title: Pathways to neurodegeneration: effects of HIV and aging on resting-state functional connectivity.
abstract: OBJECTIVE
  Resting-state functional connectivity MRI (rs-fcMRI) may provide insight into the neurophysiology of HIV and aging.
  
  
  METHODS
  In this cross-sectional study, we used rs-fcMRI to investigate intra- and internetwork connectivity among 5 functional brain networks in 58 HIV-infected (HIV+) participants (44% receiving highly active antiretroviral therapy) and 53 HIV-uninfected (HIV-) controls. An analysis of covariance assessed the relationship among age, HIV laboratory markers, or degree of cognitive impairment and brain networks.
  
  
  RESULTS
  Individuals who were HIV+ had decreased rs-fcMRI intranetwork correlations in the default mode (DMN, p = 0.01), control (CON, p = 0.02), and salience (SAL, p = 0.02) networks, but showed no changes in the sensorimotor (SMN) or dorsal attention (DAN) network. Compared with HIV- controls, participants who were HIV+ had a significant loss of internetwork correlations between the DMN-DAN (p = 0.02), trending loss in DMN-SAL (p = 0.1) and CON-SMN (p = 0.1), and trending increase in CON-SAL (p = 0.1). Neither HIV markers (plasma HIV viral load or CD4(+) cell count) nor degree of cognitive impairment correlated with rs-fcMRI measures. Aging correlated with a decrease in the magnitude of intranetwork functional connectivity within the DMN (p = 0.04) and SAL (p = 0.006) and with decreased magnitude of internetwork functional connectivity between DMN and SAL (p = 0.009) for both HIV+ and HIV- participants. No interaction was observed between HIV and aging.
  
  
  CONCLUSIONS
  HIV and aging may cause independent decreases in rs-fcMRI. HIV may lead to a baseline decrease in brain function similar to deterioration that occurs with aging.
authors: Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.
authors: Jewell B
authors: JB
authors: Thomas
authors: Matthew R
authors: MR
authors: Brier
authors: Abraham Z
authors: AZ
authors: Snyder
authors: Florin F
authors: FF
authors: Vaida
authors: Beau M
authors: BM
authors: Ances
mesh_terms: D000328:Adult; D000375:Aging / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000473:pathology; D009434:Neural Pathways / Q000503:physiopathology*; D019636:Neurodegenerative Diseases / Q000209:etiology*