Bilateral Globe Penetration From Electromyography Electrode Placement for Intraoperative Neurophysiologic Monitoring

Purpose: This interventional case report discusses inadvertent bilateral temporal globe penetration during placement of intramuscular wire electrodes to the lateral rectus muscles for intraoperative neurophysiological monitoring (IONM) via electromyography. Methods: An 11-year-old girl underwent surgical resection of massive medulloblastoma within the fourth ventricle, requiring IONM. Placement of an electrode in each lateral rectus muscle resulted in bilateral globe penetration, with choroidal rupture, retinal tears, and hemorrhage. Results: Sterile needle perforation of the globe did not result in endophthalmitis. Encircling laser retinopexy was performed, and no retinal detachments occurred. Conclusions: Insertion of needle electrodes without guidance imaging can potentially lead to globe penetration and incorrect electrode placement. Direct visualization with ultrasound, electromyography, or other advanced image-guided systems may offer a safe solution for electrode placement to avoid injury. Verbal patients should be made aware of postoperative warning signs of globe penetration. For nonverbal patients, a postoperative dilated exam is warranted.