title: Migration of intracranial hemostatic clip into the lumbar spinal canal causing sacral radiculopathy: a case report.
abstract: METHODS
  A case report.
  
  
  OBJECTIVE
  A case of spontaneous migration of intracranial hemostatic clip into the lumbar spinal canal causing a sacral radiculopathy and severe low back pain was presented.
  
  
  BACKGROUND
  Only five cases have been reported in the literature. The first report was described by Oyesiku in 1986; thereafter, four cases have been reported. This serves as the first report clearly describing the relationship between the migrated site of a foreign body and neurologic symptom, as well as achieving a remission of symptom after surgical extirpation.
  
  
  METHODS
  A patient who had received hemostatic clips to the aqueductal stenosis 31 years ago presented with low back pain and sacral radiculopathy. Plain radiography, myelography, and subsequent CT revealed that a metal foreign body was located in the subarachnoid space at L4 level. Laminectomy of L4 and extirpation of the foreign body were performed.
  
  
  RESULTS
  The foreign body was a hemostatic clip made of cobalt-based alloy that had been applied during the previous intracranial surgery. The clip irritated the adjoined intrathecal nerve root and possibly caused the adhesive arachnoiditis. All symptoms completely disappeared after the extirpation.
  
  
  CONCLUSIONS
  An uncommon case of an intracranial hemostatic clip migrating into the lumbar subarachnoid space as well as causing sacral radiculopathy was reported. The surgical extirpation provided an excellent clinical outcome.
authors.affiliation: Department of Orthopedic Surgery, Kutchan Kosei Hospital, Hokkaido, Japan.
authors.forename: Keigo
authors.initials: K
authors.lastname: Yasui
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Kotani
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Takeda
authors.forename: Akio
authors.initials: A
authors.lastname: Minami
mesh_terms: D005548:Foreign-Body Migration / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D006489:Hemostatic Techniques / Q000295:instrumentation*; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011843:Radiculopathy / Q000209:etiology*; D011859:Radiography; D012447:Sacrum; D012886:Skull / Q000000981:diagnostic imaging / Q000601:surgery; D013115:Spinal Canal / Q000000981:diagnostic imaging