• Journal of Korean Neurosurgical Society
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• v.40 no.3
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• pp.143-147
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• 2006

Objective : Brachial plexus injury can produce a intractable chronic neuropathic pain. This study was undertaken to assess the long term outcome of microsurgical dorsal root entry zonotomy[MDT]. Methods : Between October 1997 and December 2002, 21 patients received MDT because of a intractable pain resulting from brachial plexus injury. Of these, 19 patients were followed for more than 2 years. Fourteen of 19 patients were male and patient ages ranged from 22 to 69 years. Mean pain duration was 36.8 months and all patients had severe pain of $9{\sim}10$ visual analogue scale. To achieve complete destruction of abnormal dorsal horns, thermocoagulation of the posterolateral sulcus were performed and careful gluing was done to prevent postoperative adhesion and pain recurrence. Results : Of the 19 patients, 15 patients had excellent [>75% reduction in pain] and good [$51{\sim}75%$ pain relief] results in a average postoperative period of 4.1 years. One patient had a poor [less than 25% pain relief] result. Three patients were considered to have a fair result [$26{\sim}50%$ pain relief]. Postoperative complications were 2 transient ipsilateral ataxia and 1 CSF fistula that resolved without surgical revision. Conclusion : These results indicate that MDT provides excellent long-term pain relief in medically intractable chronic neuropathic pain following brachial plexus injury without significant complications.

• Journal of Korean Neurosurgical Society
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• v.39 no.4
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• pp.265-270
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• 2006

Objective : Microvascular decompression[MVD] at root exit zone[REZ] of the facial nerve has been largely popularized and it has become the standard treatment for patients with hemifacial spasm[HFS]. This sturdy is performed to evaluate the efficacy of MVD over the course of time. Methods : From 1994 to 2003, 50 patients with HFS who underwent MVD were followed up for more than 6 months. We retrospectively analyzed results with medical records and telephone researches. Results : The mean age of patients at the time operation was 57.6 years and 84% of the patients were female. The mean duration of follow-up after operation was 3.4 years [range $0.5{\sim}7.8\;years$]. One day after MVD, 54% of patients had complete relief of spasm immediately. Continuous improvements of HFS were observed during the follow-up period and these improvements were statistically significant with time (P< 0.05). Until 6 months after operation, complete relief of spasm was observed in 84% of patients. The delayed relief of spasm was observed in 35.7% of our patients who experienced complete relief. Conclusion : The efficacy of MVD in HFS is improves with time. Continuous follow-up evaluations for the duration of more than at least 6 months after MVD are important for the decision of its clinical results because delayed relief of spasms occurs.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.1
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• pp.21-29
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• 2016

To overcome the large ring gear manufacturing problems seen in slewing bearings and girth gears, pin gear drive units have been developed. Among them, a novel slewing bearing with an internal pinwheel gear set (i-PGS) is introduced in this paper. First, we consider the exact cam pinion profile of i-PGS with the introduction of a profile shift coefficient. Furthermore, a new root relief profile modification for the i-PGS cam pinion is presented. Then, the contact stresses are investigated to determine the characteristics of the surface fatigue by varying the shape design parameters. The results show that the contact stresses of i-PGS can be reduced significantly by increasing the profile shift coefficient. In addition, the contact ratio, a measure of teeth overlapping action, decreases with the decrease of the allowable pressure angle.

• Journal of Korean Neurosurgical Society
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• v.45 no.6
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• pp.336-340
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• 2009

Objective : The factors that influence the prognosis of patients with hemifacial spasm (HFS) treated by microvascular decompression (MVD) have not been definitely established. We report a prospective study evaluating the prognostic factors in patients undergoing MVD for HFS. Methods : From January 2004 to September 2006, the authors prospectively studied a series of 293 patients who underwent MVD for HFS. We prospectively analyzed a number of variables in order to evaluate the predictive value of independent variables for the prognosis of patients undergoing MVD. The patients were followed-up at regular intervals and divided into as cured and unsatisfactory groups based on symptom relief. Uni- and multivariate analyses were performed using logistic regression models. Results : A total 273 of 293 (94.2%) patients achieved symptom relief within one year after the operation. Intraoperatively, the indentation of the root exit zone was observed in 259 (88.5%) patients. Uni- and multivariate analyses revealed that the symptoms at postoperative 3 months (p<0.001) and indentation of the root exit zone (p=0.036) were associated with good outcomes. Conclusion : The intraoperative finding of root exit zone indentation will help physicians determine the prognosis in patients with HFS. To predict the prognosis of HFS, a regular follow-up period of at least 3 months following MVD should be required.

• The Korean Journal of Pain
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• v.12 no.2
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• pp.191-194
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• 1999

Background: Millions of patients with chronic sciatica are still treated with epidural corticosteroids. The efficacy of epidural corticosteroids remains questionable, especially in the failed back surgery syndrome (FBSS). We studied to evaluate outcome for 10 patients with failed back surgery syndrome treated with spinal nerve root block using corticosteroids, hyaluronidase, and local anesthetics. Methods: The affected nerve roots are localized with the help of fluoroscopy and contrast dye. Local anesthetic diluted in 1,500 U hyaluronidase and 40 mg methylprednisolone is injected. A small retrospective pilot group of 10 patients with FBSS was treated. The success rate is evaluated using a visual analogue scale at 1 week and 3 month interval after the last injection. Results: Initially, 7 patients experienced good pain relief; 5 patients suspained pain relief for 3 months. No complications were observed. Conclusions: This technique is worthwhile for patients with FBSS and where epidural fibrosis is suspected to be the pain origin.

• Journal of Environmental Health Sciences
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• v.49 no.2
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• pp.99-107
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• 2023

Background: Excessive alcohol consumption is at the root of serious social problems such as hangovers, liver dysfunction, and alcoholism. Objectives: This study was carried out to determine the hangover ameliorating effect of fermented rice extract and a combination of yeast-fermented powder and lysate containing aldehyde dehydrogenase (ALDH) (improved new ingredients) in an ethanol-induced rat study. Methods: The concentrations of alcohol, acetaldehyde, and malondialdehye in serum were evaluated to assess the anti-alcohol and anti-aldehyde hangover effect in two experiments, one with fermented rice extract) and a second with yeast-fermented powder and lysate, using animal studies. Results: Experiment 2 with yeast-fermented powder and lysate containing ALDH showed similar and higher activity, respectively, in reducing ethanol and acetaldehyde concentration compared with Experiment 1 with fermented rice extract. Experiment 2 also significantly reduced malondialdehyde, a type of lipid peroxide. The ALDH-related compound (ARC) lysate showed better hangover relief effect than ARC powder. Conclusions: These results indicate that ALDH-related compounds exhibit a hangover relief effect, and fermented lysate is considered to be a better candidate for hangover relief.

• The Korean Journal of Pain
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• v.11 no.1
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• pp.127-129
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• 1998

Intractable chest and abdominal wall pain responds well to root surgery. But it is better to perform this procedure less invasively with less complications. Cryoanalgesia has been developed to relieve several neurogenic pain without causing irrversible nerve damage. Well-selected percutaneous cryoablative procedure could be one of the technique of choice for some chronic pains because it has the advantage of easy application without any remarkable side effect. We did percutaneous cryoneurolysis of the spinal nerve root at the thoracic level to treat one patient with severe cancer pain on the chest wall(T4, 5, and 8 dermatomes) after successful percutaneous radiofrequency T6 and T7 posterior root rhizotomy. This procedure was performed under fluoroscopic guidance. We advanced 2 mm cryoprobe to the posterior, superior aspect of vertebral foramen on lateral view until the patient felt paresthesia. 3 times of 2 minutes freezing was applied to each spinal nerve root. The patient got immediate pain relief without any side effect.

• The Korean Journal of Pain
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• v.14 no.1
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• pp.123-125
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• 2001

A 50-year-old female patient developed severe right neck and upper extremity pain, hyperesthesia and allodynia during cervical epidural block. Her pain was diagnosed as neuropathic nature. She was treated with repeated stellate ganglion block (SGB) and electrical stimulation (EST). After 3 weeks of treatment, symptomatic relief was achieved, but a mild degree of hyperesthesia and motor weakness was remained. However, she refused all treatment. So treatment was stopped. In a follow-up done, 15 weeks after the nerve injury, she had recovered without complications.

• Tribology and Lubricants
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• v.16 no.5
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• pp.357-364
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• 2000

In this study, the sliding wear in spur gears, using Archard's wear model, is analyzed. Formulas of tooth sliding wear depth along the line of action are derived. The tooth profile is modified Id make a smooth transmission of the normal loads and the cylinder profile for reducing the pressure spike is suggested. The sliding wear rate is calculated with these profiling results. We expect these modification methods to contribute to the reduction of sliding wear not only in the root, but the tip of tooth and tooth edge.

• The Korean Journal of Pain
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• v.9 no.2
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• pp.390-394
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• 1996

Background: Occipital neuralgia is characterized by pain, usually deep and aching, in the distribution the second and/or third cervical dorsal root. Two broad groups of patients include primary occipital neuralgia with no apparent etiology and secondary neuralgia with structural pathology. Patients with occipital neuralgia can develop autonomic changes and hyperesthesia. In patients who have not improved with conservative treatment, we have carried out various nerve blocks and evaluated the effectiveness. Methods: In a series of 20 occipital neuralgia patients with no apparent etiolgy, we have carried out great occipital nerve blocks with needle TEAS. In patients who have not improved more than 75% on VAS with great occipital block, we have carried out C2 ganglion blocks and in patients who have not improved more than 75% with C2 ganglion block, C3 root blocks, C2/C3 facet joint blocks have been carried out in due order. Results: In 3 patients out of 10 patients who have not improved with great occipital nerve block, C2 ganglion block led to pain relief. A good response of C3 root block was achived in 2 of 7 patients without response to C2 ganglion block and C2/C3 facet joint block led to improvement in 1 of 5 patients without response to C3 root block. Conclusions: Nerve blocks like great occipital nerve block, C2 ganglion block, C3 root block, or C2/C3 facet joint block were effective in the patients who have not improved with conservative treatment.