title: Low episodic memory performance in cognitively normal elderly subjects is associated with increased posterior cingulate gray matter N-acetylaspartate: a1H MRSI study at 7 Tesla.
abstract: Low episodic memory performance characterizes elderly subjects at increased risk for Alzheimer's disease (AD) and may reflect neuronal dysfunction within the posterior cingulate cortex and precuneus (PCP) region. To investigate a potential association between cerebral neurometabolism and low episodic memory in the absence of cognitive impairment, tissue-specific magnetic resonance spectroscopic imaging at ultrahigh field strength of 7 Tesla was used to investigate the PCP region in a healthy elderly study population (n = 30, age 70 ± 5.7 years, Mini-Mental State Examination 29.4 ± 4.1). The Verbal Learning and Memory Test (VLMT) was administered as part of a neuropsychological battery for assessment of episodic memory performance. Significant differences between PCP gray and white matter could be observed for glutamate-glutamine (p = 0.001), choline (p = 0.01), and myo-inositol (p = 0.02). Low Verbal Learning and Memory Test performance was associated with high N-acetylaspartate in PCP gray matter (p = 0.01) but not in PCP white matter. Our data suggest that subtle decreases in episodic memory performance in the elderly may be associated with increased levels of N-acetylaspartate as a reflection of increased mitochondrial energy capacity in PCP gray matter.
authors.affiliation: Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Schreiner
authors.affiliation: Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kirchner
authors.affiliation: Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Wyss
authors.affiliation: Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Jiri M G
authors.initials: JMG
authors.lastname: Van Bergen
authors.affiliation: Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Frances C
authors.initials: FC
authors.lastname: Quevenco
authors.affiliation: Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Stefanie C
authors.initials: SC
authors.lastname: Steininger
authors.affiliation: Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
authors.forename: Erica Y
authors.initials: EY
authors.lastname: Griffith
authors.affiliation: Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
authors.forename: Irene
authors.initials: I
authors.lastname: Meier
authors.affiliation: Department of Neuroradiology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Lars
authors.initials: L
authors.lastname: Michels
authors.affiliation: Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Anton F
authors.initials: AF
authors.lastname: Gietl
authors.affiliation: Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Sandra E
authors.initials: SE
authors.lastname: Leh
authors.affiliation: Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
authors.forename: Adam M
authors.initials: AM
authors.lastname: Brickman
authors.affiliation: Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Hock
authors.affiliation: Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Roger M
authors.initials: RM
authors.lastname: Nitsch
authors.affiliation: Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
authors.forename: Klaas P
authors.initials: KP
authors.lastname: Pruessmann
authors.affiliation: Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland; Max Planck Institute for Biological Cybernetics, Tubingen, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Henning
authors.affiliation: Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland; Hospital for Psychogeriatric Medicine, University of Zurich, Zurich, Switzerland. Electronic address: paul.unschuld@uzh.ch.
authors.forename: Paul G
authors.initials: PG
authors.lastname: Unschuld
mesh_terms: D000368:Aged; D000375:Aging / Q000378:metabolism / Q000473:pathology* / Q000502:physiology*; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D004734:Energy Metabolism; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging* / Q000378:metabolism*; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging* / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D061212:Memory, Episodic; D008928:Mitochondria / Q000378:metabolism
chemical_list: D001224:Aspartic Acid; C000179:N-acetylaspartate
keywords: 7 Tesla; Aging; Episodic memory; Human subjects; Magnetic resonance spectroscopic imaging; Posterior cingulate