F) Brain of neonate 3: pachygyria
and severe vascular congestion.
(14) In this case, the cortical changes depicted by MRI were interpreted as lissencephaly, polymicrogyria, and pachygyria
. Polymicrogyria was suspected in the frontal lobes visualized by MRI (not shown), but the microscopic examination did not confirm it.
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).
Agyria-Pachygyria and Pachygyria
in children: Contribution of imaging.
The affected hemisphere may show focal or diffuse neuronal migration defects, with areas of polymicrogyria, pachygyria
ACC is often associated with other anomalies such as Chiari II malformation with abnormal development of cerebellar vermis and medulla oblongata, which tend to descend into the foramen magnum, usually accompanied by myelomeningocele, basilar type encephalocele and disorders of neural migration (which occurs concurrently in human brain development) such as schizencephaly, lissencephaly, pachygyria
, marked neuronal heterotopias [1-3, 7,15].
Brain Magnetic Resonance Imaging (MRI) of the proposita revealed thickening of fronto-parieal and temporal gyri (pachygyria
) and mild hypoplasia of corpus callosum (Figure -2d, e).
is a rare developmental disorder resulting from abnormalities in the brain and nervous system.
Murat Gunel, chief of the Neurovascular Surgery Program and codirector of the Program on Neurogenetics at Yale University, New Haven, Conn., recently used whole exome sequencing to determine that several distinct types of malformations of cortical development, including microcephaly, pachygyria
with cortical thickening, and hypoplasia of the corpus callosum, were all associated with recessive mutations in a single gene, WDR62 (Nature 2010;467:207-10).
Neuronal migrational defects include lissencephaly, pachygyria
, heterotopia, focal cortical dysplasia, and polymicrogyria.
Agyria (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 maternal reports, 7 were diagnosed with Down syndrome, 4 with autism, 3 with mental retardation (unspecified), 1 with pachygyria
(a genetic disorder), and one with microcephaly.