Feasibility of Gamma Knife Radiosurgery for Brain Arteriovenous Malformations According to Nidus Type

Objective@#: Gamma Knife radiosurgery (GKRS) is an effective and noninvasive treatment for high-risk arteriovenous malformations (AVMs). Since differences in GKRS outcomes by nidus type are unknown, this study evaluated GKRS feasibility and safety in patients with brain AVMs. @*Methods@#: This single-center retrospective study included patients with AVM who underwent GKRS between 2008 and 2021. Patients were divided into compact- and diffuse-type groups according to nidus characteristics. We excluded patients who performed GKRS and did not follow-up evaluation with magnetic resonance imaging or digital subtraction angiography within 36 months from the study. We used univariate and multivariate analyses to characterize associations of nidus type with obliteration rate and GKRS-related complications. @*Results@#: We enrolled 154 patients (mean age, 32.14±17.17 years; mean post-GKRS follow-up, 52.10±33.67 months) of whom 131 (85.1%) had compact- and 23 (14.9%) diffuse-type nidus AVMs. Of all AVMs, 89 (57.8%) were unruptured, and 65 (42.2%) had ruptured. The mean Spetzler-Martin AVM grades were 2.03±0.95 and 3.39±1.23 for the compact- and diffuse-type groups, respectively (p<0.001). During the follow-up period, AVM-related hemorrhages occurred in four individuals (2.6%), three of whom had compact nidi. Substantial radiation-induced changes and cyst formation were observed in 21 (13.6%) and one patient (0.6%), respectively. The AVM complete obliteration rate was 46.1% across both groups. Post-GKRS complication and complete obliteration rates were not significantly different between nidus types. For diffuse-type nidus AVMs, larger AVM size and volume (p<0.001), lower radiation dose (p<0.001), eloquent area location (p=0.015), and higher Spetzler-Martin grade (p<0.001) were observed. @*Conclusion@#: GKRS is a safe and feasible treatment for brain AVMs characterized by both diffuse- and compact-type nidi.

Measuring Defocus Curves of Monofocal, Multifocal and Extended Depth-of-focus Intraocular Lenses Using Optical Bench Test

PURPOSE: To determine the through-focus optical bench test performance of monofocal, bifocal, and extended depth-of-focus intraocular lenses (IOLs), and to measure their defocus curves.METHODS: A model eye was placed on an optical bench to test three different IOLs (TECNIS ZXR00, ZMB00, and ZCB00; Abbott Medical Optics, Santa Ana, CA, USA). The focus was changed by inserting trial lenses from +1.00 diopters to −4.00 diopters, in increments of +0.25 diopters. The 1951 United States Air Force Resolution chart was used to determine the quality of the images. The degree of similarity with reference images was given by the cross-correlation coefficient, and defocus curves were drawn and compared.RESULTS: Bifocal IOLs showed lower image quality with the addition of minus diopter trial lenses, but showed good image quality at near distance. Bifocal IOLs also showed a ‘double peak’ in their defocus curve. Monofocal IOLs showed a lower image quality and cross-correlation coefficient with addition of lower-diopter trial lenses. The extended depth of focus IOLs showed a single peak in their defocus curve, but had a wider range of diopters and better image quality than monofocal IOLs.CONCLUSIONS: Bifocal IOLs showed a double peak defocus curve, and extended depth of focus IOLs showed a wider diopter range and better image quality than monofocal IOLs.

Comparison of breast tissue markers for tumor localization in breast cancer patients undergoing neoadjuvant chemotherapy

