• Annals of Clinical Neurophysiology
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• v.23 no.1
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• pp.35-45
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• 2021

The utility and accuracy of intraoperative neurophysiological monitoring (IONM) has evolved greatly following the recent development of new devices for neurophysiological testing and advances in anesthesiology. Until recently, the need for IONM services has been limited to large academic hospitals, but the demand for neurophysiologists with expertise in IONM has grown rapidly across diverse types of hospital. The primary goal of the Korean Society of Intraoperative Neurophysiological Monitoring (KSION) is to promote the development of IONM research groups and to contribute to the improvement of fellowship among members and human health through academic projects. These guidelines are based on extensive literature reviews, recruitment of expert opinions, and consensus among KSION board members. This version of the guidelines was fully approved by the KSION, Korean Association of EMG Electrodiagnostic Medicine, the Korean Society of Clinical Neurophysiology, the Korean Academy of Rehabilitation Medicine, and the Korean Neurological Association.

• Journal of Chest Surgery
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• v.50 no.5
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• pp.391-394
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• 2017

Recurrent laryngeal nerve injury can develop following cervical or thoracic surgery; however, few reports have described intraoperative recurrent laryngeal nerve monitoring. Consensus regarding the use of this technique during thoracic surgery is lacking. We used intraoperative recurrent laryngeal nerve monitoring in a patient with contralateral vocal cord paralysis who was scheduled for completion pneumonectomy. This case serves as an example of intraoperative recurrent laryngeal nerve monitoring during thoracic surgery and supports this indication for its use.

• Journal of Korean Neurosurgical Society
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• v.29 no.6
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• pp.778-785
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• 2000

Objectives : Intraoperative neurophysiologic monitoring(INM) is a well known useful method to reduce intraoperative neurological complications during neurosurgical procedures. Furthermore, INM is required in most cerebellopontine angle(CPA) surgery because cranial nerves or brain stem injuries can result in serious complications. Object of this study is to the correlation between the changes of intraoperative monitoring modalities during cerebellopontine angle tumor surgery and post-operative functional outcomes in auditory and facial functions. Material and Methods : Fifty-seven patients who underwent intraoperative neurophysiologic monitoring during CPA tumor surgery were retrospectively reviewed. Their lesions were as follows ; vestibular schwannomas in 42, other cranial nerve schwannomas in seven, meningiomas in five and cysts in three cases. Pre- and postoperative audiologic examinations and facial nerve function tests were performed in all patients. Intraoperative neurophysiologic monitoring modalities includes brainstem auditory evoked potentials(BAEP) and facial electromyographies(EMG). We compared the events of INM during CPA tumor surgeries with the outcomes of auditory and facial nerve functions. Results : The subjects who had abnormal changes during CPA tumor surgery were twenty cases with BAEP changes and facial EMG changes in twenty one cases. The changes of intraoperative neurophysiologic monitoring did not always result in poor functional outcomes. However, most predictable intraoperative monitoring changes were wave III-V complex losses in BAEP and continuous neurotonic activities in facial EMG. Conclusion : These results indicate that intraoperative neurophysiologic monitoring in CPA tumor surgery usually provide predictive value for postoperative functional outcomes.

• Annals of Clinical Neurophysiology
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• v.10 no.1
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• pp.1-12
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• 2008

Intraoperative neuromonitoring (INM) is well known to be useful method to reduce intraoperative complications during the surgery of nervous system lesions. Evoked potentials are most commonly used among the electrophysiological tests. Brainstem auditory evoked potentials are for detecting the problems along the auditory pathways including the eighth cranial nerve and brainstem. Somatosensory evoked potentials are applied for preventing the spinal cord lesions. The INM is affected by many factors. In order to perform an optimal INM, the confounding factors including technical, anesthetical, and individual factors should be kept well under control. INM has frequent electrophysiologic changes during the surgery and it might be helpful to keep one's eyes on which monitoring modalities are reluctant to change during each operation. The skillful monitoring and timely interpretation of electrophysiologic changes can drive the patient to be undergone surgery, even in high surgical risk group.

• Annals of Clinical Neurophysiology
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• v.22 no.2
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• pp.104-108
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• 2020

We performed intraoperative neurophysiological monitoring (INM) during anteromesial temporal resection (AMTR) in a patient with lesional temporal lobe epilepsy. INM revealed a sudden decrease in N20 waves in somatosensory evoked potentials (SSEPs) and poor P100 waves in visual evoked potentials (VEPs). These changes developed after applying electrocoagulation in the right mesial temporal areas. Postoperative brain magnetic resonance imaging demonstrated right thalamic and medial occipital infarctions. SSEPs and VEPs monitoring can be useful for detecting posterior cerebral artery infarction in AMTR.

• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.367-375
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• 2019

Hemifacial spasm (HFS) is due to the vascular compression of the facial nerve at its root exit zone (REZ). Microvascular decompression (MVD) of the facial nerve near the REZ is an effective treatment for HFS. In MVD for HFS, intraoperative neurophysiological monitoring (INM) has two purposes. The first purpose is to prevent injury to neural structures such as the vestibulocochlear nerve and facial nerve during MVD surgery, which is possible through INM of brainstem auditory evoked potential and facial nerve electromyography (EMG). The second purpose is the unique feature of MVD for HFS, which is to assess and optimize the effectiveness of the vascular decompression. The purpose is achieved mainly through monitoring of abnormal facial nerve EMG that is called as lateral spread response (LSR) and is also partially possible through Z-L response, facial F-wave, and facial motor evoked potentials. Based on the information regarding INM mentioned above, MVD for HFS can be considered as a more safe and effective treatment.

• Journal of Korean Neurosurgical Society
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• v.56 no.6
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• pp.513-516
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• 2014

We report a case of cervicomedullary compression by an anomalous vertebral artery treated using microsurgical decompression with intraoperative monitoring. A 68-year-old woman presented with posterior neck pain and gait disturbance. MRI revealed multiple abnormalities, including an anomalous vertebral artery that compressed the spinal cord at the cervicomedullary junction. Suboccipital craniectomy with C1 laminectomy was performed. The spinal cord was found to be compressed by the vertebral arteries, which were retracted dorsolaterally. At that time, the somatosensory evoked potential (SSEP) changed. After release of the vertebral artery, the SSEP signal normalized instantly. The vertebral artery was then lifted gently and anchored to the dura. There was no other procedural complication. The patient's symptoms improved. This case demonstrates that intraoperative monitoring may be useful for preventing procedural complications during spinal cord microsurgical decompression.

• Journal of Korean Neurosurgical Society
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• v.56 no.6
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• pp.455-462
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• 2014

Objective : To propose a new measure for effective monitoring of intraoperative somatosensory evoked potentials (SEP) and to validate the feasibility of this measure for evoked potentials (EP) and single trials with a retrospective data analysis study. Methods : The proposed new measure (hereafter, a slope-measure) was defined as the relative slope of the amplitude and latency at each EP peak compared to the baseline value, which is sensitive to the change in the amplitude and latency simultaneously. We used the slope-measure for EP and single trials and compared the significant change detection time with that of the conventional peak-to-peak method. When applied to single trials, each single trial signal was processed with optimal filters before using the slope-measure. In this retrospective data analysis, 7 patients who underwent cerebral aneurysm clipping surgery for unruptured aneurysm middle cerebral artery (MCA) bifurcation were included. Results : We found that this simple slope-measure has a detection time that is as early or earlier than that of the conventional method; furthermore, using the slope-measure in optimally filtered single trials provides warning signs earlier than that of the conventional method during MCA clipping surgery. Conclusion : Our results have confirmed the feasibility of the slope-measure for intraoperative SEP monitoring. This is a novel study that provides a useful measure for either EP or single trials in intraoperative SEP monitoring.

• Journal of Chest Surgery
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• v.50 no.2
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• pp.94-98
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• 2017

Background: Intraoperative monitoring during carotid endarterectomy is crucial for cerebral protection. We investigated the results of carotid endarterectomy under dual monitoring with stump pressure and electroencephalography. Methods: We retrospectively reviewed the medical records of 50 patients who underwent carotid endarterectomy between March 2010 and February 2016. We inserted a temporary shunt if the stump pressure was lower than 35 mm Hg or if any intraoperative change was observed on electroencephalography. Results: Seventeen (34%) patients used a temporary shunt, and the mean stump pressure was 26.8 mm Hg in the shunt group and 46.5 mm Hg in the non-shunt group. No postoperative mortality or bleeding occurred. Postoperatively, there were 3 cases (6%) of minor stroke, all of which took place in the shunt group. A comparison of the preoperative and the intraoperative characteristics of the shunt group with those of the non-shunt group revealed no statistically significant difference between the 2 groups (p<0.01). Conclusion: Dual monitoring with stump pressure and electroencephalography was found to be a safe and reliable monitoring method with results comparable to those obtained using single monitoring. Further study should be performed to investigate the precise role of each monitoring method.

• Journal of Korean Neurosurgical Society
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• v.64 no.2
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• pp.143-150
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• 2021

Spinal dysraphism often causes neurological impairment from direct involvement of lesions or from cord tethering. The conus medullaris and lumbosacral roots are most vulnerable. Surgical intervention such as untethering surgery is indicated to minimize or prevent further neurological deficits. Because untethering surgery itself imposes risk of neural injury, intraoperative neurophysiological monitoring (IONM) is indicated to help surgeons to be guided during surgery and to improve functional outcome. Monitoring of electromyography (EMG), motor evoked potential, and bulbocavernosus reflex (BCR) is essential modalities in IONM for untethering. Sensory evoked potential can be also employed to further interpretation. In specific, free-running EMG and triggered EMG is of most utility to identify lumbosacral roots within the field of surgery and filum terminale or non-functioning cord can be also confirmed by absence of responses at higher intensity of stimulation. The sacral nervous system should be vigilantly monitored as pathophysiology of tethered cord syndrome affects the sacral function most and earliest. BCR monitoring can be readily applicable for sacral monitoring and has been shown to be useful for prediction of postoperative sacral dysfunction. Further research is guaranteed because current IONM methodology in spinal dysraphism is still deficient of quantitative and objective evaluation and fails to directly measure the sacral autonomic nervous system.