• The Korean Journal of Physiology and Pharmacology
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• 제5권3호
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• pp.213-221
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• 2001

The amygdala is known as a site for inducing analgesia, but its action on the trigeminal nucleus has not been known well. Little information is available on the effect of dynorphin on NMDA receptor-mediated electrophysiological events in the trigeminal nucleus. The purpose of this study was to investigate the changes in the single neuron spikes at the trigeminal nucleus caused by the amygdala and the action of dynorphin on the trigeminal nucleus. In the present study, extracellular single unit recordings were made in the dorsal horn of the medulla (trigeminal nucleus caudalis) and the effects of microiontophoretically applied compounds were examined. When [D-Ala2, N-Me-Phe4, Glys5-ol]enkephalin (DAMGO, 10-25 mM), a ${\mu}-opioid$ receptor agonist, was infused into the amygdala, the number of NMDA-evoked spikes at the trigeminal nucleus decreased. However, the application of naloxone into the trigeminal nucleus while DAMGO being infused into the amygdala increased the number of spikes. Low dose (1 mM) of dynorphin in the trigeminal nucleus produced a significant decrease in NMDA-evoked spikes of the trigeminal nucleus but the NMDA-evoked responses were facilitated by a high dose (5 mM) of dynorphin. After the ${\kappa}$ receptors were blocked with naloxone, dynorphin induced hyperalgesia. After the NMDA receptors were blocked with AP5, dynorphin induced analgesia. In conclusion, dynorphin A exerted dose-dependent dual effects (increased & decreased spike activity) on NMDA-evoked spikes in the trigeminal nucleus. The inhibitory effect of the dynorphin at a low concentration was due to the activation of ${\kappa}$ receptors and the excitatory effect at a high concentration was due to activation of NMDA receptors in the trigeminal neurons.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권4호
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• pp.679-700
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• 1996

Inferior alveolar nerve dysfunction may be the result of trauma, disease, or iatrogenic injury. Inferior alveolar nerve injury is inherent risk in endodontic therapy, orthognathic surgery of the mandible, and extraction of mandibular teeth, particularly the third molars. The sensory disturbances of inferior alveolar nerve associated with such injury have been well documented clinical problem that is commonly evaluated by several clinical sensory test including Tinels sign, Von Frey test(static light touch detection), directional discrimination, two-point discrimination, pin pressure nociceptive discrimination, and thermal test. These methods used to detect and assess inferior alveolar nerve injury have been subjective in nature, relying on the cooperation of the patients. In addition, many of these techniques are sensitive to differences in the examiners experience and skill with the particular technique. Data obtained at different times or by different examiners are therefore difficult to compare. Prior experimental studies have used electro diagnostic methods(sensory evoked potential) to objectively evaluate inferior alveolar nerve after nerve injury. This study was designed with inferior alveolar nerve of rabbit. Several types of injury including mind, moderate, severe compression and perforation with 19 gauze, 21 gauze needle and 6mm, 10mm traction were applied for taking the sesory evoked ppterntial. Latency and amplitude of injury rabbit inferior alveolar nerve were investigated with sensory evoked potential using unpaired t-test. The results were as follows : 1. Intensity of threshold (T1) was $128{\pm}16{\mu}A$ : latency, $0.87{\pm}0.07$ microsecond : amplitude, $0.4{\pm}0.1{\mu}V$ : conduction velocity, 23.3 m/s in sensory evoked potential of uninjured rabbit inferior alveolar nerve. 2. Rabbit inferior alveolar nerve consists of type II and III sensory nerve fiber. 3. Latency was increased and amplitude was decreased in compression injury. The more injured, the more changed in latency and amplitude. 4. Findings in perforation injury was similar to compression injury. Waveform for sensory evoked potential improved by increasing postinjured time. 5. Increasing latency was prominent in traction injury rabbit inferior alveolar nerve. 6. In microscopic histopathological findings, significant degeneration and disorganization of the internal architecture were seen in nerve facicle of severe compression and 10mm traction group. From the above findings, electrophysiological assessment(sensory evoked potential) of rabbit injured inferior alveolar nerve is reliable technique in diagnosis and prognosis of nerve injury.

