• Journal of Korean Neurosurgical Society
• /
• v.52 no.1
• /
• pp.32-36
• /
• 2012

Objective : Alcoholic neuropathy is characterized by allodynia (a discomfort evoked by normally innocuous stimuli), hyperalgesia (an exaggerated pain in response to painful stimuli) and spontaneous burning pain. The aim of the present study is to investigate the effect of rolipram, a phosphodiesterase 4 inhibitor, against alcohol-induced neuropathy in rats. Methods : Allodynia was induced by administering 35% v/v ethanol (10 g/kg; oral gavage) to Spraue-Dawley rats for 8 weeks. Rolipram and saline (vehicle) were administered intraperitoneally. Mechanical allodynia was measured by using von Frey filaments. Somatosensory evoked potential (SEP) was proposed as complementary measure to assess the integrity of nerve pathway. Results : The ethanol-induced mechanical allodynia began to manifest from 3 week, and then peaked within 1 week. Beginning from 3 week, latency significantly started to increased in control group. In rolipram treated rats, the shorter latency was sustained until 8 weeks (p<0.05). The mechanical allodynia, which began to manifest on the 3 weeks, intraperitoneal injections of rolipram sustained statistical difference until 8 weeks, the final week of the study (p<0.05). Conclusion : This study suggests that rolipram might alleviate mechanical allodynia induced by alcohol in rats, which clearly has clinical implication.

• Animal Bioscience
• /
• v.34 no.5
• /
• pp.880-885
• /
• 2021

Objective: Omasum is an important site for the absorption of short chain fatty acids. The major route for the transport of acetate is via sodium hydrogen exchanger (NHE). However, a discrepancy in the symmetry of sodium and acetate transport has been previously reported, the mechanism of which is unclear. In this study, we investigated the possible role of carbonic anhydrase (CA) for this asymmetry. Methods: Omasal tissues were isolated from healthy sheep (N = 3) and divided into four groups; pH 7.4 and 6.4 alone and in combination with Ethoxzolamide. Electrophysiological measurements were made using Ussing chamber and the electrical measurements were made using computer controlled voltage clamp apparatus. Effect(s) of CA inhibitor on acetate and sodium transport flux rate of Na22 and 14C-acetate was measured in three different flux time periods. Data were presented as mean±standard deviation and level of significance was ascertained at p≤0.05. Results: Mucosal to serosal flux of Na (JmsNa) was greater than mucosal to serosal flux of acetate (JmsAc) when the pH was decreased from 7.4 to 6.4. However, the addition of CA inhibitor almost completely abolished this discrepancy (JmsNa ≈ JmsAc). Conclusion: The results of the present study suggest that the additional protons required to drive the NHE were provided by the CA enzyme in the isolated omasal epithelium. The findings of this study also suggest that the functions of CA may be exploited for better absorption in omasum.

• Journal of Biomedical Engineering Research
• /
• v.33 no.1
• /
• pp.15-24
• /
• 2012

Classification of human thought is an emerging research field that may allow us to understand human brain functions and further develop advanced brain-computer interface (BCI) systems. In the present study, we introduce a new approach to classify various mental states from noninvasive electrophysiological recordings of human brain activity. We utilized the full spatial and spectral information contained in the electroencephalography (EEG) signals recorded while a subject is performing a specific mental task. For this, the EEG data were converted into a 2D spatiospectral pattern map, of which each element was filled with 1, 0, and -1 reflecting the degrees of event-related synchronization (ERS) and event-related desynchronization (ERD). We evaluated the similarity between a current (input) 2D pattern map and the template pattern maps (database), by taking the inner-product of pattern matrices. Then, the current 2D pattern map was assigned to a class that demonstrated the highest similarity value. For the verification of our approach, eight participants took part in the present study; their EEG data were recorded while they performed four different cognitive imagery tasks. Consistent ERS/ERD patterns were observed more frequently between trials in the same class than those in different classes, indicating that these spatiospectral pattern maps could be used to classify different mental states. The classification accuracy was evaluated for each participant from both the proposed approach and a conventional mental state classification method based on the inter-hemispheric spectral power asymmetry, using the leave-one-out cross-validation (LOOCV). An average accuracy of 68.13% (${\pm}9.64%$) was attained for the proposed method; whereas an average accuracy of 57% (${\pm}5.68%$) was attained for the conventional method (significance was assessed by the one-tail paired $t$-test, $p$ < 0.01), showing that the proposed simple classification approach might be one of the promising methods in discriminating various mental states.

