• Annals of Clinical Neurophysiology
• /
• 제4권1호
• /
• pp.44-50
• /
• 2002

Introduction : Orthostatic tremor develops in the legs while standing up with no weakness, pain or imbalance in the leg and the tremor is characteristically not observed when walking. However there have been some confusions about orthostatic tremor in several aspects. For the past ten years, we have observed 4 patients with orthostatic tremor. In each case tests were performed to investigate the following three important areas of inquiry about orthostatic tremor. Firstly, whether this disorder is an independent diagnostic entity or a variant of essential tremor. Secondly, whether the progress of this disorder is specifically related with standing posture. Lastly, the nature of the pathophysiologic mechanism behind the appearance of the tremor when standing after the lapse of a certain latent period and its disappearance upon the commencement of walking. Methods : Our 4 cases of orthostatic tremor were studied clinically, electrophysiologically, and pharmacologically. Electrophysiological tests included tremor spectrum test and electromyography. Results : We observed the presence of this tremor in several other tonic postures, as well as its absence, in a vertically lifted position from all our cases. Our cases registered a variable tremor frequency between 5 and 12 Hz according to the tremor spectrum test and EMG. Furthermore all our 4 cases demonstrated patterns of both synchronous EMG activity and alternating EMG activity at various times in homologous muscles of both legs. Orthostatic tremor was improved significantly with propranolol as well as clonazepam. Conclusions : From the results of our study we drew the following conclusions. It is probable that orthostatic tremor is simply a variant of essential tremor rather than being an independent diagnostic entity and that in most cases its development is specifically related with muscle contraction rather than merely with the act of standing. Furthermore we discovered a clue in the previously described neural control mechanism that the nuclear bag fibers in the muscle spindle have lag time of several seconds in their response to muscle strength and that their baseline does not reset fully in rapidly moving muscle. This neural control mechanism could offer sufficient explanation for the phenomena of tremor appearance when standing and disappearance when walking in orthostatic tremor.

• Annals of Clinical Neurophysiology
• /
• 제12권2호
• /
• pp.47-54
• /
• 2010

Background: Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy caused by compression of the median nerve beneath the transverse carpal ligament. CTS can be correctly diagnosed by the patients' description of symptoms and electrophysiological tests that measure nerve conduction through the wrist. Many previous studies reported various risk factors of CTS, such as obesity, diabetes mellitus, thyroid disease and trauma. Obesity is associated with both hyperlipidemia and CTS. This study focused on the relationship between severity of CTS and serum lipid level. Methods: One hundred fourteen patients with CTS and 74 controls were divided into four groups according to the severity; normal, mild, moderate and severe. And then serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL-C) and high-density lipoprotein (HDL-C) were measured in each group. Results: There was a positive correlation between TG and CTS severity (p<0.001). But TC, LDL-C and HDL-C were not correlated with CTS severity. Conclusions: These results suggest that high serum TG may act as an aggravating factor of CTS.

• BMB Reports
• /
• 제53권8호
• /
• pp.437-441
• /
• 2020

In accordance with requirements of the ICH S7B safety pharmacology guidelines, numerous next-generation cardiotoxicity studies using human stem cell-derived cardiomyocytes (CMs) are being conducted globally. Although several stem cell-derived CMs are being developed for commercialization, there is insufficient research to verify if these CMs can replace animal experiments. In this study, in vitro high-efficiency CMs derived from human embryonic stem cells (hESC-CMs) were compared with Sprague-Dawley rats as in vivo experimental animals, and primary cultured in vitro rat-CMs for cardiotoxicity tests. In vivo rats were administrated with two consecutive injections of 100 mg/kg isoproterenol, 15 mg/kg doxorubicin, or 100 mg/kg nifedipine, while in vitro rat-CMs and hESC-CMs were treated with 5 μM isoproterenol, 5 μM doxorubicin, and 50 μM nifedipine. We have verified the equivalence of hESC-CMs assessments over various molecular biological markers, morphological analysis. Also, we have identified the advantages of hESC-CMs, which can distinguish between species variability, over electrophysiological analysis of ion channels against cardiac damage. Our findings demonstrate the possibility and advantage of high-efficiency hESC-CMs as next-generation cardiotoxicity assessment.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• 제20권2호
• /
• pp.61-67
• /
• 2009

