Cerebrospinal Fluid Lumbar Tapping Utilization for Suspected Ventriculoperitoneal Shunt Under-Drainage Malfunctions

OBJECTIVE: The diagnosis of shunt malfunction can be challenging since neuroimaging results are not always correlated with clinical outcomes. The purpose of this study was to evaluate the efficacy of a simple, minimally invasive cerebrospinal fluid (CSF) lumbar tapping test that predicts shunt under-drainage in hydrocephalus patients. METHODS: We retrospectively reviewed the clinical and radiological features of 48 patients who underwent routine CSF lumbar tapping after ventriculoperitoneal shunt (VPS) operation using a programmable shunting device. We compared shunt valve opening pressure and CSF lumbar tapping pressure to check under-drainage. RESULTS: The mean pressure difference between valve opening pressure and CSF lumbar tapping pressure of all patients were 2.21±24.57 mmH₂O. The frequency of CSF lumbar tapping was 2.06±1.26 times. Eighty five times lumbar tapping of 41 patients showed that their VPS function was normal which was consistent with clinical improvement and decreased ventricle size on computed tomography scan. The mean pressure difference in these patients was −3.69±19.20 mmH₂O. The mean frequency of CSF lumbar tapping was 2.07±1.25 times. Fourteen cases of 10 patients revealed suspected VPS malfunction which were consistent with radiological results and clinical symptoms, defined as changes in ventricle size and no clinical improvement. The mean pressure difference was 38.07±23.58 mmH₂O. The mean frequency of CSF lumbar tapping was 1.44±1.01 times. Pressure difference greater than 35 mmH₂O was shown in 2.35% of the normal VPS function group (2 of 85) whereas it was shown in 64.29% of the suspected VPS malfunction group (9 of 14). The difference was statistically significant (p=0.000001). Among 10 patients with under-drainage, 5 patients underwent shunt revision. The causes of the shunt malfunction included 3 cases of proximal occlusion and 2 cases of distal obstruction and valve malfunction. CONCLUSION: Under-drainage of CSF should be suspected if CSF lumbar tapping pressure is 35 mmH₂O higher than the valve opening pressure and shunt malfunction evaluation or adjustment of the valve opening pressure should be made.

The Risk Factors for Hydrocephalus and Subdural Hygroma after Decompressive Craniectomy in Head Injured Patients

OBJECTIVE: The present study aims to investigate 1) the risk factors for hydrocephalus and subdural hygroma (SDG) occurring after decompressive craniectomy (DC), and 2) the association between the type of SDG and hydrocephalus. METHODS: We retrospectively reviewed the clinical and radiological features of 92 patients who underwent DC procedures after severe head injuries. The risk factors for developing post-traumatic hydrocephalus (PTH) and SDG were analyzed. Types of SDGs were classified according to location and their relationship with hydrocephalus was investigated. RESULTS: Ultimately, 26.09% (24/92) of these patients developed PTH. In the univariate analyses, hydrocephalus was statically associated with large bone flap diameter, large craniectomy area, bilateral craniectomy, intraventricular hemorrhage, contralateral or interhemisheric SDGs, and delayed cranioplasty. However, in the multivariate analysis, only large craniectomy area (adjusted OR=4.66; p=0.0239) and contralateral SDG (adjusted OR=6.62; p=0.0105) were significant independent risk factors for developing hydrocephalus after DC. The incidence of overall SDGs after DC was 55.43% (51/92). Subgroup analysis results were separated by SDG types. Statistically significant associations between hydrocephalus were found in multivariate analysis in the contralateral (adjusted OR=5.58; p=0.0074) and interhemispheric (adjusted OR=17.63; p=0.0113) types. CONCLUSION: For patients who are subjected to DC following severe head trauma, hydrocephalus is associated with a large craniectomy area and contralateral SDG. For SDGs after DC that occur on the interhemispherical or controlateral side of the craniectomy, careful follow-up monitoring for the potential progression into hydrocephalus is needed.

Renal Subcapsular Hematoma after Percutaneous Transfemoral Angiography

Vascular complications after percutaneous angiography include hematoma, pseudoaneurysm, arteriovenous fistula, thromboembolism, arterial laceration and infection. Hematomas may occur in the groin, thigh, retroperitoneal, intraperitoneal, or abdominal wall. A 54-year-old female underwent percutaneous transfemoral angiography for the evaluation of cerebral aneurysm. Renal subcapsular hematoma developed 3 hours after the procedure. Renal subcapsular hematoma after percutaneous angiography is very rare. We investigated the possible causes of renal subcapsular hematoma. To avoid this rare complication, we need to perform guide-wire passage carefully from the beginning of the procedure under full visual monitoring.

