Quantitative MR analyses of the hippocampus: Unspecific metabolic changes in aging

• Published in: Journal of neurology Vol. 251; no. 11; pp. 1345 - 1353
• Main Authors: SZENTKUTI, Andras, GUDERIAN, Sebastian, SCHILTZ, Kolja, KAUFMANN, Jörn, MÜNTE, Thomas F, HEINZE, Hans-Jochen, DÜZEL, Emrah
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.11.2004; Springer Nature B.V
• Subjects: Adult; Age Factors; Aged; Aging - metabolism; Analysis of Variance; Aspartic Acid - analogs & derivatives; Aspartic Acid - metabolism; Attention - physiology; Biological and medical sciences; Brain Chemistry - physiology; Choline - metabolism; Creatine - metabolism; Development. Senescence. Regeneration. Transplantation; Diffusion Magnetic Resonance Imaging - methods; Diseases of striated muscles. Neuromuscular diseases; Female; Functional Laterality - physiology; Fundamental and applied biological sciences. Psychology; Hippocampus - anatomy & histology; Hippocampus - metabolism; Humans; Image Processing, Computer-Assisted - methods; Learning - physiology; Magnetic Resonance Spectroscopy - methods; Male; Medical sciences; Middle Aged; Neurology; Neuropsychological Tests - statistics & numerical data; Problem Solving - physiology; Reproducibility of Results; Statistics as Topic; Verbal Behavior - physiology; Vertebrates: nervous system and sense organs; Weights and Measures; Nervous system diseases; Senescence; MR-spectroscopy; volumetry; Central nervous system; Diffusion imaging; NMR spectrometry; diffusion weighted imaging; Encephalon; voxel based morphometry; Voxel; aging; Morphometry; Hippocampus; Quantitative analysis
• ISSN: 0340-5354; 1432-1459
• DOI: 10.1007/s00415-004-0540-y

The age-related structural changes of the human hippocampus are not entirely understood. The goal of the present investigation was to understand better the nature of age-related hippocampal changes by a comparative MR-analysis of four complementary aspects of hippocampal integrity: total volume, metabolite concentration, neuron to glial cell ratio and amount of extracellular diffusion space for water. To that end, we applied MR-based methods of manual and computerized (voxel-based morphometry) volumetry, diffusion-weighted imaging and 1H MR spectroscopy to characterize specific age-related hippocampal effects in a group of 22 healthy old adults in comparison with a group of 13 healthy younger adults. Age-related reductions of the hippocampal N-acetyl aspartate to creatine/choline ratio together with only marginal age-related reductions in hippocampal volumes and increases in diffusion parameters suggest that the process of aging affects mainly the metabolic status of the hippocampus with little equivalent age-related changes in hippocampal cell density. The metabolic changes are unspecific as they are not restricted to the hippocampus but equally occur in measures obtained from extrahippocampal temporal lobe regions.