• Annals of Clinical Neurophysiology
• /
• v.6 no.2
• /
• pp.92-97
• /
• 2004

Background: There were several studies comparing prognostic factors in Guillain-Barre syndrome treated with intravenous immunoglobulin and plasmapheresis. However, there were controversies in what were significant factors and there were few studies so far comparing the therapeutic outcomes in patients treated with immunoglobulin. This study was aimed to determine the prognostic factors which affected the therapeutic outcome of Guillain-Barre syndrome treated with intravenous immunoglobulin. Method: We retrospectively reviewed the medical records of patients with Guillain-Barre syndrome admitted to our hospital between January 1999 and March 2004. All patients were treated with intravenous immunoglobulin. Outcome and prognosis were followed up after four weeks using the overall disability sum score. Results: Thirty-six patients were enrolled in this study. According to the clinical and electrophysiological findings, 17 patients were AIDP, 10 were axonal forms, two were mixed and seven had electrophysiologically no evidence of abnormalities. At a follow-up of four weeks, disabilities at the nadir (p<0.001) and admission (P<0.012), initial manifestations of bulbar symptom (P<0.024) and electrodiagnostic features (P<0.013) were significantly correlated with outcome in patients treated with intravenous immunoglobulin. But only disabilities at the nadir (P<0.033) and electrodiagnostic features (P<0.018) were significant in the multivariate logistic regression analysis. Conclusion: Among the patient treated with intravenous immunoglobulin, the outcomes were significantly different according to the neurological status at the nadir. Therefore early diagnosis, administration of intravenous immunoglobulin and preventing complications during acute stages are essential to minimize neurological deficit and shorten the periods of recovery.

• Annals of Clinical Neurophysiology
• /
• v.6 no.2
• /
• pp.98-102
• /
• 2004

Background: Carpal tunnel syndrome (CTS) is a common condition characterized by entrapment neuropathy of the median nerves. Clinical manifestations are the most important findings for diagnosis and assessment of therapeutic effects. But, objective indicators, such as electrophysiological findings, are also valuable supplementary tools. This study investigated the relationship between clinical grading and sensory nerve conduction velocity (SNCV) of median proper palmar digital nerve (MPPDN) in CTS patients. Method: This study was done on 90 upper limbs of 53 patients with CTS (men: 6, women: 47, age: 26~69 years, mean age; 52 years). Each SNCV of MPPDN was recorded with bar electrode using antidromic method. Each SNCV was compared with clinical grading of CTS. The clinical grades of CTS were designated as follows; group 1 is mild symptoms, 2 is moderate symptoms, and 3 is severe and longstanding symptoms. Result: In thumb, the SNCV of MPPDN was not different significantly between 3 groups (p=0.817). In the index finger, the SNCV was the fastest in the group 1, but faster in group 3 than in group 2 (p=0.001). In the middle and ring fingers, SNCV was decreased in higher clinical grading groups (middle finger: p=0.015, ring finger: p=0.044). Conclusion: SNCV of MPPDN of middle and ring finger correlated with the clinical grading of CTS. SNCV of index finger was the fastest in group 1. But SNCV of thumb did not correlate with the clinical grading of CTS.

• Annals of Clinical Neurophysiology
• /
• v.6 no.1
• /
• pp.26-30
• /
• 2004

Background: Electrophysiologic study accurately predicts the degree of degenerated motor axons but cannot give precise information on the type of injury that occurred in Bell's palsy. Because of these limitation for prognostic prediction in Bell's palsy, we evaluated divergence of electrophysiological time course for the purpose of presuming the type of injury in Bell's palsy. Methods: We did bilateral facial nerve conduction studies in 103 Bell's palsy patients, who visited to Han-Gang sacred heart hospital from 1998 to 2001. We compared the CMAP amplitude of disease site with that of normal site and suggested that decremental CMAP amplitude ratio (percentage) as a degree of denervation of affected facial nerve. Then we demonstrated the time course of denervation percentage. After defining normal range of CMAP amplitude difference from normal control group, we also evaluated if distinct time course of early minimal denervation is present. Results: Our results show that time course of the denervation in early stage of Bell's palsy reflect various injury type such as axonotmesis, neurotmesis or other unidentified type. We cannot identify the distinct time course of early minimal denervation. Conclusions: The time course as well as the maximal value of denervation are the best prognostic guidelines in Bell' s palsy. So repeated serial electrophysiologic test are inevitable to assess prognosis. As an another topic, early minimal denervation for prognostic prediction deserve to be evaluated as a future work up for prognostic prediction.

