• The Korean Journal of Physiology and Pharmacology
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• 제21권4호
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• pp.439-447
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• 2017

Myotonia congenita (MC) is a genetic disease that displays impaired relaxation of skeletal muscle and muscle hypertrophy. This disease is mainly caused by mutations of CLCN1 that encodes human skeletal muscle chloride channel (CLC-1). CLC-1 is a voltage gated chloride channel that activates upon depolarizing potentials and play a major role in stabilization of resting membrane potentials in skeletal muscle. In this study, we report 4 unrelated Korean patients diagnosed with myotonia congenita and their clinical features. Sequence analysis of all coding regions of the patients was performed and mutation, R47W and A298T, was commonly identified. The patients commonly displayed transient muscle weakness and only one patient was diagnosed with autosomal dominant type of myotonia congenita. To investigate the pathological role of the mutation, electrophysiological analysis was also performed in HEK 293 cells transiently expressing homo-or heterodimeric mutant channels. The mutant channels displayed reduced chloride current density and altered channel gating. However, the effect of A298T on channel gating was reduced with the presence of R47W in the same allele. This analysis suggests that impaired CLC-1 channel function can cause myotonia congenita and that R47W has a protective effect on A298T in relation to channel gating. Our results provide clinical features of Korean myotonia congenita patients who have the heterozygous mutation and reveal underlying pathophyological consequences of the mutants by taking electrophysiological approach.

• Annals of Clinical Neurophysiology
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• 제4권1호
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• pp.34-37
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• 2002

Background : The term "mononeuropathy multiplex" means simultaneous or sequential involvement of individual noncontiguous nerve trunks, evolving over days to years. The aim of this study was to delineate the causes, clinical features, and detailed electrophysiological findings in the patients with mononeuropathy multiplex. Methods : We analyzed the medical records of 22 patients with mononeuropathy multiplex confirmed on electrophysiological studies in Inje University Seoul Paik Hospital, Seoul Municipal Boramae Hospital, and Seoul National University Hospital between 1991 to 2000. Results : The number of male and female patients was equal. The mean age was 48 years with a peak incidence in the sixth decade. The etiology could be divided into vasculitis(11 patients) or non-vasculitis group. In vasculitis group, Churg-Strauss syndrome, polyarteritis nodosa, and rheumatoid arthritis were included. The non-vasculitis group included diabetes mellitus, leprosy, and Guillain-Barre syndrome. Ulnar and median nerves were most commonly involved(91%). In descending order of frequency, peroneal, posterior tibial, sural, and radial nerves were also involved. Bilateral involvement occurred most commonly in ulnar nerve. The symptoms and signs of mononeuropathy multiplex were the initial manifestations in 12 patients(55%), which was more frequent in vasculitis group(73%). Nerve conduction abnormalities could be divided into axonal, demyelinating, or mixed type. Most(91%) of the patients in vasculitis group revealed axonal type abnormalities. The location of the nerve lesion was frequently related to potential site of entrapment in demyelinating type. Conclusions : Mononeuropathy multiplex is the presenting features of the etiological disease frequently, especially in vasculitis group. Nerve conduction studies(NCS) reveals not only axonal type but also demyelinating type abnormalities. The etiological diseases were different in each type. Therefore, NCS is very helpful for the early etiological diagnosis and therapeutic implication in the patients with mononeuropathy multiplex.

• 대한임상검사과학회지
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• 제53권2호
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• pp.151-157
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• 2021

선천성 유전질환인 CMT와 후천성 면역 매개 질환인 CIDP는 임상적 증상이 유사하므로 두 질환의 감별진단을 위해서는 말초신경의 전기생리학적 특징을 비교하는 것이 도움이 될 수 있다. 본 연구는 CIDP와 CMT 1형으로 확진된 환자의 신경전도검사 결과 중 감각신경전도검사의 주요 지표별 결과를 후향적으로 정량분석하여 두 질환군의 전기생리학적 특징을 규명하고자 하였다. CIDP (N=35)와 CMT1 (N=30)로 확진된 환자의 dCNAP와 SNCV를 이용하여 두 질환군의 중증도 분석, 유의성 검정, 비정상 범위별 비율분석 및 상관분석을 실시하여 통계적 차이를 기반으로 특징을 비교하였다. 두 질환 모두 전신성 말초신경다발신경병증의 특징이 관찰되었고, 장딴지신경의 손상이 가장 심한 것으로 확인되었다. CMT1군은 탈수초성 및 축삭성 신경병증을 동반하는 전신성 신경병증이고, CIDP보다 더 중증의 신경병증임이 확인되었다. 또한, 상관계수 및 산점도 분석에서 CMT1은 신경 손상 범위가 전체 신경에서 균등한 전기생리학적 특징이 관찰되었다. 감각신경전도검사의 결과를 기반으로한 본 연구결과가 CIDP와 CMT 1형의 감별진단 및 연구에 도움이 될 것으로 사료된다.

