Neurophysiological monitoring during anterior cervical discectomy and fusion for ossification of the posterior longitudinal ligament

Jee-Eun Kim; Jun-Soon Kim; Sejin Yang; Jongsuk Choi; Seung-Jae Hyun; Ki-Jeong Kim; Kyung Seok Park

doi:10.1016/j.cnp.2021.01.001

Neurophysiological monitoring during anterior cervical discectomy and fusion for ossification of the posterior longitudinal ligament

Clin Neurophysiol Pract. 2021 Feb 3:6:56-62. doi: 10.1016/j.cnp.2021.01.001. eCollection 2021.

Authors

Jee-Eun Kim¹, Jun-Soon Kim², Sejin Yang², Jongsuk Choi², Seung-Jae Hyun³, Ki-Jeong Kim³, Kyung Seok Park⁴

Affiliations

¹ Department of Neurology, College of Medicine, Ewha Womans University, Seoul, Republic of Korea.
² Department of Neurology, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
³ Department of Neurosurgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.
⁴ Department of Neurology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.

Abstract

Objective: This study aimed to investigate the value of intraoperative neurophysiological monitoring (IONM) in anterior cervical spine discectomy with fusion (ACDF) for ossification of the posterior longitudinal ligament (OPLL).

Methods: Patients who underwent multimodal IONM (transcranial electrical motor-evoked potentials [tcMEP], somatosensory-evoked potentials, and continuous electromyography) for ACDF from 2009 to 2019 were compared to historical controls from 2003 to 2009. The rates of postoperative neurological deficits, neurophysiological warnings, and their characteristics were analyzed.

Results: Among 196 patients, postoperative neurological deficit rates were 3.79% and 14.06% in the IONM and historical control (non-IONM) groups, respectively (p < 0.05). The use of IONM (OR: 0.139, p = 0.003) and presence of myelopathy (OR: 8.240, p = 0.013) were associated with postoperative neurological complications on multivariate regression. In total, 23 warnings were observed during IONM (17 tcMEP and/or electromyography; six electromyography). Sensitivity and specificity of IONM warnings for detecting neurological complications were 84.2% and 93.7%, respectively.

Conclusions: IONM, especially multimodal IONM, may be a useful tool to detect neurological damage in ACDF for high-risk conditions such as OPLL with pre-existing myelopathy.

Significance: The utility of IONM in ACDF for OPLL has not been evaluated due to its rarity. This study supports the use of IONM in cervical OPLL with myelopathy.

Keywords: ACDF, anterior cervical spine discectomy with fusion; ACSS, anterior cervical spine surgery; Anterior cervical spine discectomy with fusion; EMG, electromyography; IONM, intraoperative neurophysiological monitoring; Intraoperative neurophysiological monitoring; OPLL, ossification of the posterior longitudinal ligament; Ossification of the posterior longitudinal ligament; Postoperative neurological complication; SSEP, somatosensory-evoked potential; TIVA, total intravenous anesthesia; tcMEP, transcranial electrical motor-evoked potentials.