• Journal of Korean Neurosurgical Society
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• 제61권5호
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• pp.653-659
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• 2018

Objective : Surgical obliteration of ruptured aneurysm of the proximal posterior inferior cerebellar artery (PICA) is challenging because of limited surgical accessibility. In recent years, coil embolization is the first-choice treatment for these lesions. However, coil embolization is not always easy in ruptured PICA aneurysm owing to the variable anatomical diversity of its shapes, its relationship to the parent artery, its low incidence, and accordingly, lesser neurointerventionist experience. Methods : The parent artery and microcatheter for easier navigation and the embolization technique for stable coiling were identified. Results : This study aimed to identify the more appropriate approach route, microcatheter, and strategies for an easier and safer, and more durable coil embolization in the treatment of lesions in the proximal PICA. Conclusion : Coil embolization for aneurysmal subarachnoid hemorrhage due to a ruptured proximal PICA remains a challenge, but with the appropriate coiling plan, it can be treated successfully.

• Journal of Korean Neurosurgical Society
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• 제30권9호
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• pp.1086-1093
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• 2001

Object : With the recent variable treatment modalities and the development of microsurgical techniques, outcomes of surgical and medical management of aneurysm have shown much progress in the last 10 years. However, the management of posterior circulation aneurysm is still a debatable due to its difficulty in limited surgical approach, complicated anatomical structure and many small perforators to vital structure. The purpose of this study is to compare the results of clinical manifestation and outcome of surgery with respect to anterior and posterior circulation aneurysms. Material and Methods : We evaluated the 33 patients with PCAs(posterior circulation aneurysm) and 359 patients with ACAs(anterior circulation aneurysm) treated between 1994 and 1999, retrospectively. Results : Posterior circulation aneurysms showed higher tendency(5 cases, 14.7%) to have unusual shapes, such as dissecting or fusiform compared with anterior circulation aneurysm(15 cases, 4.2%). There were more multiple aneurysms in posterior circulation aneurysm(8 cases, 26.5%) than anterior circulation aneurysm(59 cases, 16.2%). The number of patients with Hunt-Hess grade III or IV on admission were 91(25.3%) in anterior circulation aneurysms, and 14(42.4%) in posterior circulation aneurysms. There were higher incidences of vasospasm and acute hydrocephalus in patients with posterior circulation aneurysm. In cases of anterior circulation aneurysm, neck clipping was possible in 97%. But, in posterior circulation aneurysm, neck clipping was possible only in 67.7% of each. Two hundred forty four cases(85.0%) of all anterior circulation aneurysms and 22 cases(78.6%) of all posterior circulation aneurysms showed good recovery(GR) or moderate disability(MD). The postoperative mortality rates of anterior and posterior circulation aneurysms were 4.9% and 10.7%, respectively. Conclusion : These results indicate that there exist substantial differences with respect to that there were few difference in the aspect of surgery and management outcome between posterior circulation aneurysms and anterior circulation aneurysms.

• Journal of Korean Neurosurgical Society
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• 제43권5호
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• pp.232-236
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• 2008

Total laminectomy for the removal of intradural-extramedullary spinal cord tumors has been used widely, but postoperative complications often develop, such as kyphosis, spinal instability, and persistent back pain. In this study, we evaluated seven patients with intradural-extramedullary spinal cord tumors with respect to the value of unilateral limited laminectomy. Our cases included six schwannomas, and one meningioma. The cervical region was involved in four cases, the thoracolumbar region in two cases, and the lumbar region in one case. The rationale for choosing a unilateral approach is to preserve musculoligamentous attachments and posterior bony elements as much as possible. The patients were mobilized on the third postoperative day and preoperative neurological symptoms were recovered within a few weeks. We did not observe any complication relating to unilateral limited laminectomy and at follow-up evaluation (at 3 and 12 months postoperatively), none of the patients showed spinal deformity or spinal instability. We think that the unilateral limited laminectomy is a safe and efficient technique for the treatment of intradural-extramedullary spinal cord tumors. We suggest that this technique is one of the best treatments for these tumors.

