title: Crossed ataxia: a case report and a diffusion tensor imaging tractography study.
abstract: OBJECTIVE
  Ever since the seminal description of ataxic hemiparesis contralateral to a pontine lesion by Miller-Fisher, the question of why contralesional crossing pontocerebellar fibers do not more frequently produce ipsilesional hemiataxia was raised. The few cases of "quadrataxic hemiparesis" or bilateral leg ataxia remain exceptions.
  
  
  METHODS
  We report an even more unusual variant, namely "crossed ataxia" of the contralesional arm and the ipsilesional leg subsequent to an anteromedial pontine ischemic stroke.
  
  
  CONCLUSIONS
  MRI diffusion tensor imaging tractography shows that caudal contralesional crossing pontocerebellar fibers (those for the leg) travel trough the lesion, whereas more rostral fibers (those for the arm) are spared.
authors.affiliation: Neurology Department, HUG-Geneva University Hospitals, rue Gabrielle-Perret-Gentil 4, 1211 Genève 14, Switzerland. julien.bally@hcuge.ch
authors.forename: Julien
authors.initials: J
authors.lastname: Bally
authors.forename: Pierre
authors.initials: P
authors.lastname: Mégevand
authors.forename: Duy
authors.initials: D
authors.lastname: Nguyen
authors.forename: Theodor
authors.initials: T
authors.lastname: Landis
authors.forename: Cristina
authors.initials: C
authors.lastname: Granziera
mesh_terms: D001259:Ataxia / Q000175:diagnosis* / Q000209:etiology; D002545:Brain Ischemia / Q000150:complications / Q000175:diagnosis; D056324:Diffusion Tensor Imaging / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D011149:Pons / Q000473:pathology*