• Annals of Clinical Neurophysiology
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• v.3 no.1
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• pp.15-20
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• 2001

Background : Carpal tunnel syndrome(CTS) is the most common entrapment neuropathy that refers to a group of signs and symptoms resulting from compression of the median nerve at the wrist. The course of CTS in older patients is different from the younger patients. This difference may be the result of different underlying mechanisms. The different nerve conduction studies of CTS may signify different approaches in management. This study was done to assess the differences in nerve conduction study of CTS in younger and older patients. Methods : This study involved 224 patients who visited Gachon Medical School, Gil Medical Center and was diagnosed by nerve conduction study from October 1997 to October 1999. We compared the results of nerve conduction study to age, especially in between those under 60 years and those 60 years or over CTS patients. Nerve conduction study consists of motor studies of both median nerves(terminal latency, compound action potential) and sensory studies(nerve conduction velocity, nerve action potential). And we also evaluated the variables between younger and older patients group. Those variables include sex, symptom period, laterality, abnormal physical findings and radiculopathy. Results : We found that a significant increase of terminal latency(p<0.1), but a decrease in compound motor action potential(p<0.05) in older patient's group. There was no significant differences in sensory nerve conduction velocity and action potential between those under 60 years and those 60 years or even patients. And also there was no significant difference in sex, symptom period, laterality, abnormal physical findings, radiculopathy between older and younger patients. Conclusions : This study showed a significant increase in the terminal latency and a decrease in compound action potential in older patients. The different nerve conduction studies of CTS by age effect may need different approaches in management.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.11 no.2
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• pp.178-184
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• 2000

Laryngeal evoked EMG is the objective and quantitative method to measure the innervation of laryngeal muscle. If there is a mobility disorder of vocal cords, the cause and location of neural lesion co be understood by the laryngeal evoked EMG and if there is a vocal cord paralysis, the degree of recovery and the policy of treatment can be determined by it. Recently, the studies of reinnervation after recurrent laryngeal nerve injury have been actively carried out. Laryngeal evoked EMC is useful to these studies. The aim of study is to know whether noninvasive methods for stimulating the recurrent laryngeal nerve and for recording of compound action potential(CAP) using surface electrode are as useful as the invasive method using needle electrode. We obtained EMG of laryngeal muscle by various stimulating and recording methods : 1) Direct nerve stimulation by placing nerve cuff electrode made out of silastic tube and platinum wire and recording by insertion of hook wire electrode into posterior cricoarytenoid(PCA) and thyroarytenoid(TA) muscles, respectively. 2) Recording of compound action potential by surface electrode after stimulation of recurrent laryngeal nerve by the insertion of 27 gauge of needle electrode. 3) Recording of compound action potential by surface electrode after stimulating the recurrent laryngeal nerve by transcutaneous blunt rod electrode at tracheoesophageal groove. The amplitude, duration and latency of the CAP evoked by recurrent laryngeal nerve stimulation were compared among the three groups. The amplitude of CAP was smallest in the group recorded from posterior cricoarytenoid and hyroarytenoid muscle, and that recorded by surface electrode after stimulation by needle electrode was largest. The difference in amplitude between the group by hook wire recording and the two groups by surface electrode recording was significant statistically. There is no significant difference in duration and latency among three groups. Since the waveform of CAP from all three methods has similar duration, latency, we concluded that noninvasive method is a useful as invasive methods.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.5
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• pp.427-435
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• 2005

The purpose of this study was to compare clinical availability of fibrin adhesive technique with microneural suture technique. We applicated fibrin adhesive technique and microneural suture technique on cut sciatic nerve in rat and used to Compound muscle action potential of rat thigh muscle compartment and histologic finding for comparision of clinical availability. The results were as following. 1. Using latency and amplitude in Compound muscle action potential test, we compared microneural suture technique with fibrin adhesive technique for nerve regeneration effect. the means was slightly different between two method. but there's no statistically significant differences. 2. Histologic finding was similar in microneural suture technique and fibrin adhesive technique for regeneration of axon and myelin sheath in destruction site after nerve anastomosis. These results showed that the efficacy of fibrin adhesive technique was similar to that of conventional microneural suture technique. Moreover, fibrin adhesive technique is decreased operating time and imporved of incapability of accessment in conventional suture technique. Therefore this technique is a useful method to nerve anastomosis in nerve enervation and neurotransplantation.

