• Journal of Korean Neurosurgical Society
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• 제56권6호
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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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• 제50권2호
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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.

• 대한임상검사과학회지
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• 제51권4호
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• pp.453-461
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• 2019

수술 중 발생하는 신경계 손상 여부를 감별하는 검사인 수술 중 신경계 모니터링(intraoperative neurophysiological monitoring, INM) 검사는 다양한 수술에서 안정적으로 수술이 잘 진행되고 있음을 확신하며 수술을 진행할 수 있도록 도움을 주는 매우 중요한 검사다. 수술실이라는 특수한 환경에서 검사의 최적화를 위하여 침 전극을 사용하여 검사를 진행하며, 수술실검사에 대하여 정확한 자극부위와 측정부위에 대한 교재나 안내책자가 없는 것이 실정이다. 그래서 이번 논문에서 운동유발전위검사, 체성감각유발전위검사, 청각유발전위검사, 시각유발전위검사에서 올바른 자극부위와 측정부위에 대하여 자세하게 설명을 하였다. 그리고 자유진행 및 유발근전도검사(free-running and triggered EMG)는 근육에서 발생하는 근전도의 관찰로 대부분의 뇌신경(cranial nerve)과 척수신경근(spinal nerve root)의 기능상태 파악을 한다. 검사의 이해를 돕기 위해 각각의 해당 근육에 전극을 삽입하는 사진을 첨부하였고, 척수신경근에 따른 해당근육도 표로 제시하였다. 검사 후 전극제거를 할 때에도 환자와 검사자 모두 안전한 방법을 제시하여 보다 완벽한 검사가 되었으면 한다.

• Brain Tumor Research and Treatment
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• 제6권2호
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• pp.60-67
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• 2018

Background Recently, modern technology such as diffusion tensor imaging (DTI), neuro-navigation and intraoperative neurophysiological monitoring (IOM) have been actively adopted for the treatment of thalamic tumors. We evaluated surgical outcomes and efficacy of the aforementioned technologies for the treatment of pediatric thalamic tumors. Methods We retrospectively reviewed clinical data from 37 children with thalamic tumors between 2004 and 2017. There were 44 operations (27 tumor resections, 17 biopsies). DTI was employed in 17 cases, neuro-navigation in 23 cases and IOM in 14 cases. All diagnoses were revised according to the 2016 World Health Organization Classification of Tumors of the Central Nervous System. Progression-free survival (PFS) and overall survival (OS) rates were calculated, and relevant prognostic factors were analyzed. The median follow-up duration was 19 months. Results Fifteen cases were gross total resections (GTR), 6 subtotal resections (STR), and 6 partial resections (PR). Neurological status did not worsen after 22 tumor resections. There were statistically significant differences in terms of the extent of resection between the groups with DTI, neuro-navigation and IOM (n=12, GTR or STR=12) and the group without at least one of the three techniques (n= 15, GTR or STR=9, p=0.020). The mean PFS was $87.2{\pm}38.0$ months, and the mean OS $90.7{\pm}36.1$ months. The 5-year PFS was 37%, and the 5-year OS 47%. The histological grade ($p{\leq}0.001$) and adjuvant therapy (done vs. not done, p=0.016) were significantly related to longer PFS. The histological grade (p=0.002) and the extent of removal (GTR/STR vs. PR/biopsy, p=0.047) were significantly related to longer OS. Conclusion Maximal surgical resection was achieved with acceptable morbidity in children with thalamic tumors by employing DTI, neuro-navigation and IOM. Maximal tumor resection was a relevant clinical factor affecting OS; therefore, it should be considered the initial therapeutic option for pediatric thalamic tumors.

• 대한임상검사과학회지
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• 제53권1호
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• pp.122-130
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• 2021

