title: Correlation between papilledema grade and diffusion-weighted magnetic resonance imaging in idiopathic intracranial hypertension.
abstract: BACKGROUND
  To explore the relationship between diffusion-weighted magnetic resonance imaging (DWI) hyperintensity of the optic nerve head (ONH) and papilledema grade in patients with idiopathic intracranial hypertension (IIH).
  
  
  METHODS
  A retrospective chart review was conducted of patients with definitively diagnosed IIH by clinical examination and visual field (VF) analysis who underwent orbital magnetic resonance imaging (MRI) within 4 weeks of diagnosis. A neuroradiologist masked to the diagnosis assessed the results of DWI for each eye independently and graded the signal intensity of the ONH into none, mild, and prominent categories. DWI grading was compared with papilledema grade and visual field mean deviation (VFMD) by Spearman rank correlation analysis and t-tests.
  
  
  RESULTS
  Forty-two patients were included in the study. A statistically significant difference (P = 0.0195) was found between papilledema grade and patients with prominent DWI findings (n = 16; mean papilledema grade 3.75 ± 1.25) vs mild or no ONH hyperintensity (n = 26; mean papilledema grade 2.79 ± 1.24) at the time of initial diagnosis. DWI hyperintensity of the ONH at diagnosis was also found to be significantly correlated with the degree of papilledema at follow-up (ρ = 0.39, P = 0.0183) but not with VFMD.
  
  
  CONCLUSIONS
  We found a significant correlation between the severity of papilledema and ONH hyperintensity on DWI in patients with IIH but not with VF loss or other visual parameters. These findings may offer insight into the pathophysiology of papilledema in IIH and provide a surrogate marker for the presence and severity of papilledema.
authors.affiliation: Department of Ophthalmology and Visual Sciences (DMS, JBH, MOG, GPVS), Washington University, Saint Louis, Missouri; Department of Ophthalmology and Visual Sciences (LVP), Washington University, Saint Louis, Missouri; Department of Radiology (RV, AS), Mallinckrodt Institute of Radiology, Washington University School, Saint Louis, Missouri; and Department of Neurology (GPVS), Washington University, Saint Louis, Missouri.
authors.forename: David M
authors.initials: DM
authors.lastname: Salvay
authors.forename: Leena V
authors.initials: LV
authors.lastname: Padhye
authors.forename: Julie B
authors.initials: JB
authors.lastname: Huecker
authors.forename: Mae O
authors.initials: MO
authors.lastname: Gordon
authors.forename: Ryan
authors.initials: R
authors.lastname: Viets
authors.forename: Aseem
authors.initials: A
authors.lastname: Sharma
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Van Stavern
mesh_terms: D000328:Adult; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000473:pathology*; D010211:Papilledema / Q000150:complications / Q000175:diagnosis*; D011559:Pseudotumor Cerebri / Q000150:complications / Q000175:diagnosis*; D012189:Retrospective Studies; D013223:Statistics as Topic; D014794:Visual Fields / Q000502:physiology; D055815:Young Adult