1 Division of Clinical Pharmacology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa.
2 Department of Medicine, Paarl Hospital, Paarl, Western Cape, South Africa.
3 Division of Neurology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa.
4 Division of Radiodiagnosis, Department of Medical Imaging and Clinical Oncology, Cape Town, Western Cape, South Africa.
5 Biostatistics Unit, Division of Epidemiology and Biostatistics, Cape Town, Western Cape, South Africa.
6 Departments of Neurology and Medicine (Infectious Diseases), University of California San Francisco, San Francisco, CA.