Partial epilepsy: A pictorial review of 3 TESLA magnetic resonance imaging features

Epilepsy is a disease with serious consequences for patients and society. In many cases seizures are sufficiently disabling to justify surgical evaluation. In this context, Magnetic Resonance Imaging (MRI) is one of the most valuable tools for the preoperative localization of epileptogenic foci. Because these lesions show a large variety of presentations (including subtle imaging characteristics), their analysis requires careful and systematic interpretation of MRI data. Several studies have shown that 3 Tesla (T) MRI provides a better image quality than 1.5 T MRI regarding the detection and characterization of structural lesions, indicating that high-field-strength imaging should be considered for patients with intractable epilepsy who might benefit from surgery. Likewise, advanced MRI postprocessing and quantitative analysis techniques such as thickness and volume measurements of cortical gray matter have emerged and in the near future, these techniques will routinely enable more precise evaluations of such patients. Finally, the familiarity with radiologic findings of the potential epileptogenic substrates in association with combined use of higher field strengths (3 T, 7 T, and greater) and new quantitative analytical post-processing techniques will lead to improvements regarding the clinical imaging of these patients. We present a pictorial review of the major pathologies related to partial epilepsy, highlighting the key findings of 3 T MRI.

Happle-Tinschert Syndrome: Report of a Case with Hemimegalencephaly

Happle-Tinschert syndrome is a disorder causing unilateral segmentally arranged basaloid follicular hamartomas of the skin associated with ipsilateral osseous, dental and cerebral abnormalities including tumors. Although a case with hemimegalencephaly was previously described, this is the first report of Happle-Tinschert syndrome with discrepant short left leg, ipsilateral skin lesions, hemimegalencephaly and frontal polymicrogyria.

Malformations of cortical development: current concepts and advanced neuroimaging review / Malformações do desenvolvimento cortical: conceitos atuais e revisão de neuro-imagem avançada

Malformations of cortical development (MCD) result from disruptions in the complex process of the human brain cortex formation and are highly associated to severe epilepsy, neurodevelopmental delay and motor dysfunction. Nowadays, magnetic resonance imaging (MRI) is the cornerstone of the work-up of patients with epilepsy and modern advanced imaging techniques have improved not only our ability to detect and characterize cortical malformations, but also in identifying associated functional abnormalities that are far beyond the structural visualized lesions. Herein, we address the most currently used classifications of MCD and make a concise review of the embryological process of cortical development. Our main goal is to summarize recent advances and new trends in diagnostic imaging techniques concerning MCD. Thereafter, follows a brief discussion of specific disorders and their radiological features.

As malformações do desenvolvimento cortical (MDC) resultam de distúrbios no complexo processo do desenvolvimento do córtex cerebral humano e estão comumente associadas a epilepsia severa e disfunções neuropsicomotoras. Atualmente, as imagens por ressonância magnética (RM) são a pedra angular no manejo de pacientes com epilepsia e modernas técnicas avançadas de imagem melhoraram não só a nossa capacidade de detectar e caracterizar as malformações corticais, mas também levaram ao reconhecimento de anomalias funcionais associadas que estão muito além das lesões estruturais visibilizadas. Abordaremos as classificações mais utilizadas de MDC e revisaremos a embriologia do desenvolvimento cortical. Nosso principal objetivo é destacar os avanços recentes e as novas tendências em técnicas de diagnóstico por imagens relacionadas às MDC. Em seguida, faremos uma breve discussão sobre alguns transtornos específicos e suas características radiológicas.

Relación entre electroencefalograma y neuroimagen en niños con epilepsia focal de difícil control / Relation between electroencephalogram and neuroimaging present in children with epilepsy of difficult control

Las epilepsias focales son las màs frecuentes en los niños, y la resistencia al tratamiento farmacológico puede estar presente hasta en el 30 por ciento de los pacientes. Se realizó este estudio con el objetivo de dirigir la atención hacia la coincidencia topográfica de los paroxismos electroencefalográficos, con lesiones estructurales demostrables por neuroimagen, para facilitar el diseño de estrategias terapéuticas futuras. MÉTODOS. Se realizó un estudio descriptivo, longitudinal prospectivo, con 44 niños con diagnóstico de epilepsia focal de difícil control, ingresados en el Servicio de Neuropediatría del Hospital Pediátrico Docente Juan M Márquez, entre enero de 2003 y junio de 2007. Se realizaron estudios por electroencefalograma (EEG) al ingreso y videoelectroencefalograma, además de estudios de neuroimagen por tomografía axial o resonancia magnética nuclear. RESULTADOS. Los paroxismos en EEG involucraron el lóbulo frontal hasta en el 68 por ciento de los pacientes. En el 48 por ciento de los pacientes, los paroxismos electroencefalográficos coinciden con zonas de alteración estructural según neuroimagen, más frecuentes en el lóbulo frontal. En el 25 por ciento no hay coincidencia topográfica y en el 27 por ciento no se precisan alteraciones estructurales. CONCLUSIONES. En las epilepsias focales de difícil control se debe prestar especial atención a las zonas elocuentes con coincidencia entre el EEG y la neuroimagen, para evaluar de forma temprana las alternativas quirúrgicas de tratamiento.

