BACKGROUND AND PURPOSE: There have been a few national population-based epidemiological studies of myasthenia gravis (MG) with wide variation of incidence and prevalence rates worldwide. Herein we report the first nationwide population-based epidemiological study of MG in Korea. METHODS: We attempted to estimate the incidence and prevalence rates of MG using the Korean National Health Insurance claims database for 2010 to 2013. Cases with MG were defined as those having claim records with a principal diagnosis of MG and the prescription of acetylcholinesterase inhibitors or immunosuppressive agents including corticosteroids and azathioprine within 2 years after the diagnosis. The year 2010 was set as a washout period, such that patients were defined as incident cases if their first records of MG were observed in 2011. RESULTS: In 2011 there were 1,236 incident cases, and the standardized incidence rate was 2.44 per 100,000 person-years. The standardized prevalence rates were 9.67 and 10.66 per 100,000 persons in 2010 and 2011, respectively. The incidence and prevalence rates peaked in the elderly population aged 60 to 69 years for both sexes. CONCLUSIONS: This is one of the largest national population-based epidemiological studies of MG, and it has confirmed the high incidence and prevalence rates of MG in the elderly population of South Korea.
Adrenal Cortex Hormones ; Aged ; Azathioprine ; Cholinesterase Inhibitors ; Diagnosis ; Epidemiologic Studies ; Epidemiology ; Humans ; Immunosuppressive Agents ; Incidence* ; Korea* ; Myasthenia Gravis* ; National Health Programs* ; Prescriptions ; Prevalence*

PURPOSE: To investigate the role of the posterior vitreous detachment as a factor affecting visual acuity after laser treatment on macular edema in eyes with branch retinal vein occlusion (BRVO). METHODS: We retrospectively studied the medical records of 55 BRVO patients who were treated with argon laser photocoagulation for macular edema. The eyes were classified as those with posterior vitreous detachment (PVD, group I, 21 eyes) and those with no or partial PVD (group II, 34 eyes). The visual acuity before and after laser treatment was compared according to the posterior vitreous status. RESULTS: The eyes with visual acuity gaining two or more lines, final visual acuity of 0.5 or better, and mean change of visual acuity after laser treatment were 66.0%, 38.1%, and 1.8 lines in group I and 41.2%, 32.4%, and 1.6 lines in group II, respectively (p>0.05). Factors responsible for no change or decrease of visual acuity after laser treatment were macular ischemia, macular degeneration or exudate, and epiretinal membrane. CONCLUSIONS: PVD can be a prognostic factor for macular edema with BRVO. We should carefully examine for the presence of PVD in eyes with BRVO.
Argon ; Epiretinal Membrane ; Exudates and Transudates ; Humans ; Ischemia ; Light Coagulation ; Macular Degeneration ; Macular Edema* ; Medical Records ; Retinal Vein Occlusion ; Retrospective Studies ; Visual Acuity ; Vitreous Detachment

STUDY DESIGN: Retrospective case-control study OBJECTIVE: To use MRI to assess intervertebral disc degeneration at adjacent levels after spinal fusion and after discectomy. SUMMARY OF LITERATURE REVIEW: Degeneration of adjacent intervertebral discs following lumbar spinal fusion is one of the principal reasons for considering motion preservation techniques, such as placement of an artificial disc. Much attention has recently been directed toward disc morphometric studies using MRI. MATERIALS AND METHODS: Fifty-six patients who underwent spinal surgery for lumbar degenerative disease and who underwent a minimum of 2 years of follow-up MRIs were included in this study. Thirty-four patients were included in the lumbar fusion study group, and 22 patients were included in the discectomy control group. The MRI Thompson classification was used to grade both upper and lower adjacent disc degeneration preoperatively and at the time of last follow-up. RESULTS: There were significant changes in Thompson degenerative grade in the upper adjacent levels for both the fusion group patients and in the discectomy group patients. However, there was no statistically significant difference between the two groups with regard to either the upper or lower adjacent levels (p=0.146 and 0.350, respectively). CONCLUSIONS: In this short-term study comparing MRI outcomes in spinal fusion and discectomy patients, no significant difference in adjacent disc degeneration was observed between the two group.
Case-Control Studies ; Diskectomy ; Follow-Up Studies ; Humans ; Intervertebral Disc ; Intervertebral Disc Degeneration ; Retrospective Studies ; Spinal Fusion

For the diagnosis and treatment of the labral pathology, the cross sectional morphology of the labrum is needed. Fifty-four labra (male: female=44: 10) from 32 adult Korean cadavers were cut in radial and perpendicular fashions to their longitudinal axis. Each labrum was divided into 8 segments, resulting 8 equally distanced points. To analyze the 432 cut surfaces, which consisted of 378 labra and 54 transverse acetabular ligaments cut surfaces, all dimensions of the cut surfaces were measured, and the attachment patterns, including the sublabral slit, observed. The shapes of the cut surfaces were classified into four types (3 subtypes of triangle and 1 quadrangle) and the attachment patterns into five types. At the anterior portion of the labrum, which other studies reported as the predilection area for labral tears, there were several common findings: 1) Tall triangular shapes were dominant (61.1%) or relatively common type (25.9%). 2) The average heights of the labrum were longer (7.4 and 7.0 mm) than at the other sites (4.0 - 6.8 mm). 3) The attachment types with no extra-extended portion (68.5%) and sublabral slits (39.0%) were most commonly observed. It was concluded that there were different types of cut surface and attachment patterns of the acetabular labrum, and these findings had a tendency to be distributed with some labral tears. These anatomical data are believed could be useful in the management of an acetabular labral pathology.
Acetabulum/*anatomy & histology/pathology ; Adolescent ; Adult ; Aged ; Aged, 80 and over ; Female ; Human ; Magnetic Resonance Imaging ; Male ; Middle Aged

