1Department of Neurology, All India Institute of Medical Sciences, New Delhi, India.
2Department of Neurology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
*Address for correspondence: Dr. Garima Shukla, Associate Professor, Dept. of Neurology, Room # 2, 6th Floor, Neurosciences Center, All India Instt. of Medical Sciences, New Delhi - 29, Phone: +91 11 26593785 Fax: +91 11 26588166, Email: garimashukla@hotmail.com.