Regression of HIV encephalopathy and basal ganglia signal intensity abnormality at MR imaging in patients with AIDS after the initiation of protease inhibitor therapy

PURPOSE: To determine whether protease inhibitors cause regression of periventricular white matter signal intensity abnormalities in patients with human immunodeficiency virus (HIV) encephalopathy and whether the changes on magnetic resonance (MR) images correlate with cognitive improvement. MATERIALS AND METHODS: MR images were retrospectively and prospectively analyzed in 16 adult patients with HIV encephalopathy. White matter and basal ganglia signal intensity abnormalities on initial long repetition time (TR) images were compared with those on subsequent long TR images in patients who received and in patients who did not receive protease inhibitors. Clinical correlation was obtained. RESULTS: Of the nine patients receiving protease inhibitors, four showed nearly complete regression, four showed interval stability, and one showed slight progression. Thus, eight patients (89%) demonstrated either stability or improvement in white matter disease, which correlated with cognitive improvement. Of the seven patients not receiving protease inhibitors, six (86%) showed marked progression with a decline in cognitive function and one had no interval change. The difference between the two groups was statistically significant. Of the two patients receiving protease inhibitors who initially had basal ganglia signal intensity abnormalities, one demonstrated resolution and one nearly complete resolution subsequently. CONCLUSION: Although the patient population is small, protease inhibitors may cause regression of periventricular white matter and basal ganglia signal intensity abnormalities in HIV encephalopathy and may have a role in treatment.