• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권3호
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• pp.250-257
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• 2001

Sensory dysfunction following the injury of the inferior alveolar nerve requires objective examination to get a reproducible data and to provide necessary treatment. This study was designed to evaluate if the SEP(somatosensory evoked potentials) of the mental nerve can be used as an objective method for the diagnosis of nerve injury and sensory disturbances. The subjects were nineteen patients ($37.4{\pm}11.3$ years old) who had been suffered from sensory disturbance of the unilateral lower lip and mental region for over 6 months after the inferior alveolar nerve injuries confirmed by the microsurgical explorations. The clinical neurosensory tests as SLTD(static light touch discrimination), MDD(moving direction discrimination), 2PD(two point discrimination), PPN(pin prick nociception) and accompanied pain were preceded to electro-physiologic examinations as SEP. The score of sensory dysfunction (sum score of all sensory tests) ranged from 0 to 8 were compared to the latency differences of the mental nerve SEPs. The correlation between clinical sensory scores and SEPs were tested by Spearman nonparametric rank correlation analysis, the differences in SEP latency by Kruskal-Wallis test and the latency differences according to PPN and accompanied pain by Mann-Whitney U test. This study resulted that the difference of the latencies between normal side and affected side was $2.22{\pm}2.46$ msec and correlated significantly with the neurosensory dysfunction scores (p=0.0001). Conclusively, the somatosensory evoked potentials of the mental nerve can be a useful diagnostic method to evaluate the inferior alveolar nerve injuries and the change of sensory dysfunction to be reproduced as an objective assessment.

• 한국임상수의학회지
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• 제17권2호
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• pp.388-394
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• 2000

이 실험은 소형견종에 대한 정상 SEPs의 범위를 알아내기 위해 실시되었다. 임상증 상이 정상인 28두를 대상으로 자극점에서 channel 1 까지의 Pl(LPI), channel 1까지의 Nl (LN1), 자극점에서 channel 2가지의 Pl(TP1), channel 2까지의 N1(TNI)의 절대잠복기와 LP1-TN1` 의 파간잠복기를 알아내기 위해서 실시하였다. 이번 실험에서 LPI, LNI, TPI, TNI의 절대잠복기 (absolute latency)의 평균값은 2.69$\pm$0.31 msec, 4.91$\pm$0.49m/sec, 4.64$\pm$0.39 msec, 5.21$\pm$0.42 msec 띠었다. LP1과 TN1 사이의 파간절대잠복기의 핑균값은 2.52$\pm$7.19 msec 이었다. 측정 치들을 속도로 변환하였을 경우 다음과 같았다. 측, LPI, LNI. Tfl, TNI 그리고 LP1-TN1 에서의 속도의 평균값은 각각 93.11$\pm$ 8.58 m/sec, 50.99$\pm$ 5.36m/sec. 80.18$\pm$ sec, 71.31$\pm$4.79m/sec그리고 49.50$\pm$3.58m/sec 이었고. 71.66m/sec, 37.79m/sec, 65.75m/ sec, 59.33 m/sec, 40.55m/sec 의 최저속도를 초과하였을 때 정상범위로 간주하였다. LPI, LNI, TPI,TN1까지의 절대잠복기와 자극전극에 시 측정전극가지의 거리 사이에는 상관관계가 있었다 LP1, LN1, TP1, TN1의 상관계수는 각각 0.621, 0.494. 0.577,0.618 이었다 요추에서 기록된 SEPs갈은 LP1의 상관계수가 LN1 보다 높았으며 흉추에서 기록된 SEPs값은 TN1의 상관계수가 TP1보다 높았다. LP1과 TN1의 파간잠복기와 channel 1과 2의 거리차이와의 상관계수는 0.571이다. 따라서 LPI, LNI. TPI, TNI그리고 LPI-TNI 들의 최저속도를 이용 하여 척수 손상 여부를 판단할 수 있다고 생각된다.

• Annals of Clinical Neurophysiology
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• 제8권2호
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• pp.158-162
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• 2006

