Magnetic resonance spectroscopy, β-amyloid load, and cognition in a population-based sample of cognitively normal older adults
Objective: To determine the relationship between proton magnetic resonance spectroscopy (1H MRS) metabolites and β-amyloid (Aβ) load and the effects of Aβ load on the association between 1H MRS metabolites and cognitive function in cognitively normal older adults. Methods: We studied 311 cognitively normal older adults who participated in the populationbased Mayo Clinic Study of Aging from January 2009 through September 2010. Participants underwent 11C-Pittsburgh compound B (PiB) PET, 1H MRS from the posterior cingulate gyri, and neuropsychometric testing to assess memory, attention/executive, language, and visual-spatial domain functions within 6 months. Partial Spearman rank order correlations were adjusted for age, sex, and education. Results: Higher PiB retention was associated with abnormal elevations in myoinositol (mI)/creatine (Cr) (partial rs = 0.17; p = 0.003) and choline (Cho)/Cr (partial rs = 0.13; p = 0.022) ratios. Higher Cho/Cr was associated with worse performance on Auditory Verbal Learning Test Delayed Recall (partial rs = -0.12; p = 0.04), Trail Making Test Part B (partial rs = 0.12; p = 0.04), Wechsler Adult Intelligence Scale-Revised (WAIS-R) Digit Symbol (partial r s = -0.18; p < 0.01), and WAIS-R Block Design (partial r s=-0.12; p = 0.03). Associations between 1H MRS metabolites and cognitive function were not different among participants with high vs low PiB retention. Conclusion: In cognitively normal older adults, the 1H MRS metabolite ratios mI/Cr and Cho/Cr are associated with the preclinical pathologic processes in the Alzheimer disease cascade. Higher Cho/Cr is associated with worse performance on domain-specific cognitive tests independent of Aβ load, suggesting that Cho/Cr elevation may also be dependent on other preclinical dementia pathologies characterized by Cho/Cr elevation such as Lewy body or ischemic vascular disease in addition to Aβ load. © 2011 by AAN Enterprises, Inc.
Digital Object Identifier (DOI)
Kantarci, K.; Lowe, V.; Przybelski, S. A.; Senjem, M. L.; Weigand, S. D.; Ivnik, R. J.; Roberts, R.; Geda, Y. E.; Boeve, B. F.; Knopman, D. S.; Petersen, R. C.; and Jack, C. R., "Magnetic resonance spectroscopy, β-amyloid load, and cognition in a population-based sample of cognitively normal older adults" (2011). Neurology Articles. 419.