• 말소리와 음성과학
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• 제1권4호
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• pp.203-207
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• 2009

Electrically evoked compound action potentials (ECAP) have originated from the distal end of the auditory nerve. ECAP are characterized as the difference between the clearly large trough (N) and the following positive peak (P). N-wave occurs around $200-400\;{\mu}s$ after stimulus onset and P-wave at around $400-800\;{\mu}s$. Contrary to expectations, positive peaked ECAP (pp-ECAP) was dominated by a relatively large-amplitude positive following negative peak. pp-ECAP can be recorded from the sites on or near the surgically exposed nerve trunk in animal models and/or in cases of monophasic stimulation. This study will provide the causes of the appearance of pp-ECAP in cases of cochlear implant recipients using imaging studies and medical records and statistically analysis between N-P and P-N on the amplitude input-output function (amp-I/O) for the prediction of the possibilities of clinical tools. Thirteen children participated in the study and received a Cochlear CI-24RE (CA). ECAP was recorded using auto-NRT (Cochlear Ltd., Australia) at four to five weeks post surgery. pp-ECAP was measured from 36 electrodes and typical ECAP from 220 electrodes. There was no abnormality in the imaging study and operation finding in patients with typical ECAP. pp-ECAP was found at the inner ear anormaly and ossification in imaging study and gel-state inner ear fluid was observed in the operation finding. The amplitude of pp-ECAP increased depending on current intensities, but amp-I/O increase more gradually than in the case of typical ECAP (p=0.003). pp-ECAP is antidromic potential which can record from the inner ear anormaly and ossified cochlear. Amp-I/O also depends on current intensity as well typical ECAP. These results provide a useful tool for audiological evaluation for the spiral ganglion cell status to the value of pp-ECAP.

• Annals of Clinical Neurophysiology
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• 제2권2호
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• pp.101-106
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• 2000

Background and Purpose : Brainstem auditory evoked potentials(BAEPs) are responses of the brainstem by auditory stimulation. Vertebrobasilar transient ischemic attacks is the disease that occurs by insufficient circulation in the region of brainstem. The purpose of this study is to know the factors influencing the changes of BAEPs in vertebrobasilar transient ischemic attacks. Methods : The subject of study was 96 patients diagnosed as vertebrobasilar transient ischemic attacks. Patients were divided into two groups according to the BAEPs findings. Their age, sex, presence of hypertension, diabetes, hyperlipidemia, heart disease, neurologic findings, previous stroke, previous vertebrobasilar transient ischemic attacks, smoking and alcohol drinking, and time period between symptom onset and testing were compared. Results : There were no significant differences in age, sex, and presence of hypertension, diabetes, hyperlipidemia, heart disease, previous stroke history, previous vertebrobasilar transient ischemic attack, smoking, and alcohol drinking between two groups. The presence of abnormal neurologic findings in the first examination and time period between symptom onset and testing were significantly different between normal BAEPs group and abnormal BAEPs one(P<0.05). Conclusions : The factors influencing the changes of BAEPs were presence of abnormal neurologic findings and time period between symptom onset and testing. These findings suggest that BAEPs test should be performed in acute stage of ischemic attack.

• Annals of Clinical Neurophysiology
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• 제1권1호
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• pp.10-18
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• 1999

