Anatomical, radiological and clinical features of mesial temporal lobe epilepsy: two illustrated cases reports / Aspectos anatômicos, radiológicos e clínicos da epilepsia do lobo temporal mesial: relato ilustrado de dois casos

Mesial temporal lobe epilepsy is the most commom form of focal epilepsy in adults. Its clinical features include focal seizure, dysmnestic symptoms ­ such as déjà vu or jamais vu ­ and autonomic or psychic aura. We reported two cases of mesial temporal lobe epilepsy with similar clinical features, but with entirely different etiologies. Mesial temporal sclerosis contributes up to 70% of all mesial temporal lobe epilepsy cases and MRI usually shows reduced hippocampal volume and increased signal intensity on T2-weighted imaging. Incomplete hippocampal inversion has uncertain relation with epilepsy and is characterized by an atypical verticalized and medially positioned anatomical pattern of the hippocampus and also a deep collateral sulcus.

A epilepsia do lobo temporal mesial é a forma mais comum de epilepsia focal em adultos. Suas características clínicas incluem crises focais, sintomas dismnésicos - como déjà vu ou jamais vu - e aura autonômica ou psíquica. Relatamos dois casos de pacientes com epilepsia do lobo temporal mesial com manifestações clínicas semelhantes, mas com etiologias completamente diferentes. A esclerose mesial temporal contribui com até 70% de todos os casos de epilepsia do lobo temporal mesial e, geralmente, na ressonância magnética, apresenta atrofia do hipocampo e hipersinal na imagem ponderada em T2. A rotação incompleta do hipocampo possui uma relação incerta com a epilepsia e é caracterizada por alteração da estrutura interna do hipocampo, com um sulco colateral verticalizado e profundo.

Gamma radiation-induced impairment of hippocampal neurogenesis, comparison of single and fractionated dose regimens / Deterioro de la neurogénesis en el hipocampo inducida por radiación gamma, comparación de los regímenes de dosis única y fraccionada

Radiation therapy of the brain is associated with many consequences, including cognitive disorders. Pathogenesis of radiation induced cognitive disorder is not clear, but reduction of neurogenesis in hippocampus may be an underlying reason. 24 adult male rats entered to study. Radiation absorbed dose to midbrain was 10 Gy, delivered by routine cobalt radiotherapy machine which its output was measured 115.24 cGy/min. The rats were divided in four groups of sixes, including groups of control, single fraction 10 Gy, fractionated 10 Gy and finally anaesthesia sham group. Number of pyramidal nerve cells was counted in two regions of hippocampus formation (CA1 and CA3). The radiation could reduce the number of cells in two regions of hippocampus significantly (p=0.000). It seems fractionated 10 Gy irradiation to more efficient than single fraction, while role of anaesthesia drug should be cautiously assessed. Moreover the rate of neurogenesis reduction was determined the same in these regions of hippocampus meaning the same radiosensitivity of cells.

La terapia de radiación cerebral está asociada con muchas consecuencias, incluyendo los trastornos cognitivos. La patogénesis del trastorno cognitivo inducido por la radiación no está claro, pero la reducción de la neurogénesis en el hipocampo puede ser una razón subyacente. Fueron etudiadas 24 ratas macho adultas. La dosis de radiación absorbida en el mesencéfalo fue de 10 Gy, proveniente de una máquina de radioterapia de cobalto con una salida de 115,24 cGy/min. Las ratas fueron divididas en cuatro grupos de seis ratas cada uno, incluyendo un grupo control, fracción única de 10 Gy, fraccionada de 10 Gy y finalmente el grupo de anestesia simulado. El número de células nerviosas piramidales se contó en dos regiones de la formación del hipocampo (CA1 y CA3). La radiación podría reducir significativamente (p = 0,000) el número de células en dos regiones del hipocampo . Al parecer, la radiacioón fraccionada de 10 Gy es más eficiente que la fracción única, mientras que el rol de la anestesia debe ser cuidadosamente evaluado. Por otra parte la tasa de reducción de la neurogénesis fue observada en las mismas regiones del hipocampo es decir, con la misma radiosensibilidad de las células.

Esclerose hipocampal unilateral com registro subdural de crises temporais contralaterais: relato de caso / Unilateral hippocampal sclerosis with subdural strips in seizures from the contralateral temporal lobe: case report

INTRODUÇÃO: Pacientes com epilepsia temporal e esclerose hipocampal unilateral tem, na sua grande maioria das vezes, as suas crises e as alterações eletroencefalográficas interictais originando-se do lado da lesão. Mesmo alguns pacientes nos quais os registros de escalpo mostram as crises originando-se da região temporal contralateral à atrofia do hipocampo, registros invasivos têm mostrado que a região de início das crises é, na realidade, ipsilateral à atrofia. No entanto isso talvez não seja verdadeiro para todos pacientes. OBJETIVO: Nesse artigo é relatado uma paciente com atrofia hipocampal unilateral, mas cujas crises, tanto no escalpo quando com registros subdurais, mostram vir da região temporal contralateral. RESULTADO: A paciente tem atrofia hipocampal à direita mas cujo EEG interictal mostrava predomínio de descargas à esquerda, bem como crises vindo daí. O registro com strips subdurais mostrou origem das crises à esquerda. CONCLUSÃO: Possivelmente alguns pacientes com epilepsia temporal têm as crises vindo do hipocampo menos atrófico.

INTRODUCTION: Most patients with temporal lobe epilepsy and hippocampal sclerosis have the seizures and the interictal electroencephalographic abnormalities coming from the side of atrophic hippocampus. Even some patients on whom the seizures seem to arise from the contralateral temporal lobe, invasive recordings have shown that the seizures actually come from that atrophic side. But this may not be always the case. OBJECTIVE: We report a patient with a unilateral hippocampal atrophy and the seizures, seen both on the scalp as well with subdural strips, come from the contralateral temporal lobe. A patient with right hippocampal atrophy had most of the interictal discharges coming from the left temporal lobe, as well her seizures. Invasive recordings with subdural strips also showed seizures arising from the left temporal lobe. CONCLUSION: There might be some patients with temporal lobe epilepsy whose seizures come from the less.

Congenital destructive hemispheric lesions and epilepsy: clinical features and relevance of associated hippocampal atrophy

We studied the clinical, EEG and MRI findings in 19 patients with epilepsy secondary to congenital destructive hemispheric insults. Patients were divided in two groups: 10 with cystic lesions (group 1), and 9 with atrophic lesions (group 2). Seizure and EEG features, as well as developmental sequelae were similar between the two groups, except for the finding that patients of group 2 more commonly presented seizures with more than one semiological type. MRI showed hyperintense T2 signal extending beyond the lesion in almost all patients of both groups, and it was more diffuse in group 2. Associated hippocampal atrophy (HA) was observed in 70 percent of group 1 patients and 77.7 percent of group 2, and it was not correlated with duration of epilepsy or seizure frequency. There was a good concordance between HA and electroclinical localization. The high prevalence of associated HA in both groups suggests a common pathogenesis with the more obvious lesion. Our findings indicate that in some of these patients with extensive destructive lesions, there may be a more circumscribed epileptogenic area, particularly in those with cystic lesions and HA, leading to a potential rationale for effective surgical treatment