• Title/Summary/Keyword: Evoked potential

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Intraoperative monitoring of cortico-cortical evoked potentials of the frontal aslant tract in a patient with oligodendroglioma

  • Yang, Ha-rin;Ra, Young-Shin;Koo, Yong Seo
    • Annals of Clinical Neurophysiology
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    • v.24 no.1
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    • pp.21-25
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    • 2022
  • The newly identified frontal aslant tract (FAT) that connects the posterior Broca's area to the supplementary motor area is known to be involved in speech and language functions. We successfully intraoperatively monitored FAT using cortico-cortical evoked potentials generated by single-pulse electrical cortical stimulation in a patient with oligodendroglioma.

EFFECTS OF EUGENOL, CAPSAICIN AND DEMETHOXY-NE ON THE PAIN RESPONSE OF DENTAL PULP (Eugenol, Capsaicin과 Demethoxy - NE가 치수동통 반응에 미치는 영향)

  • Lee, Eun-Goo;Lee, Chung-Sik
    • Restorative Dentistry and Endodontics
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    • v.17 no.1
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    • pp.10-21
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    • 1992
  • The purpose of this study was to investigate the analgesic effect of eugenol, capsaicin and demethoxy-NE. Young adult cats, weighing 2.0 to 3.0kg, were used. Each animal was anesthetized (${\alpha}$-chloralose 60mg per kg body weight) and divided into four groups; control, eugenol, capsaicin and demethoxy-NE group. The anterior digastric muscles were exposed and a pair of electrodes was inserted to record the electromyograms. To expose the pulp, each canine teeth was prepared with a low speed bur under cooling and used for recording anterior digastric muscular EMGs evoked by noxious stimulation of dental pulp. To observe effects on jaw opening reflex, inferior alveolar nerve of both sides were exposed for drug application and wire electrodes were inserted in anterior digstric muscle for recording the EMGs. To observe effects on action potential, saphenous nerves of both sides were exposed and three tissue pools were made from surrounding tissue. The most distal pool was used for applying stimulation, the most proximal one for recording of action potential, and the other one for drug application. One side of inferior alveolar nerve and saphenous nerve were used for eugenol, capsaicin, or demethoxy-NE application, the other side of nerve for control experiments(only vehicle application). Anterior digastric muscular EMGs evoked by noxious stimulation of dental pulp were recorded before drug application, immediate after drug application, at 60 and 120 minutes, and 5 days after drug application. Action potentials were recorded before drug application, immediate after 30 minutes drug application, at 30, 60 and 120 minutes after drug had been washed out. The results were as follows; 1. Eugenol had a continuous blocking effect on the anterior digastric muscular EMGs evoked by noxious pulp stimulation and after 5 days, showed completely blocking effect. 2. After 5 days, demethoxy-NE applied to dental pulp had a considerable blocking effect on the jaw opening retlex evoked by noxious stimulation but capsaicin had no significant effect. 3. After 5 days, eugenol group showed the strongest blocking effect among the all experimental groups on the jaw opening reflex evoked by noxious stimulation of dental pulp and capsaicin group showed the weakest blocking effect. 4. Eugenol had a completely blocking effect on the action potential conductivity of peripheral nerve. Capsaicin and demethoxy-NE had the blocking effect on the action potential conductivity of ${\alpha}$-and C-nerve fibers. 5. Capsaicin, demethoxy-NE and eugenol applied to inferior alveolar nerve surppressed the jaw opening reflex evoked by noxious stimulation of dental pulp.

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Abnormal Visual Evoked Potential Response from Hypoglycemic Encephalopathy in Two Neonates (저혈당성 뇌병증에 의한 시각유발전위검사(VEP) 이상을 보인 신생아 2례)

  • Hong, Suk-Woo;Kim, Seung-Yeon;Park, Ho-Jin
    • Neonatal Medicine
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    • v.15 no.1
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    • pp.94-99
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    • 2008
  • Although neonatal hypoglycemia is a common metabolic abnormality in newborn infants, brain injuries resulting from isolated neonatal hypoglycemia are rare. Many infants who are hypoglycemic do not exhibit clinical manifestations, while other infants are symptomatic and at risk for permanent brain damage. There is no disagreement that hypoglycemia can cause neonatal encephalopathy and result in permanent brain injury. Occipital brain injury associated with neonatal hypoglycemia can result in long-term disability, epilepsy, and visual impairment. Infants should receive ongoing developmental and visual surveillance for lateonset epilepsy, and visual or cognitive impairment. We report two cases of newborn infants with abnormal visual evoked potentials (VEP) caused by neonatal hypoglycemic encephalopathy.

Enhancement of Evoked Potential Waveform using Delay-compensated Wiener Filtering (지연보상 위너 필터링에 의한 유발전위 파형개선)

  • Lee, JeeEun;Yoo, Sun K.
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.12
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    • pp.261-269
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    • 2013
  • In this paper, the evoked potential(EP) was represented by additive delay model to comply with the variational noisy response of stimulus-event synchronization. The hybrid method of delay compensated-Wiener filtered-ensemble averaging(DWEA) was proposed to enhance the EP signal distortion occurred during averaging procedure due to synchronization timing mismatch. The performance of DWEA has been tested by surrogated simulation, which is composed of synthesized arbitrary delay and arbitrary level of added noise. The performance of DWEA is better than those of Wiener filtered-ensemble averaging and of conventional ensemble averaging. DWEA is endurable up to added noise gain of 7 for 10 % mean square error limit. Throughout the experimentation observation, it has been demonstrated that DWEA can be applied to enhance the evoked potential having the synchronization mismatch with added noise.

