Diffuse cortical malformations: agyria
, pachygyria, polymicrogyria, microcephaly, megalencephaly, microdysgenesis.
, calcifications (arrows), and ventriculomegaly in frontal lobes.
Cross-sections of the brain revealed agyria
and thickening of the gray matter (pachygyria) in the frontal, parietal, temporal and occipital cortices and narrowing of the white matter of the cortex (Figure 3A) compared with the same parts of a control calf brain (Figure 3B).
Sixty-nine percent showed evidence of malformations of cortical development, including lissencephaly (relative smoothness of the brain surface) associated with pachygyria (poorly formed, broad cortical folds), agyria
(no cortical folds), or both (Figure 2, panel B).
is a condition that occurs as a result of silver particle impregnation of skin leading to blue-grey skin discolouration.
In pacygyria, there are areas where the brain is smooth, but it does not involve the complete agyria
that is present in lissencephaly.
(complete lissencephaly) or pachygyria (incomplete lissencephaly) as well as a thickened cerebral cortex are seen on imaging studies, differentiating lissencephaly from malformations of neuronal proliferation (Figure 23).
Based on the findings of the published reports, it appears three patterns of abnormalities are associated with maternal parvovirus B19 infection: positional limb deformities, radiographic evidence of intercranial calcifications, and dysplastic changes, including agyria
, macrogyria, polymicrogyria, and dysgenesis of the corpus callosum, he said.
There was almost complete agyria
with widely open sylvian fissures, and a small brain stem and cerebellum.
The supratentorial findings in these cases were hydrocephalus, corpus callosum agenesis, agyria
, cerebral atrophy, open lip schizencephaly and craniosynostosis.
and thickening of the grey matter of the telencephalon arise from disturbance of neuronal migration, resulting in structural disorganisation of the neurons that normally form the six cell layers of the brain cortex (AYALA et al.
But in some cases of ventriculomegaly, there can also be early manifestation of other anomalies such as hydrocephalus and agyria