• Annals of Clinical Neurophysiology
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• v.25 no.2
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• pp.84-92
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• 2023

Background: Clinical spectrum of immunoglobulin M (IgM) monoclonal gammopathy varies from IgM monoclonal gammopathy of unknown significance (IgM-MGUS) to hematological malignancies. We evaluated the clinical features, electrophysiological characteristics, and prognosis of patients with peripheral neuropathy associated with IgM monoclonal gammopathy (PN-IgM MG). Methods: We retrospectively evaluated 25 patients with PN-IgM MG. Peripheral neuropathy was classified as axonal, demyelinating, or undetermined, based on electrophysiological studies. We classified the enrolled patients into the IgM-MGUS and malignancy groups, and compared the clinical and electrophysiological features between the groups. Results: Fifteen patients had IgM-MGUS and 10 had hematologic malignancies (Waldenström's macroglobulinemia: two and B-cell non-Hodgkin's lymphoma: eight). In the electrophysiological evaluation, the nerve conduction study (NCS) criteria for demyelination were met in 86.7% of the IgM-MGUS group and 10.0% of the malignancy group. In particular, the distal latencies of the motor NCS in the IgM-MGUS group were significantly prolonged compared to those in the malignancy group (median, 9.1 ± 5.1 [IgM-MGUS], 4.2 ± 1.3 [malignancy], p = 0.003; ulnar, 5.4 ± 1.9 [IgM-MGUS], 2.9 ± 0.9 [malignancy], p = 0.001; fibular, 9.3 ± 5.1 [IgM-MGUS], 3.8 ± 0.3 [malignancy], p = 0.01; P-posterior tibial, 8.3 ± 5.4 [IgM-MGUS], 4.4 ± 1.0 [malignancy], p = 0.04). Overall treatment responses were significantly worse in the malignancy group than in the IgM-MGUS group (p = 0.004), and the modified Rankin Scale score at the last visit was higher in the malignancy group than in the IgM-MGUS group (2.0 ± 1.1 [IgM-MGUS], 4.2 ± 1.7 [malignancy], p = 0.001), although there was no significant difference at the initial assessment. Conclusions: The risk of hematological malignancy should be carefully assessed in patients with PN-IgM MG without electrophysiological demyelination features.

• JSTS:Journal of Semiconductor Technology and Science
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• v.5 no.1
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• pp.1-10
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• 2005

This paper presents the development of a microsystem for whole blood purification and electrophysiological analysis of the purified cells. Magnetophoresis using continuous diamagnetic capture (DMC) was utilized for whole cell purification and electrical impedance spectroscopy (EIS) was utilized for electrophysiological analysis of the purified cells. The system was developed on silicon and plastic substrates utilizing conventional microfabrication technologies and plastic microfabrication technologies. Using the magnetophoretic microseparator, white blood cells were purified from a sample of whole blood. The experimental results of the DMC microseparator show that 89.7% of the red blood cells (RBCs) and 72.7% of the white blood cells (WBCs) could be continuously separated out from a whole blood using an external magnetic flux of 0.2 T. EIS was used as a downstream whole cell analysis tool to study the electrophysiological characteristics of purified cells. In this work, primary cultured bovine chromaffin cells and human red blood cells were characterized using EIS. Further analysis capabilities of the EIS were demonstrated by successfully obtaining unique impedance signatures for chromaffin cells based on the whole cell ion channel activity.

• Annals of Clinical Neurophysiology
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• v.13 no.1
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• pp.44-47
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• 2011

Background: Miller-Fisher syndrome (MFS) is characterized by the clinical triad of ophthalmoplegia, ataxia, and areflexia, and is considered a variant form of Guillain-Barre syndrome. Although some cases of delayed-onset facial palsy in MFS have been reported, the characteristics of this facial palsy are poorly described in the literature. Methods: Between 2007 and 2010, six patients with MFS were seen at our hospital. Delayed facial palsy, defined as a facial palsy that developed while the other symptoms of MFS began to improve following intravenous immunoglobulin treatment, was confirmed in four patients. The clinical and electrophysiological characteristics of delayed facial palsy in MFS, as observed in these patients, are described here. Results: Four patients with delayed-onset facial palsy were included. Delayed facial palsy developed 8-16 days after initial symptom onset (5-9 days after treatment). Unilateral facial palsy occurred in three patients and asymmetric facial diplegia in one patient. The House-Brackmann score of facial palsy was grade III in one patient, IV in two patients, and V in one patient. None of the patients complained of posterior auricular pain. Facial nerve conduction studies revealed normal amplitude in all four patients. The blink reflex showed abnormal prolongation in two patients and the absence of action potential formation in two patients. Facial palsy resolved completely in all four patients within 3 months. Conclusions: Delayed facial palsy is a frequent symptom in MFS and resolves completely without additional treatment. Thus, standard treatment and patient reassurance are sufficient in most cases.