Do N37 and P37 Potentials Have Different Generators in Somatosensory Evoked Potential? - Analysis Using Gating Mechanism - (체성감각 유발전위에서 N37과 P37은 다른 발생기를 가지고 있는가? - gating 현상을 이용한 분석 -)

  • Park, Young Seok;Cha, Jae Kwan;Kim, Sang Ho;Kim, Jae Woo
    • Annals of Clinical Neurophysiology
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    • v.1 no.2
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    • pp.106-111
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    • 1999
  • Backgroud : The generators of N37 and P37 of posterior tibial nerve somatosensory evoked potential(PTSEP) have not been exactly known. Recently, some reports suggested that P37 and N37 might have different generator. We conducted a study to know the generators of P37 and N37 of PTSEP using gating mechanism. Methods : We evaluated subcortical and cortical somatosensoy evoked potentials(SEPs) in response to posterior tibial nerve stimulation in 3 experimental conditions of foot movement and compared them with PTSEPs in full relaxation of foot. The experimental conditions were: (a) active flexion-extention of stimulated foot, (b) isometric contraction of the stimulated foot, (c) passive flexion-extention of the stimulate foot. We analyzed the latencies and amplitudes of following potentials; P30, N37, P37, and N50. Results : The amplitude of P30 potential did not change during at any paradigms. The amplitudes of P37 and N50 were significantly attenuated in all condition. However, the amplitude of N37 showed no significant change during at any paradigms. Conclusions : These results suggest that the generators of P37 and N37 of PTSEP be different in cortex.

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Robot Control based on Steady-State Visual Evoked Potential using Arduino and Emotiv Epoc (아두이노와 Emotiv Epoc을 이용한 정상상태시각유발전위 (SSVEP) 기반의 로봇 제어)

  • Yu, Je-Hun;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.3
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    • pp.254-259
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    • 2015
  • In this paper, The wireless robot control system was proposed using Brain-computer interface(BCI) systems based on the steady-state visual evoked potential(SSVEP). Cross Power Spectral Density(CPSD) was used for analysis of electroencephalogram(EEG) and extraction of feature data. And Linear Discriminant Analysis(LDA) and Support Vector Machine(SVM) was used for patterns classification. We obtained the average classification rates of about 70% of each subject. Robot control was implemented using the results of classification of EEG and commanded using bluetooth communication for robot moving.

Brainstem auditory evoked potential findings in a French bulldog with bilaterally congenital sensorineural deafness

  • An, Daegi;Jung, Dong-In;Kim, Ha-Jung;Kang, Ji-Houn;Chang, Dong-Woo;Yang, Mhan-Pyo;Kang, Byeong-Teck
    • Korean Journal of Veterinary Research
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    • v.53 no.4
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    • pp.265-267
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    • 2013
  • A 3-month-old, intact male French bulldog was suspected of deafness. The dog was irresponsive to environmental noises generated out of sight, but normal responses were noted for visual stimuli. No abnormalities were observed on the neurological, otoscopic, radiographic, and blood examinations. To diagnose the apparent deafness, brainstem auditory evoked potential (BAEP) was recorded in the presented dog together with a normal dog. While the BAEP from the control dog showed a normal wave consisting of 5 peaks, absence of all peaks was noted in the suspected deaf dog. Therefore the dog was definitively diagnosed as bilaterally congenital sensorineural deafness.

Development of a 32 Channel EEG and Evoked Potential Mapping System (32채널 뇌파 및 뇌유발전위 Mapping 시스템 개발)

  • Ahn, C.B.;Yoon, G.B.;Park, D.J.;Yoo, S.K.;Lee, S.H.;Ham, Y.J.;Kang, M.J.;Kim, D.J.
    • Proceedings of the KOSOMBE Conference
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    • v.1995 no.11
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    • pp.86-89
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    • 1995
  • A clinically oriented 32 channel Electroencephalogram (EEG) and evoked potential (EP) mapping system has been developed. The EEG and EP signals acquired from 32-channel electrodes are amplified by the pre-amplifier located near patient and are then tither amplified by main amplifier. An automatic artifact rejection scheme is employed using a neural network by which examination time is reduced substantially. Auditary and visual stimuli are used for the evoked potential mapping. A user-friendly graphical interface based on the Microsoft Window 3.1 is developed for the operation of the system. Statistical databases for the poop and individual comparisons are also included to support statistically based diagnosis.

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Repetitive Transcranial Magnetic Stimulation Combined with Task Oriented Training to Improve Upper Extremity Function After Stroke

  • Kim, Myoung-Kwon
    • Journal of Magnetics
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    • v.19 no.2
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    • pp.170-173
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    • 2014
  • The purpose of the present study was to investigate the effect of repetitive transcranial magnetic stimulation (rTMS) in conjunction with task oriented training, on cortical excitability and upper extremity function recovery in stroke patients. This study was conducted with 31 subjects who were diagnosed as a hemiparesis by stroke. Participants in the experimental (16 members) and control groups (15 members) received rTMS and sham rTMS, respectively, during a 10 minutes session, five days per week for four weeks, followed by task oriented training during a 30 minutes session, five days per week for four weeks. Motor cortex excitability was performed by motor evoked potential and upper limb function was evaluated by motor function test. Both groups showed a significant increment in motor function test and amplitude, latency in motor evoked potential compared to pre-intervention (p < 0.05). A significant difference in post-training gains for the motor function test, amplitude in motor evoked potential was observed between the experimental group and the control group (p < 0.05). The findings of the current study demonstrated that incorporating rTMS in task oriented training may be beneficial in improving the effects of stroke on upper extremity function recovery.