수술중신경계감시에서 혼입되는 artifact의 종류는 매우 다양하고 검사에 방해 되는 artifact의 제거 또한 필수적이다. 그리고 artifact를 제거해서 검사의 질을 향상시키는 것이 검사자의 역량이며 환자의 안전을 위한 최선의 방법이다. 하지만 경험이 부족해서 수술실의 장비나 마취에 관한 사항들에 대한 숙지가 미흡한 경우 상황에 맞는 적절한 방법으로 artifact를 제거할 수 없다. 만약 artifact가 구별 및 제거되지 않고 진행된 검사의 판독은 수술 진행에 혼선을 초래하며 이는 신속하고 정교함이 요구되는 신경외과 수술에 치명적인 문제가 될 수 있다. 본 논문에서는 수술 중에 발생하는 artifact의 원인을 전기적요인과 비전기적인 요인 그리고 기타 요인들로 분류하였고 상황에 맞게 artifact를 제거하는 방법과 검사법에 대해 언급하였다. 수술실의 환경이 동시에 여러가지 상황을 고려해야 하는 매우 민감한 조건이지만, 다양한 artifact의 형태와 원인을 숙지하여 안정적이고 원활한 수술중신경계감시가 되길 바란다.

• 대한임상검사과학회지
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• 제54권1호
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• pp.61-67
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• 2022

INM은 수술의 안정성을 더해주고 고위험군의 수술을 안전하게 진행할 수 있게 도움을 주고 있다. INM검사가 적용이 되는 모든 수술에서의 수술 과정과 신경학적 결손이 발생할 수 있는 과정에서 집중적으로 검사를 진행해 보다 신속하게 수술자에게 알리지 않으면 손상이 되었을 때 그에 대한 대처가 늦어서 환자에게 돌이킬 수 없는 심각한 후유증을 가져다 줄 수 있다. 대동맥류 및 대동맥 박리로 발생되는 대동맥 치환술은 개흉 및 개복술이 진행되며 심장의 혈류를 차단하는 매우 위험한 수술이다. 대동맥에서 분지되어 척수에 혈류를 공급하는 혈관들을 교체할 때 척수로 가는 혈류가 감소해 척수 허혈이 올 수 있다. 대동맥 수술에서의 INM은 겸자시에 유발전위를 이용하여 빠르게 척수 허혈이 시작되는 시점을 찾아내고 수술자에게 보고해 척수 허혈을 방지하며 심각한 합병증을 막는 중요한 역할을 수행한다. 이에 수술의 과정과 TceMEP, SSEPs의 검사 방법 및 검사 시점, 검사 기준에 대하여 작성을 하여 INM을 시행하는 검사자들에게 도움이 되고자 본문을 작성하였다. 본문으로 인해 대동맥수술에서 INM의 필요성, 대동맥 수술에서의 흐름을 파악하고 정확하고 신속한 검사를 통한 보고로 원활한 검사가 진행되길 바라는 바이다.

• Journal of Korean Neurosurgical Society
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• 제61권3호
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• pp.363-375
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• 2018

Intraoperative monitoring (IOM) utilizes electrophysiological techniques as a surrogate test and evaluation of nervous function while a patient is under general anesthesia. They are increasingly used for procedures, both surgical and endovascular, to avoid injury during an operation, examine neurological tissue to guide the surgery, or to test electrophysiological function to allow for more complete resection or corrections. The application of IOM during pediatric brain tumor resections encompasses a unique set of technical issues. First, obtaining stable and reliable responses in children of different ages requires detailed understanding of normal age-adjusted brain-spine development. Neurophysiology, anatomy, and anthropometry of children are different from those of adults. Second, monitoring of the brain may include risk to eloquent functions and cranial nerve functions that are difficult with the usual neurophysiological techniques. Third, interpretation of signal change requires unique sets of normative values specific for children of that age. Fourth, tumor resection involves multiple considerations including defining tumor type, size, location, pathophysiology that might require maximal removal of lesion or minimal intervention. IOM techniques can be divided into monitoring and mapping. Mapping involves identification of specific neural structures to avoid or minimize injury. Monitoring is continuous acquisition of neural signals to determine the integrity of the full longitudinal path of the neural system of interest. Motor evoked potentials and somatosensory evoked potentials are representative methodologies for monitoring. Free-running electromyography is also used to monitor irritation or damage to the motor nerves in the lower motor neuron level : cranial nerves, roots, and peripheral nerves. For the surgery of infratentorial tumors, in addition to free-running electromyography of the bulbar muscles, brainstem auditory evoked potentials or corticobulbar motor evoked potentials could be combined to prevent injury of the cranial nerves or nucleus. IOM for cerebral tumors can adopt direct cortical stimulation or direct subcortical stimulation to map the corticospinal pathways in the vicinity of lesion. IOM is a diagnostic as well as interventional tool for neurosurgery. To prove clinical evidence of it is not simple. Randomized controlled prospective studies may not be possible due to ethical reasons. However, prospective longitudinal studies confirming prognostic value of IOM are available. Furthermore, oncological outcome has also been shown to be superior in some brain tumors, with IOM. New methodologies of IOM are being developed and clinically applied. This review establishes a composite view of techniques used today, noting differences between adult and pediatric monitoring.

