• The Korean Journal of Physiology and Pharmacology
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• v.9 no.3
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• pp.143-147
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• 2005

Following peripheral nerve injury, excessive nociceptive inputs result in diverse physiological alterations in the spinal cord substantia gelatinosa (SG), lamina II of the dorsal horn. Here, I report the alterations of excitatory or inhibitory transmission in the SG of a rat model for neuropathic pain ('spared nerve injury'). Results from whole-cell recordings of SG neurons show that the number of distinct primary afferent fibers, identified by graded intensity of stimulation, is increased at 2 weeks after spared nerve injury. In addition, short-term depression, recognized by paired-pulse ratio of excitatory postsynaptic currents, is significantly increased, indicating the increase of glutamate release probability at primary afferent terminals. The peripheral nerve injury also increases the amplitude, but not the frequency, of spontaneous inhibitory postsynaptic currents. These data support the hypothesis that peripheral nerve injury modifies spinal pain conduction and modulation systems to develop neuropathic pain.

• The Journal of Korean Medicine
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• v.30 no.3
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• pp.28-38
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• 2009

Background : Peripheral nerve injuries are a commonly encountered clinical problem and often result in a chronic pain and severe functional deficits. Objective : The aim of this study was to evaluate the effects of Gentianae Macrophyllae Radix (G. M. Radix) on the pain control and the recovery of the locomotor function that results from the sciatic crushed nerve injury in rats. Method : Using rats, we crushed their sciatic nerve, and then orally administered the aqueous extract of G. M. Radix. The effects of G. M. Radix on the recovery locomotor function were investigated by walking track analysis. The effects of G. M. Radix on pain control were investigated by brain-derived neurotrophic factor (BDNF) expression in the sciatic nerve, and c-Fos expression in the paraventricular nucleus (PVN) of the hypothalamus and in the ventrolateral periaqueductal gray (vlPAG). Result : G. M. RADIX facilitates motor function from the locomotor deficit, and thereby increased BDNF expression and suppressed painful stimuli in the PVN and vlPAG after sciatic crushed nerve injury. Conclusion : It is suggested that G. M. Radix might aid recovery locomotor function and control pain after sciatic crushed nerve injury. Further studies on identifying specific the component in G.M. Radix associated with enhanced neural activity in the peripheral nerve injury may be helpful to develop therapeutic strategies for the treatment of peripheral nerve injury.

• Journal of the Korean Society of Physical Medicine
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• v.8 no.1
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• pp.79-89
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• 2013

PURPOSE: To identify the effects of single trial transcutaneous electrical nerve stimulation (TENS) application on chronic neuropathic pain and the repeated TENS application to development of neuropathic pain following peripheral nerve injury. METHODS: First, 20 rats were given the median nerve ligation to induce chronic neuropathic pain. After the ligation, neuropathic pain was assessed by measuring the forepaws withdrawal threshold to von Frey filaments for 3 weeks. Afterward, rats were randomly divided into TENS group and placebo-TENS group. TENS (frequency 100Hz, pulse width $200{\mu}s$) was applied to the forearm for 20 minutes. Second, 34 rats were randomly allocated into two group after median nerve ligation: TENS group and placebo-TENS group. Both interventions were applied to the forearm for 20 minutes from 1 day to 3 weeks after injury. Neuropathic pain to mechanical was measured on each rat for 3 weeks. RESULTS: Exeprimental rats showed a clear neuropathic pain-like behaviors, such as reduced forepaw withdrawal threshold to mechanical stimulation for 3 weeks, after median nerve ligation. And, TENS decreased effectively the chronic neuropathic pain originated from median nerve injury. TENS also diminished the development of neuropathic pain after nerve injury. CONCLUSION: Our animal model studying for neuropathic pain following median nerve injury may be useful to investigate peripheral neuropathic pain in human. Also, TENS may be used to mediate chronic neuropathic pain and to prevent the development of neuropathic pain following median nerve injury.

• Journal of Acupuncture Research
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• v.29 no.6
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• pp.23-34
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• 2012

Objectives : This study was performed to define clinical character of peripheral facial nerve injury. Methods : 36 patients was identified with peripheral facial nerve injury among 1128 patients who visited the Facial Palsy Center in Kyung Hee University Hospital at Gang-dong between January 2010 and November 2011. We reviewed the medical records including gender, age, cause, symptom, period of treatment, and axonal loss. Results : Most common cause of peripheral facial nerve injury was iatrogenic surgery, followed by direct trauma, neoplastic disorders. Patients with facial nerve injury commonly complain about facial palsy(ipsilateal or bilateral), followed by paresthesia, facial spasm, facial pain, auricular pain. Peripheral facial nerve injury group showed worse electrophysiological pattern and younger onset age compared with Bell's palsy group. Conclusion : This study was designed for 36 patients and further studies are necessary.

