BACKGROUND AND PURPOSE: Recent studies have reported the clinical improvement in patients with AIDS treated with a combination of antiretroviral regimens. The purpose of our study was to describe the effects of highly active antiretroviral therapy on MR images in patients with HIV encephalopathy and to compare the clinical course with follow-up neuroimaging studies.

METHODS: Initial and follow-up MR imaging findings are described in four patients with AIDS dementia complex at baseline and after antiretroviral therapy, and correlated with clinical and immunologic findings.

RESULTS: Initial MR imaging revealed white matter signal abnormalities on long-TR images without mass effect and without enhancement on postcontrast images, consistent with HIV encephalopathy. Lesions were located in the basal ganglia and posterior fossa in two patients. All four patients showed progression of white matter disease on the first follow-up MR scan (mean, 6 months). On subsequent scans, regression was seen in three patients and stabilization of white matter disease was observed in one patient. Increases in CD4+ count and decreases in viral load below the limit of quantification were present in all patients.

CONCLUSION: Although our patient population was small, the results suggest that disease regression in patients with AIDS dementia complex after treatment with highly active antiretroviral therapy can be characterized and monitored by MR imaging.