• 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.

• 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.10 no.1
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• pp.43-47
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• 2008

Background: Acute brachial plexitis is an acute idiopathic inflammatory disease affecting brachial plexus, which is characterized by initial severe pain in shoulder followed by profound weakness of affected arm. This is a retrospective study to evaluate the clinical and electrophysiological profile of acute brachial plexitis. Methods: Sixteen patients with acute brachial plexitis were sampled. The electrodiagnostic studies included motor and sensory nerve conduction studies (NCSs) of the median and ulnar, sensory NCSs of medial and lateral antebrachial cutaneous nerves, and needle electromyography (EMG) of selected muscles of upper extremities and cervical paraspinal muscles. The studies were performed on both sides irrespective of the clinical involvement. Results: In most of our patient, upper trunk was predominantly affected (14 patients, 87.50%). Only two patients showed either predominant lower trunk affection or diffuse affection of brachial plexus. All had an acute pain followed by the development of muscle weakness of shoulder girdle after a variable interval ($7{\pm}8.95$ days). Ten patients (62.50%) had severe disability. In NCSs, the most frequent abnormality was abnormal lateral antebrachial cutaneous sensory nerve action potentials (SNAPs). On needle EMG, all the patients showed abnormal EMG findings in affected muscles. Conclusions: In this study, pain was the presenting feature in all patients, and the territory innervated by upper trunk of the brachial plexus was most frequently involved. The most common NCS abnormality was abnormal SNAP in lateral antebrachial cutaneous nerve. Our findings support that the electrodiagnostic test is useful in localizing the trunk involvement in acute brachial plexitis.

• Annals of Clinical Neurophysiology
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• v.13 no.1
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• pp.31-37
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• 2011

Background: Carpal tunnel syndrome (CTS) and tarsal tunnel syndrome (TTS) are thought to share a similar pathophysiology, compression of the median and plantar nerve by the carpal tunnel and flexor retinaculum. A few reports introduced the relationship between idiopathic CTS and TTS without definite evidence of coexistence. The current study was designed to analyze the electrophysiologic characteristics of combined idiopathic CTS and TTS by comparing with each idiopathic CTS or TTS. Methods: We retrospectively collected patients with combined idiopathic CTS and TTS (CTS-TTS group) from June 2001 to February 2009. Patients with each idiopathic CTS or TTS were collected as controls. Electrophysiologic data of median and plantar nerves were compared between CTS-TTS group and controls. Results: CTS-TTS group was composed of 31 patients. Control group of each CTS or TTS were 50 CTS and 49 TTS patients. In comparison of median nerve conduction study between CTS-TTS group and CTS control group, decreased compound muscle action potential amplitude (p<0.001), decreased median sensory nerve action potential amplitude (p<0.001) and sensory nerve conduction velocity at finger stimulation (p=0.013) were prominent in CTS-TTS group. Decreased medial plantar sensory nerve action potential amplitude (p=0.034) was indicated when CTS-TTS groups and TTS control group were compared. Conclusions: If the electrophysiology study of patients with CTS or TTS was suggestive of severe degree of nerve injury, concerns about the possibility of combined CTS and TTS would be helpful.

• Annals of Clinical Neurophysiology
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• v.9 no.1
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• pp.33-35
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• 2007

Meralgia paresthetica (MP) is a benign entrapment neuropathy which is characterized by sensory impairment and paresthesia in the cutaneous distribution of the lateral femoral cutaneous nerve. A 79-year-old woman presented with intermittent right inguinal burning sensation. The sensory nerve conduction study (NCS) showed decreased right side sensory nerve action potential (SNAP) on lateral femoral cutaneous nerve compared to the contralateral one. Abdomino-pelvic CT showed bilateral huge renal cysts (The size of largest one on right side: about $6.2{\times}5.0cm$). We report a case of MP caused by a huge abdominal renal cyst, which should be considered when conventional examination reveals no responsible etiology.

• Annals of Clinical Neurophysiology
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• v.7 no.2
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• pp.83-87
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• 2005

Background: The study of the medial antebrachial cutaneous nerve (MABCN) is an underused electrodiagnostic tool. But its use is often crucial for assessing mild lower brachial plexus or MABCN lesions, and sometimes for differentiating an ulnar mononeuropathy from a lower brachial plexopathy. This study was designed to know the difference of amplitude and velocity in a stimulation method (orthodromic vs antidromic), side of an arm and sex according by age. Method: MABCN conduction studies were performed orthodromically and antidromically in 90 subjects (42 women and 48 men, ranging from 22 to 79 years of age). We divided subjects into three groups by age (group 1: 20-39 years, group 2: 40-59 years, group 3: 60-79 years). The mean sensory nerve action potential amplitudes and sensory nerve conduction velocities in each group was compared by stimulation method, side of an arm and sex. Result: The amplitudes and velocities made a significant difference between orthodromic and antidromic method in all age groups. At comparison in amplitude and velocity by side of an arm, only amplitude was significantly higher in right arm than left by any stimulation method. The amplitudes and velocities were of no statistically differences in sex except amplitude checked orthodromically in right arm. Conclusion: This study suggests that there is the differences in conduction study of MABCN by stimulation method and side of an arm.

