Older age has been associated with increased risk of HAND independent of the duration of HIV infection.6- 8 Pathologic similarities exist between HAND and neurodegenerative disorders such as Alzheimer disease (AD), which is characterized by the presence of extracellular deposits of amyloid-?? protein 1-42 (A??42) in the form of plaques and aggregations of microtubule-associated, tau-forming, neuro