• The Journal of the Korean dental association
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• v.38 no.4 s.371
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• pp.378-384
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• 2000

• Clinical and Experimental Pediatrics
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• v.54 no.12
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• pp.507-511
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• 2011

Purpose: The aim of the present study was to evaluate the characteristics of electrophysiologic studies (EPS) and radiofrequency ablation (RFA) performed in subjects aged less than 30 years with Wolff-Parkinson-White (WPW) syndrome, particularly pediatric patients under 18 years of age, based on our experience. Methods: Two hundred and one consecutive patients with WPW syndrome were recruited and divided to 3 groups according to age: group 1, 6 to 17 years; group 2, 18 to 29 years; and group 3, 30 to 60 years. The clinical, electrophysiological, and therapeutic data for these patients were evaluated by a retrospective medical record review. Results: A total of 73 (36%) of these patients were <30 years of age. Although there were more males than females in group 2 (male:female, 31:11), there was no sex difference in group 1 (male:female, 16:15). Left accessory pathway was detected less frequently in group 1 (32%, 10/31) than in group 2 (57%, 24/42) and group 3 (63%, 81/128) (P=0.023 and P=0.002, respectively). Conclusion: The present study describes several different electrophysiological characteristics in children and adolescents with WPW syndrome. Therefore, when EPS and RFA are performed in children and adolescence with WPW syndrome, we recommend that these characteristics be considered.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.6
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• pp.533-542
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• 2015

Little human tissue data are available for slow waves and migrating motor complexes, which are the main components of small bowel motility. We investigated the electrophysiological and mechanical characteristics of human ileal motility, in vitro. Ileum was obtained from patients undergoing bowel resection. Electrophysiological microelectrode recordings for membrane potential changes and mechanical tension recordings for contraction from smooth muscle strips and ileal segments were performed. Drugs affecting the enteric nervous system were applied to measure the changes in activity. Slow waves were detected with a frequency of 9~10/min. There were no cross-sectional differences in resting membrane potential (RMP), amplitude or frequency between outer and inner circular muscle (CM), suggesting that electrical activities could be effectively transmitted from outer to inner CM. The presence of the interstitial cell of Cajal (ICC) at the linia septa was verified by immunohistochemistry. Contractions of strips and segments occurred at a frequency of 3~4/min and 1~2/min, respectively. The frequency, amplitude and area under the curve were similar between CM and LM. In segments, contractions of CM were associated with LM, but propagation varied with antegrade and retrograde directions. Atropine, $N^W$-oxide-L-arginine, and sodium nitroprusside exhibited different effects on RMP and contractions. There were no cross-sectional differences with regard to the characteristics of slow waves in CM. The frequency of contractions in smooth muscle strips and ileal segments was lower than slow waves. The directions of propagation were diverse, indicating both mixing and transport functions of the ileum.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.39 no.6
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• pp.49-58
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• 2002

Based on electrophysiological retina mechanism, a retina model is proposed, which has similar response characteristics compared with the real primate retina. Photoreceptors, horizontal cells, and bipolar cells are modeled based on the previously studied retina models. And amacrine cells known to have relation to movements detection, and bipolar cell terminals are newly modeled using 3 NDP mechanism. The proposed model verified by analyzing the spatial response characteristics to stationary and moving stimuli, and characteristics for different speeds. Through this retina model, human vision system could be applied to computer vision systems for movement detection, and it could be the basic research for the implantable artificial retina.

• Annals of Clinical Neurophysiology
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• v.8 no.2
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• pp.146-151
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• 2006

Background: Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the tibial nerve within fibrous tunnel on the medial side of the ankle. The most common cause of TTS is idiopathic. This is a retrospective study to define the electrophysiological characteristics of idiopathic TTS. Methods: We reviewed the medical and electrophysiological records of consecutive patients with foot sensory symptoms referred to electromyography laboratory. Inclusion of patients was based on clinical findings suggestive of TTS. Among them, patients with any other possible causes of sensory symptoms on the foot were excluded. Control data were obtained from 19 age-matched people with no sensory symptoms or signs. Routine motor and sensory nerve conduction study (NCS) including medial plantar nerve (MPN) using surface electrodes were performed. Result: Twenty one patients (13 women, 8 men, 9 unilateral, 12 bilateral) were enrolled to have idiopathic TTS (total 31 feet). Tinel's sign was positive in 16 feet (51.6%) of TTS and four feet (10.5%) in control group. The statistically significant electrophysiological parameter was difference of sensory conduction velocity (SCV) between sural nerve and MPN. Amplitude of sensory nerve action potential and SCV of MPN were not different significantly between idiopathic TTS feet and controls. Conclusion: Bilateral development in idiopathic TTS was more common. Tinel's sign and difference of SCV between sural nerve and MPN may be helpful for the diagnosis of idiopathic TTS.

• Science of Emotion and Sensibility
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• v.19 no.4
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• pp.111-118
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• 2016

Patients with type 2 diabetes mellitus can complain of abnormal sensation and pain which derived from the peripheral nerve damage. Various words used to be describe abnormal sense and pain, such as sharp, hot, dull, cold, sensitive, and itch. To diagnose diabetic peripheral neuropathy, several screening instruments (Neuropathic Pain Scale, NPS; Michigan Neuropathy Screening Instruments, MNSI) and electrophysiological study can be used. In this study, we aim to analyze and compare the clinical and electrophysiological characteristics of 11 patients with diabetes mellitus and abnormal sense/pain (Disease Group, DG) and 10 patients with diabetes mellitus and normal sense (Control Group, CG). In addition, we aim to reveal correlation between NPS subscore and electrophysiological parameters. As a result, the scores of NPS and MNSI in DG were significantly higher. In nerve conduction study, median motor nerve and peroneal nerve showed significant functional change. Also, median motor nerve, posterior tibial nerve and sural nerve showed negative correlation as NPS subscore increased. These results mean increased pain can be associated with abnormal nerve function. It needs to be further explored for larger size of subjects to get confirmative results.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.4
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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.