White matter abnormalities and gait disorders in older people

Abstract

White matter signal abnormality (WMSA) on MRI is a common finding in older patients, often interpreted as being normal for age. However, numerous studies have shown a correlation between WMSA and neurological impairment in older people. Most have focused on cognitive decline, but a few found a correlation between WMSA and impaired gait and balance. In this issue of the journal, Wolfson et al. examined the relationship between impaired mobility in older people and the accrual of WMSA in a longitudinal study of 14 subjects who had a baseline and follow up MRI scan performed 20 months later [ [1] Wolfson L. Wei X. Hall C.B. Panzer V. Wakefield D. Benson R.R. et al. Accrual of MRI white matter abnormalities in elderly with normal and impaired mobility. J Neurol Sci. 2005; 232: 23-27 Abstract Full Text Full Text PDF PubMed Scopus (64) Google Scholar ]. They used an automated volumetric measure of WMSA and found a significant increase in the volume of WMSA in the group with impaired mobility compared to subjects without impaired mobility. Two prior longitudinal studies of WMSA also found that a greater burden of WMSA at baseline is associated with greater progression of WMSA on follow up [ 2 Schmidt R. Fazekas F. Kapeller P. Schmidt H. Hartung H.P. MRI white matter hyperintensities: three-year follow-up of the Austrian Stroke Prevention Study. Neurology. 1999; 53: 132-139 Crossref PubMed Google Scholar , 3 Whitman G.T. Tang Y. Lin A. Baloh R.W. A prospective study of cerebral white matter abnormalities in older people with gait dysfunction. Neurology. 2001; 57: 990-994 Crossref PubMed Scopus (233) Google Scholar ]. A key question is whether the increase in volume of WMSA is the cause of the impaired mobility, or simply a surrogate marker of some other processes that is responsible for the impaired mobility. Gait and balance measurements in their small subgroup with impaired mobility did not show a significant change over the brief period of follow up. As they point out, further studies following larger groups of patients over longer periods of time are needed to answer this question. Accrual of MRI white matter abnormalities in elderly with normal and impaired mobilityJournal of the Neurological SciencesVol. 232Issues 1-2PreviewWhite matter signal abnormality (WMSA) is often present in the MRIs of older persons with mobility impairment. We examined the relationship between impaired mobility and the progressive accrual of WMSA. Mobility was assessed with the Short Physical Performance Battery (SPPB) and quantitative measures of gait and balance. Fourteen subjects had baseline and follow-up MRI scans performed 20 months apart. WMSA was detected and quantified using automated computer algorithms. In the control subjects, WMSA volume increased by 0.02±0.05% ICCV (percent intracranial cavity volume)/year while the WMSA of mobility impaired subjects increased five-times faster (0.10±0.10 ICCV/year, p=0.03). Full-Text PDF