• Journal of Korean Medicine Rehabilitation
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• v.28 no.2
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• pp.73-82
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• 2018

Objectives The purpose of this study is to systematically explore the effects and safety of acupuncture treatment for upper extremity peripheral nerve injury and to review the methodology of clinical trials. Methods We searched 9 electronic databases(3 international, 1 Chinese, 5 Korean) including English, Korean and Chinese, up to December 2017 for randomized controlled trials which evaluated the effects of the acupuncture in patients with upper extremity peripheral nerve injury. We abstracted the designs of the randomized clinical trials and the method of acupuncture treatment according to the Standards for Reporting Interventions in Clinical Trials of Acupuncture(STRICTA). Results A total of 8 papers were reviewed. All randomized clinical trials were conducted in China. Of them, five studies(62.5%) were electro-acupuncture as intervention. All randomized clinical trials reported favorable effects of acupuncture treatments compared to baseline or control group with outcomes of efficacy rate. However risk of bias seemed high. LI4, LI11, SI3, PC3, PC6 were most frequently used for acupoints to treat upper extremity peripheral nerve injury. Conclusions These results suggest that it is recommended to develop more detailed reporting standards for acupuncture treatment method. In the future, well designed randomized clinical trials which evaluate the effects and safety of acupuncture treatment for upper extremity peripheral nerve injury is highly needed.

• Journal of Korean Neurosurgical Society
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• v.39 no.1
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• pp.52-57
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• 2006

Objective : It has been suggested that the occurrence of persistent pain signal during the early postnatal period may alter an individual's response to pain later in life. The aim of this study is to assess whether neonatal nerve injury resulted in long-lasting consequences on nociceptive system in the rat. Methods : We examined whether neuropathic pain behaviors and the changes of spinal neuropeptides [SP, CGRP, VIP and VIP] induced by peripheral nerve injury within 1 day after birth [Neonate group] were different from those at 8 weeks after birth [Mature group]. Results : The Neonate group showed more robust and long-lasting pain behaviors than the Mature group. Immunohistochemical findings demonstrated that spinal SP- & CGRP-immunoreactivities[ir] of the ipsilateral to the contralateral side increased in the Neonate group, whereas those decreased in the Mature group. In addition, increase in spinal VIP- & NPY-ir of the ipsilateral to the contralateral side was more robust in the Mature group than in the Neonate group. Conclusion : These results suggest that peripheral nerve injury in the early postnatal period may result in long-lasting and potentially detrimental alterations in nociceptive pathways.

• Archives of Reconstructive Microsurgery
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• v.5 no.1
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• pp.121-127
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• 1996

Peripheral nerve injury occurs mostly by trauma and is usually associated with fracture of bone and joint, muscular injury and tendon injury and it also evokes paralysis and anesthesia. When treatment of peripheral nerve injury is considered,, the modality of treatment is decided by the general condition of the patient, type of injury, associated injuries and the condition of wound. To get the maximum results, surgical treatment and reconstruction and rehabilitation should all go in hand-in-hand. From January 1985 to December 1994, we observed 61 patients that had operation without reconstruction due to peripheral nerve injury with a follow-up period of more than 1 year. Among the 61 patients, 44 were men(72%) and 17 were women(28%). Follow-up period was average 19 months. Age distribution was mostly in their twenties with a mean age of 28 years. Time interval of operation after injury was average 11 months. Trauma was the main cause of peripheral nerve injuries with a proportion of 87%. 31 patients had neurorrhaphy, in which case 14 patients had stay suture and 17 patients did not. 14 patients had nerve graft, and 16 patients had neurolysis. We used our scales to compare the results of surgery on the basis of British Research Council System. We gave scores to every sensory and motor scale to estimate functional improvement and emphasized on motor functional improvement. The total score = sensory score + ($2{\times}motor$ score). We considered 8-9 points as excellent, 6-7 points as good, 2-5 points as fair, 0-1 points as poor result. We considered excellent and good as much improved. Excellent and good results were obtained in 13 out of 14 neurorrhaphy with stay suture(93%), 12 out of 17 neurorrhaphy without stay suture(71%), 6 out of 14 nerve graft(43%), 12 out of 16 neurolysis(75%). Among the patients with neurorrhaphy done within 3 months, 11 out of 14(86%) showed improvement, but among the patients after 4 months 3 out of 17(76%) showed improvement. 84% of improvement was observed in the patients with time interval from injury to surgery within 3 months, and 64% in the patients with time interval after 4 months. In the aspect of age, 77% with the age below 20 years, 70% with the age between 21 and 30 years, 66% with the age above 31 years showed improvement. We conclude that considering degree of injury, time interval from injury and age with the adequate method of treatment, we can obtain good results from surgery.