Microbiology and Epidemiology of Infectious Spinal Disease

OBJECTIVE: Infectious spinal disease is regarded as an infection by a specific organism that affects the vertebral body, intervertebral disc and adjacent perivertebral soft tissue. Its incidence seems to be increasing as a result of larger proportion of the older patients with chronic debilitating disease, the rise of intravenous drug abuser, and the increase in spinal procedure and surgery. In Korea, studies assessing infectious spinal disease are rare and have not been addressed in recent times. The objectives of this study are to describe the epidemiology of all kind of spinal infectious disease and their clinical and microbiological characteristics as well as to assess the diagnostic methodology and the parameters related to the outcomes. METHODS: A retrospective study was performed in all infectious spinal disease cases presenting from January 2005 to April 2010 to three tertiary teaching hospitals within a city of 1.5 million in Korea. Patient demographics, risk factors, clinical features, and outcomes were assessed. Risk factors entailed the presence of diabetes, chronic renal failure, liver cirrhosis, immunosuppressants, remote infection, underlying malignancy and previous spinal surgery or procedure. We comparatively analyzed the results between the groups of pyogenic and tuberculous spinal infection. SPSS version 14 statistical software was used to perform the analyses of the data. The threshold for statistical significance was established at p<0.05. RESULTS: Ninety-two cases fulfilled the inclusion criteria and were reviewed. Overall, patients of tuberculous spinal infection (TSI) and pyogenic spinal infection (PSI) entailed 20 (21.7%) and 72 (78.3%) cases, respectively. A previous spinal surgery or procedure was the most commonly noted risk factor (39.1%), followed by diabetes (15.2%). The occurrence of both pyogenic and tuberculous spondylitis was predominant in the lumbar spine. Discs are more easily invaded in PSI. At initial presentation, white cell blood count and C-reactive protein levels were higher in PSI compared to TSI (p<0.05). Etiological agents were identified in 53.3%, and the most effective method for identification of etiological agents was tissue culture (50.0%). Staphyococcus aureus was the most commonly isolated infective agent associated with pyogenic spondylitis, followed by E. coli. Surgical treatment was performed in 31.5% of pyogenic spondylitis and in 35.0% of tuberculous spondylitis cases. CONCLUSION: Many previous studies in Korea usually reported that tuberculous spondylitis is the predominant infection. However, in our study, the number of pyogenic infection was 3 times greater than that of tuberculous spinal disease. Etiological agents were identified in a half of all infectious spinal disease. For better outcomes, we should try to identify the causative microorganism before antibiotic therapy and make every effort to improve the result of culture and biopsy.

Assessment of the Optimal Site of Femoral Artery Puncture and Angiographic Anatomical Study of the Common Femoral Artery

OBJECTIVE: The purpose of this study was to evaluate demographic and clinical factors affecting the common femoral artery diameter and length, and anatomical relationship between the femoral head and the common femoral artery during angiography. METHODS: We retrospectively reviewed 109 femoral angiograms. We collected the clinical data of the patients and estimated the common femoral artery diameter and length. We divided the areas in the angiogram from cephalic to caudal direction (zone 0 to 5). The lowest levels of the inferior epigastric artery loop and points of the common femoral artery bifurcation were checked. RESULTS: The luminal diameter of the common femoral artery was 6.19+/-1.20 mm. Height, weight, body surface area, as well as common femoral artery diameter were significantly greater in men than in women (p<0.005). The length of the common femoral artery was 27.59+/-8.87 mm. Height, weight and body surface area showed strong positive relationships with common femoral artery diameter. All of the inferior epigastric artery loops were located above the center of the femoral head. The point of common femoral artery bifurcation was above the center of the femoral head in 4.59% of femoral angiograms. CONCLUSIONS: Males and patients with a high body surface area have a larger common femoral artery diameter. The cumulative probability of optimal targeting between the lowest margin of the inferior epigastric artery loop and the common femoral artery bifurcation is the highest in zone 3 puncture.

