title: Idiopathic orbital inflammation with extensive intra- and extracranial extension presenting as 6th nerve palsy--a case report and literature review.
abstract: BACKGROUND
  To report a case of idiopathic orbital inflammation with extensive extraorbital involvement presenting as 6th nerve palsy.
  
  
  METHODS
  The patient presented with right periorbital pain, headache, and diplopia. Orthoptic examination revealed 6th nerve palsy. Investigations, including imaging (CT, MRI, MRA, chest x-ray), lumbar puncture, and screening blood tests (autoimmune disease and TB), were normal. He was lost to follow-up but presented again with no perception of light in the right eye with almost complete ophthalmoplegia and 3 mm of proptosis four months later.
  
  
  RESULTS
  Repeat imaging showed a poorly defined mass involving the extraocular muscles in the posterior right orbit extending into the cavernous sinus and infratemporal fossa. Histopathologic examination showed a fibro-inflammatory infiltration of lymphocytes, plasma cells, and histiocytes, with widespread collagen deposition. No granulomas, vasculitis, or necrosis were seen. A tuberculosis screen (Mantoux) and lumbar puncture were negative. Idiopathic orbital inflammation (IOI) was diagnosed, and 60 mg of oral prednisolone and 300 mg of isoniazid were commenced. Fourteen months later, the patient remained blind, but ocular motility had returned to normal and no proptosis was evident.
  
  
  CONCLUSIONS
  IOI can present in an atypical fashion and early disease may be undetectable radiologically.
authors.affiliation: Oculoplastic and Orbital Service, Western Eye Hospital, London, UK.
authors.forename: Eugene
authors.initials: E
authors.lastname: Tay
authors.forename: Andrew
authors.initials: A
authors.lastname: Gibson
authors.forename: Neeraj
authors.initials: N
authors.lastname: Chaudhary
authors.forename: Jane
authors.initials: J
authors.lastname: Olver
mesh_terms: D020434:Abducens Nerve Diseases / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D000293:Adolescent; D001766:Blindness / Q000209:etiology; D004172:Diplopia / Q000175:diagnosis / Q000209:etiology; D004359:Drug Therapy, Combination; D006261:Headache / Q000209:etiology; D006801:Humans; D007538:Isoniazid / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D008297:Male; D016727:Orbital Pseudotumor / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D010146:Pain / Q000209:etiology; D011239:Prednisolone / Q000627:therapeutic use; D014057:Tomography, X-Ray Computed
chemical_list: D011239:Prednisolone; D007538:Isoniazid