title: High resolution transbulbar sonography in children with suspicion of increased intracranial pressure.
abstract: OBJECTIVE
  To evaluate the accuracy of high resolution transbulbar sonography for the estimation of intracranial pressure (ICP) in children.
  
  
  METHODS
  In children and adolescents with acute neurologic symptoms of various origin, transbulbar sonography was performed. Besides measurement of the optic nerve sheath diameter (ONSD), the ultrastructure of the subarachnoid space of the optic nerve sheath was evaluated. The results of transbulbar sonography were correlated with clinical data based on cross-sectional imaging, ICP measurement, and ophthalmologic examination.
  
  
  RESULTS
  Eighty-one patients (age 3-17.8 years, mean 11.7 years) were included. In 25 children, cross-sectional imaging and ICP measurement revealed increased intracranial pressure. The mean ONSD was 6.85 ± 0.81 mm. Twenty patients (20/25, 80 %) had a microcystic appearance of the subarachnoid space of the optic nerve. In 56 children without evidence of increased intracranial pressure, the mean ONSD was 5.77 ± 0.48 mm. Forty-nine patients (49/56, 87.5 %) had a normal homogenous appearance of the subarachnoid space. The ONSD in children with increased intracranial pressure was significantly higher than in patients without (p < 0.001).
  
  
  CONCLUSIONS
  High resolution transbulbar sonography of the optic nerve is a useful technique for the rapid and non-invasive estimation of intracranial pressure in children. Besides measurement of the optic nerve sheath diameter, evaluation of the ultrastructure of the subarachnoid space of the optic nerve is a helpful parameter.
authors.affiliation: Department of Pediatric Radiology, Staedtisches Klinikum Muenchen, Munich, Germany. steinborn@lrz.tum.de.
authors.forename: Marc
authors.initials: M
authors.lastname: Steinborn
authors.affiliation: Department of Pediatric Radiology, Staedtisches Klinikum Muenchen, Munich, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Friedmann
authors.affiliation: Department for Paediatric and Adolescent Medicine, Schwabing Hospital, Munich, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Makowski
authors.affiliation: Department of Pediatric Radiology, Staedtisches Klinikum Muenchen, Munich, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Hahn
authors.affiliation: Institute for Medical Statistics and Epidemiology, Technical University Munich, Munich, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Hapfelmeier
authors.affiliation: Department for Paediatric and Adolescent Medicine, Schwabing Hospital, Munich, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Juenger
mesh_terms: D000293:Adolescent; D019540:Area Under Curve; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D019586:Intracranial Hypertension / Q000000981:diagnostic imaging*; D007427:Intracranial Pressure / Q000502:physiology; D008297:Male; D009186:Myelin Sheath; D009900:Optic Nerve / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D013346:Subarachnoid Space / Q000000981:diagnostic imaging; D014463:Ultrasonography
keywords: Intracranial pressure; Optic nerve sheath; Sonography