Background: It has been proposed that proprioceptive input can modulate neural excitability in both primary motor cortices (M1) simultaneously, although direct evidence for this is still lacking. Previous studies showed that proprioceptive accuracy of one hand is reduced after the application of one-Hz repetitive transcranial magnetic stimulation (rTMS) for 15 minutes over the contralateral somatosensory cortex. The aim of this study was to investigate the effect of rTMS-induced central proprioceptive deafferentation to excitability of both M1 as reflected in ipsilateral and contralateral motor evoked potentials (MEP). Methods: MEPs of both abductor pollicis bravis (APB) muscles were recorded using single-pulse TMS over right M1 in seven healthy subjects. Immediately after one-Hz rTMS was applied for 15 minutes over the right somatosensory cortex, the MEP measurement was repeated. The proprioceptive function of the left thumb was assessed, before and after rTMS, using a position-matching task. Results: There was an increase in ipsilateral MEP after the rTMS: whereas no MEPs were recorded on the ipsilateral hand before the rTMS, MEPs were recorded in both ipsilateral and contralateral hand in three of seven subjects. At the same time, the mean log amplitude was reduced and the mean latency was prolonged in the contralateral MEP. Conclusions: rTMS-induced central proprioceptive deafferentation reduces the MEP generation in the contralateral hand, and fascilitates that in the ipsilateral hand. A further study with a larger sample seems warranted to confirm this finding and to elucidate the neurophysiology underlying it.

• Annals of Clinical Neurophysiology
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• 제5권2호
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• pp.187-191
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• 2003

Purpose: MEPs elicited by transmagnetic stimulations of the motor cortex are facilitated by voluntary muscle contraction. We evaluated the effects of the imagination of the movements on latencies of MEPs and reciprocal inhibition by using transmagnetic stimulations. Methods: Twenty two healthy volunteers(eight men and fourteen women) were studied. TMSs were delivered at rest and during imagining abducting or adducting right thumb. A stimulator with a round coil and a fixed intensity of 80% of maximum was used to evoke MEPs. MEPs were evoked by magnetic stimulations over the scalp and cervical spine(C7-T1), and central motor conduction times(CMCT) were calculated by subtracting the latency of compound muscle action potentials(CMAPs) obtained by stimulating over the cervical spine from that obtained by stimulating over the scalp. The motor evoked potentials were recorded from right abductor pollicis brevis muscle(APB) and adductor pollicis muscle(AP) simultaneously. Results: Imagination of abduction resulted in a shortened latency of the CMAPs in APB, and a prolonged latency in AP. Imagination of adduction resulted in a shortened latency in AP, and a prolonged latency in APB. But the imagination caused no significant change in the latency of CMAPs elicited by stimulation over cervical spine. Therefore, the changes of the CMCTs account for these latency changes with imagination of movement. With the imagination of abduction, there are significant reduction of the CMCT's in APB(10.8%) and prolongation in AP(5.8%). On the other hand, with the imagination of adduction, prolongation of the CMCT's in APB(7.3%) and reduction in AP(5.9%) were observed. Conclusion: These findings indicate that imagination of muscle contraction increases the excitability of the human corticospinal system. Reciprocal inhibition may be accountable for the prolonged latency in the antagonist muscle.

• 대한임상검사과학회지
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• 제43권1호
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• pp.19-25
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• 2011

The purpose of this study was to analyse brainstem auditory evoked potentials (BAEP) wave change data during microvascular decompression (MVD). The nerve function of Cranial Nerve VIII is at risk during MVD. Intraoperative monitoring of BAEP can be a useful tool to decrease the danger of hearing loss. Between January and December 2009, 242 patients had MVD for hemifacial spasm (HFS) and trigeminal neuralgia (TN). Among intraoperative BAEP changes, amplitude of V-V' was the most frequently observed during cerebellar retraction and decompression step of the MVD procedure. 138 patients (57%) had no BAEP change while 104 patients (42.98%) had BAEP change. 69 patients (28.5%) had Type A-I, 16 patients (6.6%) had Type A-II, 5 patients (2.1%) had Type B, and 13 patients (5.37%) had Type C. MVD is a surgical procedure to relieve the symptoms (e.g. pain, muscle twitching) caused by compression of a nerve by an artery or vein. During BAEP intraoperative monitoring, the surgical step is important in interpreting the changes of wave V. Several potential mechanisms of injury may affect the cochlear nerve, and complete loss of BAEP is often associated with postoperative hearing loss. Intraoperative BAEP monitoring may provide an early warning of hearing disturbance after MVD.

• 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.

• 한국지능시스템학회논문지
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• 제22권1호
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• pp.62-68
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• 2012

