title: Children With Arachnoid Cysts Who Sustain Blunt Head Trauma: Injury Mechanisms and Outcomes.
abstract: OBJECTIVE
  Arachnoid cysts are abnormal intracranial fluid collections, and there is concern that these cysts may bleed or rupture following blunt head trauma. Our objective was to determine the risk of cyst-related complications in a cohort of children with arachnoid cysts who were evaluated for head trauma.
  
  
  METHODS
  We analyzed the Pediatric Emergency Care Applied Research Network (PECARN) head trauma public use data set, which was the product of a study that enrolled children with blunt head trauma from June 2004 to September 2006. We identified children with arachnoid cysts on cranial computed tomography (CT) and described the patient demographics, mechanisms of injury, clinical presentations, CT evidence of traumatic brain injury (TBI), and clinical outcomes. Clinically important TBI was defined as TBI leading to: 1) death from TBI, 2) neurosurgical intervention, 3) intubation for > 24 hours for the TBI, or 4) hospitalization for 2 or more nights for the head injury in association with TBI on CT.
  
  
  RESULTS
  Data were available for 43,399 children who sustained blunt head trauma, of whom 15,899 had cranial CT scans obtained and 68 (0.4%) had arachnoid cysts. Falls were the most common mechanisms of injury (47%) and 87% of children had either moderate or severe injury mechanisms. Glasgow Coma Scale (GCS) scores ranged from 6 to 15, with 61 (90%) having GCS scores of 15. Two of the children with arachnoid cysts had TBIs on CT, one of which was clinically important. There were no identified cases of arachnoid cyst-related bleeding or complications.
  
  
  CONCLUSIONS
  In this cohort of 68 children with arachnoid cysts who sustained head trauma, none demonstrated cyst-related bleeding or complications. This suggests the risk of arachnoid cyst-related complications in children following blunt head trauma is low and evaluation should align with existing clinical decision rules.
authors.affiliation: Departments of Emergency Medicine and Pediatrics, University of Michigan, Ann Arbor, MI.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Rogers
authors.affiliation: Departments of Emergency Medicine and Pediatrics, University of California Davis School of Medicine, Sacramento, CA.
authors.forename: Nathan
authors.initials: N
authors.lastname: Kuppermann
authors.affiliation: Oakland University, William Beaumont School of Medicine, Rochester, MI.
authors.forename: Angela E
authors.initials: AE
authors.lastname: Thelen
authors.affiliation: Department of Pediatrics, Nationwide Children's Hospital, Columbus, OH.
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Stanley
authors.affiliation: Department of Neurosurgery, University of Michigan, Ann Arbor, MI.
authors.forename: Cormac O
authors.initials: CO
authors.lastname: Maher
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data; D016080:Arachnoid Cysts / Q000150:complications* / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D004636:Emergency Service, Hospital; D005260:Female; D015600:Glasgow Coma Scale; D016489:Head Injuries, Closed / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D008297:Male; D010372:Pediatrics; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed