title: Basilar invagination: Surgical results.
abstract: BACKGROUND
  Basilar invagination (BI) is a congenital craniocervical junction (CCJ) anomaly represented by a prolapsed spine into the skull-base that can result in severe neurological impairment.
  
  
  METHODS
  In this paper, we retrospective evaluate the surgical treatment of 26 patients surgically treated for symptomatic BI. BI was classified according to instability and neural abnormalities findings. Clinical outcome was evaluated using the Nürick grade system.
  
  
  RESULTS
  A total of 26 patients were included in this paper. Their age ranged from 15 to 67 years old (mean 38). Of which, 10 patients were male (38%) and 16 (62%) were female. All patients had some degree of tonsillar herniation, with 25 patients treated with foramen magnum decompression. Nine patients required a craniocervical fixation. Six patients had undergone prior surgery and required a new surgical procedure for progression of neurological symptoms associated with new compression or instability. Most of patients with neurological symptoms secondary to brainstem compression had some improvement during the follow-up. There was mortality in this series, 1 month after surgery, associated with a late removal of the tracheal cannula.
  
  
  CONCLUSIONS
  Management of BI requires can provide improvements in neurological outcomes, but requires analysis of the neural and bony anatomy of the CCJ, as well as occult instability. The complexity and heterogeneous presentation requires attention to occult instability on examination and attention to airway problems secondary to concomitant facial malformations.
authors.affiliation: Department of Neurology, Neurosurgery Division, State University of Campinas (UNICAMP), Campinas, SP, Brazil.
authors.forename: Andrei F
authors.initials: AF
authors.lastname: Joaquim
authors.affiliation: Department of Neurology, Neurosurgery Division, State University of Campinas (UNICAMP), Campinas, SP, Brazil.
authors.forename: Enrico
authors.initials: E
authors.lastname: Ghizoni
authors.affiliation: Department of Neurology, Neurosurgery Division, State University of Campinas (UNICAMP), Campinas, SP, Brazil.
authors.forename: Leonardo A
authors.initials: LA
authors.lastname: Giacomini
authors.affiliation: Department of Neurology, Neurosurgery Division, State University of Campinas (UNICAMP), Campinas, SP, Brazil.
authors.forename: Helder
authors.initials: H
authors.lastname: Tedeschi
authors.affiliation: Department of Orthopaedics, Northwestern University, Chicago, IL, USA.
authors.forename: Alpesh A
authors.initials: AA
authors.lastname: Patel
keywords: Basilar invagination; congenital craniocervical malformation; surgical treatment