Kaare Severinsen1, Ulrik Dalgas2, Kristian Overgaard2, Asger R Pedersen3, Niels Ørtenblad4, Caroline Lund5, Johannes K Jakobsen6, Henning Andersen1. 1. Department of Neurology, Aarhus University Hospital, Noerrebrogade 44, 8000, Aarhus C, Denmark. 2. Department of Public Health, Section of Sport Science Aarhus University, Denmark. 3. Hammel Neurorehabilitation and Research Centre, Aarhus University, Denmark. 4. University of Southern Denmark, Department of Sports Science and Clinical Biomechanics, SDU Muscle Research Cluster (SMRC), Odense, Denmark and Swedish Winter Sports Research Centre, Department of Health Sciences Mid Sweden University, Sweden. 5. VIA University College, Campus Aarhus N, Denmark. 6. Department of Neurology, Rigshospitalet, Denmark.
Abstract
INTRODUCTION: Skeletal muscle is changed after stroke, but conflicting data exist concerning muscle morphology and oxidative enzyme capacity. METHODS: In 36 chronic stroke patients bilateral rectus femoris muscle biopsies were analyzed, and fiber type proportions and cross-sectional areas were determined by ATPase histochemistry. Enzymatic concentrations of citrate synthase (CS) and 3-Hydroxyacyl-coenzymeA-dehydrogenase (HAD) were determined using freeze-dried muscle tissue. Findings were correlated with clinical outcomes. RESULTS: In the paretic muscles the mean fiber area was smaller (P = 0.0004), and a lower proportion of type 1 fibers (P = 0.0016) and a higher proportion of type 2X fibers (P = 0.0002) were observed. The paretic muscle had lower CS (P = 0.013) and HAD concentrations (P = 0.037). Mean fiber area correlated with muscle strength (r = 0.43; P = 0.041), and CS concentration correlated with aerobic capacity (r = 0.47; P = 0.01). CONCLUSIONS: In stroke survivors there is a phenotypic shift toward more fatigable muscle fibers with reduced oxidative enzymatic capacity that relates to clinical outcomes.
INTRODUCTION: Skeletal muscle is changed after stroke, but conflicting data exist concerning muscle morphology and oxidative enzyme capacity. METHODS: In 36 chronic strokepatients bilateral rectus femoris muscle biopsies were analyzed, and fiber type proportions and cross-sectional areas were determined by ATPase histochemistry. Enzymatic concentrations of citrate synthase (CS) and 3-Hydroxyacyl-coenzymeA-dehydrogenase (HAD) were determined using freeze-dried muscle tissue. Findings were correlated with clinical outcomes. RESULTS: In the paretic muscles the mean fiber area was smaller (P = 0.0004), and a lower proportion of type 1 fibers (P = 0.0016) and a higher proportion of type 2X fibers (P = 0.0002) were observed. The paretic muscle had lower CS (P = 0.013) and HAD concentrations (P = 0.037). Mean fiber area correlated with muscle strength (r = 0.43; P = 0.041), and CS concentration correlated with aerobic capacity (r = 0.47; P = 0.01). CONCLUSIONS: In stroke survivors there is a phenotypic shift toward more fatigable muscle fibers with reduced oxidative enzymatic capacity that relates to clinical outcomes.
Authors: Beraki Abraha; Arthur R Chaves; Liam P Kelly; Elizabeth M Wallack; Katie P Wadden; Jason McCarthy; Michelle Ploughman Journal: Front Physiol Date: 2018-07-02 Impact factor: 4.566