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: Sebastian Herminghaus, Lutz Frölich, Corrina Gorriz, Ullrich Pilatus, Thomas Dierks, Hans-Jörg Wittsack, Heinrich Lanfermann, Konrad Maurer, Friedhelm E Zanella
• Journal: Psychiatry research (Psychiatry Res) Vol. 123 Issue 3 Pg. 183-90 (Jul 30 2003) ISSN: 0165-1781 [Print] Ireland
• PMID: 12928106 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Protons
• Glutamic Acid
• Inositol

Topics

• Aged
• Alzheimer Disease (diagnosis, metabolism)
• Atrophy (pathology)
• Brain (metabolism)
• Dementia, Vascular (diagnosis, metabolism)
• Energy Metabolism (physiology)
• Female
• Glutamic Acid (metabolism)
• Humans
• Inositol (metabolism)
• Magnetic Resonance Spectroscopy (methods)
• Male
• Nerve Net (metabolism)
• Neuroglia (metabolism, pathology)
• Neurons (pathology)
• Protons