About the name of Moyamoya disease In 1950's, several reports on moyamoya disease, which was unknown disease at that time, came out from the neurosurgical institutes using various names. Their names were as follows: Hypoplasia of bilateral carotid arteries (Takeuchi K), spontaneous occlusion of the circle of Willis (Kudo T), moyamoya disease (Suzuki J), cerebral juxta-basal telangiectasia (Sano K�j, cerebral arterial rete (Handa H�j, and abnormal vascular rete at the base of the brain (Nishimoto A). Beside these, there were several nick-names such as Moya-Moya or Chiri-Chiri (-like vascular networks on cerebral angiography). Moya-moya is the Japanese word to describe the smoke of cigarette or to describe the hazy appearance, or unclear idea about something. Finally, the disease is called as moyamoya disease (named by Suzuki J, Tohoku University) and officially named as the spontaneous occlusion of the circle of Willis (named by Kudo T, Keio University). Willis comes from the name of the brain anatomist Thomas Willis (1621-1675). He was born in Wiltshire, England and studied Classics and Medicine in Oxford. He taught Philosophy at Oxford from 1660 to 1665. Then, he moved to London in 1666 and opened the clinic to work as a physician. He published the book on brain anatomy "Anatomy of the brain, with a description of the nerves and their function". In this book, he described the nine pairs of cranial nerves and arteries at the base of the brain. The arteries at the base of the brain forms the vascular circle, which functions as collaterals when one or two large vessels connecting to the circle become(s) occluded. Probably, he had never expected that his name is used for the disease commonly found in Japan.