PURPOSE: The purpose of this study was to compare the visibility of breast tissue markers in cases of breast cancer on ultrasonography (US) after neoadjuvant chemotherapy (NAC) and to analyze whether the type of marker affected the choice of localization method after NAC. METHODS: We included 153 tissue markers inserted within breast cancers that showed pathologically complete response (pCR) after NAC from January 2012 to April 2017. One of three types of markers (a surgical clip, Cormark, or UltraClip) was inserted. Medical records and imaging findings were retrospectively reviewed. We compared the visibility of the different types of tissue markers on US after NAC, and also compared the imaging modalities used in the preoperative localization. The chi-square test, Fisher exact test, and multiple logistic regression were used for analysis. RESULTS: Of the 153 tissue markers, 56 were surgical clips, 61 Cormark, and 36 UltraClip. After NAC, residual lesions were not seen on US in 42 cases (27.5%). In multivariate analysis, the visibility of the surgical clips and Cormark markers was better than that of the UltraClip markers (odds ratio [OR], 5.467; 95% confidence interal [CI], 1.717 to 17.410; P=0.004 and OR, 3.045; 95% CI, 1.074 to 8.628; P=0.036, respectively). Among the 131 cases where localization targeting the marker was required, the proportion of US-guided localizations was significantly higher when a surgical clip was used than when an UltraClip marker was used (OR, 5.566; 95% CI, 1.610 to 19.246; P=0.007) in the multivariate analysis. CONCLUSION: The type of breast tissue marker affected its visibility on US in cases with pCR after NAC, which in turn affected the localization methodology.

Application of Tetrode Technology for Analysis of Changes in Neural Excitability of Medial Vestibular Nucleus by Acute Arterial Hypotension / 대한평형의학회지

OBJECTIVES: Excitability o medial vestibular nucleus (MVN) in the brainstem can be affected by changes in the arterial blood pressure. Several animal studies have demonstrated that acute hypotension results in the alteration of multiunit activities and expression of cFos protein in the MVN. In the field of extracellular electrophysiological recording, tetrode technology and spike sorting algorithms can easily identify single unit activity from multiunit activities in the brain. However, detailed properties of electrophysiological changes in single unit of the MVN during acute hypotension have been unknown. METHODS: Therefore, we applied tetrode techniques and electrophysiological characterization methods to know the effect of acute hypotension on single unit activities of the MVN of rats. RESULTS: Two or 3 types of unit could be classified according to the morphology of spikes and firing properties of neurons. Acute hypotension elicited 4 types of changes in spontaneous firing of single unit in the MVN. Most of these neurons showed excitatory responses for about within 1 minute after the induction of acute hypotension and then returned to the baseline activity 10 minutes after the injection of sodium nitroprusside. There was also gradual increase in spontaneous firing in some units. In contrast small proportion of units showed rapid reduction of firing rate just after acute hypotension. CONCLUSIONS: Therefore, application of tetrode technology and spike sorting algorithms is another method for the monitoring of electrical activity of vestibular nuclear during acute hypotension.

Two Cases of Central Airway Obstruction Treated with an Insulation-Tipped Diathermic Knife-2 / 대한내과학회지

Central airway obstruction can result from various benign and malignant conditions, and often requires prompt palliation. The efficacies of a variety of bronchoscopic techniques for the treatment of central airway obstruction such as electrocautery, laser, brachytherapy, argon plasma coagulation and cryotherapy have been established. An insulation-tipped diathermic knife-2 (IT knife-2) was initially introduced for gastrointestinal endoscopic submucosal dissection and has been used globally as a safe and effective instrument. However, its use has not been reported for the treatment of endotracheal or endobronchial lesions. Here, we report the case of central airway obstruction in a 65-year-old male due to malignancy and a 52-year-old-female with post-radiation bronchial stenosis that were treated successfully with the IT-knife-2 via flexible bronchoscopy.

A Case of Urosepsis Caused by Aerococcus viridans / 대한내과학회지

Aerococcus viridans is a rare pathogen in humans, with only six cases of A. viridans urinary tract infections reported worldwide. Nosocomial urinary tract infections with bacteremia caused by A. viridians are even rarer, with no prior reports of urosepsis caused by A. viridans occurring in the Republic of Korea. Here we report a case of urosepsis caused by A. viridans in a 79 year-old female nursing home resident. The patient was admitted to the hospital presenting a fever of 39degrees C, chills, and oliguria for two days prior to admission. Urine culture yielded a robust growth of 105 CFU/mL of A. viridians, with blood culture positive for the same organism. Following diagnosis, the patient was treated with ciprofloxacin intravenously for 2 weeks, resulting in clearance of the infection and a full recovery from urosepsis. Although A. viridans is rarely associated with human infections, this case shows that, under the right conditions, it can be responsible for severe infections like urosepsis.

