Myoclonus of peripheral origin: Two case reports

Authors

  • Louise Tyvaert MD,

    1. Department of Neurology and Movement Disorders, Lille University Hospital, Lille Cedex, France
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  • Pierre Krystkowiak MD, PhD,

    Corresponding author
    1. Department of Neurology and Movement Disorders, Lille University Hospital, Lille Cedex, France
    2. Department of Neurology, North Hospital Amiens University, Amiens Cedex, France; 3Department of Clinical Neurophysiology, Lille University Hospital, Lille Cedex, France
    • Department of Neurology, Hôpital Nord, CHU d'Amiens, 80054 Amiens Cedex 1, France
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  • Francois Cassim MD, PhD,

    1. Department of Neurology, North Hospital Amiens University, Amiens Cedex, France; 3Department of Clinical Neurophysiology, Lille University Hospital, Lille Cedex, France
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  • Elise Houdayer PhD,

    1. Department of Neurology, North Hospital Amiens University, Amiens Cedex, France; 3Department of Clinical Neurophysiology, Lille University Hospital, Lille Cedex, France
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  • Alexandre Kreisler MD,

    1. Department of Neurology and Movement Disorders, Lille University Hospital, Lille Cedex, France
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  • Alain Destée MD, PhD,

    1. Department of Neurology and Movement Disorders, Lille University Hospital, Lille Cedex, France
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  • Luc Defebvre MD, PhD

    1. Department of Neurology and Movement Disorders, Lille University Hospital, Lille Cedex, France
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Abstract

The concept of peripheral myoclonus is not yet fully accepted by the medical community because of the difficulty in establishing a cause-and-effect relationship between trauma and subsequent movement disorders. Here, we report two cases of patients suffering from peripheral myoclonus after nerve injury. The first patient experienced myoclonus of the 4th dorsal interosseous muscle several days after trauma to the elbow. The second patient presented myoclonus of the arm stump (combined with phantom-limb pain) 1 year after amputation. In both cases, central nervous system function (spine and brain imaging, somesthetic evoked potentials, EEG back-averaging) was normal. For the second patient, local infiltration of xylocaine and botulinum toxin into the stump scar rapidly stopped myoclonus and pain. Nerve injury induces ephaptic transmission and ectopic excitation. The physiopathological mechanisms of this type of myoclonus involve a peripheral generator that induces central (spinal) generator activity. © 2008 Movement Disorder Society

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