Heterotopia associated with hippocampal sclerosis: an under-recognized cause of early onset epilepsy in children operated on for temporal lobe epilepsy.

Purpose: The aim of this study is to report on 52 children operated on for pharmacoresistant temporal lobe epilepsy, with special emphasis on histopathology and correlation with clinical features.

Methods: Charts were retrospectively analyzed. All children underwent comprehensive clinical, electrophysiological and radiological investigations before surgery.

Pontoneocerebellar hypoplasia: definition of MR features.

We report five patients with pontoneocerebellar hypoplasia. Because the issue of cerebellar malformations is a difficult subject, we tried to define criteria for diagnosis on MRI: a thin flat pons with disappearance of the anterior curve, a small cerebellum with predominant flattening of the hemispheres and shortened cerebellar fissures, in contrast to atrophy. The posterior fossa is not enlarged.

Immunocytochemical characterization of long-term persistent immune activation in human brain after herpes simplex encephalitis.

The clinical, virological and immunocytochemical features of three children who recovered from acute herpes simplex encephalitis (HSE) before the age of 2 years, and who developed secondary severe focal epilepsy after a symptom-free period, leading to neurosurgery 3-10 years later are described. In one child, relapse of HSE occurred immediately after surgery. In all three patients, brain sample biopsies showed abundant CD3-positive T lymphocytes with a majority of CD8 cells, and abundant activated macrophage-microglial cells, a pattern similar to that found in acute HSE.

Increased density of oligodendrocytes in childhood ataxia with diffuse central hypomyelination (CACH) syndrome: neuropathological and biochemical study of two cases.

We report neuropathological, biochemical and molecular studies on two patients with childhood ataxia with diffuse central nervous system hypomyelination (CACH) syndrome, a leukodystrophy recently defined according to clinical and radiological criteria. Both had severe cavitating orthochromatic leukodystrophy without atrophy, predominating in hemispheric white matter, whereas U-fibers, internal capsule, corpus callosum, anterior commissure and cerebellar white matter were relatively spared. The severity of white matter lesions contrasted with the rarity of myelin breakdown products and astroglial and microglial reactions.

[Cortical heterotopias: animal models and human disease].

Cortical heterotopia is defined as the misplacement of a group of neurons displaced to a precise localization in the neocortex and results from perturbed migration along the glial guide, either because of glial destruction or molecular anomalies. Heterotopic neurons are rarely dispersed but are rather grouped in nodules or bands. Heterotopic masses may lie in an ependymal or subcortical localization depending on whether they result from lack of migration or an arrested migration.