Format

Send to

Choose Destination
See comment in PubMed Commons below
Gait Posture. 2014;40(1):225-30. doi: 10.1016/j.gaitpost.2014.03.192. Epub 2014 Apr 12.

Higher step length variability indicates lower gray matter integrity of selected regions in older adults.

Author information

1
Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, USA. Electronic address: alr143@pitt.edu.
2
Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, USA.
3
Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, USA.
4
Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, USA.
5
Laboratory of Epidemiology, Demography, and Biometry, Intramural Research Program, National Institute on Aging, Bethesda, USA.
6
Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, USA.
7
Division of Geriatric Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, USA.
8
Department of Psychiatry, University of California, San Francisco, USA.
9
Department of Psychiatry, University of Pittsburgh, USA.

Abstract

Step length variability (SLV) increases with age in those without overt neurologic disease, is higher in neurologic patients, is associated with falls, and predicts dementia. Whether higher SLV in older adults without neurologic disease indicates presence of neurologic abnormalities is unknown. Our objective was to identify whether SLV in older adults without overt disease is associated with findings from multimodal neuroimaging. A well-characterized cohort of 265 adults (79-90 years) was concurrently assessed by gait mat, magnetic resonance imaging with diffusion tensor, and neurological exam. Linear regression models adjusted for gait speed, demographic, health, and functional covariates assessed associations of MRI measures (gray matter volume, white matter hyperintensity volume, mean diffusivity, fractional anisotropy) with SLV. Regional distribution of associations was assessed by sparse partial least squares analyses. Higher SLV (mean: 8.4, SD: 3.3) was significantly associated with older age, slower gait speed, and poorer executive function and also with lower gray matter integrity measured by mean diffusivity (standardized beta=0.16; p=0.02). Associations between SLV and gray matter integrity were strongest for the hippocampus and anterior cingulate gyrus (both β=0.18) as compared to other regions. Associations of SLV with other neuroimaging markers were not significant. Lower integrity of normal-appearing gray matter may underlie higher SLV in older adults. Our results highlighted the hippocampus and anterior cingulate gyrus, regions involved in memory and executive function. These findings support previous research indicating a role for cognitive function in motor control. Higher SLV may indicate focal neuropathology in those without diagnosed neurologic disease.

KEYWORDS:

Aging; Brain; Diffusion tensor imaging; Gait disorders

PMID:
24792638
PMCID:
PMC4071448
DOI:
10.1016/j.gaitpost.2014.03.192
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Support Center