[1] Mt Sinai Med Ctr, Dept Neurol, New York, NY 10029 USA
[2] Prince Wales Hosp, Dept Neurol, Sydney, NSW, Australia
[3] Prince Wales Med Res Inst, Sydney, NSW, Australia
[4] Westmead Hosp, Dept Rehabil Med, Sydney, NSW, Australia
[5] St Josephs Hosp, Dept Rehabil Med, Sydney, NSW, Australia
[6] Prince Henry Hosp, Dept Rehabil Med, Sydney, NSW, Australia