title: A Novel Cognitive Stress Test for the Detection of Preclinical Alzheimer Disease: Discriminative Properties and Relation to Amyloid Load.
abstract: To examine the utility of a novel "cognitive stress test" to detect subtle cognitive impairments and amyloid load within the brains of neuropsychologically normal community-dwelling elders.
  
  
  
  Participants diagnosed as cognitively normal (CN), subjective memory impairment (SMI), mild cognitive impairment (MCI), and preclinical mild cognitive impairment (PreMCI) were administered the Loewenstein-Acevedo Scale for Semantic Interference and Learning (LASSI-L), a sensitive test of proactive semantic interference (PSI), retroactive semantic interference, and, uniquely, the ability to recover from the effects of PSI. Ninety-three subjects (31 men and 62 women) were recruited from three academic institutions in a research consortium. A subset of these individuals underwent 18F florbetapir positron emission tomography scanning. Relative percentages of impairment for each diagnostic group on the LASSI-L were calculated by χ(2) and Fisher's exact tests. Spearman's rho was used to examine associations between amyloid load and different cognitive measures.
  
  
  
  LASSI-L deficits were identified among 89% of those with MCI, 47% with PreMCI, 33% with SMI, and 13% classified as CN. CN subjects had no difficulties with recovery from PSI, whereas SMI, preMCI, and MCI participants evidenced deficits in recovery from PSI effects. Among a subgroup of participants with normal scores on traditional neuropsychological tests, the strong associations were between the failure to recover from the effects of PSI and amyloid load in the brain.
  
  
  
  Failure to recover or compensate for the effects of PSI on the LASSI-L distinguishes the LASSI-L from other widely used neuropsychological tests and appears to be sensitive to subtle cognitive impairments and increasing amyloid load.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami and Center of Aging, Miami, FL; Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Miami Beach, FL; Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Gainesville, FL. Electronic address: DLoewenstein@miami.edu.
authors.forename: David A
authors.initials: DA
authors.lastname: Loewenstein
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami and Center of Aging, Miami, FL.
authors.forename: Rosie E
authors.initials: RE
authors.lastname: Curiel
authors.affiliation: Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Miami Beach, FL; Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Gainesville, FL.
authors.forename: Maria T
authors.initials: MT
authors.lastname: Greig
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, Gainesville, FL; Department of Neurology, University of Florida, Gainesville, FL.
authors.forename: Russell M
authors.initials: RM
authors.lastname: Bauer
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami and Center of Aging, Miami, FL.
authors.forename: Marian
authors.initials: M
authors.lastname: Rosado
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, Gainesville, FL; Department of Neurology, University of Florida, Gainesville, FL.
authors.forename: Dawn
authors.initials: D
authors.lastname: Bowers
authors.affiliation: Department of Clinical and Health Psychology, University of Florida, Gainesville, FL; Department of Neurology, University of Florida, Gainesville, FL.
authors.forename: Meredith
authors.initials: M
authors.lastname: Wicklund
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Miller School of Medicine, University of Miami and Center of Aging, Miami, FL.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Crocco
authors.affiliation: Avid Radiopharmaceuticals, Philadelphia, PA.
authors.forename: Michael
authors.initials: M
authors.lastname: Pontecorvo
authors.affiliation: Avid Radiopharmaceuticals, Philadelphia, PA.
authors.forename: Abhinay D
authors.initials: AD
authors.lastname: Joshi
authors.affiliation: Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Miami Beach, FL; Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Gainesville, FL.
authors.forename: Rosemarie
authors.initials: R
authors.lastname: Rodriguez
authors.affiliation: Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Miami Beach, FL; Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Gainesville, FL.
authors.forename: Warren W
authors.initials: WW
authors.lastname: Barker
authors.affiliation: Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Miami Beach, FL; Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Gainesville, FL.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Hidalgo
authors.affiliation: Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Miami Beach, FL; Wien Center for Alzheimer's Disease and Memory Disorders, Mount Sinai Medical Center, Gainesville, FL; Department of Neurology, University of Florida, Gainesville, FL; Department of Neurology, Florida International University, Miami, FL.
authors.forename: Ranjan
authors.initials: R
authors.lastname: Duara
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000523:psychology*; D000682:Amyloid / Q000378:metabolism; D000814:Aniline Compounds; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging / Q000523:psychology*; D005026:Ethylene Glycols; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D057187:Independent Living; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D058225:Plaque, Amyloid / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D062706:Prodromal Symptoms; D013315:Stress, Psychological / Q000523:psychology*
chemical_list: D000682:Amyloid; D000814:Aniline Compounds; D005026:Ethylene Glycols; D005462:Fluorine Radioisotopes; C545186:florbetapir
keywords: LASSI-L; MCI; PreMCI; amyloid; proactive interference recovery