title: Learning and memory-related brain activity dynamics are altered in systemic lupus erythematosus: a functional magnetic resonance imaging study.
abstract: BACKGROUND
  Memory impairment is prevalent in systemic lupus erythematosus (SLE); however, the pathogenesis is unknown.
  
  
  METHODS
  We studied 12 patients with SLE without clinically overt neuropsychiatric manifestations and 11 matched healthy controls, aiming to characterize neural correlates of memory impairment, using structural and functional magnetic resonance imaging (MRI). The paradigm consisted of three encoding and free-recall cycles, allowing characterization of dynamics along consecutive retrieval attempts.
  
  
  RESULTS
  During learning, patients with SLE and healthy controls showed brain activity changes in two principal networks, the default mode network (DMN) and the task-positive network (TPN). Patients with SLE demonstrated significantly less deactivation in the DMN and greater activation in the TPN, reflecting greater recruitment of both networks. The anterior medial prefrontal cortex (amPFC) of the DMN emerged as the only region where brain activity dynamics were altered both over the learning process (p < 0.006), and within free-recall period attempts (p < 0.034). Patients showed significant positive correlations between learning efficiency and hippocampal activity, and greater hippocampal functional connectivity, with pronounced connectivity to DMN structures.
  
  
  CONCLUSIONS
  Increased brain activation in patients with SLE during learning may reflect compensatory mechanisms to overcome memory impairment. Our findings localize this impairment to the amPFC, consistent with the behavioral pattern seen in SLE. Altered networking of the hippocampal subsystem of the DMN is consistent with hippocampal neuronal damage seen in SLE, and may reflect compensatory cortical reorganization to cope with dysfunction in these regions pivotal to mnemonic functions.
authors.affiliation: Functional Brain Center, Wohl Institute for Advanced Imaging.
authors.forename: Irit
authors.initials: I
authors.lastname: Shapira-Lichter
authors.forename: Eli
authors.initials: E
authors.lastname: Vakil
authors.forename: Ira
authors.initials: I
authors.lastname: Litinsky
authors.forename: Noga
authors.initials: N
authors.lastname: Oren
authors.forename: Yifat
authors.initials: Y
authors.lastname: Glikmann-Johnston
authors.forename: Dan
authors.initials: D
authors.lastname: Caspi
authors.forename: Talma
authors.initials: T
authors.lastname: Hendler
authors.forename: Daphna
authors.initials: D
authors.lastname: Paran
mesh_terms: D000328:Adult; D001931:Brain Mapping; D016022:Case-Control Studies; D005260:Female; D006624:Hippocampus / Q000378:metabolism; D006801:Humans; D007858:Learning / Q000502:physiology; D008180:Lupus Erythematosus, Systemic / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008569:Memory Disorders / Q000209:etiology / Q000503:physiopathology*; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000473:pathology; D017397:Prefrontal Cortex / Q000378:metabolism; D055815:Young Adult
keywords: Systemic lupus erythematosus; cognitive dysfunction; magnetic resonance imaging