Epilepsias en las malformaciones del desarrollo cortical / Malformations of cortical development and epilepsy

Alrededor del 15% de las epilepsias en pediatría son fármaco-resistentes y en el 40% de este grupo la etiología es una malformación del desarrollo cortical (MDC). El esquema de clasificación actual de las MDC se basa en las etapas primarias de desarrollo de la proliferación celular, migración neuronal y organización cortical. Teniendo en cuenta la clínica y las alteraciones moleculares, se propuso una clasificación basada en la disrupción de las vías principales y el fenotipo neurorradiológico. Se dividió a las MDC en cuatro grupos: la megalencefalia y las displasias corticales focales; las tubulinopatías y lisencefalias; el espectro de las polimicrogirias y las heterotopías. Hasta el momento, más de 100 genes han sido asociados con uno o más tipos de MDC. Los mecanismos biológicos y genéticos incluyen la regulación del ciclo celular en varios estadios, división celular), apoptosis, diferenciación celular, función y estructura del citoesqueleto, migración neuronal y membrana basal. El espectro de síndromes epilépticos asociados con las MDC es amplio e incluye desde encefalopatías epilépticas de comienzo temprano a epilepsias focales de debut más tardío. Teniendo en cuenta que la evolución de la epilepsia hacia la refractariedad en las MDC es importante, el diagnóstico precoz y la elección de la mejor opción terapéutica influirán en el pronóstico de los pacientes.

Around 15% of childhood epilepsies are resistant to antiepileptic drugs, 40% of which are caused by malformations of cortical development (MCD). The current classification scheme for MCD is based on the primary developmental steps of cell proliferation, neuronal migration, and cortical organization. Considering the clinic and molecular alterations, a classification based on main pathways disruption and imaging phenotype has been proposed. MCD were divided into four groups: megalencephaly and focal cerebral dysplasia; tubulinopathies and lissencephalies; polymicrogyria syndromes and heterotopia syndromes. More than 100 genes have been reported to be associated with different types of MCD. Genetic and biological mechanisms include different stages of cell cycle regulation - especially cell division -, apoptosis, cell-fate specification, cytoskeletal structure and function, neuronal migration, and basement-membrane function. The associated epileptic syndromes are varied ranging from early-onset epileptic encephalopathies to focal epilepsies. As MCD are common causes of refractory epilepsy, a prompt diagnosis and the development of different therapeutic options in order to improve the outcome of the patients are essential.

Absence of Arcuate Fasciculus in a Child with Bilateral Perisylvian Polymicrogyria

We report a case of bilateral perisylvian polymicrogyria, which was evaluated using diffusion tensor imaging (DTI) and tractography. On DTI tractography, fibers of the arcuate fasciculus (AF), which connects the posterior inferior frontal region and superior temporal gyrus were absent. It indicates that in cases of bilateral perisylvian polymicrogyria, compromised language skills might be associated with the absence of AF.

Megalencephaly-capillary malformation-polymicrogyria syndrome: the first case report in Korea / 소아과

Megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP), previously known as macrocephaly-cutis marmorata telangiectatica congenita and macrocephaly-capillary malformation syndrome, is a rare multiple-malformation syndrome that is characterized by progressive megalencephaly, capillary malformations of the midline face and body, or distal limb anomalies such as syndactyly. Herein, we report a female infant case that satisfies the recently proposed criteria of MCAP and describe the distinctive neuroradiological and morphological features. We have also reviewed recently published reports and the diagnostic criteria proposed by various authors in order to facilitate the clinical diagnosis of these children in pediatric neurology clinics.

Merosin-Deficient Congenital Muscular Dystrophy with Polymicrogyria and Subcortical Heterotopia: A Case Report

This paper reports the brain magnetic resonance imaging (MRI) findings of a case of merosin-deficient congenital muscular dystrophy (MDCMD) in a neonate and discusses the spectrum of brain involvement in MDCMD. A neonate presented hypotonia, increased serum creatine kinase levels, and polymicrogyria and subcortical heterotopia on brain MRI involving both posterior temporal and occipital lobes. Although these findings suggested Fukuyama muscular dystrophy, muscle biopsy showed dystrophic changes and an absence of merosin staining. We found that compound heterozygous mutation for c.2049_2050delAG (p.R683fs) and c.5866-2A>G in the LAMA2 gene which encodes Laminin-α2. To our knowledge, this is the second Korean case of MDCMD with polymicrogyria and subcortical heterotopias. This case shows that a range of brain structural malformations can be found in children with MDCMD and that the classification of congenital muscular dystrophy (CMD) is not complete yet, as indicated previously in reports suggesting other unclassified forms of CMD.

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.

A Study of Ulegyria as Pathognomonic Aspects of Congenital Bilateral Perisylvian Syndrome

OBJECTIVE: Congenital bilateral perisylvian syndrome (CBPS) has been defined as a characteristic malformative perisylvian polymicrogyria (PMG) in patients with clinical symptoms of pseudobulbar palsy and epileptic seizures. For the present study, we investigate clinicopathologic features of CBPS associated with timing of lesion formation. METHODS: Clinicopathologic features of CBPS from 6 patients with surgical resection of the cerebral lesions due to medically intractable seizures were studied. RESULTS: Seizure onset ranged from 1 to 10years (average 6.7years) of age, and average duration of seizure was 23years. All had complex partial seizures, and two patients had additional tonic clonic seizures. Magnetic resonance (MR) images showed polymicrogyria, atropic gyri with gliosis. In the histopathologic examination, the cortical lesions revealed features of ulegyria ; atrophic and sclerotic gyri, laminar loss of neurons, extensive lobular gliosis throughout the gray and white matter, neuronoglial nodule formation, and many amyloid bodies. Unlayered or four-layered PMG was not identified. CONCLUSION: Above data suggest that CBPS might be caused by ulegyria resulting from developmental cortical defect during early fetal stage or acquired hypoxic/ischemic injury in prenatal or postnatal life.

Schizencephaly:Correlation of Clinical Outcome with Imaging Findings

Schizencephaly is an infrequent congenital disorder of neuronal migration characterized by gray matter-lined clefts that extent through the entire cerebral hemisphere, from the ependymal lining of the lateral ventricle to the pial covering of the cortex. We have studied seven patients with schizencephaly retrospectively to correlate clinical outcome with the type, Size, and location of the clefts and to find associated brain anomalies. Three patients had bilateral clefts(one with two open lip clefts and the other two with a left open lip cleft and a right closed lip cleft), another two patients had left unilateral open lip clefts, and the rest two patients had right closed lip clefts. Clinically, these patients presented motor dysfunction such as hemiparesis, seizures, and variable developmental delay. Patients with bilateral clefts, particularly open lip type, had worse motor and developmental impairment than those with unilateral clefts. Patient with unilateral medium open lip cleft had worse motor and inte llectual impairment than those with unilateral closed lip clefts or small open lip cleft. All patients with frontal lobe involvement had motor dysfunction. Absence of septum pellucidum, gray matter heterotopia, polymicrogyria, and hypoplasia of optic nerves were also frequently found to be associated with schizencephaly. Three patients with skull canges such as enlargement of the hemicranium or erosion of the inner table of the skull were shunted but only one patient improved in the imaging study. We conclude that the severity of patient's symptoms is related to the amount, type, and location of the involved brain.

A case of Fukuyama type congenital muscular dystrophy

No abstract available.