The Trend of Occupational Injuries in Korea from 2001 to 2010

OBJECTIVES: This study is planned to assess the trend of occupational injuries in Korea from 2001 to 2010. METHODS: Ten years of occupational injuries, from 2001 to 2010, were analyzed in order to investigate the changing profiles according to the various characteristics of injuries; economic sectors, age of the injured, and type of injuries. The changing profile of occupational injuries was investigated by comparison with an index-created relative value based on the number of cases of reference category. RESULTS: The fatalities of construction, forest, agriculture, and service show the increasing trend. The nonfatal occupational injuries of the manufacturing sector were higher than those of other sectors in every year but the fatal occupational injuries of construction workers were higher than those of the manufacturing sector. Occupational injuries occurring due to amputation and those of slip and trip increased. The number of occupational injuries for the worker groups of 24 years old and below decreased and 45 years old and above increased. In comparison to the figure of fall from height, the figures of slip and trip or caught in equipment are higher in every calendar year. CONCLUSION: This study find out construction, forest, agriculture, and service sectors, aged worker with 45 years old and over can be target population for the strategies of occupational safety.

Toxicological Evaluations of Rare Earths and Their Health Impacts to Workers: A Literature Review

In concert with the development of new materials in the last decade, the need for toxicological studies of these materials has been increasing. These new materials include a group of rare earths (RE). The use of RE nanotechnology is being considered in some green applications, to increase their efficiency by using nano-sized RE compounds, and therefore hazard evaluation and risk assessment are highly recommended. This review was conducted through an extensive contemplation of the literatures in toxicology with in vitro and in vivo studies. Major aspects reviewed were the toxicological evaluations of these elements and metallic compounds at the molecular and cellular level, animal and human epidemiological studies and environmental and occupational health impacts on workers. We also discuss the future prospect of industries with appliances using RE together with the significance of preventive efforts for workers' health. To establish a safe and healthy working environment for RE industries, the use of biomarkers is increasing to provide sustainable measure, due to demand for information about the health risks from unfavorable exposures. Given the recent toxicological results on the exposure of cells, animals and workers to RE compounds, it is important to review the toxicological studies to improve the current understanding of the RE compounds in the field of occupational health. This will help to establish a sustainable, safe and healthy working environment for RE industries.

Intramural Hematoma of the Esophagus after Endoscopic Pinch Biopsy

Intramural hematoma of the esophagus (IHE) is an uncommon form of esophageal injury, which may be an intermediate of mucosal tear (Mallory-Weiss syndrome) or transmural rupture (Boerhaave's syndrome). To date, the pathogenesis of IHE has not been well documented. IHE may occur within the submucosal layer of the esophagus following dissection of the mucosa. The most commonly presented symptoms are sudden retrosternal pain, dysphagia and hematemesis. The disorder can occur spontaneously or secondarily to trauma. In this report, we present a case of IHE which occurred after endoscopic biopsy and was recovered following conservative management in a patient who was taking long-term aspirin medication.

Multiple Fusiform Cerebral Aneurysms and Highly Elevated Serum Interleukin-6 in Cardiac Myxoma

Cerebral embolic infarction is the most common neurologic complication of cardiac myxoma (CM). Development of cerebral aneurysms in CM is very rare. We present a 64-year-old woman with acute cerebral infarction and multiple cerebral aneurysms complicated by CM. The aneurysms were multiple, fusiform-shaped, and located in distal branch of major cerebral arteries. The serum interleukin (IL)-6 was highly elevated, which was normalized after surgical resection of CM. There was no regression of aneurysms on follow-up neuroimaging. Multiple cerebral aneurysms in CM are rare condition. Highly elevated serum IL-6 may be associated with increased risk of cerebral aneurysmal formation.

Acute Spinal Subdural Hematoma Presenting with Spontaneously Resolving Hemiplegia

Although prompt diagnosis and emergent surgical intervention are important in acute spinal subdural hematoma (SSDH), some cases with spontaneous remission of symptom and hematoma without surgery have been reported. We present a case of acute nontraumatic SSDH presenting with transient left hemiplegia for 4 hours. A magnetic resonance imaging study of cervical spine confirmed SSDH with C3-6 cervical cord compression at the left side. The patient had conservative management without recurrence. Although hemiplegia is an unusual clinical manifestation of SSDH, it should be differentiated from that of cerebrovascular origin promptly. Conservative management may be an alternative therapeutic option for selective cases with transient neurological deficits.

