Abstract for presentation at Australian and New Zealand Association of Neurologists Annual Scientific Meeting 2008

Electrophysiological Correlation of Beneficial Postural Manoeuvres in Orthostatic Tremor

  • Dr Robert Wilcox, Department of Neurology, Royal Brisbane and Women's Hospital, Australia
  • Dr John O'Sullivan, Department of Neurology, Royal Brisbane and Women's Hospital, Australia
  • Prof Peter Silburn, Department of Neurology, Royal Brisbane and Women's Hospital, Australia
  • Mr Michael Cole, School of Human Movement Studies, Queensland University of Technology, Australia
  • Prof Stephen Morrison, Old Dominion University, Norfolk, United States
  • Dr Graham Kerr, School of Human Movement Studies, Queensland University of Technology, Australia

    • Objectives: Orthostatic tremor (OT) is uncommon and is characterised by its fast 14-18 Hz frequency with high bilateral intermuscular coherence. OT occurs predominantly in the legs on standing, associated with often disabling unsteadiness that can usually be aborted by walking, sitting and lying. We have observed patients whose tremor and symptoms reduce when they change their standing posture. We aimed to confirm this finding with tremor analysis.
    Methods: Four patients with primary OT were studied including one studied both on and off gabapentin treatment. Patients were studied with surface EMG and accelerometry standing normally and with two postural manoeuvres; bent knees and locked knees. Tremor amplitude, frequency and coherence were analysed.
    Results: Tremor amplitude reduced during the postural manoeuvres and on gabapentin treatment. The electrophysiological changes correlated with relief of unsteadiness.
    Conclusion: Postural manoeuvres reduce tremor amplitude and symptoms in OT. Similar findings are seen after gabapentin therapy. Simple postural changes when patients with OT stand provide a clue to diagnosis and an easy means of symptom reduction.

    Conference Organiser - ICMS Pty Ltd