title: P50: A candidate ERP biomarker of prodromal Alzheimer's disease.
abstract: BACKGROUND
  Reductions of cerebrospinal fluid (CSF) amyloid-beta (Aβ42) and elevated phosphorylated-tau (p-Tau) reflect in vivo Alzheimer's disease (AD) pathology and show utility in predicting conversion from mild cognitive impairment (MCI) to dementia. We investigated the P50 event-related potential component as a noninvasive biomarker of AD pathology in non-demented elderly.
  
  
  METHODS
  36 MCI patients were stratified into amyloid positive (MCI-AD, n=17) and negative (MCI-Other, n=19) groups using CSF levels of Aβ42. All amyloid positive patients were also p-Tau positive. P50s were elicited with an auditory oddball paradigm.
  
  
  RESULTS
  MCI-AD patients yielded larger P50s than MCI-Other. The best amyloid-status predictor model showed 94.7% sensitivity, 94.1% specificity and 94.4% total accuracy.
  
  
  CONCLUSIONS
  P50 predicted amyloid status in MCI patients, thereby showing a relationship with AD pathology versus MCI from another etiology. The P50 may have clinical utility for inexpensive pre-screening and assessment of Alzheimer's pathology.
authors.affiliation: Department of Psychology, Drexel University, Stratton Hall, 3141 Chestnut Street, Philadelphia, PA 19104, USA. Electronic address: Deborah.Green4@va.gov.
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Green
authors.affiliation: Volen National Center for Complex Systems, Brandeis University, 145 South Street, Waltham, MA 02453, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Payne
authors.affiliation: Department of Electrical and Computer Engineering, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028, USA.
authors.forename: Robi
authors.initials: R
authors.lastname: Polikar
authors.affiliation: Department of Neuropsychiatry, University of Pennsylvania, 10(th) floor, Gates Building, 3401 Spruce Street, Philadelphia, PA 19104, USA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Moberg
authors.affiliation: Department of Neurology, University of Pennsylvania, Ralston House, 3615 Chestnut Street, Philadelphia, PA 19104, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Wolk
authors.affiliation: Department of Psychology, Drexel University, Stratton Hall, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
authors.forename: John
authors.initials: J
authors.lastname: Kounios
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid / Q000503:physiopathology*; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid; D015415:Biomarkers; D060825:Cognitive Dysfunction / Q000134:cerebrospinal fluid / Q000503:physiopathology; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000134:cerebrospinal fluid; D062706:Prodromal Symptoms; D011930:Reaction Time / Q000502:physiology; D018709:Statistics, Nonparametric
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42)
keywords: Alzheimer׳s disease (AD); Amyloid-beta; Auditory oddball paradigm; Cerebrospinal fluid biomarkers; Event-related potential (ERP); P50