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Challenging Standing Balance Reduces the Asymmetry of Motor Control of Postural Sway Poststroke. Motor Control 2019; 23:327-343. [DOI: 10.1123/mc.2017-0098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Vieira TM, Lemos T, Oliveira LAS, Horsczaruk CHR, Freitas GR, Tovar-Moll F, Rodrigues EC. Postural Muscle Unit Plasticity in Stroke Survivors: Altered Distribution of Gastrocnemius' Action Potentials. Front Neurol 2019; 10:686. [PMID: 31297085 PMCID: PMC6607468 DOI: 10.3389/fneur.2019.00686] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 06/12/2019] [Indexed: 11/13/2022] Open
Abstract
Neuromuscular adaptations are well-reported in stroke survivors. The death of motor neurons and the reinnervation of residual muscle fibers by surviving motor neurons, for example, seem to explain the increased density of muscle units after stroke. It is, however, unknown whether reinnervation takes place locally or extensively within the muscle. Here we combine intramuscular and surface electromyograms (EMGs) to address this issue for medial gastrocnemius (MG); a key postural muscle. While seven stroke survivors stood upright, two intramuscular and 15 surface EMGs were recorded from the paretic and non-paretic gastrocnemius. Surface EMGs were triggered with the firing instants of motor units identified through the decomposition of both intramuscular and surface EMGs. The standard deviation of Gaussian curves fitting the root mean square amplitude distribution of surface potentials was considered to assess differences in the spatial distribution of motor unit action potentials and, thus, in the distribution of muscle units between limbs. The median number of motor units identified per subject in the paretic and non-paretic sides was, respectively, 2 (range: 1–3) and 3 (1–4). Action potentials in the paretic gastrocnemius were represented at a 33% wider skin region when compared to the non-paretic muscle (Mann-Whitney; P = 0.014). Side differences in the representation of motor unit were not associated with differences in subcutaneous thickness (skipped-Spearman r = −0.53; confidence interval for r: −1.00 to 0.63). Current results suggest stroke may lead to the enlargement of the gastrocnemius muscle units recruited during standing. The enlargement of muscle units, as assessed from the skin surface, may constitute a new marker of neuromuscular plasticity following stroke.
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Affiliation(s)
- Taian M Vieira
- Laboratorio di Ingegneria del Sistema Neuromuscolare (LISiN), Dipartimento di Elettronica e Telecomunicazioni, and PoliToBIOMed Lab, Politecnico di Torino, Turin, Italy
| | - Thiago Lemos
- Programa de Pós-Graduação em Ciências da Reabilitação, Centro Universitário Augusto Motta - UNISUAM, Rio de Janeiro, Brazil
| | - Laura A S Oliveira
- Programa de Pós-Graduação em Ciências da Reabilitação, Centro Universitário Augusto Motta - UNISUAM, Rio de Janeiro, Brazil.,Graduação em Fisioterapia, Instituto Federal de Educação, Ciência e Tecnologia - IFRJ, Rio de Janeiro, Brazil
| | - Carlos H R Horsczaruk
- Programa de Pós-Graduação em Ciências da Reabilitação, Centro Universitário Augusto Motta - UNISUAM, Rio de Janeiro, Brazil
| | - Gabriel R Freitas
- Unidade de Conectividade Cerebral, Instituto D'Or de Pesquisa e Ensino - IDOR, Rio de Janeiro, Brazil
| | - Fernanda Tovar-Moll
- Unidade de Conectividade Cerebral, Instituto D'Or de Pesquisa e Ensino - IDOR, Rio de Janeiro, Brazil.,Programa de Pós-Graduação em Ciências Mofológicas, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro - UFRJ, Rio de Janeiro, Brazil
| | - Erika C Rodrigues
- Programa de Pós-Graduação em Ciências da Reabilitação, Centro Universitário Augusto Motta - UNISUAM, Rio de Janeiro, Brazil.,Unidade de Conectividade Cerebral, Instituto D'Or de Pesquisa e Ensino - IDOR, Rio de Janeiro, Brazil
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Piotrkiewicz M, Bawa PNS, Schmied A. Mechanisms underlying firing in healthy and sick human motoneurons. Front Hum Neurosci 2015; 9:174. [PMID: 25870558 PMCID: PMC4378278 DOI: 10.3389/fnhum.2015.00174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 03/12/2015] [Indexed: 11/20/2022] Open
Affiliation(s)
- Maria Piotrkiewicz
- Engineering of Nervous and Muscular System, Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences Warsaw, Poland
| | - Parveen N S Bawa
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University Burnaby, BC, Canada
| | - Annie Schmied
- Centre National de la Recherche Scientifique, Plasticité et Pathophysiologie du Mouvement, Institut de Neuroscience de la Timone, University Aix Marseilles Marseille, France
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