title: Longitudinal study of amnesic patients at high risk for Alzheimer's disease: clinical, neuropsychological and magnetic resonance spectroscopy features.
abstract: OBJECTIVE
  To prospectively follow up a group of amnesic patients at risk for Alzheimer's disease (AD), to characterize a group of patients whose features were intermediate between amnesic mild cognitive impairment (aMCI) and probable AD, prodromal AD (Prd-AD), and to investigate if these patients were at higher risk for AD conversion.
  
  
  METHODS
  A total of 109 subjects were assessed by neuropsychological evaluation and by 1H magnetic resonance spectroscopy (1H-MRS): 27 controls, and 16 aMCI, 34 probable AD and 32 Prd-AD patients.
  
  
  RESULTS
  Episodic memory and frontal test scores resulted lower in Prd-AD compared to aMCI patients. Prd-AD patients obtained significantly higher scores than AD ones in language, perception, praxis and frontal functions. Although Prd-AD and AD patients had distinct 1H-MRS features from aMCI ones, there were no 1H-MRS differences between Prd-AD and AD patients. The AD annual conversion rate after 1 year of follow-up for Prd-AD (57.1%) was higher than in aMCI patients (20%; p<0.01). A logistic regression, in which all amnesic patients were treated as a single group, showed that the Visual Memory Test was a significant neuropsychological predictor for AD conversion.
  
  
  CONCLUSIONS
  Prd-AD patients are a clinically distinguishable group, with distinct neuropsychological and 1H-MRS features and a higher conversion rate to probable AD than aMCI patients.
authors.affiliation: Department of Neurology, Alzheimer's Disease and Other Cognitive Disorders Unit, Institute of Neurosciences, Barcelona, Spain.
authors.forename: Lorena
authors.initials: L
authors.lastname: Rami
authors.forename: Beatriz
authors.initials: B
authors.lastname: Gómez-Anson
authors.forename: Raquel
authors.initials: R
authors.lastname: Sanchez-Valle
authors.forename: Beatriz
authors.initials: B
authors.lastname: Bosch
authors.forename: Gemma C
authors.initials: GC
authors.lastname: Monte
authors.forename: Albert
authors.initials: A
authors.lastname: Lladó
authors.forename: José L
authors.initials: JL
authors.lastname: Molinuevo
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D000647:Amnesia / Q000150:complications* / Q000473:pathology; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009483:Neuropsychological Tests; D011446:Prospective Studies; D012016:Reference Values; D012307:Risk Factors