TY - JOUR
T1 - Intraoperative lateral rectus electromyographic recordings optimized by deep intraorbital needle electrodes
AU - Oishi, Tatsuya
AU - Van Gompel, Jamie J.
AU - Link, Michael J.
AU - Tooley, Andrea A.
AU - Hoffman, Ernest M.
N1 - Publisher Copyright:
© 2021 International Federation of Clinical Neurophysiology
PY - 2021/10
Y1 - 2021/10
N2 - Objective: We demonstrate the advantages and safety of long, intraorbitally-placed needle electrodes, compared to standard-length subdermal electrodes, when recording lateral rectus electromyography (EMG) during intracranial surgeries. Methods: Insulated 25 mm and uninsulated 13 mm needle electrodes, aimed at the lateral rectus muscle, were placed in parallel during 10 intracranial surgeries, examining spontaneous and stimulation-induced EMG activities. Postoperative complications in these patients were reviewed, alongside additional patients who underwent long electrode placement in the lateral rectus. Results: In 40 stimulation-induced recordings from 10 patients, the 25 mm electrodes recorded 6- to 26-fold greater amplitude EMG waveforms than the 13 mm electrodes. The 13 mm electrodes detected greater unwanted volume conduction upon facial nerve stimulation, typically exceeding the amplitude of abducens nerve stimulation. Except for one case with lateral canthus ecchymosis, no clinical or radiographic complications occurred in 36 patients (41 lateral rectus muscles) following needle placement. Conclusions: Intramuscular recordings from long electrode in the lateral rectus offers more reliable EMG monitoring than 13 mm needles, with excellent discrimination between abducens and facial nerve stimulations, and without significant complications from needle placement. Significance: Long intramuscular electrode within the orbit for lateral rectus EMG recording is practical and reliable for abducens nerve monitoring.
AB - Objective: We demonstrate the advantages and safety of long, intraorbitally-placed needle electrodes, compared to standard-length subdermal electrodes, when recording lateral rectus electromyography (EMG) during intracranial surgeries. Methods: Insulated 25 mm and uninsulated 13 mm needle electrodes, aimed at the lateral rectus muscle, were placed in parallel during 10 intracranial surgeries, examining spontaneous and stimulation-induced EMG activities. Postoperative complications in these patients were reviewed, alongside additional patients who underwent long electrode placement in the lateral rectus. Results: In 40 stimulation-induced recordings from 10 patients, the 25 mm electrodes recorded 6- to 26-fold greater amplitude EMG waveforms than the 13 mm electrodes. The 13 mm electrodes detected greater unwanted volume conduction upon facial nerve stimulation, typically exceeding the amplitude of abducens nerve stimulation. Except for one case with lateral canthus ecchymosis, no clinical or radiographic complications occurred in 36 patients (41 lateral rectus muscles) following needle placement. Conclusions: Intramuscular recordings from long electrode in the lateral rectus offers more reliable EMG monitoring than 13 mm needles, with excellent discrimination between abducens and facial nerve stimulations, and without significant complications from needle placement. Significance: Long intramuscular electrode within the orbit for lateral rectus EMG recording is practical and reliable for abducens nerve monitoring.
KW - Abducens
KW - Compound muscle action potential (CMAP)
KW - Cranial nerve
KW - Craniotomy
KW - Electromyography (EMG)
KW - Extraocular muscle
KW - Intraoperative neuromonitoring (IONM)
KW - Lateral rectus
KW - Skull base tumor
UR - http://www.scopus.com/inward/record.url?scp=85114780118&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85114780118&partnerID=8YFLogxK
U2 - 10.1016/j.clinph.2021.08.002
DO - 10.1016/j.clinph.2021.08.002
M3 - Article
C2 - 34454280
AN - SCOPUS:85114780118
SN - 1388-2457
VL - 132
SP - 2510
EP - 2518
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
IS - 10
ER -