title: Hypertrophic olivary degeneration after surgical removal of cavernous malformations of the brain stem: report of four cases and review of the literature.
abstract: BACKGROUND
  Hypertrophic olivary degeneration (HOD) is a pathological phenomenon that occurs after injury to the dentato-olivary pathway. Its hallmarks include hypertrophy of the olive with increased T2 signal intensity on magnetic resonance imaging, and it often manifests with palatal tremor and oscillopsia clinically.
  
  
  METHODS
  We report the cases of four patients who developed delayed HOD after surgical resection of pontine lesions.
  
  
  RESULTS
  We discuss the anatomical and pathological details of this disease and review the few other reported cases of HOD after resection of lesions within the brainstem.
  
  
  CONCLUSIONS
  HOD should be recognized as a possible complication of surgery within the brainstem and must be diagnosed promptly so that patients can be appropriately counseled and symptoms can be treated.
authors.affiliation: Department of Neurosurgery, University of Utah, Salt Lake City, Utah 84132, USA.
authors.forename: M
authors.initials: M
authors.lastname: Hornyak
authors.forename: A G
authors.initials: AG
authors.lastname: Osborn
authors.forename: W T
authors.initials: WT
authors.lastname: Couldwell
mesh_terms: D020785:Central Nervous System Vascular Malformations / Q000601:surgery*; D005260:Female; D006801:Humans; D006984:Hypertrophy / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009847:Olivary Nucleus / Q000473:pathology*; D011183:Postoperative Complications