title: Distinct Pattern of Gray Matter Atrophy in Mild Alzheimer's Disease Impacts on Cognitive Outcomes of Noninvasive Brain Stimulation.
abstract: BACKGROUND
  Repetitive transcranial magnetic stimulation (rTMS) is a promising tool to study and modulate brain plasticity.
  
  
  OBJECTIVE
  Our aim was to investigate the effects of rTMS on cognitive functions in patients with mild cognitive impairment and Alzheimer's disease (MCI/AD) and assess the effect of gray matter (GM) atrophy on stimulation outcomes.
  
  
  METHODS
  Twenty MCI/AD patients participated in the proof-of-concept controlled study. Each patient received three sessions of 10 Hz rTMS of the right inferior frontal gyrus (IFG), the right superior temporal gyrus (STG), and the vertex (VTX, a control stimulation site) in a randomized order. Cognitive functions were tested prior to and immediately after each session. The GM volumetric data of patients were: 1) compared to healthy controls (HC) using source-based morphometry; 2) correlated with rTMS-induced cognitive improvement.
  
  
  RESULTS
  The effect of the stimulated site on the difference in cognitive scores was statistically significant for the Word part of the Stroop test (ST-W, p = 0.012, linear mixed models). As compared to the VTX stimulation, patients significantly improved after both IFG and STG stimulation in this cognitive measure. MCI/AD patients had significant GM atrophy in characteristic brain regions as compared to HC (p = 0.029, Bonferroni corrected). The amount of atrophy correlated with the change in ST-W scores after rTMS of the STG.
  
  
  CONCLUSIONS
  rTMS enhanced cognitive functions in MCI/AD patients. We demonstrated for the first time that distinct pattern of GM atrophy in MCI/AD diminishes the cognitive effects induced by rTMS of the temporal neocortex.
authors.affiliation: Applied Neuroscience Research Group, Central European Institute of Technology, Masaryk University (CEITEC MU), Brno, Czech Republic.|First Department of Neurology, St. Anne's University Hospital and School of Medicine, Masaryk University, Brno, Czech Republic.
authors.forename: Lubomira
authors.initials: L
authors.lastname: Anderkova
authors.affiliation: Applied Neuroscience Research Group, Central European Institute of Technology, Masaryk University (CEITEC MU), Brno, Czech Republic.|First Department of Neurology, St. Anne's University Hospital and School of Medicine, Masaryk University, Brno, Czech Republic.
authors.forename: Ilona
authors.initials: I
authors.lastname: Eliasova
authors.affiliation: Applied Neuroscience Research Group, Central European Institute of Technology, Masaryk University (CEITEC MU), Brno, Czech Republic.|First Department of Neurology, St. Anne's University Hospital and School of Medicine, Masaryk University, Brno, Czech Republic.
authors.forename: Radek
authors.initials: R
authors.lastname: Marecek
authors.affiliation: Institute of Biostatistics and Analyses, Faculty of Medicine, Masaryk University, Brno, Czech Republic.
authors.forename: Eva
authors.initials: E
authors.lastname: Janousova
authors.affiliation: Applied Neuroscience Research Group, Central European Institute of Technology, Masaryk University (CEITEC MU), Brno, Czech Republic.|First Department of Neurology, St. Anne's University Hospital and School of Medicine, Masaryk University, Brno, Czech Republic.
authors.forename: Irena
authors.initials: I
authors.lastname: Rektorova
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications*; D000704:Analysis of Variance; D002540:Cerebral Cortex / Q000502:physiology*; D003072:Cognition Disorders / Q000209:etiology / Q000473:pathology / Q000628:therapy; D005260:Female; D066128:Gray Matter / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D050781:Transcranial Magnetic Stimulation / Q000379:methods*; D016896:Treatment Outcome
keywords: Alzheimer’s disease; brain atrophy; cognitive functions; noninvasive brain stimulation; source-based morphometry