser o resultado da plasticidade cerebral induzida pela deficiência visual e/ou a deficiência visual em si. A integridade da via visual desempenha um papel crucial na aura enxaquecosa e na fotofobia. .

Late-onset childhood occipital epilepsy. An unusual case in adolescence and differential diagnosis with migraine / Epilepsia occipital da infância de início tardio

INTRODUCTION: The new proposed classification of ILAE Task Force (2001) proposes that the occipital epilepsies should be split into two subtypes: an early-onset benign childhood occipital epilepsy (or Panayiotopoulos type) and late-onset childhood occipital epilepsy (or Gastaut type). Migraine with visual aura must be considered as a differential diagnosis in childhood and adolescents with occipital epilepsy without motor phenomena. OBJECTIVE: The goal of our paper is to report the case a 16-year-old female, with normal psychomotor development, that during the lunch time presented an event characterized by the vision of multiple colored spots which were moving horizontally and vertically and also in circles through the visual field. Minutes after the visual event, the patient referred to a severe diffuse throbbing headache with frontal predominance. During the clinical investigation was submitted to a video-electroencephalogram exam for 12 hours with, reveling occipital sharp-waves discharges in occipital right region as well as in occipital left region. CONCLUSION: We reported of such classic type of epileptic syndrome in a patient in the unusual age of onset, the end of adolescence, considering the differential diagnosis with migraine with visual aura.

INTRODUÇÃO: A nova proposta de classificação da ILAE (2001) propõe que as epilepsias occipitais sejam classificadas em dois subtipos: epilepsia occipital benigna da infância de início precoce (ou tipo Panayiotopoulos) e epilepsia occipital benigna da infância de início tardio (ou tipo Gastaut). A migrânia com aura visual deve ser considerada como um diagnóstico diferencial nas crianças e nos adolescentes com epilepsia occiptal sem fenômenos motores associados. OBJETIVO: relatar o caso de uma paciente do sexo feminino de 16 anos, com desenvolvimento neuropsicomotor normal, que durante o almoço apresentou um evento caracterizado pela visão de múltiplas manchas coloridas que se movimentavam no sentido horizontal e vertical e também em círculos no seu campo visual. Minutos após este evento visual, a paciente passou a referir cefaléia difusa com predomínio frontal. Durante a investigação clínica foi submetida à realização de vídeo-eletrencefalograma com 12 horas de duração revelando descargas de ondas agudas ora na região occipital direita ora na região occipital esquerda. CONCLUSÃO: apresentamos um tipo clássico de síndrome epiléptica iniciando em uma idade pouco usual, o final da adolescência, considerando o diagnóstico diferencial com a migrânia com aura visual.

Estudio oftalmológico de la migraña con aura visual / Ophthalmological study of migraine with visual aura

En la migraña con aura visual, la cefalea va precedida por la aparición de escotomas centelleantes y pérdida de la visión en la mitad del campo visual entre otros síntomas. Se estudió un grupo de pacientes migrañosos con aura visual con el objetivo de determinar las alteraciones oftalmológicas y los defectos de refracción que aparecen en estos casos y cuales de éstas pueden agravar sus crisis. Se realizó un estudio oftalmológico completo, a 30 pacientes con este diagnóstico, que incluyó la refracción, la medida del punto próximo de convergencia, y la amplitud de fusión. Se considera que la disminución de la amplitu de fusión pudiera ser un factor desencadenante en la aparición de las crisis de migraña.

In the migraine with visual aura, headache is preceded by the appearance of sparkling scotomas and the loss of vision in half of the visual field, among other symptoms. A group of patients suffering from migraine with visual aura was studied aimed at determining the ophthalmological alterations and the refraction defects appearing in these cases and which of them may worsen their crises. A complete ophthalmological study was conducted in 30 patients with this diagnosis that included refraction, the measurement of the proximal point of convergence and the amplitude of fusion. It is considered that the reduction of the amplitude of fusion may be a precipitating factor in the emergence of migraine crises.