• Annals of Clinical Neurophysiology
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• v.5 no.2
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• pp.177-180
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• 2003

Background and Objectives: A nerve conduction study (NCS) has been known as a useful method to evaluate the therapeutic effect of operation in carpal tunnel syndrome (CTS). To evaluate the temporal relationship between symptomatic and electrophysiological improvement, we compared the preoperative symptoms and electrophysiological results with postoperative those. Methods: We analyzed the NCS changes before and after minimal release of carpal tunnel in 26 patients (34 hands) with CTS. The time of postoperative symptomatic changes, postoperative electrophysiological changes and temporal relationship between symptomatic and electrophysiological changes were evaluated. Results: The mean age was $49{\pm}13$ years. The proportion of males to female was 8 and 92 percent. The median interval days between date of operation and those of postoperative NCS was 28.5 days. Postoperative symptoms improved in 17 hands, slightly improved in 13 hands, and have not changed in 4 hands. Electrophysiological improvements after operation were observed in 26 hands, and mostly appeared within 2 months. Symptomatic relief accompanied with electrophysiological improvement reported in 13 hands (50%). Moreover, the four hands with symptom, not relieved by decompression, showed electrophysiological improvement. Conclusions: In this study, electrophysiological improvement was in consistency with symptomatic relief to some extent, but we got the result of disagreement between electrophysiological and symptomatic improvement.

• BMB Reports
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• v.57 no.7
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• pp.311-317
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• 2024

Brain organoid is a three-dimensional (3D) tissue derived from stem cells such as induced pluripotent stem cells (iPSCs) embryonic stem cells (ESCs) that reflect real human brain structure. It replicates the complexity and development of the human brain, enabling studies of the human brain in vitro. With emerging technologies, its application is various, including disease modeling and drug screening. A variety of experimental methods have been used to study structural and molecular characteristics of brain organoids. However, electrophysiological analysis is necessary to understand their functional characteristics and complexity. Although electrophysiological approaches have rapidly advanced for monolayered cells, there are some limitations in studying electrophysiological and neural network characteristics due to the lack of 3D characteristics. Herein, electrophysiological measurement and analytical methods related to neural complexity and 3D characteristics of brain organoids are reviewed. Overall, electrophysiological understanding of brain organoids allows us to overcome limitations of monolayer in vitro cell culture models, providing deep insights into the neural network complex of the real human brain and new ways of disease modeling.

• Annals of Clinical Neurophysiology
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• v.15 no.1
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• pp.7-12
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• 2013

Background: Local steroid injection is used to treat carpal tunnel syndrome (CTS). The aim of this study was to evaluate the clinical and electrophysiological effects of local steroid injection in patients with CTS over a 3-months period. Methods: Twenty-one patients (35 hands) with clinical and electrophysiological evidence of CTS were treated by injection of triamcinolone 40 mg to the carpal tunnel. Visual analog scale (VAS), Boston Carpal Tunnel Questionnaire (BCTQ), rates of paresthesia, night awakening, and electrophysiological studies were used as outcomes. Clinical and electrophysiological assessments were performed before, 1 and 3 months after treatment. Results: Prior to treatment, 86% of patients complained of night awakening. At 1 and 3 months after injection, only 17% and 29% of the patients, respectively, had night awakening (p<0.001). All patients complained of paresthesia before the treatment. This symptom disappeared in 60% and 31% of the patients after 1 and 3 months, respectively (p<0.001). Compared to baseline, both BCTQ and VAS show significant improvement during the 3 months of the study (p<0.005). Although significant improvements in clinical parameters were shown, electrophysiological parameters were not significantly improved at 1 and 3 months. Conclusions: Local corticosteroid injection for the treatment of CTS provides significant improvement in symptoms for 3 months. On the other hand, no significant improvement was observed in electrophysiological parameters.

• Journal of Integrative Natural Science
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• v.6 no.3
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• pp.143-150
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• 2013

Prevailing role of intracellular amyloid ${\beta}$ ($iA{\beta}$) in Alzheimer's disease (AD) initiation and progression attracts more and more attention in recent years. To address whether $iA{\beta}$ induces early alterations of electrophysiological properties in cultured human primary neurons, we delivered $iA{\beta}$ with adenovirus and measured the electrophysiological properties of infected neurons with whole-cell recordings. Our results show that $iA{\beta}$ induces an increase in neuronal resting membrane potentials, a decrease in $K^+$ currents and a hyperpolarizing shift in voltage-dependent activation of $K^+$ currents. These results suggest the electrophysiological impairments induced by $iA{\beta}$ may be responsible for its neuronal toxicity.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.145-150
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• 2012

We present a display-based visual stimulator for psychophysical and electrophysiological visual sensitivity measurements. The stimulator offers various psychophysical visual stimuli and transfers the signals from external devices along with the stimulation signals to an electrophysiological recorder. As an experimental demonstration, we perform a visual sensitivity experiment in the mesopic vision range by using the display-based stimulator. The intensity of the steady-state visual evoked potential is observed to correlate with the luminance of the flickering visual stimulation. For the psychophysically determined detection thresholds, we determine the mesopic luminance, showing agreement with the perceived brightness within the uncertainty of the luminance measurement.

