1. Division of Neurology, Department of Internal Medicine, Prince of Songkla University, Hatyai 90110, Songkhla, Thailand
2. Department of Neurology, University Hospitals Birmingham NHS Foundation Trust, Birmingham B15 2GW, UK
3. Metabolic Neurology, Institute of Metabolism and Systems Research, The Medical School, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK
4. Institute of Applied Health Research, University of Birmingham, Birmingham B15 2TT, UK