title: Isolated Internuclear Ophthalmoplegia After Massive Supratentorial Epidural Hematoma: A Case Report and Review of the Literature.
abstract: BACKGROUND
  Isolated internuclear ophthalmoplegia (INO) after traumatic brain injury (TBI) is rare, with most reported patients having minor head injuries. We report a patient with INO after a massive supratentorial epidural hematoma. We review the literature published since 1966, to summarize the mechanisms of injury and clinical outcomes of INO after TBI.
  
  
  BACKGROUND
  A 54-year-old woman had isolated INO 10 hours after emergent evacuation of a massive supratentorial epidural hematoma. The brainstem displacement caused by downward herniation led to a deficient blood supply. Magnetic resonance imaging showed an infarct at the right dorsal-medial pons. Her symptoms partially improved by 1.5 months postoperatively. A total of 27 patients, including ours, with INO after TBI have been reported over the past 50 years. Young male patients (mean age, 30.8 years; male, 67%) are more common, and INO tends to be bilateral (67%). Infarction, hemorrhage, and fiber injury are nearly equally responsible for causing INO (35%, 35%, and 30%, respectively). Most patients recover spontaneously; 65% gain full recovery at a median time of 3 months, and 91% have at least partial recovery at 4.5 months. The median time for full recovery after infarct, hemorrhage, and fiber injury is 12, 90, and 150 days, respectively.
  
  
  CONCLUSIONS
  INO should be in the differential diagnosis of patients with TBI with an adduction deficit, despite the rarity of the condition. Isolated INO is a relatively benign sequela of TBI, with all but 1 reported patient achieving at least partial recovery over 12 months.
authors.affiliation: Division of Neurosurgery, Department of Surgery, Saint Paul's Hospital, Taoyuan, Taiwan. Electronic address: chenkoting@gmail.com.
authors.forename: Ko-Ting
authors.initials: KT
authors.lastname: Chen
authors.affiliation: Department of Neurosurgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.
authors.forename: Tzu-Kang
authors.initials: TK
authors.lastname: Lin
authors.affiliation: Division of Neurosurgery, Department of Surgery, Saint Paul's Hospital, Taoyuan, Taiwan.
authors.forename: Tsung-Che
authors.initials: TC
authors.lastname: Hsieh
mesh_terms: D005260:Female; D006407:Hematoma, Epidural, Cranial / Q000601:surgery*; D006801:Humans; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000175:diagnosis / Q000209:etiology*; D011183:Postoperative Complications / Q000175:diagnosis
keywords: Brainstem infarction; Internuclear ophthalmoplegia; Medial longitudinal fasciculus; Traumatic brain injury