Disorders of migration

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Disorders of migration

Last updated on Tuesday, September 9 2008 by jdmiles

Related images:

Bilateral perisylvian ulegyria with periventricular nodular heterotopias, coronal section of brain.
Bilateral perisylvian ulegyria is felt to be a milder form of bilateral perisylvian polymicrogyria. The combination of periventricular nodular heterotopia with this bilateral pattern of cortical neuronal migration abnormality has been reported in the monosomy 1p36 deletion syndrome.

Lissencephaly, coronal section through brain.
Several genetic alterations have been linked with lissencephaly (smooth brain). X-linked lissencephaly occurs in males with doublecortin mutations. Females caring the same mutation present with subcortical band heterotopia (double cortex).

Periventricular nodular heterotopia, coronal section through occipital lobe of brain.
Bilateral periventricular nodular heterotopias has been best described as an X-linked dominant mutation with embryonic lethality in boys due to mutations in the Filamin 1 gene at Xq28.

Polygyria, dorsal surface of brain
Polygyria, also sometimes called pseudo-polymicrogyria, is seen in hydrocephalic infants secondary to compression of the developing cortex against the inner table of the skull. Microscopically, cytoarchitectonic disturbances are not identified.

Polymicrogyria, coronal section through brain.
Although genetic mutations underlying polymicrogyria have been described, the common location of this abnormality within the distribution of the middle cerebral artery suggests intrauterine ischemia within this vascular territory.

Subcortical band heterotopia, coronal section through brain
The presence of a second layer of cortex just below the definitive neocortex defines subcortical band heterotopia, which occurs in females carrying doublecortin mutations.

Zonal heterotopia, coronal sections through parietal lobes
Zonal heterotopia probably represents a milder form of subcortical band heterotopia in doublecortin deficient females.

Polymicrogyria, whole mount of coronal section, H&E stain
Cytoarchetectonic abnormalities are present within the distribution of the middle cerebral artery.