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Abstract(s)
A porencefalia é um distúrbio raro que se define como uma anomalia do sistema nervoso
central caracterizada por quistos preenchidos por líquido cefalorraquidiano, de tamanho
variável, no parênquima cerebral, que se associam a hemorragias e isquemia. A prevalência
exata é desconhecida, mas vários estudos mostraram que é semelhante no sexo masculino e
feminino. A leucomalácia periventricular constitui o hallmark da doença.
Etiologicamente divide-se em congénita ou adquirida e classifica-se como esporádica ou
hereditária. A maioria dos casos são esporádicos, resultando de hemorragia, isquemia
cerebral, obstrução do fluxo sanguíneo e infeções, alterações que ocorrem como
consequência de múltiplas condições, sendo a mais comum o enfarte hemorrágico
periventricular. Por outro lado, a porencefalia hereditária tende a desenvolver-se num
contexto pós-hemorrágico em indivíduos com trombofilias hereditárias ou com mutações dos
genes COL4A1 ou COL4A2. Estes genes são transmitidos de forma autossómica dominante,
com penetrância incompleta, sendo importantes para a criação do colagénio tipo IV, um
componente essencial à estrutura das membranas extracelular e basal.
A idade de início, os sintomas específicos, a progressão e a severidade da porencefalia variam
de indivíduo para indivíduo e dentro da mesma família. As manifestações clínicas dependem
da localização e do tamanho da lesão tendo, na maioria dos casos, início na infância.
O diagnóstico de porencefalia é imagiológico, definindo-se como um defeito cerebral
circunscrito, revelado na tomografia computorizada ou na ressonância magnética. Em casos
com história familiar positiva é importante testar as mutações do COL4A1 e COL4A2.
Não existe uma terapêutica específica para a doença, sendo o tratamento essencialmente de
suporte. As intervenções precoces são importantes para assegurar que as crianças atingem o
seu potencial de desenvolvimento máximo.
O prognóstico é pobre na maioria dos casos, não sendo dependente da causa, mas sim da
localização e extensão da lesão.
O caso clínico apresentado alerta para a dificuldade do diagnóstico diferencial imagiológico
desta patologia. A doente estudada, com 85 anos, do sexo feminino, apresentou-se nas
consultas de neurologia após descoberta incidental de um quisto intracerebral, num contexto
de cefaleias intensas e de longa duração. O diagnóstico diferencial é difícil e coloca-se entre
um quisto aracnóide, um quisto neuroepitelial e um quisto porencefálico. Com as informações
descritas nos relatórios imagiológicos é complexo definir-se um diagnóstico definitivo da
patologia, o que demonstra a falta de contacto com a mesma pela comunidade médica.
Porencephaly is a rare disorder defined as an anomaly of the central nervous system characterised by cerebrospinal fluid-filled cysts, of variable size, in the brain parenchyma, associated with haemorrhages and ischemia. The exact prevalence is unknown, but multiple studies showed it to be similar in males and females. Periventricular leukomalacia is the hallmark of the disease. Etiologically it is divided into congenital and acquired, being classified as sporadic or hereditary. Most cases are sporadic, developing as a result of cerebral haemorrhage or ischemia, obstruction of blood flow and infections, changes that occur as consequence of multiple conditions, the most common being the periventricular hemorrhagic stroke. On the other hand, hereditary porencephaly tends to develop in a post-hemorrhagic context in individuals with hereditary trombophilias or with mutations in the genes COL4A1 and COL4A2. This genes are transmitted as autossomal dominant, with incomplete penetrance. They are important for the production of type IV collagen, an essential structural component of extracellular and basal membranes. The age of onset, the specific symptoms, the progression and the severity of porencephaly differ from one individual to another and between family members. The clinical manifestations depend on the location and size of the lesion. Most cases have their onset during infancy. The diagnosis of porencephaly is imagiological and the lesion constitutes a circumscribed cerebral defect, that appears on computed tomography and magnetic resonance. In cases with positive familial history it is important to test for COL4A1 and COL4A2 mutations. There is not a specific therapy for the disease, so patients get supportive treatment. Early interventions are important in assuring that children reach their full potential for development. The prognostic is bad in most cases. It does not depend on the cause, but on the location and volume of the lesion. The clinical case presented sheds light on the difficulty of the imagiological differential diagnosis of this disease. The patient in question, a 85 year old female, visited the neurologist after incidental discovery of an intracerebral cyst, in the context of long-term, intense headaches. The differential diagnosis is complex and is made between an arachnoid cyst, a neuroepithelial cyst and a porencephalic cyst. With the information provided in the imagiological reports it is difficult to propose a definitive diagnosis for the pathology, which puts into evidence the lack of contact of the medical community with this disease.
Porencephaly is a rare disorder defined as an anomaly of the central nervous system characterised by cerebrospinal fluid-filled cysts, of variable size, in the brain parenchyma, associated with haemorrhages and ischemia. The exact prevalence is unknown, but multiple studies showed it to be similar in males and females. Periventricular leukomalacia is the hallmark of the disease. Etiologically it is divided into congenital and acquired, being classified as sporadic or hereditary. Most cases are sporadic, developing as a result of cerebral haemorrhage or ischemia, obstruction of blood flow and infections, changes that occur as consequence of multiple conditions, the most common being the periventricular hemorrhagic stroke. On the other hand, hereditary porencephaly tends to develop in a post-hemorrhagic context in individuals with hereditary trombophilias or with mutations in the genes COL4A1 and COL4A2. This genes are transmitted as autossomal dominant, with incomplete penetrance. They are important for the production of type IV collagen, an essential structural component of extracellular and basal membranes. The age of onset, the specific symptoms, the progression and the severity of porencephaly differ from one individual to another and between family members. The clinical manifestations depend on the location and size of the lesion. Most cases have their onset during infancy. The diagnosis of porencephaly is imagiological and the lesion constitutes a circumscribed cerebral defect, that appears on computed tomography and magnetic resonance. In cases with positive familial history it is important to test for COL4A1 and COL4A2 mutations. There is not a specific therapy for the disease, so patients get supportive treatment. Early interventions are important in assuring that children reach their full potential for development. The prognostic is bad in most cases. It does not depend on the cause, but on the location and volume of the lesion. The clinical case presented sheds light on the difficulty of the imagiological differential diagnosis of this disease. The patient in question, a 85 year old female, visited the neurologist after incidental discovery of an intracerebral cyst, in the context of long-term, intense headaches. The differential diagnosis is complex and is made between an arachnoid cyst, a neuroepithelial cyst and a porencephalic cyst. With the information provided in the imagiological reports it is difficult to propose a definitive diagnosis for the pathology, which puts into evidence the lack of contact of the medical community with this disease.
Description
Keywords
Porencefalia Quisto Aracnóide Quisto Neuroepitelial Quisto Porencefálico