감각신경계의 신경생리와 임상적 이용

서대원 대한임상신경생리학회 2010 Annals of Clinical Neurophysiology Vol.12 No.2

Various electrophysiological tests have provided a large body of valuable information on neuronal responses to a presented stimulus. The special and general somatic sensory pathways are main targets of evoked potentials. Two types of evoked potentials, exogenous and endogenous, are commonly used. Exogenous evoked potentials of general and special somatic sensory systems will be reviewed. One of general somatic sensory functional pathways, proprioception, can be evaluated by general somatosensory evoked potentials with electrical stimulation on nerves. The special somatosensory functional pathways,including vision, and audition, can be evaluated by visual evoked potentials and auditory evoked potentials. Also laser-evoked potentials are newly developed for pain pathway, including lateral spinothalamic pathway, and vestibular myogenic evoked potentials for sacculocollic pathways. The evoked potentials of sensory system have maximal clinical utility in evaluating functional deficits along the sensory pathways. They are used for evaluating comatose patients, hysterical patients, premature infants, patients with suspected demyelinating diseases or neoplasms, and research. We discuss the neurophysiologic tests of sensory systems in views of practical points. The organized evaluation of sensory electrophysiologic tests can be helpful in detecting and estimating the abnormalities in neurological diseases.

뇌성마비 환자에서의 뇌유발전위 평가

노혜미(Hye Mi Rhou),이건수(Keon Su Lee),안인철(Ren Zhe An) 대한소아신경학회 1999 대한소아신경학회지 Vol.7 No.2

목 적 : 뇌성마비는 주산기부터 영유아기 사이의 미숙한 뇌에 발생한 손상에 의해 초래되는 동작과 자세의 질환으로 소아장애의 주원인으로 방사선학적 검사법을 이용한 뇌손상 부위의 정확한 해부학적 진단과 뇌유발전위 검사법과 같은 신경생리 검사를 이용한 뇌기능 평가가 가능해졌다. 따라서 본 연구에서는 뇌성마비 환아에서 뇌유발전위 검사의 평가 결과 및 뇌파와 뇌전산화단층촬영이나 자기공명영상기술 결과와의 상관성에 대해 조사하였다. 방 법 : 충남대학교 병원 소아과 및 재활의학과에서 병력 및 이학적 소견으로 뇌성마비를 진단 받은 환아 중 1995년 7월부터 1999년 6월까지 뇌유발전위 검사를 시행받았던 환아 86명을 대상으로 의무기록을 검토하여 뇌유발전위 검사 결과를 조사하였으며 뇌성마비의 유형, 뇌파 및 방사선학적 검사 결과와의 통계적 상관성을 분석하였다. 결 과 : 1) 대상 환아의 뇌성마비 임상형은 강직형 85%, 무정위형 3.5%, 혼합형 3.5%, 임상형이 정확히 명기되지 않았던 예가 8.1%였다. 2) 뇌유발전위 검사결과 시각유발전위 검사 29.47%, 청각유발전위 검사 18.8%, 정중신경유발전위 검사 37.8%, 경골신경유발전위 검사 52.7%에서 비정상 소견을 보였다. 3) 뇌파 검사, 자기공명영상술, 뇌전산화촬영 결과와 뇌유발전위 검사 결과는 통계학적으로 유의한 상관성이 없었다(P>0.05). 결 론 : 뇌유발전위 검사는 비침습적인 신경 검사로써 뇌파 검사나 방사선학적 검사와의 독립적으로 뇌성마비 환아에서 향후 신경학적 발달 경과와 감각 장애의 조기 진단과 치료에 도움이 될 것으로 사료된다. Purpose : Cerebral palsy is a group of conditions characterized by nonprogressive motor and posture dysfunction developing during perinatal period due to brain damage. Combined sensory and cognitive disorders can evolve the secondary mental retardation or speech disorder. Brain evoked potential can evaluate the visual, auditory, somatosensory neuropathway, and the response of frontal, temporal, occipital lobe. We studied the usefulness of brain pvoked votential as a tool in the early diagnosis and treatment of sensory disorders in cerebral palsy. Methods : We retrospectively reviewed the records of 86 cerebral palsy patients who were practiced brain evoked potential study in Chungnam National University Hospital from July, 1995 to June, 1999. We analyzed the visual, auditory, somatosensory evoked potential result and the correlations between the electroencephalography, radiologic brain imaging study and the brain evoked potential. Results : 1) Clinical types of cerebral palsy were spastic type(85.0%), athetoid type(3.5%), mixed type(3.5%) and the remaining cases did not manifest any one the types above. 2) Abnormal evoked potential fingings were 25 cases(29.4%) in visual evoked potential, 16 cases(18.8%) in auditory evoked potential, 28 cases(37.8%) in median nerve evoked potential, 39 cases(52.7%) in tibial nerve evoked potential. 3) Electroencephalography, radiologic brain imaging study manifested no statistically significant correlations with the brain evoked potential result(P>0.05). Conclusion : As a noninnvasive neurophysiologic study, Brain evoked potential is a useful method predicting neurologic developmental progress and helpful to early diagnosis of sensory disorder in cerebral palsy patients.

