Citation

Bunce D, Haynes BI, Lord SR, Gschwind YJ, Kochan NA, Reppermund S, Brodaty H, Sachdev PS, Delbaere K. J. Gerontol. A Biol. Sci. Med. Sci. 2016; 72(6): 832-837.

Affiliation

Falls and Balance Research Group, Neuroscience Research Australia, University of New South Wales, Sydney, Australia.

Copyright

(Copyright © 2016, Gerontological Society of America)

DOI

10.1093/gerona/glw164

PMID

27591431

Abstract

BACKGROUND: Reaction time measures have considerable potential to aid neuropsychological assessment in a variety of health care settings. One such measure, the intraindividual reaction time variability (IIV), is of particular interest as it is thought to reflect neurobiological disturbance. IIV is associated with a variety of age-related neurological disorders, as well as gait impairment and future falls in older adults. However, although persons diagnosed with Mild Cognitive Impairment (MCI) are at high risk of falling, the association between IIV and prospective falls is unknown.

METHODS: We conducted a longitudinal cohort study in cognitively intact (n = 271) and MCI (n = 154) community-dwelling adults aged 70-90 years. IIV was assessed through a variety of measures including simple and choice hand reaction time and choice stepping reaction time tasks (CSRT), the latter administered as a single task and also with a secondary working memory task.

RESULTS: Logistic regression did not show an association between IIV on the hand-held tasks and falls. Greater IIV in both CSRT tasks, however, did significantly increase the risk of future falls. This effect was specific to the MCI group, with a stronger effect in persons exhibiting gait, posture, or physiological impairment.

CONCLUSIONS: The findings suggest that increased stepping IIV may indicate compromised neural circuitry involved in executive function, gait, and posture in persons with MCI increasing their risk of falling. IIV measures have potential to assess neurobiological disturbance underlying physical and cognitive dysfunction in old age, and aid fall risk assessment and routine care in community and health care settings.

© The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Language: en