title: Transcranial direct current stimulation in mild cognitive impairment: Behavioral effects and neural mechanisms.
abstract: BACKGROUND
  The long preclinical phase of Alzheimer's disease provides opportunities for potential disease-modifying interventions in prodromal stages such as mild cognitive impairment (MCI). Anodal transcranial direct current stimulation (anodal-tDCS), with its potential to enhance neuroplasticity, may allow improving cognition in MCI.
  
  
  METHODS
  In a double-blind, cross-over, sham-controlled study, anodal-tDCS was administered to the left inferior frontal cortex during task-related and resting-state functional magnetic resonance imaging (fMRI) to assess its impact on cognition and brain functions in MCI.
  
  
  RESULTS
  During sham stimulation, MCI patients produced fewer correct semantic-word-retrieval responses than matched healthy controls, which was associated with hyperactivity in bilateral prefrontal regions. Anodal-tDCS significantly improved performance to the level of controls, reduced task-related prefrontal hyperactivity and resulted in "normalization" of abnormal network configuration during resting-state fMRI.
  
  
  CONCLUSIONS
  Anodal-tDCS exerts beneficial effects on cognition and brain functions in MCI, thereby providing a framework to test whether repeated stimulation sessions may yield sustained reversal of cognitive deficits.
authors.affiliation: Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia; Department of Neurology, Charité University Medicine, Berlin, Germany. Electronic address: m.meinzer@uq.edu.au.
authors.forename: Marcus
authors.initials: M
authors.lastname: Meinzer
authors.affiliation: Department of Neurology, Charité University Medicine, Berlin, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Lindenberg
authors.affiliation: Department of Neurology, Charité University Medicine, Berlin, Germany.
authors.forename: Mai Thy
authors.initials: MT
authors.lastname: Phan
authors.affiliation: Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia; Department of Neurology, Charité University Medicine, Berlin, Germany; NeuroCure Clinical Research Center, Charité University Medicine, Berlin, Germany.
authors.forename: Lena
authors.initials: L
authors.lastname: Ulm
authors.affiliation: Department of Neurology, Charité University Medicine, Berlin, Germany.
authors.forename: Carina
authors.initials: C
authors.lastname: Volk
authors.affiliation: Department of Neurology, Charité University Medicine, Berlin, Germany; NeuroCure Clinical Research Center, Charité University Medicine, Berlin, Germany.
authors.forename: Agnes
authors.initials: A
authors.lastname: Flöel
mesh_terms: D000339:Affect / Q000502:physiology; D000368:Aged; D003071:Cognition / Q000502:physiology*; D060825:Cognitive Dysfunction / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006801:Humans; D007807:Language Tests; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000503:physiopathology; D009483:Neuropsychological Tests; D011897:Random Allocation; D012146:Rest; D012660:Semantics; D065908:Transcranial Direct Current Stimulation / Q000379:methods
keywords: Aging; Functional magnetic resonance imaging; Language; Mild cognitive impairment; Resting-state fMRI; Transcranial direct current stimulation