title: [Isolated hemi-ataxia as a sign of mesencephalic lacunar infarction].
abstract: BACKGROUND
  Lesions of the dento-rubro-thalamo-cortical pathway may cause homolateral or contralateral hemiataxia, depending on whether they are found above or below the decussation which occurs at the level of the inferior colliculus. Most mesencephalic infarctions causing hemiataxia also show oculomotor involvement with nuclear or fascicular lesions of the third cranial nerves. This was not seen in the case we report.
  
  
  METHODS
  We describe the case of a diabetic patient with a permanent right appendicular hemiataxia, without oculomotor involvement, caused by a lacunar infarct shown on MR imaging which was situated in the antero-external part of the left superior mesencephalum.
  
  
  CONCLUSIONS
  This case helps to clarify the topography of the thalamic radiations of the mesencephalic calotte, including the decussated superior dento-rubro-thalamic pathway to the red nucleus. Involvement of this, situated in the mesencephalic lateral vascular territory causes contralateral hemiataxia.
authors.affiliation: Servicio de Neurología, Hospital de Conxo (CHUS), Departamento de Medicina de la Universidad de Santiago de Compostela, España. mariasg@meditex.es
authors.forename: M
authors.initials: M
authors.lastname: Arias
authors.forename: I
authors.initials: I
authors.lastname: Requena
authors.forename: C
authors.initials: C
authors.lastname: Lema
authors.forename: I
authors.initials: I
authors.lastname: Pereiro
authors.forename: C
authors.initials: C
authors.lastname: Villalba
authors.forename: C
authors.initials: C
authors.lastname: Iglesias
mesh_terms: D000368:Aged; D001259:Ataxia / Q000175:diagnosis / Q000209:etiology*; D002544:Cerebral Infarction / Q000150:complications* / Q000175:diagnosis; D005158:Facial Paralysis / Q000209:etiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008636:Mesencephalon / Q000473:pathology*