[1] Bankstown Lidcombe Hospital, Dept Aged Care & Rehabil, Bankstown, NSW, Australia
[2] Univ New S Wales, Fac Med, S Western Sydney Clin Sch, Sydney, NSW, Australia
[3] Liverpool Hosp, Dept Neurophysiol, Liverpool, Merseyside, England
[4] St George Hosp, Dept Neurol & Neurophysiol, Kogarah, NSW, Australia