소아 사립체 질환에서 시각 유발전위검사의 유용성

송지은,김헤민,박윤길,변석호,이준수,김흥동,이영목,이상철 대한소아청소년과학회 2009 Clinical and Experimental Pediatrics (CEP) Vol.52 No.4

Purpose : Mitochondrial disorders are a clinical entity characterized by diverse symptoms and signs of involvement of various systems. Furthermore, the disorders are known to show ophthalmologic manifestations as well as neurological findings. Visually evoked potential is a sensitive measure to check the integrity of the visual pathway. In this study, we have investigated the value of visually evoked potential in mitochondrial disorders with respiratory chain defects. Methods : Nineteen patients diagnosed with mitochondrial respiratory chain complex I defect as confirmed by spectrophotometric enzyme assay in muscle samples were enrolled for this study. The patients underwent a visually evoked potential study. We classified the results into four groups and compared these with clinical ophthalmologic findings. Results : Among the 19 patients, 14 showed abnormal visually evoked potential findings. Seven patients showed abnormal clinical ophthalmologic findings. All patients with abnormal ophthalmologic findings showed abnormal visually evoked potential findings. Among the 12 patients with normal ophthalmologic findings, seven showed abnormal results in visually evoked potential. Conclusion : Visually evoked potential study could be used as an effective screening tool for mitochondrial disorders to detect ophthalmologic and neurological abnormalities. 목 적 : 사립체 질환은 여러 가지 장기의 증상을 나타내는 에너지 대사 질환으로, 뇌병증과 더불어 안과적 증상도 다양한 형태로 표현된다. 본 연구에서는 시신경에서 후두부의 뇌피질에 이르는 신경계를 평가하는 시각전위유발 검사를 사립체 질환 환아에서 시행하여 그 유용성과 가치를 분석하고자 하였다. 방 법 : 근육 조직을 이용한 분광광도 검사법에서 사립체 호흡 연쇄 복합체 I 결함으로 확진된 환아 19명을 대상으로 섬광자극 시각 유발전위검사를 시행하여, 그 결과를 정상 반응군(Ⅰ), 잠복기 지연군(Ⅱ), 비정상 파형군(Ⅲ), 무반응 이상군(Ⅳ)으로 나누어 판정하였으며, 환아들의 임상양상과 비교하였다. 결 과 : 전체 19명 중 시각전위 유발검사에서 이상소견을 보인 환아는 14명이었고, 무반응 이상군(Ⅳ)이 6명, 비정상 파형군(Ⅲ)이 6명, 잠복기 지연군(Ⅱ)이 2명 관찰되었다. 망막과 시신경 검사를 포함한 안과 검진에서 이상 소견을 보인 환아는 7명이었으며, 망막 색소 침착이 3명, 시신경 위축 3명, 사시 3명, 안구진탕 1명, 시력 소실이 1명에서 나타났다. 안과 검진에서 이상 소견을 보인 7명은 모두 시각 유발전위검사에서 이상 소견을 나타내었으며, 안과 검진에서 정상 소견을 보인 12명 중에서도 7명이 시각전위유발 검사에서 이상 소견을 나타내었다. 결 론 : 시각 유발전위검사는 안과 증상을 포함하여 다양한 중추신경계 관련 증상이 동반되는 사립체 질환에서 유용한 선별 검사이다.

