ISSN:
1433-0350
Keywords:
Lissencephaly
;
Agyria
;
Neuronal migration
;
Miller-Dieker syndrome
;
Walker-Warburg syndrome
;
Congenital muscular dystrophy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The neuropathological findings at autopsy in four cases of type I and three of type II lissencephaly are presented. Type I lissencephaly is characterized by agyriapachygyria with a markedly thickened cerebral cortex with four coarse histological layers. The normally myelinated white matter, often with neuronal heterotopias, is very narrow, and the gray-to-white matter ratio is inverted (about 4:1); there are no white-gray interdigitations. Claustrum and capsula extrema are absent. Ventricular dilatation is present, especially of the occipital horns. In the hypoplastic brain stem large olivary heterotopias can often be observed. Severe cerebellar malformations, obstructive hydrocephalus, severe eye abnormalities, and congenital muscular dystrophy are not seen. Clinically, type I lissencephaly presents as “isolated lissencephaly sequence” or as “Miller-Dieker syndrome” with characteristic facial dysmorphism. The long survival of 20 years achieved by one of our patients is very uncommon. Type II lissencephaly is characterized by widespread agyria. Usually, obstructive hydrocephalus is present with a thin cerebral mantle showing a slightly thickened cortex and a narrow, hypomyelinated white matter often with neuronal heterotopias (gray-to-white matter ratio about 1:1). The border between gray and white matter is blurred. Claustrum and capsula extrema are absent. Histologically, the cortex appears disorganized without layering; widespread leptomeningeal gliomesenchymal proliferations and glioneuronal heterotopias are present. Hydrocephalus is caused by obstruction of the subarachnoid space, aqueductal stenosis, and Dandy-Walker malformation. The latter is a typical finding in type II lissencephaly together with severe cerebellar cortical dysplasias. Aplasia of the olfactory nerves, gliotic fusion of the frontal lobes, and an occipital cephalocele may be found. Type II lissencephaly occurs in clinical syndromes with severe eye abnormalities and congenital muscular dystrophy (the so-called “Walker-Warburg syndrome”). The congenital muscular dystrophies have no dystrophin deficiency, as we were able to show immunohistochemically in the muscle biopsies of two further patients with this syndrome.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00306191
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