Microencephaly in children congenitally infected with human immunodeficiency virus--a gross-anatomical morphometric study.

A quantitative technique involving serial sectioning and semiautomatic morphometric analysis was used to assess the severity of the reduction in size of the major brain structures in cerebral hemispheres of children congenitally infected with HIV-1. Cerebral hemispheres from 12 children (18-48 months of age) who died of AIDS were sectioned into 5-mm-thick serial slabs and photographed. The cross-sectional areas of grossly recognizable brain structures were digitized, and the volumes were calculated according to Cavalieri's principle. The results were compared with those of an identically processed group of control brains from non-AIDS children. Analysis of the brain weight showed that there was a significant reduction in supratentorial and infratentorial weight in the AIDS group. The results of the morphometric study revealed that the loss in brain mass was associated with a statistically significant reduction in the total volume of both hemispheres, the entire cortex, white matter, and basal ganglia. Detailed analysis of individual brain structures also showed a significant reduction in volume of all cortical regions and most of the subcortical gray matter (e.g., caudate nucleus, putamen, globus pallidus, claustrum, and thalamus). It appears that in the microencephaly observed as a frequent sequel in pediatric AIDS, the loss of brain tissue is global and includes an almost proportional loss of cortex, subcortical gray matter and white matter.