title: No difference in paired associative stimulation induced cortical neuroplasticity between patients with mild cognitive impairment and elderly controls.
abstract: OBJECTIVE
  Paired associative stimulation (PAS) is a widely used transcranial magnetic stimulation (TMS) paradigm to induce synaptic long-term potentiation (LTP)-like plasticity in the intact human brain. The PAS effect is reduced in Alzheimer's dementia (AD) but has not yet been assessed in patients with mild cognitive impairment (MCI).
  
  
  METHODS
  PAS was assessed in a group of 24 MCI patients and 24 elderly controls. MCI patients were further stratified by their cognitive profile as well as hippocampal atrophy and Apolipoprotein E (ApoE) genotype.
  
  
  RESULTS
  There was no difference in PAS effects between MCI patients and healthy controls. MCI patients tended to show a higher response rate and an average PAS effect. PAS effects were not correlated with markers of disease severity or ApoE genotype but were more pronounced in individuals with shorter sleep duration and in MCI subjects with higher ratings of subjective alertness.
  
  
  CONCLUSIONS
  Contrary to our initial hypothesis, there was no clear difference in PAS between MCI patients and healthy controls.
  
  
  CONCLUSIONS
  Our results argue against a continuous reduction of LTP-like plasticity along the spectrum of clinical MCI when stratified by MCI-subtype, APOE genotype or hippocampus atrophy.
authors.affiliation: Freiburg Brain Imaging, University Medical Center Freiburg, Freiburg, Germany; Department of Psychiatry and Psychotherapy, University Medical Center Freiburg, Freiburg, Germany; Department of Neurology, University Medical Center Freiburg, Freiburg, Germany. Electronic address: jacob.lahr@uniklinik-freiburg.de.
authors.forename: Jacob
authors.initials: J
authors.lastname: Lahr
authors.affiliation: Freiburg Brain Imaging, University Medical Center Freiburg, Freiburg, Germany; Department of Psychiatry and Psychotherapy, University Medical Center Freiburg, Freiburg, Germany; Department of Neurology, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Jessica
authors.initials: J
authors.lastname: Peter
authors.affiliation: Freiburg Brain Imaging, University Medical Center Freiburg, Freiburg, Germany; Department of Psychiatry and Psychotherapy, University Medical Center Freiburg, Freiburg, Germany; Department of Psychology, Laboratory for Biological and Personality Psychology, University of Freiburg, Freiburg, Germany.
authors.forename: Lora
authors.initials: L
authors.lastname: Minkova
authors.affiliation: Freiburg Brain Imaging, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Eliza
authors.initials: E
authors.lastname: Lauer
authors.affiliation: Department of Neurology, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Janine
authors.initials: J
authors.lastname: Reis
authors.affiliation: Department of Neurology, University Medical Center Freiburg, Freiburg, Germany; Center of Geriatrics and Gerontology Freiburg, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Heimbach
authors.affiliation: Center of Geriatrics and Gerontology Freiburg, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Hüll
authors.affiliation: Department of Psychiatry and Psychotherapy, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Normann
authors.affiliation: Department of Psychiatry and Psychotherapy, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Nissen
authors.affiliation: Freiburg Brain Imaging, University Medical Center Freiburg, Freiburg, Germany; Department of Psychiatry and Psychotherapy, University Medical Center Freiburg, Freiburg, Germany; Department of Neurology, University Medical Center Freiburg, Freiburg, Germany; Center of Geriatrics and Gerontology Freiburg, University Medical Center Freiburg, Freiburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Klöppel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D060825:Cognitive Dysfunction / Q000175:diagnosis / Q000503:physiopathology*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D010153:Paired-Associate Learning / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
keywords: Apolipoprotein E (ApoE); Hippocampal volumetry; LTP-like plasticity; Long-term potentiation (LTP); Mild cognitive impairment (MCI); Neural plasticity; Paired associative stimulation (PAS); Transcranial magnetic stimulation (TMS); Verbal learning