Tracheoesophageal Fistula: A Fatal Complication of Endotracheal Intubation / 대한신경손상학회지

Tracheoesophageal fistula (TEF) is a rare disease which develops as a result of congenital or acquired causes. We report on two TEF female stroke patients with associated endotracheal intubation. Endotracheal intubation was kept for 13-14 days because of decreased mentality by intracranial hemorrhage. Recurrent pneumonia was a predominant symptom. Computed tomography and bronchoscopy were used to diagnose TEF. Both patients expired by sepsis and recurrent pneumonia before definite TEF treatment. The excessive dilatation of the cuff balloon of the endotracheal tube was considered one of the main causes of TEF. Prevention is most important and early treatment is required in this fatal disease.

Tracheoesophageal Fistula: A Fatal Complication of Endotracheal Intubation / 대한신경손상학회지

Tracheoesophageal fistula (TEF) is a rare disease which develops as a result of congenital or acquired causes. We report on two TEF female stroke patients with associated endotracheal intubation. Endotracheal intubation was kept for 13-14 days because of decreased mentality by intracranial hemorrhage. Recurrent pneumonia was a predominant symptom. Computed tomography and bronchoscopy were used to diagnose TEF. Both patients expired by sepsis and recurrent pneumonia before definite TEF treatment. The excessive dilatation of the cuff balloon of the endotracheal tube was considered one of the main causes of TEF. Prevention is most important and early treatment is required in this fatal disease.

Dysregulated Expression Profiles of MicroRNAs of Experimentally Induced Cerebral Aneurysms in Rats

OBJECTIVE: Cerebral aneurysm (CA) is an important acquired cerebrovascular disease that can cause catastrophic results. MicroRNAs (miRNAs) are small non-coding RNAs, playing essential roles in modulating basic physiologic and pathological processes. Currently, evidences have been established about biologic relationship between miRNAs and abdominal aortic aneurysms. However, biologic roles of miRNAs in CA formation have not been explained yet. We employed microarray analysis to detect and compare miRNA expression profiles in late stage of CA in rat model. METHODS: Twenty-six, 7-week-old male Sprague-Dawley rats underwent a CA induction procedure. The control animals (n=11) were fed a normal diet, and the experimental animals (n=26) were fed a normal diet with 1% normal saline for 3 months. Then, the rats were sacrificed, their cerebral arteries were dissected, and the five regions of aneurysmal dilation on the left posterior communicating artery were cut for miRNA microarrays analysis. Six miRNAs (miRNA-1, miRNA-223, miRNA-24-1-5p, miRNA-551b, miRNA-433, and miRNA-489) were randomly chosen for validation using real-time quantitative PCR. RESULTS: Among a set of differentially expressed miRNAs, 14 miRNAs were over-expressed more than 200% and 6 miRNAs were down-expressed lower than 50% in the CA tissues. CONCLUSION: The results show that miRNAs might take part in CA formation probably by affecting multiple target genes and signaling pathways. Further investigations to identify the exact roles of these miRNAs in CA formation are required.

Rat Peripheral Nerve Regeneration Using Nerve Guidance Channel by Porcine Small Intestinal Submucosa

OBJECTIVE: In order to develop a novel nerve guidance channel using porcine small intestinal submucosa (SIS) for nerve regeneration, we investigated the possibility of SIS, a tissue consisting of acellular collagen material without cellular immunogenicity, and containing many kinds of growth factors, as a natural material with a new bioactive functionality. METHODS: Left sciatic nerves were cut 5 mm in length, in 14 Sprague-Dawley rats. Grafts between the cut nerve ends were performed with a silicone tube (Silicon group, n=7) and rolled porcine SIS (SIS group, n=7). All rats underwent a motor function test and an electromyography (EMG) study on 4 and 10 weeks after grafting. After last EMG studies, the grafts, including proximal and distal nerve segments, were retrieved for histological analysis. RESULTS: Foot ulcers, due to hypesthesia, were fewer in SIS group than in Silicon group. The run time tests for motor function study were 2.67 seconds in Silicon group and 5.92 seconds in SIS group. Rats in SIS group showed a better EMG response for distal motor latency and amplitude than in Silicon group. Histologically, all grafts contained some axons and myelination. However, the number of axons and the degree of myelination were significantly higher in SIS group than Silicon group. CONCLUSION: These results show that the porcine SIS was an excellent option as a natural biomaterial for peripheral nerve regeneration since this material contains many kinds of nerve growth factors. Furthermore, it could be used as a biocompatible barrier covering neural tissue.

