title: [Arnold-Chiari I malformation: three unusual manifestations].
abstract: BACKGROUND
  Arnold-Chiari Syndrome I is a malformation of the cervicomedullary junction, manifesting usually with downbeat nystagmus, palsy of the caudal cerebral nerves, headache, and vertigo.
  
  
  METHODS
  We present three patients with unusual symptomatology.
  
  
  RESULTS
  A two-year-old child with isolated non-ocular torticollis, a 52-year-old male patient, and a 42-year-old female patient, both with gaze-evoked nystagmus, underwent a cerebral MRI examination. The findings of the first two patients were typical for an Arnold-Chiari syndrome. The malformation in the third patient was found only by reviewing the initial MRI.
  
  
  CONCLUSIONS
  Arnold-Chiari malformation may manifest atypically. An important step in the work-up of these patients is to ask the neuroradiologist to include the cervicomedullary junction in his evaluation.
authors.affiliation: Abteilung für Orthoptik und Neuroophthalmologie, Kantonsspital Sankt Gallen, Schweiz.
authors.forename: N
authors.initials: N
authors.lastname: Pellanda
authors.forename: D
authors.initials: D
authors.lastname: Mojon
mesh_terms: D000328:Adult; D001139:Arnold-Chiari Malformation / Q000175:diagnosis* / Q000601:surgery; D001933:Brain Stem / Q000473:pathology; D002531:Cerebellum / Q000473:pathology; D002574:Cervical Vertebrae / Q000473:pathology; D002675:Child, Preschool; D003389:Cranial Nerve Diseases / Q000209:etiology; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013115:Spinal Canal / Q000473:pathology; D014103:Torticollis / Q000209:etiology