정상상태시각유발전위 (Steady-State Visually Evoked Potentials)는 특정 주파수를 가진 시각자극에 대한 자연반응 신호이며 3.5Hz~75Hz의 주파수 범위를 갖는 시각 자극에 의해 동일한 주파수로 후두엽 영역이 전기적 활성화되는 특성이 있다. 본 논문에서 이러한 SSVEP 특성을 기반으로 EEG 분석을 수행하는 실험 패러다임을 구축하여 행동유발특성을 가지는 특정 객체에 대한 영상입력 시각자극에서의 주파수 패턴에 대응하는 EEG의 주파수 특징을 검출하고 이를 기반으로 객체와 관련된 행동유발특성을 Mirror Neuron System을 통해 측정한다. 이 때 측정된 EEG 기반 행동유발특성 데이터에 대한 선형판별분석을 수행하여 객체 패턴분류를 실시간으로 수행한다. 이러한 SSVEP 관측 실험을 기반으로 사용자의 내재적 의도를 파악하기 위한 Brain-Computer Interface(BCI) 시스템을 제안했다. Speller 등으로 대표되는 기존의 SSVEP 응용시스템은 격자영상패턴에 대응하는 뇌파특성 분석에 따른 패턴분류의 수행이 가능하나 본 논문의 SSVEP 기반 BCI는 다양한 형태의 사물을 입력객체로 활용하여 분류가 가능함으로 인해 범용성이 높아졌다.

• 한국임상수의학회지
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• 제19권3호
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• pp.277-282
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• 2002

본 실험은 각각의 마취방법이 체성감각유발전위 (SEPs) 파형에 미치는 영향을 알아보고 SEP의 측정에 적절한 마취방법을 찾고자 시행하였다. 임상적으로 건강하고 크기와 나이가 비슷한 다섯 마리의 잡종견을 대상으로 SEPs를 측정하고 각각의 측정값을 분석하였다. SEPs측정을 위해 후 경골신경을 자극하였고 요추 5-6번 사이에서 channel 1의 LP1과 LN1, 흉추 11-12사이에서 channel 2의 TP1, TN1을 기록하였다. 실험에 사용한 마취방법 중. Acepromazine + Thiopental Na + Isoflurane, Acepromazine + Propofol + Isoflurane, Diazepam + Xylazine, Xylazine + Ketamine, Acepromazine + Propofol infusion, 및 Propofol infusion등의 방법만이 SEPs측정이 가능하였고, 파형은 명확하였으며, 측정에 요구되어지는 일정 시간인 25분 이상 동안 마취 유지가 가능하였다. 또한 각 마취군에서의 SEPs 파형을 Acepromazine + Thiopental Na + Isoflurane군과 비교해 보았을 때 latency의 경우, Acepromazine + Propofol + Isoflurane군의 ST(stimulating point)-LN1, SP-TP1, Diazepam + Xylazine 군의 Chl-Ch2, Xylazine + Ketamine군의 Chl-Ch2, Acepromazine + Propofol infusion군의 ST-LP1와 Chl-Ch2에서 부분적으로 유의적인 차가 있었다. Conduction velocity의 경우, Acepromazine + Propofol + Isoflurane군의 ST-LN1, Diazepam + Xylazine군의 Chl-Ch2, Xylazine + Ketamine군의 Chl-Ch2, Acepromazine + Propofol infusion군의 ST-LP1, 그리고 Propofol infusion군의 ST-LN1의 측정값에서 유의적인 차가 있었지만 전반적으로는 전체적인 파형의 유의적인 변화는 없었다. 이상의 결과를 토대로 SEPs 측정시 흡입마취로는 Acepromazine + Thiopental + Isoflurane과 Acepromazine + Propofol + Isoflurane, 주사마취로는 Diazepam + Xylazine과 Xylazine + Ketamine, 점적마취로는 Acepromazine + Propofol infusion과 Propofol infusion 방법이 사용 가능한 것으로 확인되었다.

• 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.

• 대한임상검사과학회지
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• 제48권3호
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• pp.262-268
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• 2016

편측성 안면경련(hemifacial spasm)은 불수의적으로 안면의 근육에서 발작적인 경련이 일측성으로 반복해서 발생하는 질환이다. 한 근육의 수축으로 인해 동시적으로 여러 근육이 동시에 수축되는 동시 수축성(synkinesia)이 특징이다. 발병원인은 제 7뇌신경인 안면신경이 혈관에 의해 압박을 받아서 나타나게 된다. 본 연구는 편측성 안면경련 환자의 미세혈관 감압 수술을 받은 환자를 대상으로 수술 중 진행되는 신경계 감시검사 방법들에 대해 다루었다. 청각유발전위 검사에서는 수술용 뇌 견인기의 사용시 주의 사항과 검사시기에 대해 언급하였다. 안면신경의 근전도검사에서는 잡파의 혼입과 신경손상 시 근전도 파형의 감별에 대해, 측면전파 반응 검사에서는 마취의 유지의 중요성에 대해 그리고 체성감각 유발전위검사에서는 환자를 좀더 자세하게 검사할 수 있도록 새로운 방법을 제안하였다. 위에 언급한 내용들을 토대로 검사한다면 수술 중 신경계 감시 검사를 원활하게 할 수 있으리라 생각된다.