• 생물정신의학
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• 제22권1호
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• pp.20-27
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• 2015

Objectives It is increasingly thought that the human cerebellum plays an important role in emotion and cognition. Although recent evidence suggests that the cerebellum may also be implicated in fear learning, only a limited number of studies have investigated the cerebellar abnormalities in panic disorder. The aim of this study was to evaluate the cerebellar gray matter deficits and their clinical correlations among patients with panic disorder. Methods Using a voxel-based morphometry approach with a high-resolution spatially unbiased infratentorial template, regional cerebellar gray matter density was compared between 23 patients with panic disorder and 33 healthy individuals. Results The gray matter density in the right posterior-superior (lobule Crus I) and left posterior-inferior (lobules Crus II, VIIb, VIIIa) cerebellum was significantly reduced in the panic disorder group compared to healthy individuals (p < 0.05, false discovery rate corrected, extent threshold = 100 voxels). Additionally, the gray matter reduction in the left posterior-inferior cerebellum (lobule VIIIa) was significantly associated with greater panic symptom severity (r = -0.55, p = 0.007). Conclusions Our findings suggest that the gray matter deficits in the posterior cerebellum may be involved in the pathogenesis of panic disorder. Further studies are needed to provide a comprehensive understanding of the cerebro-cerebellar network in panic disorder.

• Advances in pediatric surgery
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• 제13권1호
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• pp.76-80
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• 2007

The authors applied anterior sagittal transrectal apporach (ASTRA) for the repair of urethrovaginal fistula which developed after total repair of persistent cloaca. The patient had been diagnosed to have persistent cloaca, double uterus and double vagina, and received PSARP, excision of right-side uterus and vagina, and left vaginal switch operation at 22 months old. After operation, the patient admitted several times due to frequent urinary tract infection and ectopic stone formation in bladder and neovagina. Urethro-neovaginal fistula was confirmed by cystoscopy and corrected with ASTRA. Postoperative voiding cystourethrogram showed no fistula tract. ASTRA showed improved surgical field, minimized ureterocystic damage, and preserved perirectal nerve due to limited incision of rectum.

• Journal of Korean Neurosurgical Society
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• 제46권3호
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• pp.221-225
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• 2009

Objective : Surgical treatment of posterior inferior cerebellar artery (PICA) aneurysms is challenging due to limited surgical accessibility. Endovascular approach has a benefit of avoiding direct injury to the brainstem or lower cranial nerves. Therefore, it has recently been considered an alternative or primary modality for PICA aneurysms. We retrospectively assessed outcomes following detachable coil embolization of saccular PICA aneurysms. Methods : From February 1997 to December 2007, we performed endovascular procedures to treat 15 patients with 15 PICA aneurysms. Fourteen patients with 14 PICA aneurysms morphology of which was saccular were reviewed retrospectively. Twelve patients had ruptured aneurysms. The aneurysms arose from the PICA origin site (n=12), the PICA lateral medullary segment (n=1), or the PICA tonsilomedullary segment (n=1). Results : Complete aneurysm occlusion was achieved in 10 patients, residual neck in 3, and residual sac in one. Radiological follow-up was performed in 7 patients with mean duration of 34.7 months (range, 1-97 months) and showed stable or complete occlusion in 6 patients. There were no rebleeding or retreatment after endovascular treatment. Thromboembolism was the only procedure-related complication (n=4 ; 28.6%). Asymptomatic PICA infarction occurred in two patients and symptomatic PICA infarction in two elderly patients with poor clinical grade. Of these procedural PICA infarction cases, 1 symptomatic PICA infarction patient developed ventriculitis and septic shock leading to death. The clinical outcome was good in 10 patients (71.4%). Conclusions : In the present study, detachable coil embolization has shown as an efficient modality for PICA saccular aneurysms challenging indications of microsurgery. However, thromboembolic complications should be considered, especially in poor clinical elderly patients with ruptured aneurysms.

• Communications for Statistical Applications and Methods
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• 제11권2호
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• pp.399-411
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• 2004

A common method of handling nonresponse in sample survey is to delete the cases, which may result in a substantial loss of cases. Thus in certain situation, it is of interest to create a complete set of sample values. In this case, a popular approach is to impute the missing values in the sample by the mean or the median of responders. The difficulty with this method which just replaces each missing value with a single imputed value is that inferences based on the completed dataset underestimate the precision of the inferential procedure. Various suggestions have been made to overcome the difficulty but they might not be appropriate for public-use files where the user has only limited information for about the reasons for nonresponse. In this note, a multiple imputation method is considered to create complete dataset which might be used for all possible inferential procedures without misleading or underestimating the precision.