• Journal of Haehwa Medicine
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• v.25 no.1
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• pp.99-108
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• 2016

While axons in the peripheral nerve can regenerate and lead to functional recovery to a certain extent after injury, its efficacy varies depending on the severity and duration of the injury. Here, we investigated the effects of Boyanghwano-tang (BYHOT) treatment on the regenerative responses in the sciatic nerves after prolonged transection and coaptation surgery. In mice given crush injury, axonal regeneration was completed when analyzed 1 week later and did not show any difference in regenerative reponses in the distal portion of the nerve between saline- and BYHOT-treated groups. In animal models with transection and reconnection, axonal regeneration was markedly retarded compared to animals with crush injury. Regenerating axons were extended into the reconnected distal portion of the nerve more actively in animals treated with BYHOT than saline controls. Cdc2 protein was similarly induced in nerves with crush injury and with transection and recollection, and its level was lower in BYHOT-treated animal than saline control when measured 2 weeks after nerve reconnection. These results suggest that BYHOT may be useful to promote axonal regeneration in the peripheral nerve after severe injury.

• Archives of Plastic Surgery
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• v.42 no.5
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• pp.626-629
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• 2015

Peripheral nerve injuries remain a challenge for reconstructive surgeons with many patients obtaining suboptimal results. Understanding the level of injury is imperative for successful repair. Current methods for distinguishing healthy from damaged nerve are time consuming and possess limited efficacy. Confocal laser endomicroscopy (CLE) is an emerging optical biopsy technology that enables dynamic, high resolution, sub-surface imaging of live tissue. Porcine sciatic nerve was either left undamaged or briefly clamped to simulate injury. Diluted fluorescein was applied topically to the nerve. CLE imaging was performed by direct contact of the probe with nerve tissue. Images representative of both damaged and undamaged nerve fibers were collected and compared to routine H&E histology. Optical biopsy of undamaged nerve revealed bands of longitudinal nerve fibers, distinct from surrounding adipose and connective tissue. When damaged, these bands appear truncated and terminate in blebs of opacity. H&E staining revealed similar features in damaged nerve fibers. These results prompt development of a protocol for imaging peripheral nerves intraoperatively. To this end, improving surgeons' ability to understand the level of injury through real-time imaging will allow for faster and more informed operative decisions than the current standard permits.

• Journal of Korean Biological Nursing Science
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• v.4 no.1
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• pp.101-112
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• 2002

Peripheral nerve injury results in plastic changes in the dorsal ganglia (DRG) and spinal cord, and is often complicated with neuropathic pain. The mechanisms underlying these changes are not known, but these changes seem to be most likely related to the neurotrophic factors. This study investigated the effects of mechanical peripheral nerve injury on expression of brain-derived neurotrophic factor(BDNF) in the DRG and spinal cord in rats. 1) Bennett model and Chung model groups showed significantly increased percentage of small, medium and large BDNF-immunoreactive neurons in the ipsilateral $L_4$ DRG compared with those in the contralateral side at 1 and 2 weeks of the injury. 2) In the ipsilateral $L_5$ DRG of the Chung model, percentage of medium and large BDNF-immunoreactive neurons increased significantly at 1 week, whereas that of large BDNF-immunoreactive neurons decreased at 2 week when compared with those in the contralateral side. The intensity of immunoreactivity of each neuron was lower in the ipsilateral than in the contralateral DRG. 3) In the spinal cord, the Bennett and Chung model groups showed a markedly increased BDNF-immunoreactivity in axonal fibers of both superficial and deeper laminae. The present study demonstrates that peripheral nerve injury in neuropathic models altered the BDNF expression in the DRG and spinal cord. This may suggest important roles of BDNF in sensory abnormalities after nerve injury and in protecting the large-sized neurons in the damaged DRG.