Infarct hemisphere and noninfarcted brain volumes affect locomotor performance following stroke

Abstract

Objective: Brain damage within the right middle cerebral artery (MCA) territory is particularly disruptive to mediolateral postural stabilization. The objective of this cross-sectional study was to test the hypothesis that chronic right MCA infarcts (as compared to left) are associated with slower and more bilaterally asymmetrical gait. We further hypothesized that in those with chronic right MCA infarct, locomotor performance is more dependent on gray matter (GM) volumes within noninfarcted regions of the brain that are involved in motor control yet lie outside of the MCA territory.Methods: Gait speed was assessed in 19 subjects with right MCA infarct, 20 with left MCA infarct, and 108 controls. Bilateral plantar pressure and temporal symmetry ratios were calculated in a subset of the cohort. GM volumes within 5 regions outside of the MCA territory (superior parietal lobe, precuneus, caudate, putamen, and cerebellum) were quantified from anatomic MRIs.Results: Right and left infarct groups had similar poststroke duration (7.6 6 6.0 years), infarct size, and functional independence. The right infarct group demonstrated slower gait speed and greater asymmetry compared to the left infarct group and controls (p , 0.05). In the right infarct group only, those with larger GM volumes within the cerebellum (r 2 5 0.32, p 5 0.02) and caudate (r 2 5 0.56, p , 0.001) exhibited faster gait speed.Conclusion: Individuals with chronic lesions within the right MCA territory, as compared to the left MCA territory, exhibit slower, more asymmetrical gait. For these individuals, larger GM volumes within regions outside of the infarcted vascular territory may help preserve locomotor control. Although approximately two-thirds of stroke survivors regain the ability to walk, 1 many present with diminished locomotor performance characterized by slow walking speed and bilaterally asymmetrical walking patterns. 2,3 Lesions within the right hemisphere of the brain, as compared to the left, appear to be more disruptive to both gait and postural control.4-9 More specifically, lesions within the right middle cerebral artery (MCA) territory are particularly disturbing to both the sense of postural verticality and the ability to stabilize the body in the frontal plane. 8,[10][11][12][13] Recent studies, however, have also indicated that the complex motor control system can compensate for impairment to one or more elements of the system by placing increased reliance on remaining intact elements.14 As such, the extent of residual gait abnormality following an infarct may be dependent on not only infarct hemisphere but also on the integrity of noninfarcted brain regions.The objectives of the study were to investigate the effects of infarct hemisphere, as well as gray matter (GM) volumes within regions outside of the infarcted vascular territory, on locomotor performance in individuals with chronic MCA infarcts. We hypothesized that individuals with

Stroke Lesion Impact on Lower Limb Function

“…The above VLSM studies shed light on the functional neuroanatomy of different gait parameters and HLL motor function ( Miyai et al, 2000 ; Jayaram et al, 2012 ; Kaczmarczyk et al, 2012 ; Chen et al, 2014 ; Nadeau et al, 2016 ). Damage to the corticospinal tract, basal ganglia and adjacent structures was shown to affect both HLL motor function (impairment level) and walking capacity (activity level).…”

“…The effects of lesion characteristics on HLL movement quality and walking capacity were reported in several studies. However, in many of these studies ( Miyai et al, 2000 ; Jayaram et al, 2012 ; Kaczmarczyk et al, 2012 ; Chen et al, 2014 ) lesion location was not determined in a voxel-based manner, producing methodological limitations due to gross parcellation of anatomical templates (e.g., Nadeau et al, 2016 ), use of a restricted set of regions of interest (e.g., Jayaram et al, 2012 ), or use of statistical procedures precluding direct inference of structure-function relationships (e.g., Kaczmarczyk et al, 2012 ).…”

Ipsilateral hippocampal atrophy is associated with long‐term memory dysfunction after ischemic stroke in young adults

“…Furthermore, apart from these functional changes, atrophy of nonischemic remote brain regions, presumably due to neuropathological consequences of ischemic stroke, has been observed [Chen et al, 2014;Xie et al, 2011;Zhang et al, 2012].…”

“…Infarctions located anywhere in the brain can induce widespread effects causing disruption of functional networks of the cortical regions [Snaphaan et al, 2009;Tuladhar et al, 2013]. Furthermore, apart from these functional changes, atrophy of nonischemic remote brain regions, presumably due to neuropathological consequences of ischemic stroke, has been observed [Chen et al, 2014;Xie et al, 2011;Zhang et al, 2012].…”

Central vestibular disorder due to ischemic injury on the parieto-insular vestibular cortex in patients with middle cerebral artery territory infarction

“…[ 5 , 6 ] Patients with MCA territory infarction may reveal deficits in posture control and balance. [ 7 – 9 ]…”