신체장해평가 환자에서 시유발전위 검사의 유용성

박명진,임상현,이성진,박성희 대한안과학회 2006 대한안과학회지 Vol.47 No.2

Purpose: This study aimed to find out whether the pattern and flash visual evoked potentials (VEP) is useful as methods to examine functional visual loss (FVL) among patients complaining of decreased visual acuity after trauma. Methods: The medical records of trauma-related patients entrusted to the department of ophthalmology for evaluation from January 2001 to October 2004 were reviewed, Correlation were then analyzed by comparing visual acuity, visual field, and visual evoked potentials. Results: There were 45 subjects, 23 of whom complained of symptoms including decreased visual acuity or visual field constriction in one eye. However no abnormalities were found in ophthalmologic tests, and pattern of flash visual evoked potentials were found to be normal for their eyes. Therefore, the cases were diagnosed with functional visual loss. Among the 23 cases, 4 showed abnormal results in the pattern visual evoked potentials, but findings for the eyes in terms of flash visual evoked potentials were normal, so these were also diagnosed with functional visual loss. Conclusions: With visual evoked potentials only, one cannot diagnosed functional visual loss, but, it could be employed usefully as complementary test in the examination of patients for whom functional visual loss is doubted clinically.

Effects of Caffeine on Auditory- and Vestibular-Evoked Potentials in Healthy Individuals: A Double-Blind Placebo-Controlled Study

Elham Tavanai,Saeid Farahani,Mansoureh Adel Ghahraman,Saleheh Soleimanian,Shohreh Jalaie 대한청각학회 2020 Journal of Audiology & Otology Vol.24 No.1

Background and Objectives:The blockage of adenosine receptors by caffeine changes the levels of neurotransmitters. These receptors are present in all parts of the body, including the auditory and vestibular systems. This study aimed to evaluate the effect of caffeine on evoked potentials using auditory brainstem responses (ABRs) and cervical vestibular-evoked myogenic potentials (cVEMPs) in a double-blind placebo-controlled study. Subjects and Methods: Forty individuals (20 females and 20 males; aged 18-25 years) were randomly assigned to two groups: the test group (consuming 3 mg/kg pure caffeine powder with little sugar and dry milk in 100 mL of water), and the placebo group (consuming only sugar and dry milk in 100 mL water as placebo). The cVEMPs and ABRs were recorded before and after caffeine or placebo intake. Results: A significant difference was observed in the absolute latencies of I and III (p<0.010), and V (p<0.001) and in the inter-peak latencies of III–V and I–V (p<0.001) of ABRs wave. In contrast, no significant difference was found in cVEMP parameters (P13 and N23 latency, threshold, P13-N23 amplitude, and amplitude ratio). The mean amplitudes of P13-N23 showed an increase after caffeine ingestion. However, this was not significant compared with the placebo group (p>0.050). Conclusions: It seems that the extent of caffeine’s effects varies for differently evoked potentials. Latency reduction in ABRs indicates that caffeine improves transmission in the central brain auditory pathways. However, different effects of caffeine on auditory- and vestibular-evoked potentials could be attributed to the differences in sensitivities of the ABR and cVEMP tests.

객관적인 후각 기능 평가를 위한 후각 전위 유발 검사

최윤석,윤석영,고국진,한길수,장태영 대한이비인후과학회 2007 대한이비인후과학회지 두경부외과학 Vol.50 No.8

Background and Objectives:proper management of olfactory dysfunction. But there is no confirmative objective method for olfactory function evaluation. Recently, olfactory evoked potential by jet steam method was introduced as an objective method for the evaluation of olfactory function. The purpose of this study is to evaluate clinical eficacy of olfactory evoked potential. Subjects and Method:Thirty two normal individuals were evaluated with olfactory evoked potential and their olfactory thresholds were within normal range were averaged by Neuropack Four Computer. Results:Twenty-nine individuals had typical positive waves with latency near 0.1ms, but three individuals had no typical positive wave. The threshold of twenty individuals in electro-olfactometry was E1 with E1 recognition or detection threshold in T&T olfactometry. The threshold of other nine individuals in electro-olfactometry was E2 with E1 recognition and detection threshold in T&T olfactometry. Conclusion:Olfactory evoked potential has good (Korean J Otorhinolaryngol-Head Neck Surg 2007 ;50 :672-6)

