title: Lumbar epidural gas-containing pseudocysts as a cause of severe radicular pain.
abstract: OBJECTIVE
  Intradiscal gas can herniate to the epidural space, and herniated epidural gas may produce pseudocysts. We assessed the characteristics of and surgical treatments for lumbar epidural gas-containing pseudocysts as a cause of severe radicular pain.
  
  
  METHODS
  We surgically treated epidural gas-containing pseudocysts in a total of 22 patients. We reviewed radiological parameters including the concomitant presence of vacuum discs, segmental instability, spinal stenosis, and location of pseudocysts. We retrospectively reviewed preoperative clinical parameters such as age, sex, clinical symptoms, neurologic deficits, and surgical methods.
  
  
  RESULTS
  We observed 25 levels of gas-containing pseudocysts in 22 patients. Twelve (48.0%) pseudocysts were in the canal, eight (32.0%) were in the foramen, and five (20.0%) were of extraforaminal type. All of the patients had degenerative vacuum discs in the affected levels. The incidence of neurologic deficits in patients with spinal stenosis was significantly higher than in patients without spinal stenosis (P<0.05). We performed pseudocyst removal, neural decompression, and fusion surgery in 12 patients with symptomatic spinal stenosis or instability, and microscopic removal of pseudocysts in 10 patients without symptomatic spinal stenosis or instability.
  
  
  CONCLUSIONS
  We propose that lumbar gas-containing pseudocysts can produce radicular pain and/or neurologic symptoms, and that surgical removal of pseudocysts with or without optimal stabilization operations can significantly improve symptoms. The selection of surgical methods may depend on the presence of concomitant spinal stenosis or segmental instability.
authors.affiliation: Department of Neurosurgery, The Spine and Spinal Cord Institute, Gangnam Severance Spine Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sung Uk
authors.initials: SU
authors.lastname: Kuh
authors.forename: Dong Hwa
authors.initials: DH
authors.lastname: Heo
authors.forename: Keun Su
authors.initials: KS
authors.lastname: Kim
authors.forename: Yong Jun
authors.initials: YJ
authors.lastname: Cho
mesh_terms: D000368:Aged; D003560:Cysts / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D004824:Epidural Space / Q000473:pathology; D005260:Female; D005740:Gases; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D010146:Pain / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D011843:Radiculopathy / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D013122:Spinal Diseases / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology
chemical_list: D005740:Gases