EARLY BRAIN-LESIONS IN HIV-INFECTION POST -MORTEM RADIOPATHOLOGY CORRELATIONS IN ASYMPTOMATIC NON-AIDS SEROPOSITIVE PATIENTS

In order to evaluate the diagnostic and prognostic value of MRI in the very early stages of HIV infection, we have compared the results of p ostmortem brain MRI and neuropathological studies in 7 asymptomatic HI V seropositive individuals, 8 seronegative controls with similar cause of death and 6 patients who died of AIDS in the absence of focal cere bral changes (opportunistic infection or tumour). Cerebral atrophy was consistently evaluated by both techniques. Seropositive asymptomatic cases were significantly more atrophic than the seronegative controls and significantly less atrophic than AIDS patients. Small high signal intensity areas in the white matter and basal ganglia were not signifi cantly more frequent in seropositives than in seronegatives. No corres ponding lesion was found at neuropathological examination. Diffuse mye lin pallor of the cerebral white matter on myelin preparation was some what more severe in seropositive asymptomatic cases than in seronegati ve controls and less than in AIDS cases. However, these differences we re not statistically significant. No significant correlation could be found between neuropathological myelin pallor and diffuse signal abnor malities of the white matter on MRI. We conclude that brain abnormalit ies are present at the early asymptomatic stage of HIV infection. Thes e include vasculitis with opening of the blood brain barrier and conse quent myelin pallor and gliosis of the white matter, and moderate brai n atrophy. However MRT. correlates are discrete or non specific on pos t mortem examination, and some probably correspond to scars of transie nt vascular inflammation. It is very unlikely that MRI examination has any diagnostic or pronostic value at the early stages of the disease.