• 대한임상검사과학회지
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• 제52권4호
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• pp.317-326
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• 2020

마취는 의식의 차단 역할을 하는 주 마취제와 감각, 운동, 반사의 차단을 하는 부 마취제인 근이완제로 구분된다. 깊은 의식의 차단만으로는 심한 자극에 대한 반응을 막을 수 없고, 다량의 진통제만으로는 무의식을 보장할 수 없다. 그러므로 마취는 동시에 두 가지를 모두 만족시켜야 한다. 근 이완제는 흡입 또는 정맥마취제의 투여 용량을 감소시키면서 기관지내 삽입관, 수술 시야 및 수술적 환경(operating conditions)을 향상시킬 수 있으며, 수술 중 기계적 조절 환기(controlled mechanical ventilation) 시 호흡 관리를 위하여 매우 중요하다. 이러한 근이완제는 투여 용량이 과다하면 수술 중 신경 검사가 안 되는 영향을 줄 수 있고, 투여 용량이 부족하게 되면 환자가 수술 중 움직일 수 있어서 근 이완 마취 심도와 수술 중 감시 검사는 밀접한 관계가 있다. 근 이완제를 많이 사용하면, 수술 중 신경생리학적 검사가 원활하게 되지 않는 단점과 수술 이후에 완전히 근 이완효과를 제거하기 어렵다는 단점도 갖고 있다. 수술 중 감시 검사를 하는 수술에서 마취과에서는 어떠한 기준으로 근 이완제를 투여하며 유지하는지에 대하여 국내뿐만 아니라 전 세계적인 동향을 살펴 봄으로써 보다 원활한 수술 중 신경 검사가 되길 바란다.

• Journal of Gastric Cancer
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• 제19권1호
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• pp.49-61
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• 2019

Purpose: The perigastric vagus nerve may play an important role in preserving function after gastrectomy, and intraoperative neurophysiologic tests might represent a feasible method of evaluating the vagus nerve. The purpose of this study is to assess the feasibility of neurophysiologic evaluations of the function and viability of perigastric vagus nerve branches during gastrectomy. Materials and Methods: Thirteen patients (1 open total gastrectomy, 1 laparoscopic total gastrectomy, and 11 laparoscopic distal gastrectomy) were prospectively enrolled. The hepatic and celiac branches of the vagus nerve were exposed, and grabbing type stimulation electrodes were applied as follows: 10-30 mA intensity, 4 trains, $1,000{\mu}s/train$, and $5{\times}$frequency. Visible myocontractile movement and electrical signals were monitored via needle probes before and after gastrectomy. Gastrointestinal symptoms were evaluated preoperatively and postoperatively at 3 weeks and 3 months, respectively. Results: Responses were observed after stimulating the celiac branch in 10, 9, 10, and 6 patients in the antrum, pylorus, duodenum, and proximal jejunum, respectively. Ten patients responded to hepatic branch stimulation at the duodenum. After vagus-preserving distal gastrectomy, 2 patients lost responses to the celiac branch at the duodenum and jejunum (1 each), and 1 patient lost response to the hepatic branch at the duodenum. Significant procedure-related complications and meaningful postoperative diarrhea were not observed. Conclusions: Intraoperative neurophysiologic testing seems to be a feasible methodology for monitoring the perigastric vagus nerves. Innervation of the duodenum via the celiac branch and postoperative preservation of the function of the vagus nerves were confirmed in most patients.

• Journal of Korean Neurosurgical Society
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• 제66권2호
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• pp.211-218
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• 2023

Pediatric nondysraphic intramedullary lipoma is very rare, and only limited cases have been reported. In the present case, we present two infant patients with these pathologies who were surgically treated. Previous literature on 20 patients with these diseases who had undergone surgical treatments was analyzed. Surgical treatment should be considered in most symptomatic patients, and laminoplastic laminotomy and internal debulking of the lipoma under intraoperative neurophysiological monitoring are mostly recommended.