Focal epilepsies are the more frequent conditions in children and a pharmacologic treatment resistance could be present up to 30 percent of patients. Aim of present paper was to direct the attention to topographic coincidence of electroencephalographic paroxysms with structural lesions by neuroimaging facilitating the future therapeutical strategies design. METHODS: A descriptive, longitudinal, prospective study was conducted in 44 children diagnosed with epilepsy of difficult control admitted in Neuropediatrics Service of Juan Manuel Marquez Teaching Children Hospital from January, 2003 to June, 2007. At admission, we made electroencephalogram (EEG) and videoelectroencephalogram (VEEG) studies as well as neuroimaging studies by axial tomography (AT) or nuclear magnetic resonance (NMR). RESULTS: Paroxysms in EEG involved frontal lobule up to the 68 percent of patients. In 48 percent, electroencephalographic paroxysms coincide with structural alteration zones according neuroimaging, more frequent in frontal lobule. In 25 percent there is not topographic coincidence, and in 27 percent there are not specified structural alterations. CONCLUSIONS: In focal epilepsies of difficult control, we must to take care of eloquent zones with coincident between EEG and neuroimaging to assess in time the surgical treatment options.

Lesiones pseudo quísticas cerebrales: diagnóstico diferencial prenatal de esquizencefalia-porencefalia / Pseudo cystic brian injury: differential and prenatal diagnosis of schizencephaly and porencephaly

Congenital anomalies of the central nervous system (CNS), although relatively frequent, can present prenatally with a wide dysmorphic spectrum. CNS anomalies can be classified into two groups; those in which a neurulation defect occurs during the first weeks of development, widely known as neural tube defects (NTDs), and those affecting lately the development of the brain during the time of neural proliferation, migration or organization. In addition, there are pseudo-cystic lesions affecting the brain parenchyma, which origin can be difficult to establish during examination of the fetal brain. Schizencephaly is a typical example of neural migration disorder and porencephaly is usually secondary to an external insult either caused by an infection, hemorrhage, or trauma. These lesions present several features at ultrasound and magnetic resonance imaging that can be used in the differential diagnosis. We review this topic and propose some imaging signs which may help in establishing the prenatal diagnosis.

Las anomalías congénitas que comprometen el Sistema Nervioso Central (SNC) son relativamente frecuentes aunque presentan un amplio espectro dismorfico en la etapa fetal. Estas lesiones pueden ser clasificadas en dos grupos, aquellas con defecto de la neurulación que ocurren durante las primeras semanas de la gestación, clásicamente conocidos como defectos del tubo neural (DTN), y las anomalías que comprometen posteriormente el desarrollo del cerebro durante la etapas de proliferación, migración u organización neuronal. Existen sin embargo, lesiones pseudo quísticas del parénquima cerebral que pueden llevar a confusión durante el examen cerebral fetal. La esquizencefalia es un típico ejemplo de defecto de migración neuronal y la porencefalia habitualmente es secundaria a una injuria externa de tipo infecciosa, hemorrágica o traumática. Estas lesiones presentan algunas características típicas al ultrasonido (US) y a la resonancia magnética (RM) que pueden ser considerados criterios para el diagnóstico diferencial prenatal. Se revisa el tema y se proponen algunos signos imagenológicos para clarificar el diagnóstico prenatal.

The clinical spectrum of malformations of cortical development

BACKGROUND: Malformations of cortical development (MCD) usually manifest in childhood with epilepsy, developmental delay and focal neurological abnormalities. OBJECTIVE: To evaluate the presentation and severity of epilepsy in the different types of MCD. METHOD: We evaluated the first 100 consecutive patients with a neuroimaging diagnosis of MCD. They were identified among all the high resolution magnetic resonance imaging exams performed at our service between 1997 and 2001. The causes of referral were diverse, according to the routine of the neurology outpatient clinic. After magnetic resonance imaging diagnosis of the subtype of MCD a detailed clinical assessment was performed. RESULTS: There were 55 females and 45 males, with ages ranging from five months to 71 years old (mean=15.2 years). Seventy-seven patients presented with epilepsy. Sixty-one had partial epileptic syndromes, 13 secondary generalized syndromes, and in three, the type of epileptic syndrome could not be established. Epilepsy was less frequent in patients with the MCD subtypes of polymicrogyria and schizencephaly (p<0.001). Patients with schizencephaly and polymicrogyria had their seizures more easily controlled by antiepileptic drugs (p<0.001). CONCLUSION: That the frequency of epilepsy is lower and seizures are more easily controlled in the setting of polymicrogyria and schizencephaly. Patients with MCD frequently present with secondary generalized epilepsy early in childhood.

INTRODUÇÃO: As malformações do desenvolvimento cortical (MDC) geralmente se manifestam na infância, na forma de crises epilépticas, retardo do desenvolvimento neuropsicomotor ou anormalidades focais. OBJETIVO: Avaliar a apresentação clínica e a gravidade da epilepsia nos diferentes tipos de MDC. MÉTODO: Cem pacientes com diagnóstico de MDC estabelecido por neuroimagem foram avaliados. Os pacientes foram identificados através de exames de ressonância magnética de alta resolução realizados entre 1997 e 2001. As causas para investigação por imagem foram diversas, conforme as indicações de rotina dos ambulatórios de neurologia. Após a determinação do subtipo de MDC, uma avaliação clínica detalhada foi realizada. RESULTADOS: Entre os 100 pacientes, 55 eram do sexo feminino e 45 do masculino, com idade variando entre 5 meses e 71 anos (média=15,2 anos). Setenta e sete pacientes apresentaram epilepsia. Sessenta e um tinham síndrome epiléptica parcial, 13 síndrome epiléptica secundariamente generalizada e em três, o tipo de crise não pode ser definido. Epilepsia foi menos freqüente em pacientes com polimicrogiria e esquizencefalia (p<0.001). As crises epilépticas foram controladas mais facilmente por drogas antiepilépticas em pacientes com polimicrogiria e esquizencefalia (p<0.001). CONCLUSÃO: A freqüência de epilepsia é menor e as crises são mais facilmente controladas em pacientes com polimicrogiria e esquizencefalia. Pacientes com MDC freqüentemente apresentam síndrome epiléptica secundariamente generalizada.