Infarct hemisphere and noninfarcted brain volumes affect locomotor performance following stroke.
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 ± 6.0 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) = 0.32, p = 0.02) and caudate (r(2) = 0.56, p < 0.001) exhibited faster gait speed.


CONCLUSIONS
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.
From the Division of Gerontology (I.H.C., V.N., B.M.), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; Institute for Aging Research (B.M.), Hebrew SeniorLife, Boston; Department of Physical Therapy and Assistive Technology (I.H.C.), National Yang-Ming University, Taipei; and the Center for Dynamical Biomarkers and Translational Medicine (I.H.C., V.N., B.M.), National Central University, Jhongli, Taiwan.
I-Hsuan
IH
Chen
Vera
V
Novak
Brad
B
Manor
D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D005684:Gait / Q000502:physiology; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D008124:Locomotion / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D012189:Retrospective Studies