title: Acute deterioration of a Chiari I malformation: an uncommon neurosurgical emergency.
abstract: OBJECTIVE
  Report and discuss acute neurological deterioration of Chiari I malformation (CMI), surgical treatment and timing, clinical outcome and literature review.
  
  
  METHODS
  We report a recent case of a 15-year-old girl admitted for an acute neurological deterioration caused by an undiagnosed hindbrain herniation that required an urgent foramen magnum decompression and external ventricular drainage insertion. Moreover, we report and discuss the literature. To the authors' knowledge, this is only the third paediatric patient identified in this setting to be treated for an acute neurological deterioration due to a previous asymptomatic hindbrain herniation. The patient made an uncomplicated recovery and was discharged home on the seventh postoperative day and has remained well at review.
  
  
  CONCLUSIONS
  Acute deterioration of CMI in completely asymptomatic patients in absence of concomitant pathological findings is rarely reported in the literature, and exceptional in children.
  
  
  CONCLUSIONS
  CMI is typically treated electively, but as this case illustrates, it can present with rapidly deteriorating neurological signs. Symptoms usually respond well to surgical intervention with rapid improvement.
authors.affiliation: Department of Paediatric Neurosurgery, Birmingham Children's Hospital, Steelhouse Lane, B4 6NH, Birmingham, UK. benedettaludovica@virgilio.it
authors.forename: Benedetta Ludovica
authors.initials: BL
authors.lastname: Pettorini
authors.forename: Anna
authors.initials: A
authors.lastname: Gao
authors.forename: Desiderio
authors.initials: D
authors.lastname: Rodrigues
mesh_terms: D000293:Adolescent; D001139:Arnold-Chiari Malformation / Q000000981:diagnostic imaging* / Q000601:surgery*; D019299:Decompression, Surgical / Q000379:methods*; D004638:Emergency Treatment / Q000379:methods*; D004677:Encephalocele / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006801:Humans; D011859:Radiography; D012249:Rhombencephalon / Q000000981:diagnostic imaging / Q000601:surgery