Objectives: The purpose of this study was to examine the performance and electrophysiological characteristics of drug-naive children with attention-deficit/hyperactivity disorder(ADHD) during the Go/NoGo task. Methods: Twenty-three boys with ADHD and 18 age-matched normal boys were recruited at a child psychiatric outpatient clinic in Seoul. All subjects were assessed by the Kiddie Schedules for Affective Disorders and Schizophrenia Present and Lifetime version. The investigator also assessed all subjects using the ADHD Rating Scale-IV(ADHDRS). Event-related potentials were recorded from 8 scalp electrodes during the visual Go/NoGo task. Results: Children with ADHD showed a larger mean of standard deviation of response time during the Go/NoGo task than normal children. The temporal N200 and P300 amplitudes were larger in children with ADHD relative to controls. The parietal N200 and P300 latencies were more prolonged in children with ADHD compared to normal controls. Conclusion: These results suggest that psychotropic-naive children with ADHD may have more variable performance ability, more difficulty in discriminating visual stimuli, and slower information processing speed than their normal age-matched counterparts.

• Clinical and Experimental Pediatrics
• /
• 제59권sup1호
• /
• pp.161-164
• /
• 2016

Guillain-$Barr{\acute{e}}$ syndrome and acute transverse myelitis manifest as demyelinating diseases of the peripheral and central nervous system. Concurrency of these two disorders is rarely documented in literature. A 4-year-old girl presenting with cough, fever, and an impaired walking ability was admitted to hospital. She had no previous complaints in her medical history. A physical examination revealed lack of muscle strength of the lower extremities and deep tendon reflexes. MRI could not be carried out due to technical problems; therefore, both Guillain-$Barr{\acute{e}}$ syndrome and acute transverse myelitis were considered for the diagnosis. Intravenous immunoglobulin treatment was started as first line therapy. Because this treatment did not relieve the patient's symptoms, spinal MRI was carried out on the fourth day of admission and demyelinating areas were identified. Based on the new findings, the patient was diagnosed with acute transverse myelitis, and high dose intravenous methylprednisolone therapy was started. Electromyography findings were consistent with acute polyneuropathy affecting both motor and sensory fibers. Therefore, the patient was diagnosed with concurrency of Guillain-$Barr{\acute{e}}$ syndrome and acute transverse myelitis. Interestingly, while concurrency of these 2 disorders is rare, this association has been demonstrated in various recent publications. Progress in diagnostic tests (magnetic resonance imaging and electrophysiological examination studies) has enabled clinicians to establish the right diagnosis. The possibility of concurrent Guillain-$Barr{\acute{e}}$ syndrome and acute transverse myelitis should be considered if recovery takes longer than anticipated.

• Annals of Clinical Neurophysiology
• /
• 제16권2호
• /
• pp.62-69
• /
• 2014

Background: Neuromodulation therapy has been used to an adjunctive treatment promoting motor recovery in stroke patients. The objective of the study was to determine the effect of repetitive transcranial magnetic stimulation (rTMS) on neurobehavioral recovery and evoked potentials in rats with middle cerebral artery occlusion. Methods: Seventy Sprague-Daley rats were induced permanent middle cerebral artery occlusion (MCAO) stroke model and successful stroke rats (n=56) assigned to the rTMS (n=28) and sham (n=28) group. The 10 Hz, high frequency rTMS gave on ipsilesional forepaw motor cortex during 2 weeks in rTMS group. The somatosensory evoked potential (SSEP) and motor evoked potential (MEP) were used to evaluate the electrophysiological changes. Behavioral function of the stroke rat was evaluated by the Rota rod and Garcia test. Results: Forty rats ($N_{rTMS}=20;\;N_{sham}=20$) completed all experimental course. The rTMS group showed better performance than sham group in Rota rod test and Garcia test at day 11 (p<0.05) but not day 18 (p>0.05). The amplitude of MEP and SSEP in rTMS group was larger than sham group at day 18 (p<0.05). Conclusions: These data confirm that the high frequency rTMS on ipsilesional cerebral motor cortex can help the early recovery of motor performance in permanent middle cerebral artery stroke model and it may simultaneously associate with changes in neurophysiological activity in brain.

