title: Optic nerve sheath diameter used as ultrasonographic assessment of the incidence of raised intracranial pressure in preeclampsia: a pilot study.
abstract: BACKGROUND
  In some cases of severe preeclampsia/eclampsia, brain imaging displays signs compatible with raised intracranial pressure. We aimed to estimate the incidence of raised intracranial pressure in preeclampsia using ocular ultrasonography.
  
  
  METHODS
  Optic nerve sheath diameter (ONSD) measurements were compared in 26 preeclamptic and 25 healthy pregnant women. For each optic nerve, two measurements were made (transverse plane and sagittal plane) using a 7.5 MHz ultrasound linear probe. Preeclamptic patients were followed-up until postpartum day 7.
  
  
  RESULTS
  Median ONSD values were significantly greater in preeclamptic patients compared with healthy pregnant women at delivery (5.4 mm (95% CI: 5.2, 5.7) vs. 4.5 mm (95% CI: 4.3, 4.8), P < 0.0001). At delivery, 5/26 (19%) of preeclamptic patients had ONSD values above 5.8 mm (value associated in the literature with 95% risk of raised intracranial pressure) whereas none of the healthy pregnant group had such high ONSD values. In the preeclamptic group, ONSD decreased after the third postpartum day. ONSD values at day 7 were not significantly different from those obtained in the normal pregnancy group (P = 0.10).
  
  
  CONCLUSIONS
  In about 20% of preeclamptic patients, ONSD reaches values compatible with intracranial pressure above 20 mmHg. Further work is needed to confirm this incidence and to better understand the diagnostic and therapeutic usefulness of this easy-to-do monitoring technique.
authors.affiliation: Département d'Anesthésie-Réanimation, Hôpital Antoine Béclère, Clamart, France. clement.dubost@hotmail.fr
authors.forename: Clément
authors.initials: C
authors.lastname: Dubost
authors.forename: Agnès
authors.initials: A
authors.lastname: Le Gouez
authors.forename: Viridiana
authors.initials: V
authors.lastname: Jouffroy
authors.forename: Sandrine
authors.initials: S
authors.lastname: Roger-Christoph
authors.forename: Dan
authors.initials: D
authors.lastname: Benhamou
authors.forename: Frédéric J
authors.initials: FJ
authors.lastname: Mercier
authors.forename: Thomas
authors.initials: T
authors.lastname: Geeraerts
mesh_terms: D000328:Adult; D000773:Anesthesia, Obstetrical; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D006801:Humans; D019586:Intracranial Hypertension / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000209:etiology; D007427:Intracranial Pressure / Q000502:physiology*; D009186:Myelin Sheath / Q000000981:diagnostic imaging*; D009900:Optic Nerve / Q000000981:diagnostic imaging*; D010865:Pilot Projects; D049590:Postpartum Period; D011225:Pre-Eclampsia / Q000453:epidemiology / Q000503:physiopathology*; D011247:Pregnancy; D014463:Ultrasonography