Low episodic memory performance in cognitively normal elderly subjects is associated with increased posterior cingulate gray matter N-acetylaspartate: A1 H MRSI Study at 7 Tesla

• Published in: Neurobiology of aging
• Main Authors: Schreiner, S.J, Kirchner, T, Wyss, M, Van Bergen, J.M.G, Quevenco, F.C, Steininger, S.C, Griffith, E.Y, Meier, I, Michels, L, Gietl, A, Leh, S.E, Brickman, A.M, Hock, C, Nitsch, R.M, Pruessmann, K.P, Henning, A, Unschuld, P.G
• Format: Journal Article
• Language: English
• Published: 2016
• Subjects: Internal Medicine; Neurology; Posterior cingulate; Human subjects; Magnetic resonance spectroscopic imaging; Aging; Episodic memory; 7 Tesla
• ISSN: 0197-4580; 1558-1497
• DOI: 10.1016/j.neurobiolaging.2016.08.022

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 region (PCP). To investigate a potential association between cerebral neuro-metabolism and low episodic memory in the absence of cognitive impairment, tissue specific magnetic resonance spectroscopic imaging (MRSI) at ultra-high 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 VLMT 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 NAA as a reflection of increased mitochondrial energy capacity in PCP-gray matter.