OBJECTIVES: The purpose of this study was to evaluate the performance of half-dose chest CT using an iterative reconstruction technique in patients with lung malignancies. METHODS: The Dual-source CT scans were obtained and half-dose datasets were reconstructed with 5 different strengths in 38 adults with lung malignancies. Two radiologists graded subjective image quality; noise, contrast and sharpness at the central/peripheral lung, mediastinum and chest wall of the reconstructed half-dose images, compared with those of standard-dose images, using a three-point scale. A lesion assessment; lesion conspicuity and diagnostic confidence, was also performed. The quantitative image noises; contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were measured and compared with those of standard-dose images. RESULTS: The subjective image noise in the half-dose images was less than that of the standard-dose images. The contrast in strengths 2 to 5 was superior, the sharpness of the lung parenchyma in strengths 3 to 5 was inferior, and the CNR/SNR in all strengths were higher than those of standard-dose images (P < 0.05). The improvement of subjective image noise and contrast, the decrease in sharpness, were correlated with strength level (P < 0.05). The lesion conspicuity in half-dose images of strengths 4 and 5 was decreased. The diagnostic confidence of the half-dose images of all strengths was comparable to that of the standard-dose images (P < 0.05). CONCLUSIONS: Half-dose chest CT images using an iterative reconstruction technique show decreased image noise, increased contrast, and diagnostic confidence comparable to standard-dose images. Images reconstructed with strength 2 and 3 appear to be the optimal choice in clinical practice.
Adult ; Dataset ; Humans ; Lung* ; Mediastinum ; Noise ; Signal-To-Noise Ratio ; Thoracic Wall ; Thorax* ; Tomography, X-Ray Computed

STUDY DESIGN: Prospective observational study. OBJECTIVES: The aim of this study was to examine the usefulness of a fentanyl matrix patch in the management of chronic low back pain. SUMMARY OF LITERATURE REVIEW: Chronic low back pain is a significant disabling disease with high medical costs and socioeconomical effects. Oral medication is a fundamental tool for conservative treatment. The fentanyl matrix patch is currently regarded as an alternative method for oral medication, however, the usefulness of the fentanyl matrix patch has not been fully evaluated. MATERIALS AND METHODS: From September 2008 to May 2009, a multicenter, open, prospective observational study was conducted. The inclusion criteria included chronic pain patients that did not respond to conservative pain management. The clinical usefulness was evaluated with pain intensity, and the KEQ-5D (Korean version of Euro QoL-5 dimension). RESULTS: Overall, 538 patients were included in this study. The pain intensity decreased about 1.84 +/- 1.91 at the second visit and further decreased by about 2.52 +/- 2.34 at the third visit (p<0.0001). The KEQ-5D score decreased about 0.12 +/- 0.18 at the second visit, and decreased further to 0.18 +/- 0.24 at the third visit (p<0.0001). The number of patients with adverse effects was 121 (22.49%). CONCLUSIONS: The fentanyl matrix patch improves the pain and disability in patients with chronic low back pain. It is a useful alternative method for the management of chronic low back pain.
Chronic Pain ; Fentanyl* ; Humans ; Low Back Pain* ; Observational Study ; Pain Management ; Prospective Studies

BACKGROUND/AIMS: The effect of dietary micronutrients on non-erosive reflux disease (NERD) and reflux esophagitis is unclear. We aim to evaluate the gender-specific effect of micronutrient on erosive esophagitis and NERD. METHODS: A total of 11 690 participants underwent endoscopy and completed 3-day recordings for dietary intake and questionnaires for reflux symptoms from 2004 to 2008. To evaluate the effect of dietary micronutrients on NERD or erosive esophagitis, adjusted regression analysis with odds ratio (OR) and 95% confidence interval (CI) was used. In addition, we performed gender-specific analysis. RESULTS: Prevalence of NERD and erosive esophagitis was 6.8% and 11.2% in men and 9.1% and 2.4% in women. In adjusted analysis, high intake of vitamin A (OR, 0.78; 95% CI, 0.64–0.96), retinol (OR, 0.73; 95% CI, 0.59–0.90), vitamin B2 (OR, 0.68; 95% CI, 0.54–0.87), vitamin B6 (OR, 0.75; 95% CI, 0.58–0.96), folic acid (OR, 0.77; 95% CI, 0.62–0.96), calcium (OR, 0.66; 95% CI, 0.53–0.82), and iron (OR, 0.68; 95% CI, 0.53–0.87) had an inverse association with NERD. However, erosive esophagitis has no relationship with micronutrients except vitamin C (OR, 0.78; 95% CI, 0.62–0.98). High dietary intake of calcium reduced the risk of NERD in men and high dietary intake of many micronutrients reduced NERD in women. CONCLUSIONS: While many dietary micronutrients reduced NERD, they had no effect on erosive esophagitis. The effect of micronutrient on NERD was more prominent in women than men.
Ascorbic Acid ; Calcium ; Endoscopy ; Esophagitis ; Esophagitis, Peptic ; Female ; Folic Acid ; Gender Identity ; Humans ; Iron ; Male ; Micronutrients ; Odds Ratio ; Prevalence ; Riboflavin ; Vitamin A ; Vitamin B 6