백서에서 삼차신경 유발전위의 특성과 경로 분석

김세혁,조춘식,권오규,이배환,박용구,정상섭,Kim, Se-Hyuk,Zhao, Chun-Zhi,Kwon, Oh-Kyoo,Lee, Bae-Hwan,Park, Yong-Gou,Chung, Sang-Sup 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.8

Objective : There are some advantages of trigeminal evoked potential(TEP) recording compared to other somatosensory evoked potential(SSEP) recordings. The trigeminal sensory pathway has a pure sensory nerve branch, a broader receptive field in cerebral cortex, and a shorter pathway. Despite these advantages, there is little agreement as to what constitutes a normal response and what wave forms truly characterize the intraoperative TEP. This study presents the normative data of TEP recorded on the epidural surface of the rat with a platinum ball electrode. Materials & Methods : Under general anesthesia with urethane, the adult Sprague-Dawley male rats(300-350g) were given electrical stimulation with two stainless steel electrodes which were inserted into the subcutaneous layer of the area around whiskers. A reference electrode was positioned in the temporalis muscle ipsilateral to the recording site. Results : TEPs were recorded in the Par I area of somatosensory cortex and recorded most apparently on the point of 2mm posterior from the bregma and 6mm lateral from the midline. The typical wave form consisted of 5 peaks (N1-P1-N2-P2-N3 according to emerging order, upward negativity). Each latency to corresponding peaks was not influenced by the different intensities of stimulation, especially from 1 to 5mA. Average latencies of 5 peaks were in the following order ; 7.7, 11.1, 15, 22.3, 29.4ms. There was also no significant difference between latencies before and after administration of muscle relaxant(pancuronium). For the electrophysiological localization of recorded waves, the action potential of a single unit was recorded with glass microelectrode(filled with 2M NaCl, $3-5M{\Omega}$) in the thalamus of rat. A sharp wave was recorded in the VPM nucleus, in which the latency was shorter than that of N1. This suggests that all 5 peaks were generated by neural activities in the suprathalamic pathway. Conclusion : In terms of recording near-field potentials, our data also suggests that TEP in the rat may be superior to other SSEPs. In overall, these results may afford normative data for the studies of supratentorial lesions such as hydrocephalus or cerebral ischemia which can have an influence on near-field potentials.

P1-N1-P2 Complex and Acoustic Change Complex Elicited by Speech Sounds: Current Research and Applications

한우재 한국청각언어재활학회 2010 Audiology and Speech Research Vol.6 No.2

Auditory cortical-evoked potentials reflect neural activity related to the detection, perception, discrimination, and cognition of incoming sounds from their timing (latency) and magnitude (amplitude) at the levels of primary auditory cortex and associated areas of the temporal lobe. Researchers have become interested in cortical-evoked potentials elicited by speech stimuli, referred to as speech-evoked potentials (SEPs). SEPs can provide information about a listener’s speech perception abilities at the auditory cortical level, primarily regarding features within speech signals that yield a greater chance of extracting essential cues for human auditory/oral communication. However, to date, relatively little data exist based on naturally produced speech stimuli, which include the listener’s perceptual information, such as specific acoustic/phonetic features, and unmodified spectral/temporal cues produced in natural speech. This tutorial paper reviews current SEP studies and provides feasible applications, focusing on two components of auditory potentials: P1-N1-P2 complex and acoustic change complex (ACC). SEPs offer a powerful objective technique for understanding speech perception of both normal and hearing-impaired listeners, particularly infants and elderly patients who cannot be assessed reliably using typical behavioral speech perception measures; SEPs also provide a means to investigate how acoustical characteristics of various naturally spoken speech stimuli are reflected in the evoked responses for both populations.

