This pilot study focuses on the persistence of central nervous system (CNS) immune activation that has been observed in the presence of 'effective' combination antiretroviral therapy (cART). Attention to this issue is based on the fear that chronic CNS immunoactivation can cause indolent brain injury that will eventually compromise brain function as patients survive for years on treatment. A leading hypothesis explaining this continued immunoactivation is that viral replication continues within the brain at a level too low for detection in cerebrospinal fluid (CSF), yet sufficient to stimulate local immunoactivation. Based on this hypothesis, we propose to use augmented treatment with raltegravir to test whether additional suppression of this hypothesized CNS HIV-1 replication will reduce continued CNS immunoactivation.