title: An Open-Label Exploratory Study with Memantine: Correlation between Proton Magnetic Resonance Spectroscopy and Cognition in Patients with Mild to Moderate Alzheimer's Disease.
abstract: OBJECTIVE
  To characterize progression of Alzheimer's disease (AD) using proton magnetic resonance spectroscopy ((1)H MRS).
  
  
  METHODS
  Eleven subjects with mild to moderate AD underwent neurocognitive testing and single-voxel (1)H MRS from the precuneus and posterior cingulate region at baseline, after 24 weeks of monotherapy with a cholinesterase inhibitor, and after another 24 weeks of combination therapy with open-label memantine and a cholinesterase inhibitor. Baseline metabolites [N-acetylaspartate (NAA), myo-inositol (mI), choline (Cho), and creatine (Cr)] and their ratios in AD subjects were compared with those of an age-matched control group of 28 cognitively normal subjects.
  
  
  RESULTS
  AD subjects had significantly higher mI/Cr and lower NAA, NAA/Cr, NAA/Cho, and NAA/mI. Baseline Alzheimer's Disease Cooperative Study Activities of Daily Living (ADCS-ADL) scores significantly correlated with NAA/Cr, mI/Cr, and NAA/mI. There was an increase in mI and a decrease in NAA/mI, but no significant change in other metabolites or ratios, or neurocognitive measures, when memantine was added to a cholinesterase inhibitor.
  
  
  CONCLUSIONS
  Metabolite ratios significantly differed between AD and control subjects. Baseline metabolite ratios correlated with function (ADCS-ADL). There was an increase in mI and a decrease in NAA/mI, but no changes in other metabolites, ratios, or cognitive measures, when memantine was added to a cholinesterase inhibitor.
authors.affiliation: The Litwin-Zucker Research Center, The Feinstein Institute for Medical Research, Manhasset, N.Y., USA.
authors.forename: Marc L
authors.initials: ML
authors.lastname: Gordon
authors.forename: Peter B
authors.initials: PB
authors.lastname: Kingsley
authors.forename: Terry E
authors.initials: TE
authors.lastname: Goldberg
authors.forename: Jeremy
authors.initials: J
authors.lastname: Koppel
authors.forename: Erica
authors.initials: E
authors.lastname: Christen
authors.forename: Lynda
authors.initials: L
authors.lastname: Keehlisen
authors.forename: Nina
authors.initials: N
authors.lastname: Kohn
authors.forename: Peter
authors.initials: P
authors.lastname: Davies