1. Division of Cardiovascular Medicine, Department of Medicine, Kurume University School of Medicine , 67 Asahi-machi, Kurume city, Fukuoka 830-0011 , Japan
2. Department of Neurology, Graduate School of Medical Sciences, Kumamoto University , 1-1-1 Honjo, Chuo-ku, Kumamoto city, Kumamoto 860-8556 , Japan