Past Stimulant Abuse is Associated with Reduced Basal Ganglia and Hippocampal Integrity in Older HIV+ Adults: A Diffusion Tensor Imaging Study
Human Immunodeficiency Virus (HIV) and current stimulant abuse have both been shown to damage basal ganglia and hippocampus. While the effects of current stimulant abuse on neurological functioning is welldocumented, whether residual damage can be detected in patients with a distant history of past stimulant abuse/ dependence remains to be understood. Given that past stimulant abuse is common among HIV-infected individuals; this is a question of considerable clinical significance. The present study employed Diffusion Tensor Imaging (DTI) and structural MRI to examine brain integrity (as measured by FA and MD) and volume in the basal ganglia (BG) and hippocampus among older HIV-infected adults with histories of stimulant abuse. Lower fractional anisotropy and greater diffusivity (representative of microstructural breakdown) in basal ganglia and hippocampal structures were documented among former stimulant abusers compared to stimulant-naïve individuals. Length of abstinence was also associated with BG integrity, such that those with shorter abstinence periods demonstrated greater MD of the BG. Our findings suggest that past stimulant abuse is associated with neurological dysfunction, though this improves with increasing abstinence.