• The Korean Journal of Physiology and Pharmacology
• /
• 제23권5호
• /
• pp.393-402
• /
• 2019

Aurora kinases inhibitors, including ZM447439 (ZM), which suppress cell division, have attracted a great deal of attention as potential novel anti-cancer drugs. Several recent studies have confirmed the anti-cancer effects of ZM in various cancer cell lines. However, there have been no studies regarding the cardiac safety of this agent. We performed several cytotoxicity, invasion and migration assays to examine the anti-cancer effects of ZM. To evaluate the potential effects of ZM on cardiac repolarisation, whole-cell patch-clamp experiments were performed with human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and cells with heterogeneous cardiac ion channel expression. We also conducted a contractility assay with rat ventricular myocytes to determine the effects of ZM on myocardial contraction and/or relaxation. In tests to determine in vitro efficacy, ZM inhibited the proliferation of A549, H1299 (lung cancer), MCF-7 (breast cancer) and HepG2 (hepatoma) cell lines with $IC_{50}$ in the submicromolar range, and attenuated the invasive and metastatic capacity of A549 cells. In cardiac toxicity testing, ZM did not significantly affect $I_{Na}$, $I_{Ks}$ or $I_{K1}$, but decreased $I_{hERG}$ in a dose-dependent manner ($IC_{50}$: $6.53{\mu}M$). In action potential (AP) assay using hiPSC-CMs, ZM did not induce any changes in AP parameters up to $3{\mu}M$, but it at $10{\mu}M$ induced prolongation of AP duration. In summary, ZM showed potent broad-spectrum anti-tumor activity, but relatively low levels of cardiac side effects compared to the effective doses to tumor. Therefore, ZM has a potential to be a candidate as an anti-cancer with low cardiac toxicity.

• Annals of Clinical Neurophysiology
• /
• 제23권2호
• /
• pp.108-116
• /
• 2021

Background: Nitrous oxide (N₂O) is used in surgery and dentistry for its anesthetic and analgesic effects. However, neurological and psychiatric manifestations of N₂O abuse have been increasingly reported among Korean adults. The aim of this study was to demonstrate laboratory findings of N₂O abuse in Korean patients. Methods: Patients diagnosed with N₂O-induced neuropathy or myelopathy from August 2018 to December 2019 were enrolled. Their clinical presentations and laboratory and imaging findings were analyzed. Results: Sensory changes and limb weakness were present in nine of the enrolled patients. The laboratory findings revealed that seven patients had high homocysteine levels and five had high methylmalonic acid levels in their blood. Nerve conductions studies indicated that axonal neuropathy was present in four cases and longer F-wave and Hoffman's-reflex latencies were present in two cases. Signal changes in cervical spine imaging occurred in five patients, while two had normal results. Conclusions: Chronic N₂O abuse can cause neurological damage or psychiatric problems. Because N₂O is illegal for recreational use in Korea, patients tend to hide their history of use. Even though the spinal imaging results were normal, clinicians should consider the possibility of N₂O use, and further electrophysiological tests should be applied for precise evaluations.

• Clinical and Experimental Pediatrics
• /
• 제49권11호
• /
• pp.1158-1166
• /
• 2006