• Journal of Life Science
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• v.16 no.1
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• pp.114-119
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• 2006

The purpose of this study was to determine effects of the Ga-As (Gallium-Arsenide) Dens-Bio laser on mechanically injured sciatic nerves of rats. The improvement of the injured rat sciatic nerve was evaluated by measuring of nerve conduction velocity and amplitude of compound muscle action potential. The sciatic nerves of forty male Sprague-Dawley rats were compressed with hemostatic forceps for 30 seconds. The experimental group was divided into 4 subgroups according to the duration of treatment. Lower power infrared laser irradiation was done transcutaneously to the injured sciatic nerve area, 3 minutes daily to each of four treatment groups for 1, 3, 5, and 7 weeks, respectively. Compound muscle action potential and nerve conduction velocity of sciatic nerve were obtained before nerve injury and at 1, 3, 5, and 7 weeks after injury. There were significant difference of the nerve conduction velocity and amplitudes of compound muscle action potential between the treatment group and non-treatment group at 1, 3, and 5 weeks after laser treatment. However, there were no differences found between the electrophysiologic parameters that were measured after 7 weeks in two groups. There was significant correlation between the increment of compound muscle action potential and nerve conduction velocity after time course according to laser treatment. In conclusion, the low power laser treatment had improved the sciatic nerve function, and therefore these results may provide the basic data to clarify the neurological recovery and treatment after incomplete peripheral nerve injury.

• Journal of Korean Physical Therapy Science
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• v.12 no.4
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• pp.43-55
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• 2005

This study was performed to investigate the effects of low-power Helium Neon Infra Red(He-Ne IR)laser irradiation and exercise on the regeneration of experimentally cut sciatic nerve in rats. The thrity Sprague-Dawley adult mail rats were assigned to the 6 groups : normal group(1), injured control groups(2), experimental groups(3). There was made artificial injured in the sciatic nerve of rats the each experimental laser group and exercise group were treated from 3 days after being injured for the 5 minutes(laser group), 10 minutes(exercise group), and 15 minutes(exercise and laser group) everyday during 2 weeks. There were measured the changes of amplitude of compound muscle action potential and histological change by the light microscopy on the sciatic nerve injured rats. The results obtained as follows : 1. In the control groups, the regeneration were slowly and slightlly progressed to compared with the experimental groups. Inflammation were much more observed, and fibrous adhesion was also observed around the sutured region of the cut sciatic nerve. 2. The amplitude of compound muscle action potential in the experimental groups were significantly increased to the injured control groups at 1 week(p<.05). The compound muscle action potential of the exercise and lased group was significantly decreased to be similar to normal group at 2 weeks(p<.05). 3. In histologic finding, in the experimental groups were observed the proliferation of the schwann cells, the infiltration of inflammatory cells and the extent of destruction at adjacent tissue were remarkably decreased on the 2 weeks. From these experimental results, it may be suggested that the laser and exercise were effected the heeling process of peripheral nerve injuried rats.

• Annals of Clinical Neurophysiology
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• v.8 no.2
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• pp.125-134
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• 2006

Among the various physiological factors that affect nerve conduction velocity (NCV), temperature is the most important. Because the influence of temperature is the most important source of error. It is known from animal experiments that conduction is eventually completely blocked at low temperatures, the myelinated A fibers being the first affected and the thin fibers of group C the last. Many studies showed that the NCV decreases linearly with lowering temperature within the physiological range. The distal motor latency increased by $0.2msec/^{\circ}C$ drop in temperature between $25^{\circ}C$and $35^{\circ}C$ in the median, ulnar and peroneal nerves. The temperature affect the neuromuscular transmission; The miniature endplate potential (MEPP) and endplate potential (EPP) are increase with increasing temperature. In myasthenia gravis, the reduction in the decremental response is observed following cooling. The lowering temperature make increase the amplitude of sensory compound action potential; make enlarge the surface area of compound muscle action potential with very little increase in amplitude; make diminish the fibrillation potential and increase the myotonia in needle electromyography (EMG). Because of these findings mentioned above, the skin temperature should be routinely monitored and controlled during nerve conduction tests and needle EMG and should be taken into account when interpreting the findings.