• Annals of Clinical Neurophysiology
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• 제15권2호
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• pp.48-52
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• 2013

Background: Meralgia paresthetica (MP) is a mononeuropathy affecting the lateral femoral cutaneous nerve. The disease is often diagnosed clinically, but electrophysiological tests play an important role. The aim of this study is to clarify clinical characteristics of MP as well as the role of sensory nerve conduction study (NCS) in the diagnosis of MP. Methods: Sixty-five consecutive patients with clinical diagnosis of MP between March 2001 and June 2012 were retrospectively reviewed at a single tertiary center. General demographics, clinical characteristics and sensory NCS findings were investigated. Measurements of sensory NCS included the baseline-to-peak amplitude, side-to-side amplitude ratio and the conduction velocity. To compare between the normal and abnormal NCS groups, independent t-tests and chisquare test were performed. Results: Sixty-five patients had male predominance (56.9%) with mean age of $48.4{\pm}13.4$ years (range: 16-75). Seven patients (13.5%) had undergone operation or procedure before the symptom onset. The sensory nerve action potentials were obtainable in 52 (80%) of 65 clinically diagnosed MP patients. Sensory NCS revealed abnormalities in 38 patients (73.1%), and others (n=14, 26.9%) showed normal findings. Between the normal and abnormal NCS groups, there is no statistically significant difference on demographics or clinical features. Conclusions: We clarify the clinical features and sensory NCS findings of MP patients. Due to several limitations of sensory NCS, the diagnosis of MP could be accomplished both clinically and electrophysiologically.

• 수면정신생리
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• 제7권2호
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• pp.84-87
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• 2000

The periodic limb movement (PLM) disorder is a disease of motor sign mainly in the lower extremities, whereas the restless leg syndrome (RLS) accompanies sensory symptoms in the lower extremities. These two disorders may occur in the one patient, which implies possible common pathophysiological background in those disorders. The aim of this article is to review the clinical features, diagnostic criteria, electrophysiological characteristics of the two disorders and their relation to neurological disorders.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1998년도 학술발표회
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• pp.34-34
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• 1998

Tolaasin is a channel forming bacterial toxin produced by Pseudomonas tolaasii and causes a brown blotch disease on cultivated oyster mushrooms. When tolaasin molecules form channels in the membranes of mushroom cells, they destroy cellular membrane structure, known as 'colloid osmotic lysis'. In order to understand the molecular mechanisms forming membrane channels by tolaasin molecules, we have investigated the electrophysiological characteristics of tolaasin-induced channels in lipid bilayer.(omitted)

• The Korean Journal of Physiology and Pharmacology
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• 제9권2호
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• pp.131-135
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• 2005

Potassium channels in human skin fibroblast have been studied as a possible site of Alzheimer disease pathogenesis. Fibroblasts in Alzheimer disease show alterations in signal transduction pathway such as changes in $Ca^{2+}$ homeostasis and/or $Ca^{2+}-activated$ kinases, phosphatidylinositol cascade, protein kinase C activity, cAMP levels and absence of specific $K^+$ channel. However, little is known so far about electrophysiological and pharmacological characteristics of large-conductance $Ca^{2+}$-activated $K^+$ ($BK_{Ca}$) channel in human fibroblast (CRL-1474). In the present study, we found Iberiotoxin- and TEA-sensitive outward rectifying oscillatory current with whole-cell recordings. Single channel analysis showed large conductance $K^{+}$ channels (106 pS of chord conductance at +40 mV in physiological $K^+$ gradient). The 106 pS channels were activated by membrane potential and $[Ca^{2+}]_i$, consistent with the known properties of $BK_{Ca}$ channels. $BK_{Ca}$ channels in CRL-1474 were positively regulated by adenylate cyclase activator ($10{\mu}M$ forskolin), 8-Br-cyclic AMP ($300{\mu}M$) or 8-Br-cyclic GMP ($300{\mu}M$). These results suggest that human skin fibroblasts (CR-1474) have typical $BK_{Ca}$ channel and this channel could be modulated by c-AMP and c-GMP. The electrophysiological characteristics of fibroblasts might be used as the diagnostic clues for Alzheimer disease.

