Morphometry, histopathology, and tomography of cerebral atrophy in the acquired immunodeficiency syndrome

Patients with the acquired immunodeficiency syndrome (AIDS) commonly display evidence of gross cerebral atrophy, but its true incidence and pathophysiology in the general AIDS population are unknown. In this study, we measured cerebrospinal fluid (CSF) spaces in 64 consecutively autopsied patients with AIDS, compared them with age‐matched non‐AIDS subjects, and correlated them with the microscopic neuropathology at autopsy. Thirty‐seven of the patients with AIDS (58%) had a CSF space index greater than two standard deviations above the mean of the age‐matched control subjects. CSF spaces were expanded the most in frontal and temporal lobes; ventricular spaces were expanded more than sulcal spaces. Regression analysis between age and the measured CSF indexes showed that practically none of the deviation in patients with AIDS could be explained by age‐related atrophy. Patients with atrophy were much more likely to have human immunodeficiency virus type 1–associated histopathological changes in their brains, but the relationships were too weak to establish the microscopic cause of the atrophy. Measurement of CSF spaces in antemortem computed tomographic (CT) scans from 47 of the patients with AIDS revealed the same regional pattern of brain wasting. CT diagnosis of cerebral atrophy was strongly concordant with the postmortem diagnosis, but its severity was diagnosed slightly more conservatively at autopsy. Thus, quantitative analysis of CSF spaces in a robust sampling of patients with AIDS confirms that cerebral atrophy is a sensitive, common, and frequently subtle indication of central nervous system human immunodeficiency virus type 1 infection that may occur independently from any single specific microscopic abnormality. Its presence, severity, and regional pattern are detected with reasonable consistency using CT scanning.