BACKGROUND: Spontaneous intracranial hypotension (SIH) is a condition caused by spontaneous leakage of cerebrospinal fluid, with postural headache as the primary symptom. Orthostatic headache caused by SIH is often not resolved by conservative management. CASE: We performed 15 epidural blood patch treatments in a 43-year-old female patient; however, they were only transiently effective. To improve the patient's SIH and orthostatic headache, epidural fibrin glue patch treatment was attempted. Fibrin glue is a substance that can act as a bio-friendly adhesive by facilitating the coagulation cascade. In our case, 3 epidural fibrin glue patch treatments were performed and the symptoms completely resolved. CONCLUSIONS: The epidural fibrin glue patch may be beneficial for the treatment of refractory postural headaches caused by SIH.
Adhesives ; Adult ; Blood Patch, Epidural ; Cerebrospinal Fluid ; Female ; Fibrin Tissue Adhesive ; Fibrin ; Headache ; Humans ; Intracranial Hypotension

PURPOSE: KLF6, a member of the KLF family, is a ubiquitous zinc finger tumor suppressor protein that is mutated in several human cancers. Our aim was to determine whether the expression pattern of KLF6 might be associated with gastric cancer development and, if so, to determine to which pathologic parameter it is linked. MATERIALS AND METHODS: For the construction of the gastric cancer tissue microarray, 85 paraffin-embedded tissues containing gastric cancer areas were cored 3 times and transferred to the recipient master block. The expression pattern of KLF6 was examined on tissue microarray slides by using immunohistochemistry and was compared with pathologic parameters, including histologic type, depth of invasion, lymph node metastasis, and peritoneal dissemination. RESULTS: The KLF6 protein was expressed on superficial and foveolar epithelial cells in the gastric mucosa. We found loss of KLF6 expression in 28 (32.9%) of the 85 gastric cancer tissues. There was a significant correlation between loss of KLF6 expression and lymph-node metastasis. However, other pathologic parameters, such as histologic type, depth of invasion, and peritoneal dissemination, were not statistically associated with loss of KLF6 expression. CONCLUSION: Our findings suggest that loss of KLF6 expression may contribute to abnormal regulation of gastrointestinal epithelial cell growth and differentiation and to the development and/or progression of Korean gastric cancer.
Apoptosis ; Epithelial Cells ; Gastric Mucosa ; Humans ; Immunohistochemistry ; Lymph Nodes ; Neoplasm Metastasis ; Stomach Neoplasms* ; Zinc Fingers

BACKGROUND: The currently available reverse shoulder arthroplasty (RSA) designs can be classified into medial glenoid/medial humerus (MGMH), lateral glenoid/medial humerus (LGMH), and medial glenoid/lateral humerus (MGLH) prosthesis designs. The purpose of this study was to radiologically analyze the effect of different RSA designs on humeral position following RSA. METHODS: A total of 50 patients who underwent primary RSA were retrospectively analyzed. Among 50 patients, 33 patients (group A: MGMH) underwent RSA with Aequalis system (Wright, Inc, Bloomington, MN, USA), 6 (group B: LGMH) with Aequalis system using bony increased offset, and 11 (group C: MGLH) with Aequalis Ascend Flex system. The acromiohumeral distance, acromioepiphyseal distance (AED), lateral humeral offset (LHO), LHO from the center of rotation (LHO(COR)), and deltoid length were radiologically measured to quantify the distalization and lateralization of the humerus. RESULTS: The increment in postoperative AED was 19.92 ± 3.93 mm in group A, 24.52 ± 5.25 mm in group B, and 25.97 ± 5.29 mm in group C, respectively (p=0.001). The increment in postoperative LHO was 0.13 ± 6.30 mm, 8.00 ± 12.14 mm, and 7.42 ± 6.88 mm, respectively (p=0.005). The increment in postoperative LHOCOR was 20.76 ± 6.06 mm, 22.04 ± 5.15 mm, and 28.11 ± 4.14 mm, respectively (p=0.002). CONCLUSIONS: The radiologic analysis of the effect of different RSA designs on humeral position following RSA showed significant differences in the increment in postoperative AED, LHO, and LHO(COR) between the 3 groups. Therefore, MGLH design seems to be more effective for humeral distalization and lateralization compared to original Grammont design.
Arthroplasty ; Humans ; Humerus ; Prosthesis Design ; Retrospective Studies ; Shoulder