title: Sudden deterioration due to intra-tumoral hemorrhage of ependymoma of the fourth ventricle in a child during a flight: a case report.
abstract: BACKGROUND
  To the best of our knowledge, the association between air travel and intra-tumoral hemorrhage in pediatric populations has never been described previously.
  
  
  METHODS
  We report the case of a two-and-a-half-year-old Caucasian, Iranian boy with a hemorrhaging brain tumor. He had a posterior fossa midline mass and severe hydrocephalus. He had been shunted for hydrocephalus four weeks earlier and was subsequently referred to our center for further treatment. The hemorrhage occurred in an infra-tentorial ependymoma, precipitated by an approximately 700-mile air journey at a maximum altitude of 25,000 feet.
  
  
  CONCLUSIONS
  A pre-existing intra-cranial mass lesion diminishes the ability of the brain to accommodate the mild environmental disturbances caused by hypercarbia, increased venous pressure and reduced cerebral blood flow during long air journeys. This is supported by a literature review, based on our current knowledge of physiological changes during air travel.
authors.affiliation: Department of Neurosurgery, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran. nejat@sina.tums.ac.ir.
authors.forename: Ali
authors.initials: A
authors.lastname: Mahdavi
authors.forename: Nima
authors.initials: N
authors.lastname: Baradaran
authors.forename: Farideh
authors.initials: F
authors.lastname: Nejat
authors.forename: Mostafa
authors.initials: M
authors.lastname: El Khashab
authors.forename: Maryam
authors.initials: M
authors.lastname: Monajemzadeh