BACKGROUND AND PURPOSE: Youthful memory performance in older adults may reflect an underlying resilience to the conventional pathways of aging. Subjects having this unusual characteristic have been recently termed “superagers.” This study aimed to explore the significance of imaging biomarkers acquired by ¹H-MRS to characterize superagers and to differentiate them from their normal-aging peers. MATERIALS AND METHODS: Fifty-five patients older than 80 years of age were screened using a detailed neuropsychological protocol, and 25 participants, comprising 12 superagers and 13 age-matched controls, were statistically analyzed. We used state-of-the-art 3T ¹H-MR spectroscopy to quantify 18 neurochemicals in the posterior cingulate cortex of our subjects. All ¹H-MR spectroscopy data were analyzed using LCModel. Results were further processed using 2 approaches to investigate the technique accuracy: 1) comparison of the average concentration of metabolites estimated with Cramer-Rao lower bounds <20%; and 2) calculation and comparison of the weighted means of metabolites9 concentrations. RESULTS: The main finding observed was a higher total N-acetyl aspartate concentration in superagers than in age-matched controls using both approaches (P = .02 and P = .03 for the weighted means), reflecting a positive association of total N-acetyl aspartate with higher cognitive performance. CONCLUSIONS: ¹H-MR spectroscopy emerges as a promising technique to unravel neurochemical mechanisms related to cognitive aging in vivo and providing a brain metabolic signature in superagers. This may contribute to monitoring future interventional therapies to avoid or postpone the pathologic processes of aging.

Summary: Objectives: The aim of this study was to evaluate angle-of-motion values for the forelimb and hindlimb in clinically healthy adult Santa Ines sheep by means of a standard goniometer.Methods: Twenty female Santa Ines sheep, ranging in age between three- to six-yearsold, and weighing 32–45 kg (mean ± standard deviation [SD]: 30.4 ± 3.7) were used. A standard transparent plastic goniometer was used to measure passive maximum flexion, maximum extension, and range-of-motion (ROM) of the shoulder, elbow, carpal, hip, stifle, and tarsal joints in the right and left limbs. The goniometric measurements were done with the sheep awake and in a standing position. The measurements were made in triplicate by two independent investigators.Results: In all evaluated joints, there was no significant difference either between the means of the two sides or between measurements performed by the two investigators. The mean ± SD values of the measurements (degrees) were as follows: 20 ± 1 (flexion), 170 ± 2 (extension), and 150 ± 2 (ROM) for the carpal joint; 34 ± 4 (flexion), 145 ± 6 (extension), and 110 ± 4 (ROM) for the elbow joint; 88 ± 2 (flexion), 144 ± 6 (extension), and 56 ± 5 (ROM) for shoulder joint; 35 ± 4 (flexion), 163 ± 3 (extension), and 129 ± 4 (ROM) for tarsal joint; 46 ± 4 (flexion), 146 ± 6 (extension), and 100 ± 4 (ROM) for the stifle joint; 54 ± 3 (flexion), 143 ± 7 (extension), and 89 ± 5 (ROM) for the hip joint.Clinical significance: The data obtained provide useful and objective information on the joints. More studies are necessary using other sheep breeds.