연구배경 및 목적 : 시각 인지 과정은 영장류 실험을 통하여 다소 정보를 얻을 수 있었으나 인간에서는 아직 완전하게 이해되지 않고 있다. 이 연구의 목적은 뇌자극과 시가유발전위 검사를 토대로 인간의 시각피질의 기능적 분화와 시간 순으로 활성화되는 양상을 보고자 한 것이다. 연구방법 : 간질 수술을 위하여 후두엽과 인접 부위에 광범위하게 피질하전극을 넣은 22명의 환자를 대상으로 전기적 뇌자극과 시각유발전위 검사를 시행하였다. 뇌자극시 나타나는 반응은 형태, 색, 및 움직임의 세 가지로 크게 나누고 형태는 다시 단순, 중간 및 복잡한 형태로 세분하였다. 시각유발전위는 P1 혹은 IV파의 latency를 측정하였다. 결과 : 단순 혹은 중간 형태는 흔히 occipital pole과 striate cortex에서 발생하였다. 색반응은 후두엽의 기저부 즉, fusiform, lingual, inferior occipital gyri를 자극할 때 관찰되었다. 움직임 반응은 내측기저부 및 외측의 측후두엽 혹은 측두정후두부의 경계부에서 주로 나타났다. 결론 : 이러한 결과는 인간의 시각피질이 시각의 여러 가지 구성성분 즉, 형태, 색, 및 움직임에 대해서 각각 별도로 분화되어 있다는 것을 보여준다. 도한 시각자극이 전해지면 striate cortex와 occipital pole이 가장 먼저 활성화되고 이어서 내측 및 외측 후두엽 부위가 활성화된다는 것을 알 수 있다. 이러한 사실을 종합하여 보면 인간의 시각피질은 시각의 여러 구성성분별로 별도로 발달된 해부학적 경로를 통하여 각각의 기능에 대하여 특수하게 분화된 뇌세포에서 시각정보를 각각 분석하되 일정한 시간순서에 의한다는 것을 시사하는 것이다.

• Journal of Korean Neurosurgical Society
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• 제63권2호
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• pp.202-209
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• 2020

Objective : The purpose of this study was to evaluate the efficacy of the anterior approach following intraoperative reduction under general anesthesia in patients with cervical facet fracture and dislocation. Methods : Twenty-three patients with single level cervical facet fracture and dislocation who were subjected to the anterior approach alone following immediate intraoperative reduction under general anesthesia from March 2013 to December 2017 were enrolled in this study. Neurological status, clinical outcome, and radiological studies were evaluated preoperatively, postoperatively, and during the follow-up period. Results : The cohort comprised 15 men and eight women with a mean age of 57 years (from 24 to 81). All patients were operated on within the first 8 hours following the injury. After gentle manual reduction or closed reduction with Gardner-Wells traction, under general anesthesia monitored by somatosensory-evoked potentials, all operations were successfully completed using the anterior approach alone except in two patients, who had a risk of over-distraction. In them, a satisfactory gentle manual reduction or closed reduction was not possible, and required open posterior reduction of the locked facets followed by anterior cervical discectomy and fusion. In one patient, screw retropulsion was observed in 1 month after surgery. There were no reduction-related complications or neurological aggravations after surgery. All patients showed evidence of stability at the instrumented level at the final follow-up (mean follow-up, 12 months). Conclusion : Anterior approach following intraoperative reduction monitored by somatosensory-evoked potentials under general anesthesia for cervical dislocation and locked facets is a relatively safe and effective alternative when cervical alignment is achieved by intraoperative reduction.

• Clinical and Experimental Pediatrics
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• 제53권4호
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• pp.607-611
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• 2010

Bickerstaff 뇌간 뇌염은(BBE) 4주 이내의 진행성이며, 비교적 대칭성으로 오는 안근 마비와 실조증, 의식 장애 또는 심부건 반사 항진 등의 임상적 특징을 가지며, 뇌간을 침범하는 타 질환을 배제하였을 때 진단할 수 있는 드문 질환이다. 혈청 또는 뇌척수액의 항 Ganglioside 항체(GM, GD and GQ) 는 때로 BBE의 진단에 도움이 되기도 하며, 뇌 자기 공명 영상, 뇌 척수액 검사, 신경 전도 검사 및 근 전도 검사 등은 진단에 크게 도움이 되지 않는다. 저자들은 안근 마비, 실조증, 언어 운동 장애, 연하 장애, 점진적 사지 마비, 의식 저하 등의 증상을 보이며 혈청과 뇌척수액에서 anti-GM1 항체의 증가를 보여 BBE로 진단하고 면역 글로불린과 스테로이드 치료 후 완치되었던 9세의 여아의 증례를 경험하였기에 문헌 고찰과 함께 이를 보고하는 바이다.