목 적 : 늘어지는 증상을 주소로 신생아 및 소아 중환자실에 입원한 영아들의 임상적, 신경학적, 전기생리학적 소견 및 유전적 진단 결과를 통한 분석을 통해 늘어지는 영아 증후군의 진단적 분류 및 진단 방법에 대한 고찰을 하고자 하였다. 방 법 : 1993년도부터 2005년까지 13년간 서울대학교 병원 어린이병원 신생아 중환자실 및 소아 중환자실에 늘어지는 증상을 주된 주소로 입원한 영아들을 대상으로 하였다. 후향적 의무기록조사를 통해 임상 소견 및 검사 소견들을 조사하였고 최종 진단명을 분류하였다. 결 과 : 늘어지는 증상을 주소로 내원한 영아들은 21명이었다. 최종 진단명은 중추성 기원이 7명(33.3%), 말초성 기원이 11명(52.4%), 나머지 3명은(14.3%) 두 그룹 중 어느 그룹으로도 분류되지 못하였다. 중추성 기원은 저산소-허혈성 뇌증이 3명으로 가장 많았고, 그 외에 Prader-Willi 증후군 2명, 염색체 이상 1명, 일과성 저긴장증 1명이 있었다. 말초성 기원은 myotubular 근병증이 4명으로 가장 많았고, SMA 1형이 3명, 선천성 근긴장성 이영양증 2명, 선천성 근이영양증 1명, 그 외 분류되지 않은 운동신경질환 1명이 있었다. 가족력이 있었던 경우는 말초성 그룹에서만 3명이 있었고, 신경학적 검진 상 근력은 중추성 그룹에서 평균 Grade 3 이상이었고 건반사도 활발하게 나타난 경우가 많아 다른 그룹의 환자들과 차이를 보였다. 검사상의 소견은 근전도 검사에서 말초성 그룹이 66%의 민감도를 보였고 근생검은 말초성 그룹에서 진단적이었다. 중추성 그룹에서 뇌 영상 검사가 진단적이었고 진단율이 높지는 않았지만 Prader-Willi FISH 나 염색체 검사를 통해 진단이 되었던 경우가 있었다. 그외의 분자 유전학적 검사로 확진 가능한 말초성 그룹의 환자들이 있었다. 입원 기간 및 기관 삽관 기간은 말초성 그룹에서 현저하게 길었고, 추적 관찰 시 사망 및 심한 발달 지체의 비율도 말초성 그룹에서 높게 나타났다. 결 론 : 본 연구의 늘어지는 영아들의 임상상을 바탕으로 진단적 분류를 시행하고 각 진단 분류에 유용한 검사를 순서대로 진행시킨다면 효과적인 진단이 이루어질 수 있을 것이다.

• Journal of Preventive Medicine and Public Health
• /
• 제28권4호
• /
• pp.899-910
• /
• 1995

1994년 1월 24일부터 동년 4월 8일까지 부산 메리놀병원 내과 및 신경과에서 당뇨병으로 진단되어 당뇨교실에서 치료를 받고 있는 입원 및 외래환자 67명(남37명, 여 30명 : 평균연령 $52.55{\pm}13.67$세)라 병력 및 이학적 소견상 말초신경에 이상이 없다고 진단된 직원 및 그 가족 53명(남 28명, 여 25명 : 평균연령 $45.75{\pm}12.21$세)을 대상으로 본 병원 신경생리검사실에서 가중침자감각역치와 감각신경전도검사를 측정한 결과는 다음과 같다. 1. 가중침자감각역치는 양측 손과 발의 측정한 모든 부위에서 당뇨병 환자 중 증상군, 무증상군 그리고 대조군간에 있어서 통계학적으로 유의한 차이를 나타냈는데, 대조군이 당뇨병 환자군보다 낮았고 당뇨병 환자 중 무증상군이 증상군보다 낮게 나타났다. 2. 당뇨병 환자에 있어서 가중침자감각역치는 증상군과 무증상군 모두 연령과 당뇨병유병기간과는 통계학적으로 유의한 상관관계를 나타내어 연령이 많고 유병기간이 길수록 가중침자감각역치는 높았으며 기타 체중, 신장 및 교육수준과는 유의한 상관성이 없었다. 3. 대조군에 있어서 가중침자감각역치는 연령과는 통계학적으로 유의한 상관관계를 나타냈고 교육수준과는 역상관관계를 나타내어 연령이 많고 교육수준이 낮을수록 가중침자감각역치는 높았으며 체중과 신장과는 유의한 상관성이 없었다. 4. 가중침자감각역치에 있어서 연령을 보정한 후의 각 부위별 세 군간의 차이는 우측 제5수지와 좌측 발에서는 세 군 서로 모두 통계학적으로 유의한 차이를 나타냈으나(p<0.05), 양측 제2수지와 좌측 제5수지 그리고 우측 발에서의 가중침자감각역치는 증상군과 대조군, 그리고 무증상군과 대조군간에서만 통계학적으로 유의한 차이를 나타내었다(p<0.05). 5. 각 부위별 가중침자감각역치와 감각신경의 전도 속도 및 활동전위 진폭과의 상관관계는 측정한 모든 부위에서 통계학적으로 유의한 상관관계를 나타냈다(p<0.05). 이상의 결과로 보아 감각신경 전도검사가 가중침자감각역치보다 정확한 검사이긴 하지만 가중침자감각역치는 말초감각장애 정도를 외래에서 신속히 알고 싶을 때나, 감각신경 전도검사가 불가능한 상황에서 매우 유용한 검사방법이라 생각된다.