False-negative transcranial motor-evoked potentials during scoliosis surgery causing paralysis: a case report with literature review.
METHODS
Case report.


OBJECTIVE
To report a case of false-negative intraoperative motor-evoked potentials (MEP) that developed paraplegia after surgery.


BACKGROUND
Although several false-negative results have been reported with somatosensory-evoked potentials, there is no report noted with MEP. Therefore, several authors have preferred using MEPs as a gold standard in neuromonitoring.


METHODS
We report a case of false-negative MEP during the scoliosis surgery which is the first report showing false-negative MEPs during operation.


RESULTS
A 15-year-old girl with severe kyphoscoliosis (Cobb angle, 140 degrees) in neurofibromatosis was operated for correction and posterior spinal fusion surgery, using pedicle screw instrumentation. Intraoperative neuromonitoring did not show any change in MEPs throughout the procedure, however, she woke-up with paraplegia. Immediate implant release could not recover her neurology functionally at last follow-up. Positive event during the operation was massive blood loss which could not show drop in MEPs as an ischemic cord injury (probable cause). Postoperative CT scan in both patients did not show any injury with pedicle screw as implants were well placed within the pedicles. Reviewing the literature, we could not find out any prospective study in animals identifying false-negative results with MEPs.


CONCLUSIONS
From our experience of false-negative MEPs, we conclude that unwanted events with use of MEP in scoliosis or other spinal surgeries. We propose further prospective research on animals to solve this issue.
Modi
Hitesh N
HN
Department of Orthopedics, Korea University Guro Hospital, Scoliosis Research Institute, Seoul, South Korea.
Suh
Seung-Woo
SW
Yang
Jae-Hyuk
JH
Yoon
Ji-Yeol
JY
D000293:Adolescent; D016063:Blood Loss, Surgical / Q000503:physiopathology / Q000517:prevention & control; D004558:Electric Stimulation; D004568:Electrodiagnosis / Q000295:instrumentation / Q000379:methods; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D007049:Iatrogenic Disease / Q000517:prevention & control; D007431:Intraoperative Complications / Q000209:etiology / Q000503:physiopathology; D007738:Kyphosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods*; D009431:Neural Conduction / Q000502:physiology; D010264:Paraplegia / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D011183:Postoperative Complications / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D011859:Radiography; D019651:Plastic Surgery Procedures / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D013116:Spinal Cord / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D020760:Spinal Cord Ischemia / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D013123:Spinal Fusion / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome