• International Journal of Oral Biology
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• 제45권3호
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• pp.84-91
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• 2020

The present study investigated the participation of D-serine and NR2 in antinociception produced by blockade of central erythropoietin-producing hepatocellular carcinoma (Eph) A4 (EphA4) signaling in rats with trigeminal neuropathic pain. Trigeminal neuropathic pain was modeled in male Sprague-Dawley rats using mal-positioned dental implants. The left mandibular second molar was extracted under anesthesia, and a miniature dental implant was placed to induce injury to the inferior alveolar nerve. Our current findings showed that nerve injury induced by malpositioned dental implants significantly produced mechanical allodynia; additionally, the inferior alveolar nerve injury increased the expression of D-serine and NR2 subunits in the ipsilateral medullary dorsal horn (trigeminal subnucleus caudalis). Intracisternal administration of EphA4-Fc, an EphA4 inhibitor, inhibited nerve injury-induced mechanical allodynia and upregulated the expression of D-serine and NR2 subunits. Moreover, intracisternal administration of D-amino acids oxidase, a D-serine inhibitor, inhibited trigeminal mechanical allodynia. These results show that D-serine and NR2 subunit pathways participate in central EphA4 signaling after an inferior alveolar nerve injury. Therefore, blockade of D-serine and NR2 subunit pathways in central EphA4 signaling provides a new therapeutic target for the treatment of trigeminal neuropathic pain.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권3호
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• pp.227-237
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• 2007

Microglial cell activation is known to contribute to neuropathic pain following spinal sensory nerve injuries. In this study, I investigated its mechanisms in the case of trigeminal sensory nerve injuries by which microglial cell and p38 mitogen-activated protein kinase (p38 MAPK) activation in the medullary dorsal horn (MDH) would contribute to the facial pain hypersensitivity following mandibular nerve transection (MNT). And also investigated the changes of trigeminal ganglion neurons and ERK, p38 MAPK manifestations. Activation of microglial cells was monitored at 1, 3, 7, 14, 28 and 60 day using immunohistochemical analyses. Microglial cell activation was primarily observed in the superficial laminae of the MDH. Microglial cell activation was initiated at postoperative 1 day, maximal at 3 day, maintained until 14 day and gradually reduced and returned to the basal level by 60 days after MNT. Pain hypersensitivity was also initiated and attenuated almost in parallel with microglial cell activation pattern. To investigate the contribution of the microglial cell activation to the pain hypersensitivity, minocycline, an inhibitor of microglial cell activation by means of p38 MAPK inhibition, was administered. Minocycline dose-dependently attenuated the development of the pain hypersensitivity in parallel with inhibition of microglial cell and p38 MAPK activation following MNT. Mandibular nerve transection induced the activation of ERK, but did not p38 MAPK in the trigeminal ganglion. These results suggest that microglial cell activation in the MDH and p38 MAPK activation in the hyperactive microglial cells play an important role in the development of facial neuropathic pain following MNT. The results also suggest that ERK activation in the trigeminal ganglion contributes microglial cell activation and facial neuropathic pain.

• Journal of Oral Medicine and Pain
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• 제40권1호
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• pp.35-40
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• 2015

Purpose: This study aims to assess the psychological characteristics of patients with iatrogenic damage of the trigeminal nerve using Symptom Checklist-90-Revised (SCL-90-R). Methods: A total of 22 patients who visited the clinic of Department of Oral Medicine, School of Dentistry, Chosun University were evaluated in the months from December 2012 to December 2014. Patients were included in the study if they presented with reported sensory changes due to iatrogenic trigeminal nerve injury. A total of 37 control group who has no symptoms of pain and sensory change were included in the study. All participants filled out the SCL-90-R instrument to assess psychosocial symptoms. Results: The T-scores of most of the SCL-90-R symptom dimensions were within normal range (less than 55) in the patients and the control group. The patients group showed higher T-scores of SCL-90-R than those of the control group, with statistically significance of somatization, anxiety, psychoticism, and positive symptoms distress. Female patients group had higher Tscores of SCL-90-R than those of male patients group, but there was no statistical difference, except for the positive symptom global index. The chronic patients group showed higher Tscores of SCL-90-R than those of the acute patients group, but there was no statistical difference, except for the Positive symptom global index. Conclusions: According to the psychological assessment of iatrogenic trigeminal nerve injury patients using SCL-90-R, the patients group, as compared to the control group shows a significantly higher score for somatization, anxiety, and psychoticism. Therefore, assessment of psychological state would be considered to treat patients with iatrogenic trigeminal nerve injury.

• The Korean Journal of Pain
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• 제9권1호
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• pp.83-88
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• 1996

This is a retrospective analysis of 158 patients who visted our Neuro-Pain clinic, April 1992 to March 1996, suffering from trigeminal neuralgia. Most patients received nerve blocks in its triggering peripheral branches of pain. All patients experienced pain relief for 3 months after initial successful nerve block. Twenty two patients complained of recurring pain within 4 to 32 months. Mean duration of pain relief was as follows: infraorbital nerve block 15.2 months, maxillary nerve block 16.8 months, and mandibular nerve block 23.4 months. Demographic and clinical characteristics of all patients were also evaluated. This study demonstrates that alcohol block is a safe and effective method of treating trigeminal neuralgia.

• Journal of Oral Medicine and Pain
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• 제46권4호
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• pp.136-142
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• 2021

Purpose: Oral and facial sensation is affected by various factors, including trauma and disease. This study assessed the clinical profile of patients diagnosed with sensory dysfunction and investigated their sensory perception using simple qualitative sensory tests. Methods: Based on a retrospective review of the medical records, we analyzed a total of 68 trigeminal nerve branches associated with sensory dysfunction in 52 subjects. We analyzed the frequency and etiology of sensory dysfunction, and the frequency of different types of sensory perception in response to qualitative sensory testing using tactile and pin-prick stimuli. Results: The inferior alveolar nerve branch was the most frequently involved in sensory dysfunction (88.5%). Third molar extraction (36.5%) and implant surgery (36.5%) were the most frequent etiological factors associated with sensory dysfunction. Hypoesthesia was the most frequent sensory response to tactile stimuli (60.3%). Pin-prick stimuli elicited hyperalgesia, hypoalgesia, and analgesia in 32.4%, 27.9%, and 36.8%, respectively. A significant association was found between the two kinds of stimuli (p=0.260). Conclusions: Sensory dysfunction frequently occurs in the branches of the trigeminal nerve, including the inferior alveolar nerve, mainly due to trauma associated with dental treatment. Simple qualitative sensory testing can be conveniently used to screen sensory dysfunction in patients with altered sensation involving oral and facial regions.

• Journal of Korean Neurosurgical Society
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• 제63권6호
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• pp.814-820
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• 2020

Objective : Trigeminal neuralgia (TN) is a severe neuropathic condition that affects several elderly patients. It is characterized by uncontrolled pain that significantly impacts the quality of life of patients. Therefore, the condition should be treated as an emergency. In the majority of patients, pain can be controlled with medication; however, other treatment modalities are being explored in those who become refractory to drug treatment. The use of the trigeminal nerve block with a local anesthetic serves as an excellent adjunct to drug treatment. This technique rapidly relieves the patient of pain while medications are being titrated to effective levels. We report the efficacy and safety of percutaneous trigeminal nerve block in elderly patients with TN at our outpatient clinic. Methods : Twenty-one patients older than 65 years with TN received percutaneous nerve block at our outpatient clinic. We used bupivacaine (1 mL/injection site) to block the supraorbital, infraorbital, superior alveolar, mental, and inferior alveolar nerves according to pain sites of patients. Results : All patients reported relief from pain, which decreased by approximately 78% after 2 weeks of nerve block. The effect lasted for more than 4 weeks in 12 patients and for 6 weeks in two patients. There were no complications. Conclusion : Percutaneous nerve block procedure performed at our outpatient clinic provided immediate relief from pain to elderly patients with TN. The procedure is simple, has no serious side effects, and is easy to apply.

• Journal of Oral Medicine and Pain
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• 제41권3호
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• pp.118-125
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• 2016

Purpose: The aims of this study were to evaluate the clinical characteristics of patients with altered sensation and/or pain, and to determine outcome predictors affecting persistent neuropathy. Methods: Patients who complained an altered sensation or pain following trigeminal nerve trauma were involved in this study. To determine outcome predictors affecting persistent neuropathy, the patients were divided into two groups; transient vs. persistent, and the clinical phenotypes are compared between groups. Data were analyzed with t-tests, chi-square, and multiple regression analyses with 95% confidence interval and p<0.05 significance level. Results: A total of 111 patients were included: 23 with transient and 88 persistent groups. The panoramic result and pin-prick test score were statistically different between the groups. Radiating symptoms after blunt and pinprick stimuli were also significantly different between groups. The results revealed that the presence of a neurologic lesion in the panoramic view result, reduced sensation in the pinprick test, and radiation in the pinprick test could affect the persistent group. Conclusions: The presence of a neurologic lesion in panoramic view result and reduced sensation and radiating symptoms in the pin prick test would be defining features of one of the main clinical features of persistent neuropathy. These features could serve as outcome predictors diagnosing the permanent nerve injury in trigeminal nerve.

• The Korean Journal of Pain
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• 제18권2호
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• pp.279-283
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• 2005

Biplane fluoroscopy is usually used in angiography. Biplane fluoroscopy gives a biplane image with high resolution during the performance of operations. Trigeminal nerve blocks are effective treatment modalities for trigeminal neuralgia, and maxillary nerve block is the most dangerous procedure among them. The anatomic structures can change after head and neck surgery, so the trigeminal nerve block procedures cannot be done so easily. We used biplane fluoroscopy in these difficult cases. Our first case was a 60-year-old man who had undergone maxillary nerve block. The second case was of a 64-year-old man who had pulsed radiofrequency lesioning of mandibular nerve performed after head and neck surgery. With biplane fluoroscopy, we got good results without any complications.

• The Korean Journal of Pain
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• 제22권2호
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• pp.167-170
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• 2009

Pharmacological management is the first choice for treatment of the trigeminal neuralgia patients; however, if this mode of treatment fails a minimally invasive procedure should be performed. One of the most commonly used procedures is conventional radiofrequency lesioning of the Gasserian ganglion. Despite its popularity and success rate, this technique has disadvantages such as diminished corneal reflex, masseter weakness, numbness and anesthesia dolorosa. As a result, many studies have been conducted in an attempt to find a better method of treating trigeminal neuralgia. We report here a case of a trigeminal neuralgia patient that was treated with pulsed radiofrequency lesioning of the supraorbital and supratrochlear nerve due to pain in the frontal head that was refractory to the pharmacological treatments. Following the procedure, the Visual Analogue Scale score for pain decreased to 1-2/10 and the pain relief persisted for 7 months. These results indicate that pulsed radiofrequency treatment of the peripheral nerve may be useful for trigeminal neuralgia patients that do not respond to pharmacological treatments.

• The Korean Journal of Pain
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• 제9권2호
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• pp.395-398
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• 1996

A retrospective analysis of 175 patients who were suffering from trigeminal neuralgia was done. We found 21 cases (12.0%) of abnormal findings including brain tumors and cerebrovascular disease on brain MRI. All patients were transferred to department of neurosurgery for operation. Among them, 7 patients refused or gave up operation and received nerve blocks with pure alcohol. Their MRI findings were meningioma, arachnoid cyst, arteriovenous malformation, venous angioma, and frontal sinus cancer This study demonstrates that peripheral nerve block or trigeminal nerve block with pure alcohol would be possible in case of elderly patients, patients who have poor general condition, patients who refuse operation, and brain tumor or cerebrovascular disease which located in dangerous area to be operated.