Experience of Meningovascular Syphilis in Human Immunodeficiency Virus Infected Patient

Since the start of the antibiotic era, syphilis has become rare. However, in recent times, it has tended to be prevalent concomitantly with human immunodeficiency virus (HIV) infection and coinfection in North America and Europe. Now, such cases are expected to increase in elsewhere including Korea. A 40-year-old male patient visited hospital complaining of a headache for about one month. Brain computed tomography and magnetic resonance imaging, showed leptomeninged enhancing mass with edema an right porisylvian region, which was suspected to be glioma. Patient underwent a blood test and was diagnosed with syphilis and acquired immune deficiency syndrome. Partial cortical and subcortical resection were performed after small craniotomy. The dura was thick, adhered to the brain cortex, and was accompanied by hyperemic change of the cortex. The pathologic diagnosis was meningovascular syphilis (MS) in HIV infection. After the operation, the patient was treated with aqueous penicillin G. Thereafter, he had no neurological deficit except intermittent headache. At first, this case was suspected to be glioma, but it was eventually diagnosed as MS in HIV coinfection. At this point the case was judged to be worth reporting.

A Case of Dementia with Transient Splenial lesion on MRI after Hypoglycemia

We report a rare case having dementia with transient splenial lesion on MRI after hypoglycemia. A 75-year-old woman with type 2 diabetes was admitted with mental change after medication of a hypoglycemic agent. Initial serum glucose was 22 mg/dL. High signal intensity in the splenium on diffusion-weighted MRI was shown. After conservative management, she was gradually improved and splenial lesion was disappeared, but her cognitive impairment remained.

Genetic Polymorphism of Thymidylate Synthase Enhancer Region (TSER) in Patients with Silent Brain Infarction

BACKGROUND: Hyperhomocysteinemia is an independent risk factor for silent brain infarction (SBI). The plasma homocysteine (pHcy) level is influenced by the activities of enzymes such as 5,10-methylenetetrahydrofolate reductase (MTHFR). Thymidylate synthase (TS) also competes with MTHFR for their common cofactor, 5,10-methylenetetrahydrofolate (5,10-meTHF). The polymorphism of thymidylate synthase enhancer region (TSER) might affect homocystein metabolism by modulating the activity of TS, and may be a determinant of SBI by elevating pHcy concentrations. Therefore, we studied the polymorphism of TSER in patients with SBI. METHODS: 98 patients with SBI and 92 healthy controls were included in the study. The genotypes of TSER and MTHFR were identified with the PCR-RFLP methods. RESULTS: The mean pHcy level was significantly higher in SBI patients (13.5+/-8.5 micro mol/L) than in controls (10.3+/-4.1 micro mol/L)(p<0.01). The frequencies of MTHFR C677T genotype and TSER 28 bp tandem repeat genotype were not different between the patients and the controls. The pHcy concentrations were not considerably different between the 3R3R and 2R3R genotypes in the population as a whole (p=0.712), nor in subsets of patients with SBI (p=0.484). However, in cases with the TSER 3R3R genotype, the pHcy level was significantly higher in patients (14.0+/-10.26 micro mol/L) than in controls (9.9+/-3.1 micro mol/L)(p=0.006). Folate and pHcy was inversely correlated in the SBI patients with the TSER 3R3R genotype (r=-0.424, p=0.039). CONCLUSIONS: Our findings suggest that the TSER genotype is not a major determinant of pHcy concentrations and is neither a risk factor for SBI in the Korean population. However, further study will be needed to confirm this findings.