• Annals of Clinical Neurophysiology
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• 제2권1호
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• pp.13-20
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• 2000

Background and Objective : Visual evoked potentials(VEPs) is considered to be a reliable diagnostic procedure for examining patients with anterior visual pathways. Some abnormalities in the recordings on monocular stimulation have been said to indicate retrochiasmal lesion, but less consistent results have been reported. This study is to evaluate the positive predictability of VEP for the detection of retrochiasmal lesion. Methods : We reviewed VEPs that could be interpreted as indicative of a retrochiasmal lesions, based on amplitude or latency asymmetry recorded on the left(O1) and right(O2) occipital regions. Bilateral absent VEPs on both recording(O1 and O2) without evidence of prechiasmal lesion were included. During 5 years, we identified 31 patients who met the above criteria and who had undergone magnetic resonance imaging(MRI) of brain(one patient underwent computerized tomography). Twenty three patients underwent pattern reversal VEPs and others underwent flash goggle VEPs. Results : Brain imagings were abnormal in 29 and were normal in 2. Of the 29 abnormal scans, lesions in posterior visual pathway were detected in 21 scans(predictive value=68%). The predictive value was not significantly different between flash goggle VEP(75%) and pattern reversal VEP(68%). The predictive value was higher in patient with visual field defect(100%) than those without visual field defect(25%). The pathologic nature of lesion also showed close relations to the predictive value. VEPs is usually paradoxically lateralized(78%), but not in all patients. Conclusion : VEPs abnormalities suggesting retrochiasmal lesion were usually corresponded with brain MRI findings. Diagnostic reliability could be increased when considering the visual field defect and nature of lesion. Therefore, the authors suggest that VEPs studies could be useful in evaluating the patients with the retrochismal lesion.

• 대한임상검사과학회지
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• 제53권2호
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• pp.193-198
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• 2021

척수경막동정맥루의 수술적기법은 동정맥루에 결찰을 통해 혈액공급을 원활하게 하여 신경학적 손상을 막는 수술법이다. 이에 INM 검사는 환자의 신경학적 증상에 따른 수술 후의 부작용을 최소화하기 위해 복합(multimodal)적인 신경계검사가 요구된다. TceMEP는 환자의 피질척수로(corticospinal tract)의 상태를 확인할 수 있는 검사이다. 척수경막동정맥루에서 결찰할 때마다 TceMEP를 분단위로 검사를 진행해 이상 유무를 확인해야 한다. 하지만 검사자가 수술과정이나 검사에 대한 술기가 부족하거나 검사자와 집도의 간에 원활하지 못한 의사소통으로 TceMEP의 잘못된 자극 시점은 수술진행에 방해가 되며 수술 후 환자에게 마비와 위약과 같은 부작용이 생길 수 있다. 척수경막동정맥루 결찰술에서 INM은 앞으로 더 많은 연구와 함께 추가적인 증례보고들이 필요할 것이라고 생각하며 검사자들 또한 환자의 신경학적 손상을 최소화하기 위해 노력해야 할 것이다.

• Journal of Audiology & Otology
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• 제25권3호
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• pp.152-158
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• 2021

Background and Objectives: Balance control is maintained in stationary and dynamic conditions, with coordinated muscle responses generated by somatosensory, vestibular, and visual inputs. This study aimed to investigate how the vestibular system is affected in the presence of an optical illusion to better understand the interconnected pathways of the visual and vestibular systems. Subjects and Methods: The study involved 54 young adults (27 males and 27 females) aged 18-25 years. The recruited participants were subjected to the cervical vestibular evoked myogenic potentials (cVEMP) test and video head impulse test (vHIT). The cVEMP and vHIT tests were performed once each in the absence and presence of an optical illusion. In addition, after each test, whether the individuals felt balanced was determined using a questionnaire. Results: cVEMP results in the presence of the optical illusion showed shortened latencies and increased amplitudes for the left side in comparison to the results in the absence of the optical illusion (p≤0.05). When vHIT results were compared, it was seen that the right lateral and bilateral anterior canal gains were increased, almost to 1.0 (p<0.05). Conclusions: It is thought that when the visual-vestibular inputs are incompatible with each other, the sensory reweighting mechanism is activated, and this mechanism strengthens the more reliable (vestibular) inputs, while suppressing the less reliable (visual) inputs. As long as the incompatible condition persists, the sensory reweighting mechanism will continue to operate, thanks to the feedback loop from the efferent vestibular system.