• Restorative Dentistry and Endodontics
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• 제43권4호
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• pp.38.1-38.9
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• 2018

The restoration of endodontically treated teeth (ETT) with more than one cusp missing and thin remaining walls is challenging for the general practitioner. The use of posts combined with full coverage restorations is a well-established approach, yet not following the minimal invasive principles of adhesive dentistry. Endocrowns are indirect monoblock restorations that use the pulp chamber of the ETT for retention. In this study the fabrication of 4 endocrowns and their clinical performance will be discussed. Two clinical cases include computer-aided design/computer-aided manufacturing manufactured molar endocrowns (one feldspathic ceramic and one hybrid composite-ceramic restoration) and the other two are dental laboratory manufactured resin composite premolar endocrown restorations. The modified United States Public Health Service criteria were used to assess the clinical behavior of the restorations at different follow up periods. Endocrown restorations present a satisfactory clinical alternative, either by the use of resin composite or glass ceramic and hybrid materials. Specific guidelines with minimal alterations should be followed for an endocrown restoration to be successful. Due to limited evidence regarding the long term evaluation of this restorative technique, a careful selection of cases should be applied.

• Structural Engineering and Mechanics
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• 제87권1호
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• pp.1-18
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• 2023

The paper presents a Bayesian Finite element (FE) model updating methodology by utilizing modal data. The dynamic condensation technique is adopted in this work to reduce the full system model to a smaller model version such that the degrees of freedom (DOFs) in the reduced model correspond to the observed DOFs, which facilitates the model updating procedure without any mode-matching. The present work considers both the MPV and the covariance matrix of the modal parameters as the modal data. Besides, the modal data identified from multiple setups is considered for the model updating procedure, keeping in view of the realistic scenario of inability of limited number of sensors to measure the response of all the interested DOFs of a large structure. A relationship is established between the modal data and structural parameters based on the eigensystem equation through the introduction of additional uncertain parameters in the form of modal frequencies and partial mode shapes. A novel sampling strategy known as the Metropolis-within-Gibbs (MWG) sampler is proposed to sample from the posterior Probability Density Function (PDF). The effectiveness of the proposed approach is demonstrated by considering both simulated and experimental examples.

• The Korean Journal of Pain
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• 제26권1호
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• pp.27-31
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• 2013

Background: Neuroplasty using a Racz catheter or epiduroscope and percutaneous endoscopic laser discectomy are performed as treatment for chronic refractory low back and/or lower extremity pain, but they are limited in that they cannot completely remove the causing pathology. Lately, epiduroscopic laser neural decompression (ELND) has been receiving attention as an alternative treatment, but there are insufficient reports of results. Hence we aimed to investigate and report the data in our hospital. Methods: Seventy-seven patients were selected who had received ELND via the anterior and posterior epidural approach through the pain clinic in our hospital from March 2011 to July 2012. Their medical records including age, diagnosis, epiduroscopic findings and degree of symptom relief were investigated. The degree of symptom relief following the procedure was categorized into 5 stages of very good (5), good (4), no change (3), bad (2), and very bad (1) at 2 weeks and 1 month after the procedure. Results: The subjects were 30 males and 47 females. Mean age was 54.6 for males and 59.6 for females, so the overall mean age was 58.1 years old, with the youngest being 23 and the oldest 88 years old. In epiduroscopic images of all patients, more than one situation of herniated disc, fibrous tissue and adhesion, or inflammation was observed. Sixty-seven patients (87.0%) showed symptom relief 2 weeks after the procedure and 63 patients (81.8%) showed relief after 1 month. Conclusions: ELND is considered to be an effective treatment alternative for chronic refractory low back and/or lower extremity pain, including lumbar disc herniation, lumbar spinal stenosis, and failed back surgery syndrome which cannot be alleviated with existing non-invasive conservative treatment.