1. Department of Preventive Medicine and Public Health, Catholic Kwandong University College of Medicine, Gangneung, Korea.
2. Department of Neurology, Seoul St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
3. Department of Neurology, Yongin Severance Hospital, Yonsei University College of Medicine, Yongin, Korea.
4. Department of Neurology, Rehabilitation Institute of Neuromuscular Disease, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.