Cortical cerebral blood flow in HIV-1-related dementia complex.

Dementia complex is a syndrome that affects a high percentage of AIDS patients. Neuroradiological findings may be non-specific and the diagnosis can be difficult in its earlier stages. Preliminary radionuclide studies have recently reported derangements of regional cerebral blood flow (CBF) which may be present before overt anatomical injury. This study reports on cortical and cerebellar CBF changes in 26 patients studied with 99Tcm-HM-PAO and single photon emission computed tomography (SPECT). Extensive cortical CBF derangements were observed in all patients and an evident cerebellar hypoperfusion was also present in three. The prevalence of hypoperfusion was highest in the frontal and parietal lobes. The extension of the hypoperfusion showed a highly significant correlation with the severity of the dementia complex (P less than 0.01 by chi 2 test). The SPECT also showed hypoperfused areas in three patients with normal CT scans and in two patients with normal MRI scans. These results confirm previous preliminary reports on the high prevalence of cortical hypoperfusion in dementia complex and suggest the use of this radionuclide technique to assist in the early diagnosis and follow-up of AIDS patients, especially when CT and MRI are still normal.