1Department of Neurology, College of Medicine, Seoul National University, Seoul, Korea
2Department of Neurology, Seoul National University Hospital, Seoul, Korea
3Department of Neurology, Seoul National University Bundang Hospital, Seongnam, Korea
4Department of Neurology, CheongShim International Medical Center, Gapyeong, Korea
Copyright © 2017 The Korean Movement Disorder Society
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.