• Annals of Clinical Neurophysiology
• /
• v.6 no.1
• /
• pp.14-19
• /
• 2004

Backgrounds and objectives: POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) syndrome is the rare cause of polyneuropathy. Although the polyneuropathy is essential for the diagnosis of the disease, the pattern of electrodiagnostic abnormalities has not been characterized in detail. The purpose of this study was to elucidate the features of nerve conduction abnormalities in POEMS syndrome. Methods: We reviewed the medical records and nerve conduction studies (NCS) of 12 consecutive patients with POEMS. Results: A total of 68 motor and 46 sensory nerves were examined. Compound muscle action potentials (CMAPs) and sensory nerve action potentials were abnormally attenuated or not elicited in majority of motor and sensory nerves (80.88% in motor, and 82.6% in sensory nerves). Frequency of the nerves with no potential was significantly higher in lower limbs than in upper limbs (p<0.01 in both motor and sensory nerves), and CMAP amplitude was more reduced in lower limbs than in upper limbs (p<0.01). Conduction slowing was very frequently observed with 95% and 76% of motor and sensory nerves, respectively, having the abnormally reduced values of conduction velocity. Distal motor latencies were abnormally prolonged in 75% of motor nerves, and terminal latency indices were significantly higher in patients than in normal controls (p < 0.05). Conduction block was observed only in 5% of motor nerves. Conclusions: NCS in POEMS syndrome showed characteristic patterns, in which conduction abnormalities were more frequently and severely affected in the lower limbs, and more predominantly in the intermediate nerve segments than in the distal portions. The recognition of these characteristic patterns may be helpful in early diagnosis of polyneuropathy in POEMS syndrome.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.7 no.2
• /
• pp.179-189
• /
• 1996

Objective : This study was conducted to find out the electrophysiological abnormalities of the patients with attention-deficit/hyperactivity disorder(abbr. ADHD) through identifying the profiles of the event-related potentials. Methods : Through measuring event-related potentials of 20 patients with ADHD and 16 normal control children using Oddball paradigm, we evaluated the latencies and amplitudes of each wave form. Results : In the group older than 9 years old, the latencies that reflect selective attention and discriminative capacity of the patients with ADHD were significantly longer than those of normal controls, which suggests that patients with ADHD be more distractible to non-significant stimuli and that they be in lark of sustained attention and discriminative ability. Conclusions : We concluded that the patients with ADHD are more distractible to trivial stimuli than normal children but they lack discriminative, sustained ability of attention.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.11
• /
• pp.1429-1436
• /
• 2000

Objectives : This study was performed in cultured rat hippocampal neurons to investigate the acute electrophysiological features of ionotropic glutamate receptors which act as a major excitatory neurotransmitter in mammalian brain. Method : Glutamate receptor agonists were applied into the bath solution embedding in whole-cell patch-clamp recording of single hippocampal neuron. Results : In voltage-clamped at -60mV and the presence of 1mmol $Mg^{2+}$, extracellulary applied NMDA did not induce any inward current. Both the elimination of $Mg^{2+}$ and addition of glycine in bath, however, elicited a NMDAinduced inward current. $Mg^{2+}$ block current was increased gradually in more negative potentials from -30mV, showing a negative slope in I-V plot with $Mg^{2+}$. Glutamate-induced current represented an outward rectification. A non-NMDA receptor component occupied about 40% of glutamate-induced current in the voltage range of -80mV to +60mV. Conclusion : Present study suggests that glutamate activates acutely the non-NMDA receptors which induces an inward current in the level of resting membrane potential. This makes the membrane potential increase and can activate the NMDA receptors that permit calcium influx against $Mg^{2+}$ block. At the depolarized state of neuron, there may be recovery mechanisms of membrane potential to repolarize irrespective of voltage-dependent potassium channels in the hippocampal neurons.

• Annals of Clinical Neurophysiology
• /
• v.20 no.2
• /
• pp.71-78
• /
• 2018

Nerve conduction study (NCS) is an electrophysiological tool to assess the overall function of cranial and peripheral nervous system, therefore NCS has been diagnostically helpful in the identification and characterization of disorders involving nerve roots, peripheral nerves, muscle and neuromuscular junction, and are frequently accompanied by a needle Electromyography. Furthermore, NCS could provide valuable quantitative and qualitative results into neuromuscular function. Usually, motor, sensory, or mixed nerve studies can be performed with using NCS, stimulating the nerves with the recording electrodes placed over a distal muscle, a cutaneous sensory nerve, or the entire mixed nerve, respectively. And these findings of motor, sensory, and mixed nerve studies often show different and distinct patterns of specific abnormalities indicating the neuromuscular disorders. The purpose of this special article is to review the neurophysiologic usefulness of NCS, to outline the technical factors associated with the performance of NCS, and to demonstrate characteristic NCS changes in the setting of various neuromuscular conditions.