1. From the Department of Medicine, Faculty of Medical and Health Sciences, The University of Auckland, New Zealand (W.K.D., M.T.M.W., P.A.B.)
2. Department of Neurology (W.K.D., B.L., P.A.B.), Auckland City Hospital, New Zealand.
3. Department of Radiology (J.A.S., S.B., J.R.C., B.M.), Auckland City Hospital, New Zealand.
4. Department of Anaesthesia and Perioperative Medicine (D.C.), Auckland City Hospital, New Zealand.