• The Korean Journal of Pain
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• v.34 no.1
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• pp.124-131
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• 2021

Background: Sciatic nerve injury due to intramuscular injection (SNIII) is still a health problem. This study aimed to determine whether there is a correlation between neuropathic pain and electrodiagnostic findings in SNIII. Methods: Patients whose clinical and electrodiagnostic findings were compatible with SNIII participated in this retrospective cohort study. Compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes of the sural, superficial peroneal, peroneal, and tibial nerves were graded from 1 to 4. Leeds assessment of neuropathic symptoms and signs scale (LANSS) was applied to all patients. Results: Forty-eight patients were included in the study, 67% of whom had a LANSS score ≥ 12. Sural SNAP amplitude abnormalities were present in 8 (50%) out of 16 patients with a LANSS score < 12, and 28 (87.5%) out of 32 patients with a LANSS score ≥ 12, with significant differences between the groups (P = 0.011). There was a positive correlation between the LANSS score and the sural SNAP amplitude grading (P = 0.001, r = 0.476). A similar positive correlation was also found in the LANSS score and the tibial nerve CMAP amplitude grading (P = 0.004, r = 0.410). Conclusions: This study showed a positive correlation between the severity of tibial nerve CMAP/sural SNAP amplitude abnormality and LANSS score in SNIII. Neuropathic pain may be more common in SNIII patients with sural nerve SNAP amplitude abnormality.

• PNF and Movement
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• v.16 no.2
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• pp.287-294
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• 2018

Purpose: The neurodynamic test used to implicate symptoms arising from the nerve is proposed to selectively increase the strain of the nerve without increasing the strain of adjacent tissue, although this has not yet been established in the time of nerve tension application. This study aimed to investigate the acute effects of nerve stretching time on nerve excitability using compound nerve action potential (CNAP) analysis. Methods: Thirty healthy young adults (mean age=23.10 years) with no medical history of neurological or musculoskeletal disorder voluntarily participated in this study. Nerve excitability was assessed using the median nerve conduction velocity test. The amplitude of the CNAP was measured under three conditions: resting phase (supra-maximal stimulus, without nerve stretching), baseline phase (two-thirds of the supra-maximal stimulus, without nerve stretching), and stretch phase (two-thirds of the supra-maximal stimulus, with 1-5 minutes nerve stretching). One-way repeated measures ANOVA was conducted to compare the latency and amplitude of CNAP. A post-hoc test was analyzed using the contrast test. Results: The latency was significantly delayed after 1 min. of nerve stretching in comparison with the baseline test. However, no significant difference was found during the nerve stretching (1-5 min.). The amplitude was significantly increased by nerve stretching. Conclusion: Nerve stretching can induce nerve excitability without any nerve injury. Based on the results, more than 1 min. of nerve stretching as a neurodynamic test can be a useful method in the clinical setting.

• The Korean Journal of Physiology
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• v.28 no.2
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• pp.123-132
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• 1994

The present study was undertaken to elucidate the desensitization of cutaneous receptors and the conduction block of the afferent nerves induced by direct application of allyl isotheocyanate (mustard oil) to the receptive field (RF) or onto the afferent nerve, respectively. Dorsal horn cell responses to mechanical stimulations of RF were completely suppressed when mustard oil was applied to either the afferent nerve or the whole area of RF. C-fiber responses of dorsal horn cells were more susceptive to mustard oil than A-fiber activities. This was confirmed by the experiment in which the compound action potentials recorded from rat tibial nerve before and after topical application of mustard oil were compared. The higher the concentration of mustard oil and the longer the application time, the more powerful desensitization or conduction block was induced. From the results of the present study, it is suggested that the desensitization of the afferent fiber and sensory receptors induced by mustard oil results mainly from the conduction block of C-fiber in the primary afferent nerve.

• Annals of Clinical Neurophysiology
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• v.12 no.1
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• pp.11-15
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• 2010

Background: In belly-tendon (bipolar) montage, reference (R2) electrode placed on muscle's tendon has traditionally been considered to be electrically inactive. However, recent studies have revealed that R2 electrode is not simply referential, but actively contributes to compound muscle action potential (CMAP) waveform morphology. These findings suggest that CMAP onset latency and amplitude may also be influenced by the position of R2 electrode. This study was performed in order to evaluate the effect of R2 electrode position on CMAP onset latency and amplitude. Methods: We performed motor nerve conduction studies of median, ulnar, tibial and peroneal nerves on bilateral limbs of 20 normal subjects. We used traditional bipolar and monopolar montage and compared their CMAP onset latencies and amplitudes. In bipolar montage, recording (R1) electrode was placed on mid-belly of muscle with R2 electrode on the tendon of the muscle. In monopolar montage, R1 electrode was placed on the same site of bipolar montage, while R2 electrode was placed on the contralateral limb. Results: The mean CMAP onset latencies of median and peroneal nerves in bipolar montage were significantly different (p<0.05) with those in monopolar montage. And those of ulnar and tibial nerves were not significantly different (p>0.05). The mean CMAP amplitudes of all the tested nerves except ulnar nerve were significantly different (p<0.05). Conclusions: This study shows that change in R2 electrode position can affect the CMAP onset latency and amplitude, and these differences seem to be related to the generation of far field potential by CMAP.