Concentric needle jitter on voluntary activated frontalis in 20 healthy subjects

Authors

  • João A. Kouyoumdjian MD, PhD,

    Corresponding author
    • Faculdade de Medicina de São José do Rio Preto (FAMERP), Department of Neurological Sciences, São José do Rio Preto, São Paulo, Brazil
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  • Erik V. Stålberg MD, PhD

    1. Department of Clinical Neurophysiology, University Hospital, Institute of Neuroscience Uppsala University, Uppsala, Sweden
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Faculdade de Medicina de São José do Rio Preto, Rua Luiz Antônio da Silveira 1661, 15025-020 São José do Rio Preto, São Paulo, Brazil. E-mail: jaris@terra.com.br

Abstract

Introduction: Normative data for jitter parameters using a disposable concentric needle have been described in a few studies. Methods: Jitter, expressed as the mean consecutive difference (MCD), was measured in the frontalis muscle in 20 subjects by voluntary contraction. Results: Mean MCD for individual studies (20, Gaussian), all potentials (400, non-Gaussian), and 18th highest value (20, Gaussian) were 19.9 ± 2.9 μs, 19.9 ± 6.6 μs, and 26.9 ± 4.4 μs, respectively. Conclusion: The suggested upper normal limit for mean MCD is 26 μs and for outliers is 36 μs. Muscle Nerve 47:440-442, 2013

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