Early brain atrophy in HIV infection: a radiological-stereological study

Patients with the acquired immunodeficiency syndrome (AIDS) frequently develop neurological abnormalities, and atrophy has been reported in neuropathological studies of brains from patients with AIDS. Our aim was to see whether increased ventricular volume, indicating central cerebral atrophy develops at an early stage of HIV-infection, before patients are severely immunodeficient. We also wished to follow ventricular size over time and to investigate whether enlargement would be more marked in patients, who became clinically demented. We studied 32 HIV-seropositive men who had several CT studies. At the time of the first CT the patients were divided into two groups, an immunocompetent group (IC) with CD4 cell count >400 and an immunodeficient group (ID) with CD4 cell count <400. These were compared with a control group of 44 seronegative men. Subsequent CT studies were used to measure changes in ventricular size with time. Ventricular volume was estimated with an unbiased stereological method previously applied to CT. Mean (geometric) ventricular volume was 15 ml (6-54 ml) in the controls, 23 ml (10-72 ml) in the IC group and 27 ml (8-80 ml) in the ID group. The increase in size in both patient groups was statistically significant compared with controls: P=0.005 (IC) and 9 x 10(-5)(ID). Regression analysis of the follow-up CT studies showed a significant increase in volume in the HIV group (r=0.74, P=0.002), but not in the AIDS group (r=0.41, P<0.1).