Delays in auditory-cued step initiation are related to increased volume of white matter hyperintensities in older adults

Abstract

An increased volume of white matter hyperintensities (WMH) on MRI has been associated with mobility impairments in older adults. The objective of this preliminary study was to investigate the relationship between the volume of WMH and delays in auditory-cued step initiation. Eight subjects aged 75-83 y participated. The WMH volume in the corticospinal tracts and anterior thalamic radiations were summed. Subjects performed an auditory-cued stepping task that included two simple reaction time (SRT) trials and three choice reaction time (CRT) trials. SRT trials required subjects to step as quickly as possible with the right foot from a symmetric standing position to a single target position in response to an auditory stimulus. For the CRT trials, subjects stepped as quickly as possible to one of two possible locations, depending on the auditory stimulus. The time from the stimulus onset to the reaction time of the anticipatory postural adjustment (APA RT ) and liftoff (LO) of the right foot was computed for each stimulus. The mean APA RT and LO were greater for the CRT steps compared with the SRT steps to the same location. Increases in WMH were significantly associated with larger APA RT and LO during both SRT and CRT for both target locations. These data suggest that increased volume of WMH is associated with greater central processing time during voluntary step initiation, and highlight a possible mechanism that can help to explain how damage to white matter tracts affects mobility in older adults.

Measurement of brain activation during an upright stepping reaction task using functional near‐infrared spectroscopy

“…Analysis of fNIRS data consisted of four steps: (i) analysis of force‐plate data to identify onset of the steps and infer the amount of cognitive load for the different step task conditions [Sparto et al, ], (ii) analysis of the parametric stepping responses using a fNIRS‐specific general linear model [Abdelnour and Huppert, ; Ye et al, ], (iii) intrasubject registration of the location of the fNIRS sensors via the three‐dimensional Polhemus data [Abdelnour and Huppert, ], and (iv) reconstruction of the group‐level oxy‐ and deoxyhemoglobin images using a random‐effect model [Abdelnour and Huppert, ]. These steps will now be described in detail.…”

“…2). This harness has been used in previous studies and does not interfere with stepping ability [Sparto et al, 2008].…”

A protocol for a randomized clinical trial of interactive video dance: potential for effects on cognitive function

“…The attention domain is also assessed by two subtests that require focused concentration and rapid shifting of attention between presented stimuli. To measure attention deployment and visuo-spatial skills, participants also perform the Useful Field of View test (UFOV) [ 82 ] and Step Reaction Tasks (SRTs) [ 83 ]. The Useful Field of View test is a computer-based measure, where participants are seated in front of a computer screen and must localize a quickly flashed target among a multitude of distractors.…”

Timing paradox of stepping and falls in ageing: not so quick and quick(er) on the trigger

“…Such RT delays are often attributed to age-related changes in sensorimotor speed and central neural processing. In this regard, associations between slowed RT stepping performance and white matter hyperintensities (WMHs) affecting the integrity and function of neural networks linked with sensorimotor processing and cognitive executive processes have been shown (Sparto et al 2008;Zheng et al 2012). With an increased WMH volume, CRT slowing appeared to be mediated through slower cognitive processing and not through reduced sensorimotor functioning (Zheng et al 2012).…”

“…In this regard, associations between slowed RT stepping performance and white matter hyperintensities (WMHs) affecting the integrity and function of neural networks linked with sensorimotor processing and cognitive executive processes have been shown (Sparto et al . ; Zheng et al . ).…”