Is it real false negative finding in motor evoked potential monitoring during corrective surgery of ankylosing spondylitis? A case report

Ki Tack Kim, Sang Hun Lee, Yoon Ho Kwack, Eon Seok Son

Research output: Contribution to journalArticle


We performed L1 posterior vertebral columnar resection and posterior correction for Andersson's lesion and thoracolumbar kyphosis in an ankylosing spondylitis patient during motor evoked potential (MEP) monitoring. We checked MEP intra-operatively, whenever a dangerous procedure for neural elements was performed, and no abnormal findings were seen during surgery. After the operation, we examined neurologic function in the recovery room; the patient showed a progressive neurologic deficit and no response to MEP. After emergency neural exploration and decompression surgery, the neurologic deficit was recovered. We questioned whether to acknowledge the results of this case as a false negative. We think the possible reason for this result may be delayed development of paralysis. So, we recommend that MEP monitoring should be performed not only after important operative steps but also after all steps, including skin suturing, for final confirmation.

Original languageEnglish (US)
Pages (from-to)50-54
Number of pages5
JournalAsian Spine Journal
Issue number1
StatePublished - Mar 1 2012
Externally publishedYes



  • Deformity correction
  • Delayed paraplegia
  • Motor evoked potential
  • Spine operation

ASJC Scopus subject areas

  • Surgery
  • Orthopedics and Sports Medicine

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