• Molecules and Cells
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• 제37권3호
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• pp.202-212
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• 2014

ClC-1 is a member of a large family of voltage-gated chloride channels, abundantly expressed in human skeletal muscle. Mutations in ClC-1 are associated with myotonia congenita (MC) and result in loss of regulation of membrane excitability in skeletal muscle. We studied the electrophysiological characteristics of six mutants found among Korean MC patients, using patch clamp methods in HEK293 cells. Here, we found that the autosomal dominant mutants S189C and P480S displayed reduced chloride conductances compared to WT. Autosomal recessive mutant M128I did not show a typical rapid deactivation of Cl- currents. While sporadic mutant G523D displayed sustained activation of $Cl^-$ currents in the whole cell traces, the other sporadic mutants, M373L and M609K, demonstrated rapid deactivations. $V_{1/2}$ of these mutants was shifted to more depolarizing potentials. In order to identify potential effects on gating processes, slow and fast gating was analyzed for each mutant. We show that slow gating of the mutants tends to be shifted toward more positive potentials in comparison to WT. Collectively, these six mutants found among Korean patients demonstrated modifications of channel gating behaviors and reduced chloride conductances that likely contribute to the physiologic changes of MC.

• The Korean Journal of Physiology and Pharmacology
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• 제23권1호
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• pp.71-79
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• 2019

Body surface potential map, an electric potential distribution on the body torso surface, enables us to infer the electrical activities of the heart. Therefore, observing electric potential projected to the torso surface can be highly useful for diagnosing heart diseases such as coronary occlusion. The BSPM for the heart of a patient show a higher level of sensitivity than 12-lead ECG. Relevant research has been mostly based on clinical statistics obtained from patients, and, therefore, a simulation for a variety of pathological phenomena of the heart is required. In this study, by using computer simulation, a body surface potential map was implemented according to various occlusion locations (distal, mid, proximal occlusion) in the left anterior descending coronary artery. Electrophysiological characteristics of the body surface during the ST segment period were observed and analyzed based on an ST isointegral map. We developed an integrated system that takes into account the cellular to organ levels, and performed simulation regarding the electrophysiological phenomena of the heart that occur during the first 5 minutes (stage 1) and 10 minutes (stage 2) after commencement of coronary occlusion. Subsequently, we calculated the bipolar angle and amplitude of the ST isointegral map, and observed the correlation between the relevant characteristics and the location of coronary occlusion. In the result, in the ventricle model during the stage 1, a wider area of ischemia led to counterclockwise rotation of the bipolar angle; and, during the stage 2, the amplitude increased when the ischemia area exceeded a certain size.

• Annals of Clinical Neurophysiology
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• 제1권1호
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• pp.1-9
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• 1999

Since Hans Berger reported the first paper on the human electroencephalogram in 1920s, huge technological advance have made it possible to use a number of electrophysiological approaches to neurological diagnosis in clinical neurology. In majority of the neurology training hospitals they have facilities of electroencephalography(EEG), electromyography(EMG), evoked potentials(EP), polysomnography(PSG), electronystagmography(ENG) and, transcranial doppler(TCD) ete. Clinicials and electrophysiologists should understand the technologic characteristics and general applications of each electrophysiological studies to get useful informations with using them in clinics. It is generally agreed that items of these tests are selected under the clinical examination, the tests are performed by the experts, and the test results are interpretated under the clinical background. Otherwise these tests are sometimes useless and lead clinicians to misunderstand the lesion site, the nature of disease, or the disease course. In this sense the clinical utility of neurophysiological tests could be summerized in the followings. First, the abnormal functioning of the nervous system and its environments can be demonstrated when the history and neurological examinations are equivocal. Second, the presence of clinically unsuspected malfunction in the nervous system can be revealed by those tests. Finally the objective changes can be monitored over time in the patient's status. Also intraoperative monitoring technique becomes one of the important procedures when the major operations in the posterior fossa or in the spinal cord are performed. In 1996, the Korean Society for Clinical Neurophysiology(KSCN) was founded with the hope that it will provide the members with the comfortable place for discussing their clinical and academic experience, exchanging new informations, and learning new techniques of the neurophysiological tests. The KSCN could collaborate with the International Federation of Clinical Neurophysiology(IFCN) to improve the level of the clinical neurophysiologic field in Korea as will as in Asian region.1 In this paper the clinical neurophysiological tests which are commonly used in clinical neurology and which will be delt with and educated by the KSCN in the future will be discussed briefly in order of EEG, EMG, EP, PSG, TCD, ENG, and Intraoperative monitoring.