The Efficiency of Simultaneous Binaural Ocular Vestibular Evoked Myogenic Potentials: A Comparative Study with Monaural Acoustic Stimulation in Healthy Subjects

김민범,반재호 대한이비인후과학회 2012 Clinical and Experimental Otorhinolaryngology Vol.5 No.4

Objectives. To evaluate the test-retest reliability and convenience of simultaneous binaural acoustic-evoked ocular vestibular evoked myogenic potentials (oVEMP). Methods. Thirteen healthy subjects with no history of ear diseases participated in this study. All subjects underwent oVEMP test with both separated monaural acoustic stimulation and simultaneous binaural acoustic stimulation. For evaluating test-retest reliability, three repetitive sessions were performed in each ear for calculating the intraclass correlation coefficient (ICC) for both monaural and binaural tests. We analyzed data from the biphasic n1-p1 complex, such as latency of peak, inter-peak amplitude, and asymmetric ratio of amplitude in both ears. Finally, we checked the total time required to complete each test for evaluating test convenience. Results. No significant difference was observed in amplitude and asymmetric ratio in comparison between monaural and binaural oVEMP. However, latency was slightly delayed in binaural oVEMP. In test-retest reliability analysis, binaural oVEMP showed excellent ICC values ranging from 0.68 to 0.98 in latency, asymmetric ratio, and inter-peak amplitude. Additionally, the test time was shorter in binaural than monaural oVEMP. Conclusion. oVEMP elicited from binaural acoustic stimulation yields similar satisfactory results as monaural stimulation. Further, excellent test-retest reliability and shorter test time were achieved in binaural than in monaural oVEMP. Objectives. To evaluate the test-retest reliability and convenience of simultaneous binaural acoustic-evoked ocular vestibular evoked myogenic potentials (oVEMP). Methods. Thirteen healthy subjects with no history of ear diseases participated in this study. All subjects underwent oVEMP test with both separated monaural acoustic stimulation and simultaneous binaural acoustic stimulation. For evaluating test-retest reliability, three repetitive sessions were performed in each ear for calculating the intraclass correlation coefficient (ICC) for both monaural and binaural tests. We analyzed data from the biphasic n1-p1 complex, such as latency of peak, inter-peak amplitude, and asymmetric ratio of amplitude in both ears. Finally, we checked the total time required to complete each test for evaluating test convenience. Results. No significant difference was observed in amplitude and asymmetric ratio in comparison between monaural and binaural oVEMP. However, latency was slightly delayed in binaural oVEMP. In test-retest reliability analysis, binaural oVEMP showed excellent ICC values ranging from 0.68 to 0.98 in latency, asymmetric ratio, and inter-peak amplitude. Additionally, the test time was shorter in binaural than monaural oVEMP. Conclusion. oVEMP elicited from binaural acoustic stimulation yields similar satisfactory results as monaural stimulation. Further, excellent test-retest reliability and shorter test time were achieved in binaural than in monaural oVEMP.

요추 척추관 협착증 환자에 대한 전기진단학적 연구

김상범 동국대학교 경주대학 1993 東國論集 Vol.12 No.-

Lumbar spinal stenosis is one of the main causes of the low back pain and defined as any type of narrowing of spinal canal of nerve root canals of intervertebral foramina. But, the value of electrodiagnostic study has been controversial due to variable clinical findings and electrodiagnostic tests are not stadardized as yet. So to determine the electrodiagnostic features of the spinal stenosis and sensitivities of the electrodiagnostic tests. we studied conventional electromyography and somatosensory evoked potentials in 48 lumbar spinal stenosis patients and compared these electrodiagnostic findings with radiologic findings and surgical findings. The conclusions are as follows 1) The sensitivities of the electrodiagnostic tests when using raidologic findings as the GOLD standard are nerve conduction study 21%, needle EMG 79%, somatosensory evoked potential 88% and 94% when we combined the study of needle EMG and somatosensory evoked potentials. So, somatosensory evoked potentials are superior to conventional EMG in detecting clinical symptoms. 2) The sensitivities of the electrodiagnostic tests when using operative findings are nerve conduction study 35%, needle EMG 80%, somatosensory evoked potential 85% and 95% when we combined the study of needle EMG and somatosensory evoked potentials. 3) The electrodiagnostic characteristics of the spinal stenosis are bilateral multiradicular involvement and more frequent high radicular involvement that simple herniated nucleus pulposus in lumber spinal stenosis. So electromyographer should explore bilateral and multiple nerve roots in spinal stenosis.