Nadkarni N, Lopez O, Perera S, Studenski S, Snitz B, Ericksen K, Mathis C, Nebes R, Redfern MS, Klunk W; Cerebral amyloid deposition and dual-tasking in cognitively normal, mobility unimpaired older adults; Journals of Gerontology Series A: Biological Sciences and Medical Sciences, vol. 72(3), pp. 431-437, 2017.

Abstract

Background:

We examined relationships between cerebral amyloid-beta (Aβ) and cognitive-gait dual-task performance in 27 cognitively normal, mobility unimpaired elders.

Methods:

We assessed Aβ on Pittsburgh Compound B (PiB)-PET. We measured gait speed separately and while performing working-memory, response-inhibition, motor-sequencing, and phone-dialing tasks. We compared dual-task costs on gait and cognitive performance in high-Aβ (PiB(+)) and low-Aβ (PiB(−)) groups and examined the association between Aβ and dual-task performance decrements.

Results:

PiB(+) (n = 16) were comparable with the PiB(−) (n = 11) individuals on demographics, general cognitive and physical performance, and key brain MRI characteristics. PiB(+) group demonstrated greater dual-task costs on gait speed on all cognitive tasks (p < .05) except on response inhibition. Dual-task costs on cognition were similar between groups. Overall, Aβ was associated with dual-task decrement on gait speed but not on dual-task decrement on cognitive performance.