Abstract：
OBJECTIVE: The objective of this study was to describe the quantitative features of intraoperative electromyographic recordings obtained from cranial nerve III, IV, and VI neuromonitoring using 25-mm intraorbital electrodes, in the larger context of demonstrating the practicality of this technique during neurosurgical cases.
METHODS: A 25-mm-long shaft-insulated intraorbital needle electrode is routinely used at the authors\' institution for extraocular muscle (EOM) electromyographic monitoring of the inferior rectus, superior oblique, and/or lateral rectus muscles when their function is at risk. Cases monitored between January 1, 2021, and December 31, 2022, were reviewed for patient demographics, tumor location and pathology, EOMs monitored, pre- and postoperative examination, and complications from electrode placement. Compound muscle action potentials on triggered electromyography, as well as neurotonic discharges on free-run electromyography, were described quantitatively.
RESULTS: There were 141 cases in 139 patients reviewed during the 24-month time span, with 278 EOMs monitored (inferior rectus/superior oblique/lateral rectus muscles 68/68/142). Triggered electromyography yielded biphasic or triphasic compound muscle action potentials from EOMs with a mean onset latency of 1.51 msec (range 0.94-3.22 msec), mean maximal peak-to-trough amplitude of 1073.93 μV (range 76.75-7796.29 μV), and high specificity for the channel in nearly all cases. Neurotonic discharges were recorded in 30 of the 278 EOMs (with all 3 muscles represented) and associated with a greater incidence of new or worsened ophthalmoparesis (OR 4.62, 95% CI 1.3-16.4). There were 2 cases of small periorbital ecchymosis attributed to needle placement; additionally, 1 case of needle-related intraorbital hematoma occurred after the review period.
CONCLUSIONS: The 25-mm shaft-insulated intraorbital electrode facilitates robust and consistent electromyographic recordings of EOMs that are advantageous over existing techniques. Combined with the relative ease of needle placement and low rate of complications, the technique is practical for neuromonitoring during craniotomies.
METHODS: A 25-mm-long shaft-insulated intraorbital needle electrode is routinely used at the authors\' institution for extraocular muscle (EOM) electromyographic monitoring of the inferior rectus, superior oblique, and/or lateral rectus muscles when their function is at risk. Cases monitored between January 1, 2021, and December 31, 2022, were reviewed for patient demographics, tumor location and pathology, EOMs monitored, pre- and postoperative examination, and complications from electrode placement. Compound muscle action potentials on triggered electromyography, as well as neurotonic discharges on free-run electromyography, were described quantitatively.
RESULTS: There were 141 cases in 139 patients reviewed during the 24-month time span, with 278 EOMs monitored (inferior rectus/superior oblique/lateral rectus muscles 68/68/142). Triggered electromyography yielded biphasic or triphasic compound muscle action potentials from EOMs with a mean onset latency of 1.51 msec (range 0.94-3.22 msec), mean maximal peak-to-trough amplitude of 1073.93 μV (range 76.75-7796.29 μV), and high specificity for the channel in nearly all cases. Neurotonic discharges were recorded in 30 of the 278 EOMs (with all 3 muscles represented) and associated with a greater incidence of new or worsened ophthalmoparesis (OR 4.62, 95% CI 1.3-16.4). There were 2 cases of small periorbital ecchymosis attributed to needle placement; additionally, 1 case of needle-related intraorbital hematoma occurred after the review period.
CONCLUSIONS: The 25-mm shaft-insulated intraorbital electrode facilitates robust and consistent electromyographic recordings of EOMs that are advantageous over existing techniques. Combined with the relative ease of needle placement and low rate of complications, the technique is practical for neuromonitoring during craniotomies.
摘要：
目的：本研究的目的是描述从颅神经III获得的术中肌电图记录的定量特征，IV,和使用25毫米眶内电极的VI神经监测，在更大的背景下证明这种技术在神经外科病例中的实用性。
方法：作者机构通常使用25毫米长的轴绝缘眶内针状电极进行下直肌的眼外肌（EOM）肌电图监测，上斜，和/或外侧直肌功能处于危险之中。2021年1月1日至2022年12月31日期间监测的病例进行了患者人口统计学审查，肿瘤位置和病理，监测到的EOM，术前和术后检查，和电极放置的并发症。触发肌电图上的复合肌肉动作电位，以及自由运行肌电图上的神经放电，进行了定量描述。
结果：在24个月的时间范围内，对139例患者进行了检查，共141例，监测278个EOM（下直肌/上斜肌/侧直肌68/68/142）。触发肌电图从EOM产生双相或三相复合肌肉动作电位，平均发作潜伏期为1.51毫秒（范围为0.94-3.22毫秒），平均最大峰谷振幅为1073.93μV（范围为76.75-7796.29μV），在几乎所有情况下，该通道的特异性都很高。在278例EOM中，有30例记录了中子放电（所有3条肌肉均为代表），并且与新发或恶化的眼瘫发生率更高相关（OR4.62，95％CI1.3-16.4）。有2例归因于针头放置的小眶周瘀斑；此外，1例针眼相关性眶内血肿在复查期后发生。
结论：25毫米轴绝缘眶内电极有助于EOM的可靠和一致的肌电图记录，这优于现有技术。再加上置针相对容易,并发症发生率低,该技术适用于开颅手术期间的神经监测。
方法：作者机构通常使用25毫米长的轴绝缘眶内针状电极进行下直肌的眼外肌（EOM）肌电图监测，上斜，和/或外侧直肌功能处于危险之中。2021年1月1日至2022年12月31日期间监测的病例进行了患者人口统计学审查，肿瘤位置和病理，监测到的EOM，术前和术后检查，和电极放置的并发症。触发肌电图上的复合肌肉动作电位，以及自由运行肌电图上的神经放电，进行了定量描述。
结果：在24个月的时间范围内，对139例患者进行了检查，共141例，监测278个EOM（下直肌/上斜肌/侧直肌68/68/142）。触发肌电图从EOM产生双相或三相复合肌肉动作电位，平均发作潜伏期为1.51毫秒（范围为0.94-3.22毫秒），平均最大峰谷振幅为1073.93μV（范围为76.75-7796.29μV），在几乎所有情况下，该通道的特异性都很高。在278例EOM中，有30例记录了中子放电（所有3条肌肉均为代表），并且与新发或恶化的眼瘫发生率更高相关（OR4.62，95％CI1.3-16.4）。有2例归因于针头放置的小眶周瘀斑；此外，1例针眼相关性眶内血肿在复查期后发生。
结论：25毫米轴绝缘眶内电极有助于EOM的可靠和一致的肌电图记录，这优于现有技术。再加上置针相对容易,并发症发生率低,该技术适用于开颅手术期间的神经监测。
