N Kumar1, P Gupta2, M K Meena3. 1. Department of Neurology, All India Institute of Medical Sciences, Virbhadra Road, Rishikesh, Dehradun, Uttarakhand, India. 2. Department of Microbiology, All India Institute of Medical Sciences, Virbhadra Road, Rishikesh, Dehradun, Uttarakhand, India. 3. Department of General Medicine, All India Institute of Medical Sciences, Virbhadra Road, Rishikesh, Dehradun, Uttarakhand, India.