title: Reply.
authors.affiliation: Department of Neurology, University of Shimane, Shimane, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kimachi
authors.affiliation: Department of Neurology, Mishima Hospital, Niigata, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Yuki
authors.affiliation: Department of Neurology, Dokkyo Medical University, Tochigi, Japan.
authors.forename: Norito
authors.initials: N
authors.lastname: Kokubun
authors.affiliation: Department of Neurology, University of Shimane, Shimane, Japan.
authors.forename: Shuhei
authors.initials: S
authors.lastname: Yamaguchi
authors.affiliation: Department of Neurology, Gloucestershire Royal Hospital, Gloucester, UK.|Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Wakerley