• 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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• 제29권6호
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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.

• Journal of Korean Neurosurgical Society
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• 제29권5호
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• pp.635-639
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• 2000

Objective : Surgery for the microvascular decompression is mostly concerned with injury to the cranial nerves or brain stem by cerebellar retraction. Intraopeartive brain stem auditory evoked potentials(BAEPs) has been continuously monitored on surgery to evaluate the extent of injury, recovery of the nerves and prognosis. Methods : Of the 161 cases of CP angle surgery from Feb. 1996 to Apr. 1998, 103 cases were monitored during operation. Thirty five patients who had undergone similar surgery were selected and evaluated ; 23 patients were monitored and 12 were not during surgery. If monitor showed more than 0.5 mSec delay of latency, surgeon was given a warning not to retract brain any more. If more than 1mSec delay, surgeon was informed to stop surgery and wait for the returning of evoked potentials. The level of amplitudes and delay of latencies during the initial stage of operation, opening the dura, insertion of teflon patches, and closing the dura and recovery were then compared. Resuls : Twenty patients were male and 15 were female. Their average age was 50.26 years. Mean amplitude during the initial stage of operation was $0.60{\pm}0.25mV$, at opening the dura $0.56{\pm}0.26$, after teflon patches insertion $0.49{\pm}0.20$, and after closure of dura $0.47{\pm}0.28mV$. Mean latency during the early stage of operation was $6.08{\pm}0.67mSec$, at opening of dura $6.38{\pm}0.55$, insertion of teflon $6.97{\pm}0.59$, and closing the dura $6.17{\pm}0.54$. There was statistical significance in the difference of amplitudes between each procedures, and in the difference of latencies. For the complete recovery of amplitude and latency, it usually took average 5.65 minutes(0-20 min). In monitored group, only one patient required more than 20 minutes to recover and suffered from hearing disturbance after surgery. Others were recovered within 10 minutes without complications. However, 4 out of 12 patients who were not monitored showed hearing disturbance, and 1 patient had temporary facial palsy and dizziness(p＝0.000). Conclusion : The results indicate that continuous intraoperative monitoring of BAEPs during CP angle surgery is seen mandatory procedure to prevent operative complications.

• 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.