title: The relationship between basal cisterns on CT and time-linked intracranial pressure in paediatric head injury.
abstract: OBJECTIVE
  Although intracranial pressure (ICP) monitoring is a cornerstone of care for severe traumatic brain injury (TBI), the indications for ICP monitoring in children are unclear. Often, decisions are based on head computed tomography (CT) scan characteristics. Arguably, the patency of the basal cisterns is the most commonly used of these signs. Although raised ICP is more likely with obliterated basal cisterns, the implications of open cisterns are less clear. We examined the association between the status of perimesencephalic cisterns and time-linked ICP values in paediatric severe TBI.
  
  
  METHODS
  ICP data linked to individual head CT scans were reviewed. Basal cisterns were classified as open or closed by blinded reviewers. For the initial CT scan, we examined ICP values for the first 6 h after monitor insertion. For follow-up scans, we examined ICP values 3 h before and after scanning. Mean ICP and any episode of ICP ≥ 20 mmHg during this period were recorded.
  
  
  RESULTS
  Data from 104 patients were examined. Basal cisterns were patent in 51.72% of scans, effaced in 34.48% and obliterated in 13.79%. Even when cisterns were open, more than 40% of scans had at least one episode of ICP ≥ 20 mmHg, and 14% of scans had a mean ICP ≥ 20 mmHg. The specificity of open cisterns in predicting ICP < 20 mmHg was poor (57.9%). Age-related data were worse.
  
  
  CONCLUSIONS
  Children with severe TBI frequently may have open basal cisterns on head CT despite increased ICP. Open cisterns should not discourage ICP monitoring.
authors.affiliation: Division of Neurosurgery, School of Child and Adolescent Health, Red Cross War Memorial Children's Hospital, University of Cape Town, Cape Town, South Africa.
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Kouvarellis
authors.forename: Ursula K
authors.initials: UK
authors.lastname: Rohlwink
authors.forename: Vishesh
authors.initials: V
authors.lastname: Sood
authors.forename: Devon
authors.initials: D
authors.lastname: Van Breda
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Gowen
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Figaji
mesh_terms: D000293:Adolescent; D001930:Brain Injuries / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D002946:Cisterna Magna / Q000000981:diagnostic imaging*; D005260:Female; D049690:History, Ancient; D006801:Humans; D019586:Intracranial Hypertension / Q000175:diagnosis*; D007427:Intracranial Pressure; D008297:Male; D008991:Monitoring, Physiologic; D014057:Tomography, X-Ray Computed