title: Detection of raised intracranial pressure by ultrasound measurement of optic nerve sheath diameter in African children.
abstract: OBJECTIVE
  To evaluate optic nerve sheath (ONS) ultrasound as a non-invasive method of detecting raised intracranial pressure (ICP) and to establish normal ONS diameter data for African children.
  
  
  METHODS
  Children with acute neurological disease admitted to the Paediatric Department of Queen Elizabeth Central Hospital, Malawi had ultrasound measurements of ONS diameter. Controls were children admitted to the same department with non-neurological disease. The mean of three measurements of the ONS diameter was used for analysis. Children were assessed for clinical signs of raised ICP. Patients had CT brain scans if required for their normal clinical care.
  
  
  RESULTS
  In 14 children with neurological disease and clinical signs suggestive of raised ICP, the mean ONS diameter was 5.4 mm (range 4.3-6.2 mm). Radiological signs on CT scans substantiated the presence of raised ICP in eight (all those scanned). In seven children with neurological disease but no specific signs of raised ICP the mean ONS diameter was 3.6 mm (range 2.8-4.4 mm). None of four of these patients examined by CT scan had signs of elevated ICP. The mean ONS diameter in 30 controls without neurological disease was 3.5 mm (range 2.5-4.1 mm). If 4.2 mm is taken as the upper limit of normal the sensitivity and specificity of this test for elevated ICP is 100% and 86%, respectively.
  
  
  CONCLUSIONS
  ONS ultrasound is an accurate method for detecting raised ICP that can be applied in a broad range of settings. It has the advantages of being a non-invasive, bedside test, which can be repeated multiple times for re-evaluation.
authors.affiliation: St Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK. nbeare@btinternet.com
authors.forename: Nicholas A V
authors.initials: NA
authors.lastname: Beare
authors.forename: Sam
authors.initials: S
authors.lastname: Kampondeni
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Glover
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Molyneux
authors.forename: Terrie E
authors.initials: TE
authors.lastname: Taylor
authors.forename: Simon P
authors.initials: SP
authors.lastname: Harding
authors.forename: Malcolm E
authors.initials: ME
authors.lastname: Molyneux
mesh_terms: D017677:Age Distribution; D016022:Case-Control Studies; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D019586:Intracranial Hypertension / Q000000981:diagnostic imaging*; D008295:Malawi; D008297:Male; D009186:Myelin Sheath / Q000000981:diagnostic imaging*; D009422:Nervous System Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009900:Optic Nerve / Q000000981:diagnostic imaging*; D019095:Point-of-Care Systems; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods; D014463:Ultrasonography