Epilepsy, AEDs and Balance Function - A Twin and Sibling Study

  • Dr Sandra Petty, The University of Melbourne, Australia
  • Dr Natalie El Haber, The University of Melbourne, Australia
  • Ms Lynda Paton, The University of Melbourne, Australia
  • A/Prof Terence O'Brien, The University of Melbourne, Australia
  • Ms Kate Lawrence, Epilepsy Research Centre, The University of Melbourne, Australia
  • Prof Samuel Berkovic, Epilepsy Research Centre, The University of Melbourne, Australia
  • Prof Keith Hill, La Trobe University, Australia
  • Prof John Wark, The University of Melbourne, Australia

    • Background:
    Patients with epilepsy taking anti-epileptic drugs (AEDs) have increased incidence of fractures. Despite the well-documented side effect of gait unsteadiness with AED usage, their balance function remains under-investigated.
    Aims:
    To investigate the effect of chronic AED use on falls risk using an AED-discordant twin and sibling matched pair approach. Additionally, to assess these measures in clinically-relevant subgroups: patients taking AED polytherapy, those taking AED for a longer time, and those with a history of falls.
    Methods:
    Validated clinical and laboratory tests of strength, gait and balance were performed, including Chattecx Balance Platform, Lord’s Balance test, KinCom and manual muscle strength testing, computerized gait measurement and clinical tests of gait and balance. AED levels were measured. Paired t-tests were used to calculate mean within pair differences (WPDs).
    Results:
    In 29 AED-discordant pairs (mean age 44.9 years, 59% female, 41% male) studied there were significant mean within pair differences (WPDs) in tests of static and dynamic balance, with the AED user having poorer balance function than the AED-non-user. No difference was seen in lower limb strength or gait measures. Participants taking AED polytherapy, taking AED for longer than median duration, or with history of falls had poorer balance performance. Using multiple regression, increased duration of AED therapy and current polytherapy were independent predictors of poorer balance performance.
    Conclusion:
    Balance performance is impaired in AED users compared to their matched non-user siblings, particularly with AED polytherapy, longer duration usage, or recent falls. These balance deficits may contribute to the increased fracture risk.