title: Postoperative epidural hematoma contributes to delayed upper cord tethering after decompression of Chiari malformation type I.
abstract: BACKGROUND
  Symptomatic arachnoiditis after posterior fossa surgical procedures such as decompression of Chiari malformation is a possible complication. Clinical presentation is generally insidious and delayed by months or years. It causes disturbances in the normal flow of cerebrospinal fluid and enlargement of a syrinx cavity in the upper spinal cord. Surgical de-tethering has favorable results with progressive collapse of the syrinx and relief of the associated symptoms.
  
  
  METHODS
  A 30-year-old male with Chiari malformation type I was treated by performing posterior fossa bone decompression, dura opening and closure with a suturable bovine pericardium dural graft. Postoperative period was uneventful until the fifth day in which the patient suffered intense headache and progressive loose of consciousness caused by an acute posterior fossa epidural hematoma. It was quickly removed with complete clinical recovering. One year later, the patient experienced progressive worsened of his symptoms. Upper spinal cord tethering was diagnosed and a new surgery for debridement was required.
  
  
  CONCLUSIONS
  The epidural hematoma compressing the dural graft against the neural structures contributes to the upper spinal cord tethering and represents a nondescribed cause of postoperative fibrosis, adhesion formation, and subsequent recurrent hindbrain compression.
authors.affiliation: Department of Neurosurgery, Virgen Macarena and Virgen del Rocío University Hospitals, Seville, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: López-González
authors.affiliation: Department of Neurosurgery, La Fe University and Polytechnic Hospital, Valencia, Spain.
authors.forename: Estela
authors.initials: E
authors.lastname: Plaza
authors.affiliation: Department of Neurosurgery, Virgen Macarena and Virgen del Rocío University Hospitals, Seville, Spain.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Márquez-Rivas
keywords: Arachnoiditis; arnold-chiary malformation; dural graft; posterior fossa; tethering