¹Department of Neurology, Gyeongsang National University Hospital, Jinju, Korea
²Department of Neurology, Eulji University Hospital, Eulji University School of Medicine, Daejeon, Korea
³Department of Neurology, Seoul National University School of Medicine, Seoul, Korea
⁴Department of Pathology, Seoul National University School of Medicine, Seoul, Korea
⁵Department of Neurology, Korea University School of Medicine, Seoul, Korea

Corresponding author:  Jung-Joon Sung, Tel: +82-2-2072-2820, Fax: +82-2-3672-7553, 
Email: jjsaint@snu.ac.kr

Received: 27 January 2016   • Accepted: 1 June 2016