• Journal of Korean Neurosurgical Society
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• v.37 no.1
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• pp.8-15
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• 2005

Objective: We evaluate temporal correlations between postoperative symptomatic and electrophysiological improvements, and assessed the recovery time required for patients with carpal tunnel syndrome(CTS) before returning to routine activities. Methods: 30 CTS patients were treated via the endoscopic monoportal approach, from March 2001 to September 2003. We assessed the symptoms (hyperesthesia in the finger tips, or abnormal sensations and painful numbness or night pain) and electrophysiological changes in the preoperative state, 1 month and 6 months after surgery. We marked the times at which patients became able to return to activities of daily living and work, after undergoing endoscopic carpal tunnel release. Results: At the end of the follow-up period, high levels of achievement and good outcomes were observed, with respect to both the symptoms and electrophysiological studies. We discovered significant differences between the preoperative and postoperative periods, especially in terms of motor nerve onset latency from $4.50{\pm}1.43$ to $3.97{\pm}0.69$ and sensory nerve conduction velocity, the wrist-to-finger from $19.81{\pm}10.03$ to $28.18{\pm}11.01$ and wrist-to-palm from $23.34{\pm}13.40$ to $31.79{\pm}13.38$(P<0.05 for each comparison). The average time interval required before return to activities of daily living was 26.4 days, and time interval required before return to work was 48.08 days. Conclusion: Electrophysiological improvements are largely consistent with symptomatic relief, but there is some disparity between electrophysiological and symptomatic improvement.

• Annals of Clinical Neurophysiology
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• v.16 no.1
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• pp.21-26
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• 2014

Background: Electrophysiological study has been known as a useful method to evaluate the therapeutic effect of operation in idiopathic carpal tunnel syndrome (CTS). The purpose of this study was to evaluate the clinical and electrophysiological changes after carpal tunnel release (CTR) compared to the preoperative results. Methods: We analyzed the changes of nerve conduction study (NCS) before and after minimal open carpal tunnel release in 18 patients (25 hands) with CTS. Follow-up study was performed over 6 months after operation. Results: Clinical improvement was seen in all cases after CTR. In contrast, electrophysiological improvement was various depending on the parameters; the mean median sensory latency and nerve conduction velocity (NCV) improved significantly (p = 0.001). The mean median motor latency also improved, but NCV and compound muscle action potential (CMAP) amplitude did not change. The extent of improvement was evident in moderate CTS, but not in severe CTS. Conclusions: In this preliminary study, all subjects who underwent CTR achieved a clinical relief along with a significant improvement of electrophysiological parameters such as median sensory latency, sensory NCV and median distal motor latency. After CTR, a number of cases with mild to moderate CTS showed a prominent improvement of clinical and electrophysiological parameters, while fewer improvements were seen in severe CTS, although it did not reach the statistical significance.

• 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.3 no.2
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• pp.156-159
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• 2001

Miller Fisher syndrome(MFS) has been the focus of conflicting opinions regarding the peripheral versus the central nature of the site of major neural injury. We present our electrophysiological findings in one case of MFS to help clarify the pattern of peripheral nerve injury in this syndrome. A 45-year-old man visited our hospital due to sudden diplopia. Initial examination revealed internuclear opthalmoplegia. The next day, his symptoms rapidly aggravated to complete external ophthalmoplegia, ataxia, and areflexia with hand and foot numbness. Serial electrophysiological studies were performed. The results of brainstem evoked potential(BAEP) and blink reflex were normal in the serial studies. Motor and sensory nerve conduction study(NCS) were normal findings in second hospital day, but ulnar sensory nerve shows no sensory nerve action potential(SNAP) and sural sensory conduction velocity was delayed in 7th hospital day. Our patient's clinical presentation began to improve on 15th hospital day, and his electrophysiologic study showed improvement on 29th hospital day. We believe that all the manifestations of MFS can be explained by the involvement of peripheral nerves without brainstem or cerebellar lesion with the serial electrophysiological studies.