| Lissencephaly and pachygyria
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Etiology Both lissencephaly (smooth brain) and pachygyria (large
gyri) are seen in chromosomal defects, after intrauterine exposure to toxins and sporadically of unknown
etiology.
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Pathogenesis Lissencephaly and pachygyria are due to neuronal migration
defects, usually genetic or toxic in origin.,
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Epidemiology Lissencephaly and pachygyria are rare, although focal
areas of pachygyria are less rare and often seen with
seizures, although not a comman cause.
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General Gross Description In lissencephaly the brain is small and smooth although
it may also show areas of pachygyria. In pachygyria
the brain has large misshapen gyri that do not have
the normal pattern. The brain in pachygyria is also
small.
Examples:
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General Microscopic Description The brain in lissencephaly has a four layered cortex
which is very thick often with little white matter and
enlarged ventricles. The neurons of the cortex are not
well organized and other structures such as the basal
ganglia are small also. Examples:
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References 1. Poirier, Gray, and Escourolle. Manual of Basic
Neuropathology 1990. pp 200.
2. Cotran, Kumar, and Robbins. Pathologic Basis of
Disease 5th edition. pp 1302.
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| Lissencephaly and pachygyria
| | Synopsis by: Dr MLGrunnet (TX2000M25440)[483]
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