• Journal of the Korean Academy of Clinical Electrophysiology
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• v.5 no.2
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• pp.47-59
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• 2007

The purpose of this study were to investigate the effects of electroacupuncture(EA) on sensory nerve function in acute hyperglycemia rats. Male Sprague-Dawley rats weighing 250~270 g(8 weeks of age) were used in this study, and the induced hyperglycemia rats were produced by intraperitoneal injection of streptozotocin(70 mg/kg body weight). Only animals with blood glucose levels of 300 mg/dl or higher were used in this study. Animal were divided into two groups: the control group and EA group (n=7 in each group). For EA, two stainless-steel needles were inserted into Zusanli (ST36) which is located at the anterior tibial muscle and about 10mm below the knee joint. Pulsed current(2 Hz, 0.3 ms) were applied to the inserted needle for 20 mim. We measured glucose level, weigh, sensory nerve conduction and somatosensory evoked potential(5EP) before and after injecting streptozotocin, 2 weeks, 4 weeks. The change of blood glucose on EA group trended to decrease compared with the control group and there were significant differences(p<0.05). The body weight of the EA group trended to be reduced compared with the control group and there were significant differences(p<0.05). The amplitude of sensory nerve action potential on EA group to increase compared with the control group and there were significant differences(p<0.05). There were no significant differences in SEP. These results suggest that EA has beneficial effect on diabetic neuropathy and this effect may be related in part with prevention of hyperglycemia.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5305-5310
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• 2012

This study is Carpal tunnel syndrome(CTS) disorder of median nerve at wrist. It is usually diagnosed through clinical manifestation and Nerve Conduction Study(NCS). NCS of the median nerve before and after operation were compared in twenty four patient's with CTS, in order to seventeen patient's evaluate the prognostic value of that findings. Analysis result symptom profile of CTS in total number of patient's 17 (Female:17, Male:0), 21 hands (Rt:9, Lt:4, Both:4), Ages(31~60), Mean duration of symptom months($46.6{\pm}36.1$), Mean interval between 1st and 2nd NCS months($20.5{\pm}7.1$), Sensory symptoms(Tingling:21, Numbness:19, Noctunal paresthesia:17), Motor symptoms(Thenar atrophy:20, Trigger finger:2, Morning stiffness:3), Post-operative symptoms(Free:38.1%, >50% improve:52.4%, <50% improve:9.5%). NCS was normal range after operation than before in Sensory nerve conduction study 4 patients's and Motor nerve conduction study 5 patients. Surgery before and after Sensory nerve action potential (SNAP) responses showed improvement over the previous results. Forward by the patient's occupation and occupation patterns of CTS, other treatment methods and surgical treatment of CTS by comparing the degree of improvement to identify and correct nerve conduction study to judge whether the patient's operation.

• Annals of Clinical Neurophysiology
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• v.6 no.1
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• pp.31-34
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• 2004

Backgrounds: The pathway of the sural nerve (SN) is variable, but usually divided into medial and lateral sural branches joining the posterior tibial nerve (PTN) and the peroneal nerve (PN). The sural nerve may be affected by PN palsy. The frequency or the severity of SN involvement in peroneal palsy is not known. The purpose of the study is to investigate the frequency and the severity of the SN involvement by the peroneal nerve palsy. Methods: Total 85 patients were included with peroneal palsy. Amplitudes of distal peroneal, sural, and superficial peroneal nerves (SPN) were compared between normal and paralyzed sides. The frequency and severity of SN involvement by peroneal palsy were investigated. Results: Mean age was $48.4{\pm}17.4$ years old at the time of the test. Peroneal palsy was right side in 32, left in 38, and bilateral in 15 patients. Mean amplitudes of affected distal PN, SPN, and SN were $1.51{\pm}1.64mV$, $3.50{\pm}4.86{\mu}V$, and $10.42{\pm}6.59{\mu}V$ in right side, and $1.19{\pm}1.57mV$, $4.38{\pm}5.67{\mu}V$, and $11.06{\pm}6.87{\mu}V$ in left side, respectively. Sensory nerve action potential (SNAP) amplitude of the SN in the affected side was average $73.7{\pm}33.1%$ of normal, which was significantly lower than that in the normal side(p<0.01). The decrease of the sural SNAP amplitude was more than 15% in 39 out of 70 patients with unilateral peroneal palsy. Peroneal compound muscle action potential (CMAP) amplitude was not correlated with the amplitude of the sural SNAP. By complete peroneal palsy, SN SNAP amplitude was decreased to 4% of SNAP and $57.7{\pm}31.8%$ of that in normal side. Conclusions: PN injury without PTN involvement may induce reduction of sural SNAP amplitude. Because of the anatomic variation of SN, the electrophysiological findings are variable. It should be considered to interpret the location of the PN lesion.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.2
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• pp.151-157
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• 2021

Charcot-Marie-Tooth disease (CMT) is a slowly progressive hereditary degenerative disease and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired immune-mediated disorder characterized by weakness and sensory deficits. The purpose of this study was to analyze and compare the electrophysiological characteristics observed in sensory nerve conduction studies (SNCS) of both diseases. A retrospective study of 65 patients with a diagnosis of CIDP (N=35) and CMT type I (N=30) was performed. This study analyzed No potentials ratio, distal compound nerve action potential (dCNAP) of various nerve types, and a correlation coefficient analysis of the sensory nerve conduction velocity (SNCV). As a result, I found that CMT 1 was more severe systemic demyelinating and axonal polyneuropathy better than CIDP (P<0.05). In a quantitative analysis of dCNAP and SNCV, especially sural nerve was the most severe nerve injury observed in both diseases. In correlation and scatter plot analysis, CMT 1 showed relatively high correlations compared to CIDP based on the correlation coefficient analysis (Fisher's Z test) of SNCV. The results of this study suggested that CMT 1 showed the slowness in SNCV, one of the characteristics of demyelinating polyneuropathy, and this slowing had a uniform pattern. In conclusion, electrophysiological characteristic of SNCS may be useful in the diagnosis and research between patients with CMT 1 and CIDP.