Professor Tan is a senior consultant neurologist and internist who joined Universiti Malaya since 1999 and went on to complete subspecialisation in neurology, stroke and neurosonology with attachments in the United States, Hong Kong and Singapore. He is the immediate past President of the Malaysian Society of Neurosciences, a position he held from 2008 until 2010. He has also published more than 120 publications in international peer-reviewed journals, conference proceedings and chapters in international textbooks. His research interests include clinical trials, neurosonology and stroke in young adults.