title: 1H-MR spectroscopy metabolite levels correlate with executive function in vascular cognitive impairment.
abstract: BACKGROUND
  White matter hyperintensities (WMHs) are associated with vascular cognitive impairment (VCI) but fail to correlate with neuropsychological measures. As proton MR spectroscopy ((1)H-MRS) can identify ischaemic tissue, we hypothesised that MRS detectable brain metabolites would be superior to WMHs in predicting performance on neuropsychological tests.
  
  
  METHODS
  60 patients with suspected VCI underwent clinical, neuropsychological, MRI and CSF studies. They were diagnosed as having subcortical ischaemic vascular disease (SIVD), multiple infarcts, mixed dementia and leukoaraiosis. We measured brain metabolites in a white matter region above the lateral ventricles with (1)H-MRS and WMH volume in this region and throughout the brain.
  
  
  RESULTS
  We found a significant correlation between both total creatine (Cr) and N-acetylaspartyl compounds (NAA) and standardised neuropsychological test scores. Cr levels in white matter correlated significantly with executive function (p=0.001), attention (p=0.03) and overall T score (p=0.007). When lesion volume was added as a covariate, NAA also showed a significant correlation with executive function (p=0.003) and overall T score (p=0.015). Furthermore, while metabolite levels also correlated with total white matter lesion volume, adjusting the Cr levels for lesion volume did not diminish the strength of the association between Cr levels and neuropsychological scores. The lowest metabolite levels and neuropsychological scores were found in the SIVD group. Finally, lesion volume alone did not correlate significantly with any neuropsychological test score.
  
  
  CONCLUSIONS
  These results suggest that estimates of neurometabolite levels provide additional and useful information concerning cognitive function in VCI not obtainable by measurements of lesion load.
authors: Department of Neurology, University of New Mexico Health Sciences Center, Albuquerque, NM 87131-0001, USA.
authors: Charles
authors: C
authors: Gasparovic
authors: Jillian
authors: J
authors: Prestopnik
authors: Jeffrey
authors: J
authors: Thompson
authors: Saeid
authors: S
authors: Taheri
authors: Branko
authors: B
authors: Huisa
authors: Ronald
authors: R
authors: Schrader
authors: John C
authors: JC
authors: Adair
authors: Gary A
authors: GA
authors: Rosenberg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000209:etiology / Q000523:psychology; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002545:Brain Ischemia / Q000523:psychology; D002794:Choline / Q000097:blood; D003072:Cognition Disorders / Q000209:etiology / Q000523:psychology; D003401:Creatine / Q000097:blood; D003627:Data Interpretation, Statistical; D015140:Dementia, Vascular / Q000378:metabolism* / Q000473:pathology / Q000523:psychology*; D056344:Executive Function; D005260:Female; D006801:Humans; D049292:Leukoaraiosis / Q000209:etiology; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D012044:Regression Analysis
chemical_list: D015415:Biomarkers; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline
keywords: MRI; MRS; Neurochemistry; Neuropsychiatry; Vascular Dementia