Desvendando a relação entre Migranea e alterações inespecíficas da substância branca em estudos de ressonância magnética : uma revisão sistemática

Migranea é uma doença altamente prevalente na população geral, e por mais intensas e debilitantes que possam ser as crises de dor, acredita-se ser de natureza benigna. No entanto, frente o aumento de frequência das crises ou mesmo a piora na intensidade da dor, o paciente portador da doença é submetido a investigação por exame de Ressonância Magnética. Em uma parcela considerável desta população, um achado peculiar nestes exames são lesões em substância branca, geralmente em localização profunda, as quais ainda não são completamente compreendidas fisiopatologicamente, e presume-se estarem relacionadas à migranea em si. Na literatura médica atual, há uma quantidade limitada de estudos investigando a natureza destas anormalidades e existem duas metanálises publicadas previamente que estabelecem uma provável relação causal entre migranea e alterações da substância branca. No entanto, os mecanismos fisiopatológicos por trás deste fenômeno ainda não foram elucidados. Materiais e Métodos: Nesta revisão sistemática da literatura, for realizada busca de artigos completos em três plataformas digitais de literatura científica médica (Embase, MEDLINE/PubMed e LiLaCs)por meio das palavras chaves "migraine", "MRI scan", "white matter" e termos análogos. A busca foi realizada no dia 31 de Maio de 2020. Os critérios de inclusão compreendiam: estudos publicados em periódicos indexados, realizados entre 1990 e 2020, compreendendo população acima de 18 anos e com exames realizados em equipamento de RM com campo magnético igual ou superior a 1,5 Tesla. Estudos com pacientes portadores de outras doenças do sistema nervoso central, doenças autoimunes ou com desfechos relacionados a alterações cardiovasculares e neurovasculares foram excluídos. Resultados: Foram selecionados nove artigos entre os 168 artigos originais, satisfazendo os critérios de inclusão e exclusão. Devido a heterogeneidade dos resultados dos artigos selecionados, a análise estatística por metanálise não foi realizada. Dos artigos selecionados, cinco artigos estabeleceram provável relação entre o tempo de doença e a frequência das crises migranosas com a presença de alterações da substância branca em pacientes portadores de migranea. Os achados reforçam a necessidade de estudos com um número maior de pacientes, onde idealmente a seleção de participantes se dê por meio dos critérios diagnósticos postulados pela International Headache Society (IHS) em sua versão mais recente, com protocolos de aquisição de imagem de RM padronizados e reprodutíveis, softwares validados e se possível com padrão estabelecido para aferição do número de lesões e respectivos volumes, reportando sua localização no 9 tecido cerebral e nos lobos cerebrais, além de controles pareados e posterior comparação de seguimento após pelo menos 36 meses.Migraine is a highly prevalent condition among the general population, and as intense and debilitating as the headache crisis may be, it is believed to be benign. However, when there is an increase in crisis frequency or even a worsening in pain intensity, the patient may be submitted to an investigation with a MRI scan. At a considerable parcel of this population, a peculiar finding at their exams are white matter lesions, generally located at the deep white matter, which are not fully comprehended physiopathologicaly, and are presumably related to migraine itself. At current medical literature, there is a limited quantity of studies investigating the nature of such alterations, and there are two previously published metanalysis that established a probable causal relation between migraine and white matter abnormalities. However, the physiopathological mechanisms behind this phenomena are not yet elucidated. Materials and Methods: At this systematic review, we searched full text articles at three medical scientific literature online platforms (Embase, MEDLINE/PubMed e LiLaCs) through the keywords "migraine", "MRI scan", "white matter" and their analog terms. This search was performed on May 31st 2020. The inclusion criteria comprehended: studies published in indexed periodics performed between 1990 and 2020, with patients with minimum age of 18 years old and MRI scans performed at equipment with a resolution equal or superior to 1,5 Tesla. Studies with patients bearing other central nerve system pathologies, auto-immune diseases or with outcomes related to cardiovascular or neurovascular alteration were excluded. Results: Nine among the 168 studies were selected, satisfying the inclusion and exclusion criteria. Due to the heterogeneity of the selected studies findings, statistical analysis through metanalysis was not performed. Five studies among the selected studies established probable relation among time of disease and migraine crises frequency with the presence of white matter abnormalities in patients with migraine. These findings reinforce the need of studies with a larger number of patients, where ideally the diagnostic criteria established by the International Headache Society (IHS) at the latest version available is used to select the participants, with standardized and reproducible MRI acquisition protocols, validated software for imaging analysis and with a standard pattern for assessed the lesional volume and number, reporting their location in the brain tissue and cerebral lobes, also matched controls and posterior follow-up comparison of at least 36 months

The central vein sign in multiple sclerosis : a biomarker evaluated on a 3T MRI scanner

The central vein sign (CVS) is a promising MRI biomarker in multiple sclerosis (MS). CVS has recently been proposed to improve the accuracy and speed of MS diagnosis. Evidence indicates that the presence of CVS in individual lesions can accurately differentiate MS from other diseases that mimic this condition, such as hypertensive microangiopathy, atypical demyelination, and neuromyelitis optica. Most studies have used 7T MRI scanners, which limits their clinical applicability. Recently, it has been demonstrated that the fusion of the FLAIR and SWI sequences, generating FLAIR*, allows CVS visualization even on 3T scanners. Many studies have confirmed that CVS at 3T is a specific imaging finding for MS

The central vein sign in multiple sclerosis: a biomarker evaluated on a 3T MRI scanner

The central vein sign (CVS) is a promising MRI biomarker in multiple sclerosis (MS). CVS has recently been proposed to improve the accuracy and speed of MS diagnosis. Evidence indicates that the presence of CVS in individual lesions can accurately differentiate MS from other diseases that mimic this condition, such as hypertensive microangiopathy, atypical demyelination, and neuromyelitis optica. Most studies have used 7T MRI scanners, which limits their clinical applicability. Recently, it has been demonstrated that the fusion of the FLAIR and SWI sequences, generating FLAIR*, allows CVS visualization even on 3T scanners. Many studies have confirmed that CVS at 3T is a specific imaging finding for MS

The central vein sign in multiple sclerosis: a biomarker evaluated on a 3T MRI scanner

The central vein sign (CVS) is a promising MRI biomarker in multiple sclerosis (MS). CVS has recently been proposed to improve the accuracy and speed of MS diagnosis. Evidence indicates that the presence of CVS in individual lesions can accurately differentiate MS from other diseases that mimic this condition, such as hypertensive microangiopathy, atypical demyelination, and neuromyelitis optica. Most studies have used 7T MRI scanners, which limits their clinical applicability. Recently, it has been demonstrated that the fusion of the FLAIR and SWI sequences, generating FLAIR*, allows CVS visualization even on 3T scanners. Many studies have confirmed that CVS at 3T is a specific imaging finding for MS