Efficacy and limitations of current methods of intraoperative spinal cord monitoring.
The purpose of this study was to evaluate the efficacy and reliability of intraoperative spinal monitoring using spinal cord-evoked and compound muscle action potentials. We reviewed 716 cases of spinal monitoring performed over 15 years. The series contained 672 patients with spinal functions that could be monitored intraoperatively; 44 (6.1%) were impossible to record. Based on the 21 impossible-to-record patients, it is evident that missing a serious case such as a Frankel B type spinal cord injury indicates the limitations of the current monitoring methods for stimulating and recording. The monitoring outcomes were true-negative in 652 patients, true-positive in 12, false-negative in four, and false-positive in four. In two of the patients with false-negative results, postoperative myelomere motor paralysis was observed temporarily even though it was possible to record the muscle-evoked potential after electrical stimulation to the brain [Br(E)-MsEP] at the end of the operation. In cases in which the spinal parenchyma or spinal nerve root might be selectively damaged, Br(E)-MsEPs may not diagnose the disorder accurately. By employing multimodal monitoring, it should be possible to eliminate patients with false-negative results and to detect spinal disorders during the early stages, as well as to examine whether the abnormality that had been recorded by a single method is false-positive.
Iwasaki
Hiroshi
H
Department of Orthopedic Surgery, Wakayama Medical University, 811-1 Kimiidera, Wakayama 641-8510, Japan.
Tamaki
Tetsuya
T
Yoshida
Munehito
M
Ando
Muneharu
M
Yamada
Hiroshi
H
Tsutsui
Shunji
S
Takami
Masanari
M
D000200:Action Potentials; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D004558:Electric Stimulation; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D012189:Retrospective Studies; D013116:Spinal Cord / Q000502:physiology*; D013120:Spinal Cord Neoplasms / Q000503:physiopathology; D013122:Spinal Diseases / Q000601:surgery*; D013128:Spinal Osteophytosis / Q000503:physiopathology