Get access

Alteration of central motor excitability in a patient with hemimasticatory spasm after treatment with botulinum toxin injections

Authors

  • Pablo Mir MD,

    1. Sobell Department of Movement Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, United Kingdom
    2. Servicio de Neurología, Hospital Universitario Virgen del Rocío, Seville, Spain
    Search for more papers by this author
  • Francesca Gilio MD,

    1. Department of Neurological Sciences, University of Rome La Sapienza, INM Neuromed IRCCS, Pozzilli, IS, Italy
    Search for more papers by this author
  • Mark Edwards MBBS,

    1. Sobell Department of Movement Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, United Kingdom
    Search for more papers by this author
  • Maurizio Inghilleri MD,

    1. Department of Neurological Sciences, University of Rome La Sapienza, INM Neuromed IRCCS, Pozzilli, IS, Italy
    Search for more papers by this author
  • Kailash P. Bhatia MD,

    1. Sobell Department of Movement Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, United Kingdom
    Search for more papers by this author
  • John C. Rothwell PhD,

    1. Sobell Department of Movement Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, United Kingdom
    Search for more papers by this author
  • Niall Quinn MD

    Corresponding author
    1. Sobell Department of Movement Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London, United Kingdom
    • Sobell Department of Movement Neuroscience and Movement Disorders, Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom
    Search for more papers by this author

Abstract

Hemimasticatory spasm (HMS) is a condition characterized by paroxysmal involuntary contraction of masticatory muscles. We performed an electrophysiological investigation of a single patient with HMS to identify any pathophysiological changes associated with the condition. We identified a delayed M wave and jaw jerk on the affected side and an absent masseteric silent period during spasm. Botulinum toxin injections successfully treated the clinical symptoms and resulted in a significant reduction in the excitability of the blink reflex recovery cycle. These data suggest that HMS may be due to ectopic activity in the motor portion of the trigeminal nerve that is capable of inducing changes in the excitability of central reflex pathways. These changes can be altered by successful treatment with botulinum toxin. © 2005 Movement Disorder Society

Get access to the full text of this article

Ancillary