title: Pallidal and caudate volumes correlate with walking function in multiple sclerosis.
abstract: BACKGROUND
  Walking dysfunction is common in multiple sclerosis (MS). The thalamus and basal ganglia seemingly have important associations with walking performance. The contribution of these subcortical gray matter (SGM) structures for walking dysfunction is poorly understood in MS.
  
  
  OBJECTIVE
  This study examined associations among volumes of the thalamus and basal ganglia with walking outcomes in MS.
  
  
  METHODS
  We enrolled 61 MS patients who underwent brain MRI and completed the 6-minute walk (6MW) and timed 25-foot walk (T25FW). Volumes of the thalamus, caudate, putamen, and pallidum as well as whole-brain white matter (WM) and gray matter (GM) were calculated from 3D T1-weighted structural brain images. We examined associations using bivariate correlations (r) and partial correlations (pr) that controlled for age, MS clinical course, and whole-brain WM and GM volumes. We further performed hierarchical linear regression (HLR) for identifying the strongest SGM correlate of walking performance.
  
  
  RESULTS
  The 6MW and T25FW correlated significantly with volumes of the thalamus (r's=.382 & .383), caudate (r's=.388 & .416), pallidum (r's=.457 & .457), and putamen (r's=.258 & .293) in bivariate correlations. The 6MW and T25FW remained significantly correlated with caudate (pr's=.243 & .312) and pallidum (pr's=.321 & .345) volumes in partial correlations. Pallidum volume was the strongest SGM correlate of 6MW (β=.39) and T25FW (β=.40) performance in HLR.
  
  
  CONCLUSIONS
  We provide novel evidence of possible SGM structures, particularly the pallidum and perhaps caudate, as correlates of walking performance in MS.
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, USA. Electronic address: robmotl@illinois.edu.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Motl
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Hubbard
authors.affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, USA.
authors.forename: Niranjana
authors.initials: N
authors.lastname: Sreekumar
authors.affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, USA.
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Wetter
authors.affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, USA.
authors.forename: Bradley P
authors.initials: BP
authors.lastname: Sutton
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, USA.
authors.forename: Lara A
authors.initials: LA
authors.lastname: Pilutti
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, USA.
authors.forename: Jacob J
authors.initials: JJ
authors.lastname: Sosnoff
authors.affiliation: Department of Neurology, University at Buffalo, State University of NY, School of Medicine and Biomedical Sciences, USA.
authors.forename: Ralph H B
authors.initials: RH
authors.lastname: Benedict
mesh_terms: D000328:Adult; D002421:Caudate Nucleus / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005917:Globus Pallidus / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000639:trends; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis* / Q000378:metabolism*; D009929:Organ Size; D016138:Walking / Q000502:physiology*
keywords: Basal ganglia; Imaging; MRI; Multiple sclerosis; Thalamus; Walking