Frontiers in Integrative Neuroscience (Dec 2014)

Preservation of common rhythmic locomotor control despite weakened supraspinal regulation after stroke

  • Taryn eKlarner,
  • Taryn eKlarner,
  • Taryn eKlarner,
  • Trevor Scott Barss,
  • Trevor Scott Barss,
  • Trevor Scott Barss,
  • Yao eSun,
  • Yao eSun,
  • Yao eSun,
  • Chelsea eKaupp,
  • Chelsea eKaupp,
  • Chelsea eKaupp,
  • E Paul eZehr,
  • E Paul eZehr,
  • E Paul eZehr,
  • E Paul eZehr

DOI
https://doi.org/10.3389/fnint.2014.00095
Journal volume & issue
Vol. 8

Abstract

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The basic pattern of arm and leg movement during rhythmic locomotor tasks is supported by common central neural control from spinal and supraspinal centers in neurologically intact participants. The purpose of this study was to test the hypothesis that following a cerebrovascular accident, shared systems from interlimb cutaneous networks facilitating arm and leg coordination persist across locomotor tasks. Twelve stroke participants (>6 months post CVA) performed arm and leg (A&L) cycling using a stationary ergometer and walking on a motorized treadmill. In both tasks cutaneous reflexes were evoked via surface stimulation of the nerves innervating the dorsum of the hand (superficial radial; SR) and foot (superficial peroneal; SP) of the less affected limbs. Electromyographic (EMG) activity from the tibialis anterior, soleus, flexor carpi radialis, and posterior deltoid were recorded bilaterally with surface electrodes. Full-wave rectified and filtered EMG data were separated into eight equal parts or phases and aligned to begin with maximum knee extension for both walking and A&L cycling. At each phase of movement, background EMG data were quantified as the peak normalized response for each participant and cutaneous reflexes were quantified as the average cumulative reflex over 150 ms following stimulation. In general, background EMG was similar between walking and A&L cycling, seen especially in the distal leg muscles. Cutaneous reflexes were evident and modified in the less and more affected limbs during walking and A&L cycling and similar modulation patterns were observed suggesting activity in related control networks between tasks. After a stroke common neural patterning from conserved subcortical regulation is seen supporting the notion of a common core in locomotor tasks involving arm and leg movement. This has translational implications for rehabilitation where A&L cycling could be usefully applied to improve walking function.

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