Forebrain anomalies

• Most are idiopathic

• Polymicrogyria: disorganization of the cortex with many small, worm-looking gyri

• Microcephaly (small head or small brain)

  • FAS most common cause

  • Also from congenital HIV and chromosomal abnormalities

• Holoprosencephaly

  • There’s a single frontal lobe and a single lateral ventricle because of incomplete separation

  • Severe cases have facial deformities like cyclopia and a nose in the forehead (nose cannot descend to where it needs to be since that one big eye is in the way)

  • Mildest cases involve total lack of olfactory bulbs (arrhinencephaly)

  • Associated with trisomy 13

• Agenesis of the corpus callosum can produce anything from a mentally retarded kid to a totally normal kid

Category: Pathology Notes