The Effect of Folic Acid to the Level of Homocysteine and Analysis of the Factors in Epilepsy Patients / 대한간질학회지

BACKGROUND: Folic acid has been frequently used for hyperhomocyesteinemia in various diseases and decreases the level of homocysteine. OBJECTIVES: To assess the effect of folic acid in the level of homocysteine in epilepsy patients, and to analyze factors affecting its responsiveness and the difference of its efficacy according to methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism. METHODS: Total 75 epilepsy patients with antiepileptic drugs (AEDs) therapy were included. 41 patients had normal level of homocysteine and 34 patients with hyperhomocysteinemia (> or =12 micro mol/ ) were supplemented with folic acid for 1 year. Thirty-four patients with hyperhomocyteinemia were divided into two groups according to the responsiveness of homocysteine to folic acid; decrease group (DG) and non-decrease group (NDG). RESULTS: The level of homocysteine in patients with hyperhomocysteinemia was significantly decreased after administration of folic acid, comparing with patients with normal level. DG was younger and had more male gender, shorter duration of seizure, and initial higher homocysteine level, compared to NDG (p<0.05). Patients with mutant type of MTHFR (CT+TT) had more decreased homocysteine level after supplement of folic acid, but had more increased homocysteine level without supplement of folic acid. Comparing between MTHFR genotypes, TT type had the most decreased homocysteine level than others, but there was no significance. CONCLUSION: Folic acid is useful treatment of hyperhomocysteinemia in epilepsy patients and the supplement of folic acid might be considered in patients with mutant type of MTHFR regardless of homocysteine level. The effect of folic acid supplement is greater in younger age, male sex, shorter duration of seizure, and initial higher homocysteine level.

Spontaneous Intracerebral Hemorrhage in the Patients Undergoing Dialysis Therapy / 대한뇌혈관외과학회지

OBJECTIVE: The management of spontaneous intracerebral hemorrhage in the patients with chronic renal failure is frequently influenced by factors such as coagulopathy, electrolyte imbalance, hemodialysis and malnutrition. This study aimed at evaluating the aggravating factors in the patients with intracerebral hemorrhage and who also underwent dialysis therapy. METHODS: Eight patients with chronic renal failure and who suffered from intracerebral hemorrhage were investigated. The clinical features, the location and amount of the hematomas, the treatment methods and the hemodialysis patterns were compared. RESULTS: The locations of hematoma were the subcortex (3 cases), putamen (2 cases), thalamus (2 csaes), and intraventricle (1 case), respectively. The types of dialysis were hemodialysis (6 cases), peritoneal dialysis (1 case), and a continuous form of renal replacement therapy (1 case). The average GCS was 8.4 (range: 5-14). All the patients underwent surgical treatment, which were EVD (3 cases), streotactic hematoma aspiration (2 cases), and decompressive craniectomy with hematoma removal (3 cases). The clinical outcomes were good recovery (1 case), moderate disability (1 case), a vegetative state (1 case) and death (5 cases). For the cases of death, the factors for aggravating the outcome were brain swelling (1 case), rebleeding (2 cases), aspiration pneumonia (1 case), and uncontrolled bleeding during the operation (1 case). The poor outcomes of intracerebral hemorrhage in the dialysis failure patients were caused by poor consciousness during bleeding, (ED note: this word ictus seems to makes no sense here.) and a high risk of rebleeding and brain edema due to anticoagulant and dialysis. CONCLUSION: We suggest that consideration of the patients' medical problems and an adequate environment for dialysis should be taken into account to achieve favorable patient outcomes.

Significance of Aspect Ratio as Predictor of Intracranial Aneurysm Rupture / 대한뇌혈관외과학회지

OBJECTIVE: The size of intracranial aneurysm has been well known as a risk factor of aneurysmal rupture. The aneurysmal shape affects risk of rupture differently even though the size is similar. Aspect ratio corresponds well with morphologic variability. In this study we investigated the significance of aspect ratio as a predictor of intracranial aneurysm rupture. METHODS: The authors reviewed the retrospectively the medical records of consecutive patients with ruptured and unruptured intracranial aneurysms who underwent cerebral angiography from January 2001 to December 2005. A total of 156 patients underwent cerebral angiography and 171 aneurysms were detected. One hundred forty ruptured and 31 unruptured aneurysms were included. We measured aspect ratio which aneurysmal dome distance and neck width on angiographic images. To compare the difference of size and aspect ratio between ruptured and unrupteured aneurysms, we performed statistical analysis of aspect ratio to obtain the odds ratio(OR) for risk of rupture. RESULTS: The mean aspect ratio was 2.33+/-0.96 for ruptured aneurysms, compared with 1.71+/-0.55 for unruptured aneurysms. The difference of the aspect ratios between ruptured and unruptured groups was statistically significant (p<0.001). The odds ratio of rupture was 6.3 fold greater when the aspect ratio was larger than 2.66 compared with an aspect ratio less than 1.54. CONCLUSION: We suggest that aspect ratio is a significant independent predictor for aneurysmal rupture. The rupture risk was increased significantly when aspect ratio increased.

