title: Atypical features prompting neuroimaging in acute optic neuropathy in adults.
abstract: BACKGROUND
  Acute optic neuropathy due to an intracranial lesion may masquerade as optic neuritis or nonarteritic anterior ischemic optic neuropathy (NAION). We reviewed the records of patients who presented with acute unilateral optic neuropathy that was initially diagnosed as optic neuritis or NAION but who ultimately proved to have an underlying structural lesion.
  
  
  METHODS
  Retrospective observational case series. We reviewed the records of patients with the initial diagnosis of optic neuritis or NAION in whom the diagnosis was changed to an intracranial etiology at four tertiary care neuro-ophthalmology centres between 1995 and 1998.
  
  
  RESULTS
  Eight cases were identified in which atypical features prompted further investigation, including neuroimaging, leading to the diagnosis of an intracranial etiology for the optic neuropathy. Five patients were discovered to have neoplasms (a tuberculum sellae meningioma in two cases, an optic nerve sheath meningioma in two cases and a metastatic lesion in one case), and three patients had intracranial sarcoidosis. Atypical features for optic neuritis included a progressive course, absence of pain, optic atrophy at presentation, lack of significant visual improvement and age over 40 years. For NAION, the atypical features included progressive course, optic atrophy on presentation, absence of vasculopathic risk factors and preceding transient visual loss.
  
  
  CONCLUSIONS
  Clinicians should be aware that patients with intracranial lesions may present with acute optic neuropathy mimicking optic neuritis or NAION and that certain atypical features should warrant consideration for neuroimaging.
authors.affiliation: Department of Ophthalmology, University of Iowa Hospitals and Clinics, Iowa City 52242, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Lee
authors.forename: D J
authors.initials: DJ
authors.lastname: Lin
authors.forename: M
authors.initials: M
authors.lastname: Kaufman
authors.forename: K C
authors.initials: KC
authors.lastname: Golnik
authors.forename: M S
authors.initials: MS
authors.lastname: Vaphiades
authors.forename: E
authors.initials: E
authors.lastname: Eggenberger
mesh_terms: D000208:Acute Disease; D000328:Adult; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009900:Optic Nerve / Q000473:pathology*; D009902:Optic Neuritis / Q000175:diagnosis* / Q000209:etiology; D018917:Optic Neuropathy, Ischemic / Q000175:diagnosis* / Q000209:etiology; D012189:Retrospective Studies