[1] Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum-695 011, Kerala
[2] Department of Medicine, Brigham and Women's Hospital, Boston University School of Medicine, Boston, MA
[3] Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala
[4] Achutha Menon Centre for Health Science Studies, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala
[5] Health Action by People, Kerala
[6] Cardiology Section and Preventive Medicine and Epidemiology, Department of Medicine, Boston University School of Medicine, Boston, MA