Malformed cerebral hemispheres

[Dorothey Allen]

Cerebral hemispheres may be large, small, or asymmetric; the gyri may be absent, unusually large, or multiple and small.
In addition to the grossly visible malformations, microscopic sections of normal-appearing brain may show disorganization of the normal laminar neuronal arrangement. Localized deposits of gray matter may be present in regions normally occupied only by white matter (heterotopic gray matter).
Malformations of the cerebral hemispheres may be due to genetic or acquired causes. Acquired causes include infections (eg, cytomegalovirus) and vascular events that interrupt the blood supply to the developing brain.
Microcephaly or macrocephaly, moderate to severe motor and intellectual disability, and epilepsy often occur with these defects, with highly variable manifestations.
Treatment is supportive, including antiseizure drugs, if needed.