INCREASED CEREBRAL BLOOD-VOLUME IN HIV-POSITIVE PATIENTS DETECTED BY FUNCTIONAL MRI

Objective: To study changes in cerebral hemodynamics related to HIV in fection. Background: Cerebral injury is a well-known manifestation of HIV infection. Physiologic changes in the HIV brain may precede struct ural changes and may be detected by functional MRI (fMRI). Methods: Dy namic contrast fMRI was used to measure the cerebral blood volume (CBV ) in 13 patients infected with HIV and in 7 healthy control subjects. Results: Significant increases in dynamic CBV were found in the deep ( p < 0.001) and cortical gray matter (p < 0.05) of HIV-positive (HIV+) patients. Patients with definite cognitive impairment showed significa ntly greater increases in CBV in the deep gray matter (DGM) compared w ith those without impairment. In one patient with rapidly progressive cognitive impairment, these abnormalities reversed and paralleled clin ical improvement after initiation of zidovudine monotherapy. Conclusio ns: This study supports the hypothesis that HIV infection is associate d with significant cerebral hemodynamic changes, particularly in the D GM, that may contribute to cognitive dysfunction in AIDS. Functional M RI may be useful for early detection of cerebral injury and for the as sessment of novel therapies.