[1] Univ Newcastle, Inst Translat & Clin Res, Newcastle Upon Tyne, Tyne & Wear, England
[2] Univ Sydney, Sydney Med Sch, Brain & Nerve Res Ctr, Concord Clin Sch, Sydney, NSW, Australia
[3] Royal Victoria Infirm, Dept Neurophysiol, Newcastle Upon Tyne, Tyne & Wear, England
[4] Royal Victoria Infirm, Dept Neurol, Newcastle Upon Tyne, Tyne & Wear, England