title: Magnetic resonance spectroscopy as a predictor of conversion of mild cognitive impairment to dementia.
abstract: OBJECTIVE
  Proton magnetic resonance spectroscopy ((1)H-MRS) is one of the imaging techniques that could be potentially useful for identification of patients with mild cognitive impairment (MCI) who are at increased risk of developing dementia. The aim of the study was to investigate if there is a difference in brain metabolism between stable MCI patients and converters to dementia and if a use of (1)H-MRS can predict the conversion from MCI to dementia.
  
  
  METHODS
  Forty-one amnestic MCI patients and 35 cognitively unimpaired controls were examined by (1)H-MRS (TE - 35 ms) at baseline. Metabolite ratios (NAA/Cr, Cho/Cr, mI/Cr, Glx/Cr, NAA/Cho) were estimated in four different brain regions: posterior cingulate gyrus (PCG), left hippocampus (LH), cortical area of right (RPL) and left parietal lobe (LPL). Participants were followed up for a period of 12 months.
  
  
  RESULTS
  Twelve subjects with MCI progressed to Alzheimer's disease (AD) after one year. Analysis showed that the NAA/Cr ratio in the LH was significantly lower in MCI patients than in controls (p=0.008), but there were no differences in metabolite ratios at baseline between MCI converters and stable subjects. mI/Cr ratio in RPL predicted the conversion to AD with sensitivity 70% and specificity 85% (p<0.0004). Coexistence of diabetes improved prediction, yielding 70% sensitivity and 96% specificity (p<0.0001).
  
  
  CONCLUSIONS
  (1)H-MRS in MCI can be a predictor of cognitive decline and conversion to dementia, especially in MCI patients with coexisting diabetes. Further studies are needed to confirm this finding.
authors.affiliation: Department of Neurology, University Hospital in Katowice, Poland. Electronic address: m.targosz.gajniak@gmail.com.
authors.forename: Magdalena G
authors.initials: MG
authors.lastname: Targosz-Gajniak
authors.forename: Joanna S
authors.initials: JS
authors.lastname: Siuda
authors.forename: Magdalena M
authors.initials: MM
authors.lastname: Wicher
authors.forename: Tomasz J
authors.initials: TJ
authors.lastname: Banasik
authors.forename: Malgorzata A
authors.initials: MA
authors.lastname: Bujak
authors.forename: Aleksandra M
authors.initials: AM
authors.lastname: Augusciak-Duma
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Opala
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001224:Aspartic Acid / Q000378:metabolism; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D002794:Choline / Q000378:metabolism; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000503:physiopathology*; D003401:Creatine / Q000378:metabolism; D003704:Dementia / Q000175:diagnosis* / Q000378:metabolism*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007294:Inositol / Q000378:metabolism; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D011522:Protons
chemical_list: D011522:Protons; D001224:Aspartic Acid; D007294:Inositol; D003401:Creatine; D002794:Choline
keywords: Alzheimer's disease; Brain metabolism; Cognition disorders; Dementia; Magnetic resonance spectroscopy; Mild cognitive impairment