title: Muscle molecular phenotype after stroke is associated with gait speed.
abstract: The disability of patients after stroke is generally attributed to upper motor neuron defects, but secondary changes in paretic muscle may enhance the disability. We analyzed the molecular phenotype and metabolic profile of the paretic and nonparetic vastus lateralis (VL) and we measured the severity of gait deficit in 13 patients at least 6 months after ischemic stroke. The results showed a significant increase in the proportion of fast myosin heavy chain (MHC, 68 +/- 14%) in the paretic compared to the nonparetic VL (50 +/- 13%). The specific activity of citrate synthase and glyceraldehyde phosphodehydrogenase was not significantly different between the two sides. The proportion of fast MHC was inversely associated with severity of gait deficit indexed by self-selected walking speed in the paretic leg, but not the nonparetic leg. Our findings demonstrate significant and potentially modifiable secondary biologic changes in hemiparetic muscle phenotype that may contribute to the disability of stroke.
authors.affiliation: Departments of Physical Therapy and Rehabilitation Science, University of Maryland School of Medicine, Baltimore, Maryland, USA. pdedeyne@dpyus.jnj.com
authors.forename: Patrick G
authors.initials: PG
authors.lastname: De Deyne
authors.forename: Charlene E
authors.initials: CE
authors.lastname: Hafer-Macko
authors.forename: Frederick M
authors.initials: FM
authors.lastname: Ivey
authors.forename: Alice S
authors.initials: AS
authors.lastname: Ryan
authors.forename: Richard F
authors.initials: RF
authors.lastname: Macko
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000150:complications; D002950:Citrate (si)-Synthase / Q000378:metabolism; D005260:Female; D005684:Gait; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D006429:Hemiplegia / Q000209:etiology* / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology*; D006615:Hip; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism / Q000503:physiopathology*; D018995:Myosin Heavy Chains / Q000378:metabolism; D010641:Phenotype; D020521:Stroke / Q000150:complications* / Q000209:etiology; D013997:Time Factors
chemical_list: D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D002950:Citrate (si)-Synthase; D018995:Myosin Heavy Chains