1980 - 1983 Instructor in Neurology at University of Illinois, Chicago, USA
1983 - 1987 Medical Officer at National Institute of Neurological Diseases, Washington, USA
1989 - 1999 Director at Centre for Ageing Research, New Delhi
1989 - 1999 Adjunct Assisstant Professor at University of Pittsburg, USA
2000 - 2013 Regional Adviser, Neurosciences at World Health Organization, New Delhi
2013 - 2015 Additional Director & Head at Dept of Neurology, Fortis Hospital, Vasant Kunj