A Case of Valproate-Induced Hyperammonemic Encephalopathy with Triphasic Waves / 대한간질학회지

Valproate is a widely used antiepileptic drug with rarely occurring serious side effects. However, valproate may induce hyperammonemic encephalopathy. A 85-year-old woman was admitted with stuporous mental status. Brain MRI showed old cerebral infarction and EEG showed sharp waves in the right frontal region. Under the impression of postictal confusion, we used phenytoin and then she was improved. However, the intermittent vacant staring was seen, and valproate was administered additionally. On the 5th day after adding valproate, her mentality was deteriorated and intermittent triphasic waves appeared on EEG. Due to confused mentality and hyperactivities, we injected lorazepam and then semicomatous mentality was developed. Follow-up EEG showed nearly continuous triphasic waves and slightly elevated ammonia with normal liver function was shown. After stopping antiepileptic drugs, we used lactulose and flumazenil, and then she was fully recovered with normalized EEG. This is a rare case of valproate-induced hyperammonemic encephalopathy with triphasic waves.

Reconstruction of the Posterior Cruciate Ligament by the Modified Tibial Inlay Method / 대한정형외과학회잡지

PURPOSE: To introduce the modified tibial inlay technique and evaluate the clinical results of 44 patients who underwent PCL reconstruction by this method and were followed-up for more than 2 years. MATERIALS AND METHODS: The clinical results were assessed using the Orthopadishe Arbeitsgruppe Knie (OAK) and International Knee Documentation Committee (IKDC) knee scoring systems. The integrities of the reconstructed PCLs were assessed using posterior stress radiographs and the manual maximum displacement test using a KT-1000 (TM) arthrometer. RESULTS: The average 65.8+/-9.4 OAK score, 10.8+/-4.6 mm displacement by stress radiographs and 9.4+/-4.1 mm displacement by KT-1000 (TM) arthrometer, were improved to an average 87.5+/-7.8, 3.4+/-0.4 mm, 2.7+/-0.9 mm, respectively, at the last follow-up. By the IKDC and OAK scoring systems, 35 cases (79%) and 40 cases (90%), respectively, showed satisfactory clinical outcome. A second arthroscopic examination was performed in 20 of 44 cases. No case showed rupture of the grafted tendon. However, 3 cases showed recurrence of posterior instability, which requried a retightening at the tibial bone block site. CONCLUSION: The modified tibial inlay technique may improve the quality of outcome of arthroscopic PCL reconstruction, because this technique can avoid grafted tendon abrasion at the posterior orifice, and this preserve the remnant PCL bundle, and it allows the retightening of loose grafted tendon to be performed easily.

Reliability of the Manual Maximal Displacement Test and Quadriceps Active Test with KT-1000 TM Arthrometer in the assessment of Posterior Instability of the Knee

Authors measured the degree of posterior instability of the knee in 21 patitients who had posterior cruciate ligament(PCL) injury or have been reconstructed the PCL by using the manual maximal displacement test and quadriceps active test with KT-1000 arthrometer. To compare the reliability between the manual maximal displacement test and the quadriceps active test, two testers participated in the experiment. One tester was a novice and the other tester had substantial clinical experiences with the KT-1000 arthrometer. The quadriceps neutra! Angle was measured in the uninjured knee, and then quadriceps active test was done. Manual maximal displacement test and Quadriceps active test were done by each tester. In manual maximal displacement test, the Pearson correlation coefficient of the uninjured knee between two testers was 0.852 and that of PCL injured knee between two testers was 0.802. In quadriceps achive test, the Pearson correlation coefficient between two testers was 0.173. As a result, the manual maximal displacement test was more reliable for th measurement of the degree of the posterior instability in patients with posterior cruciate ligament tear or reccnstruction.