title: Brain metabolism in Alzheimer disease and vascular dementia assessed by in vivo proton magnetic resonance spectroscopy.
abstract: Proton magnetic resonance spectroscopy (MRS) allows the assessment of various cerebral metabolites non-invasively in vivo. Among 1H MRS-detectable metabolites, N-acetyl-aspartate and N-acetyl-aspartyl-glutamate (tNAA), trimethylamines (TMA), creatine and creatine phosphate (tCr), inositol (Ins) and glutamate (Gla) are of particular interest, since these moieties can be assigned to specific neuronal and glial metabolic pathways, membrane constituents, and energy metabolism. In this study on 94 subjects from a memory clinic population, 1H MRS results (single voxel STEAM: TE 20 ms, TR 1500 ms) on the above metabolites were assessed for five different brain regions in probable vascular dementia (VD), probable Alzheimer's disease (AD), and age-matched healthy controls. In both VD and AD, ratios of tNAA/tCr were decreased, which may be attributed to neuronal atrophy and loss, and Ins/tCr-ratios were increased indicating either enhanced gliosis or alteration of the cerebral inositol metabolism. However, the topographical distribution of the metabolic alterations in both diseases differed, revealing a temporoparietal pattern for AD and a global, subcortically pronounced pattern for VD. Furthermore, patients suffering from vascular dementia (VD) had remarkably enhanced TMA/tCr ratios, potentially due to ongoing degradation of myelin. Thus, the metabolic alterations obtained by 1H MRS in vivo allow insights into the pathophysiology of the different dementias and may be useful for diagnostic classification.
authors.affiliation: Institute of Neuroradiology, Johann W. Goethe University, Schleusenweg 2-16, Frankfurt/Main 60590, Germany. shermingh@aol.de
authors.forename: Sebastian
authors.initials: S
authors.lastname: Herminghaus
authors.forename: Lutz
authors.initials: L
authors.lastname: Frölich
authors.forename: Corrina
authors.initials: C
authors.lastname: Gorriz
authors.forename: Ullrich
authors.initials: U
authors.lastname: Pilatus
authors.forename: Thomas
authors.initials: T
authors.lastname: Dierks
authors.forename: Hans-Jörg
authors.initials: HJ
authors.lastname: Wittsack
authors.forename: Heinrich
authors.initials: H
authors.lastname: Lanfermann
authors.forename: Konrad
authors.initials: K
authors.lastname: Maurer
authors.forename: Friedhelm E
authors.initials: FE
authors.lastname: Zanella
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000378:metabolism*; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000378:metabolism*; D015140:Dementia, Vascular / Q000175:diagnosis* / Q000378:metabolism*; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D007294:Inositol / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D009415:Nerve Net / Q000378:metabolism; D009457:Neuroglia / Q000378:metabolism / Q000473:pathology; D009474:Neurons / Q000473:pathology; D011522:Protons
chemical_list: D011522:Protons; D018698:Glutamic Acid; D007294:Inositol