The Usefulness of Electrical Stimulation for Assessing Pedicle Screw Placements

Toleikis, J. Richard; Skelly, Jon; Carlvin, Arnold O.; Toleikis, Sandra C.; Bernard, Thomas N.; Burkus, J. Kenneth; Burr, Max; Dorchak, John; Goldman, Marc; Walsh, Thomas

doi:10.1097/00002517-200008000-00003

Cited by 72 publications

(26 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The literature suggests that eEMG is more useful for the detection of a pedicle wall breakthrough, but free-running EMG is more sensitive to nerve root manipulation/irritation in order to predict new postoperative neurologic deficit. 3,8,16,17,19,21,23 For surgery on the cauda equina, we also used intraoperative CMAP responses by direct electrical stimulation in order to identify neural structures as an additional monitoring tool. We, as well as others, have found this extremely helpful.…”

Section: Intraoperative Electromyographic Changesmentioning

confidence: 99%

“…1,2 Numerous intraoperative neurophysiologic monitoring methods are available including continuous free running electromyography (EMG), evoked electromyography (eEMG), compound muscle action potentials (CMAP), rectal and urinary sphincteric electromyography, motor-evoked potentials, dermatomalevoked responses, somatosensory-evoked potentials (SSEPs), and, most recently, spinal cord mapping. [2][3][4][5][6][7][8] Each modality monitors different pathways or parts of the nervous system, and conceptually, multimodality monitoring could be more powerful for identifying potential injury to neural structures during complex spinal procedures. 1,2 Somatosensory-evoked potentials are useful for monitoring dorsal column spinal cord function during surgery on or in the vicinity of the spinal cord, and their use during correction of deformities has been shown to improve neurologic outcome.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Real-Time Continuous Intraoperative Electromyographic and Somatosensory Evoked Potential Recordings in Spinal Surgery: Correlation of Clinical and Electrophysiologic Findings in a Prospective, Consecutive Series of 213 Cases

Gunnarsson¹,

Krassioukov²,

Sarjeant³

et al. 2004

Spine

181

View full text Add to dashboard Cite

Intraoperative electromyographic activation has a high sensitivity for the detection of a newpostoperative neurologic deficit but a low specificity. In contrast, somatosensory-evoked potentials have low sensitivity but high specificity. Combined intraoperative neurophysiologic monitoring with electromyography and somatosensory-evoked potentials is helpful for predicting and possibly preventing neurologic injury during thoracolumbar spine surgery.

show abstract

Section: Intraoperative Electromyographic Changesmentioning

confidence: 99%

mentioning

confidence: 99%

Real-Time Continuous Intraoperative Electromyographic and Somatosensory Evoked Potential Recordings in Spinal Surgery: Correlation of Clinical and Electrophysiologic Findings in a Prospective, Consecutive Series of 213 Cases

Gunnarsson¹,

Krassioukov²,

Sarjeant³

et al. 2004

Spine

181

View full text Add to dashboard Cite

show abstract

“…Conversely, if the pedicle's bony margins were intact, these same weak stimulus pulses would fail to depolarize nerve root axons due to the higher impedance of the (intact) cortical bone lining the pedicle's walls. By most accounts and based upon its widespread adoption, 11,25,31,40,44,57,67 this approach was reasonably good at detecting malpositioned lumbosacral pedicle screws.…”

mentioning

confidence: 99%

Neuromonitoring with pulse-train stimulation for implantation of thoracic pedicle screws: a blinded and randomized clinical study. Part 1. Methods and alarm criteria

Calancie¹,

Donohue

Harris

et al. 2014

SPI

View full text Add to dashboard Cite

Object Reports of the accuracy of existing neuromonitoring methods for detecting or preventing medial malpositioning of thoracic pedicle screws have varied widely in their claimed effectiveness. The object of this study was to develop, test, and validate a novel neuromonitoring method for preventing medial malpositioning of pedicle screws in the thoracic spine during surgery. Methods This is a prospective, blinded and randomized study using a novel combination of input (4-pulse stimulus trains delivered within the pedicle track) and output (evoked electromyography from leg muscles) to detect pedicle track trajectories that—once implanted with a screw—would cause that screw to breach the pedicle's medial wall and encroach upon the spinal canal. For comparison, the authors also used screw stimulation as an input and evoked electromyogram from intercostal and abdominal muscles as output measures. Intraoperative electrophysiological findings were compared with postoperative CT scans by multiple reviewers blinded to patient identity or intraoperative findings. Results Data were collected from 71 patients, in whom 802 screws were implanted between the T-1 and L-1 vertebral levels. A total of 32 screws ended up with screw threads encroaching on the spinal canal by at least 2 mm. Pulse-train stimulation within the pedicle track using a ball-tipped probe and electromyography from lower limb muscles correctly predicted all 32 (100%) of these medially malpositioned screws. The combination of pedicle track stimulation and electromyogram response from leg muscles proved to be far more effective in predicting these medially malpositioned screws than was direct screw stimulation and any of the target muscles (intercostal, abdominal, or lower limb muscles) we monitored. Based on receiver operating characteristic analysis, the combination of 10-mA (lower alarm) and 15-mA stimulation intensities proved most effective for detection of pedicle tracks that ultimately gave rise to medially malpositioned screws. Additional results pertaining to the impact of feedback of these test results on surgical decision making are provided in the companion report. Conclusions This novel neuromonitoring approach accurately predicts medially malpositioned thoracic screws. The approach could be readily implemented within any surgical program that is already using contemporary neuromonitoring methods that include transcranial stimulation for monitoring motor evoked potentials.

show abstract

“…With threshold of 5~7 mA, there was a 58% likelihood that the screw should be removed and redirected. A stimulation threshold of less than 5 mA was associated with a significant cortical perforation and direct contact with a nerve root (Toleikis et al, 2000). A stimulus threshold of less than 6 mA correlated with misplaced drill bits and screws that breached the cortex in 144 screws and 95 drill bits tested in 29 patients (Maguire et al, 1995).…”

Section: Evaluation Of Lumbosacral Pedicel Screwsmentioning

confidence: 93%

“…Hypovascularity at the junction of the proximal and middle 1/3 of the dorsal and ventral roots place nerve roots more susceptible to injury (Berthold et al, 1984). Intraoperative free-run EMG is utilized to detect motor nerve root compromise during decompression for spinal stenosis and spondylosis, correction of spinal deformity, radiculopathy secondary to disc herniation, and removal of tumor involving neural tissue in anterior and posterior surgical approaches (Holmes et al, 1993;Beatty et al, 1995;Maguire et al, 1995;Welch et al, 1997;Balzer et al, 1998;Toleikis et al, 2000;Bose et al, 2002;Chung et al, 2011). To determine any pre-existing nerve root injury, baseline EMG recording is made before surgery starts.…”

Section: Free-run Emgmentioning

confidence: 99%