Identification of MicroRNAs with Altered Expression Profiles in a Rat Model of Experimentally Induced Early Cerebral Aneurysms / 대한신경손상학회지

OBJECTIVE: Structural adaptation of the vascular wall may occur due to various factors, such as shear stress, pressure, injury or inflammation. The role of microRNAs (miRNAs) in the development of vascular remodeling has been investigated in several studies. Recently, the authors reported altered expression profiles of miRNAs in late stage of experimentally induced giant cerebral aneurysm (CA) in rat models. But, early biologic roles of miRNAs in CA formation have not been explained yet. We employed microarrays analysis to identify miRNA expression profiles in early stage of CA in rat model and to compare with those in late stage of giant CA. METHODS: Seventy, 7-week-old male Sprague-Dawley rats underwent a CA induction procedure. The control animals (n=11) were fed a regular diet, and the experimental animals (n=59) were fed a regular diet with 1% normal saline for two months. Then, the rats were killed, their cerebral arteries were dissected, and the 13 regions of early aneurysmal change on the right olfactory artery-anterior cerebral artery bifurcation were cut for miRNA microarrays analysis. Six miRNAs (miRNA-1, miRNA-448, miRNA-352, miRNA-551b, miRNA-431, and miRNA-485) were randomly chosen for validation using real-time quantitative polymerase chain reaction. RESULTS: Among a set of differentially expressed miRNAs, 15 miRNAs were up-regulated more than 200% and five miRNAs were down-regulated less than 50% in the early CA tissues. CONCLUSIONS: This study provides an overall view of miRNA expression profiles in experimentally induced early CAs and strongly supports the idea that some miRNAs, such as miR-31 and miR-27a, play an important role in pathological processes in early CA formation. Further investigations to detect their exact roles of these miRNAs in the pathogenesis of CA are needed.

Risk Factors for the Post-Traumatic Hydrocephalus Following Decompressive Craniectomy in Severe Traumatic Injury Patients / 대한신경손상학회지

OBJECTIVE: The goal of this study was to assess the incidence and risk factors for post-traumatic hydrocephalus (PTH) following decompressive craniectomy (DC). An additional objective was to investigate the relationship between hydrocephalus and subdural hygroma (SDG) after DC. METHODS: We conducted a retrospective study of 94 patients who were admitted to our department between 2007 and 2010 with severe head injury requiring DC. Post-traumatic hydrocephalus was defined as: frontal horn index (FHI) > or =0.4 or modified FHI > or =0.33 accompanying transependymal edema; the presence of either clinical worsening or failure to make neurological improvement over time; and clinical improvement after ventriculoperitoneal shunt. Post-traumatic SDG was defined as the presence of low density at computerized tomography (CT) of more than 5mm thickness. RESULTS: Among the 94 patients, we could follow up more than 3 months and obtain more than 4 serial CT scans in 41 patients. PTH developed in 29.3% (12/41) and SDG developed in 48.8% (20/41) of these patients. The development of PTH was significantly associated with delayed craniplasty after DC and with interhemispheric SDG. No relationship was found between PTH and age, sex, Glasgow Coma Scale (GCS) score, intraventricular hemorrhage, subarachnoid hemorrhage, midline shift, basal cistern effacement, or cortical opening during DC. CONCLUSION: Hydrocephalus occurred in 29.3% of the patients with severe traumatic brain injury who required DC. Delayed cranioplasty and interhemispheric SDG after DC were risk factors for the development of PTH.

Effects of Atorvastatin on the Induction of Experimental Cerebral Aneurysm in a High Lipid Diet Rat Model / 대한뇌혈관외과학회지

OBJECTIVE: Previously, we reported that a high lipid diet significantly increases the induction rate of cerebral aneurysm (CA) formation in an experimentally induced CA rat model, suggesting that hypercholesterolemia with chronic inflammation leads to aneurysm formation. To elucidate the role of hypercholesterolemia in CA formation, experimentally induced CA was evaluated in rats fed a high lipid diet and treated with low and high doses of atorvastatin. METHODS: Thirty-seven, 7-week-old male Sprague-Dawley rats underwent a CA induction procedure. The control animals (n = 11) were fed a normal diet, and the experimental animals (n = 26) were fed a diet containing high lipid content for 3 months. The experimental group comprised a high-dose atorvastatin group (20 mg/kg/day, n = 15) and low-dose atorvastatin group (1 mg/kg/day, n = 11). Three months after the operation, induction of CA formation in the three groups was analyzed. RESULTS: Induced CA formation was 67%, 63%, and 36% in the control, high lipid/high atovastatin, and high lipid/low atovastatin group, respectively. The differences resulting from high-dose and low-dose atorvastatin were significant (Pearson k2, P = 0.028 and 0.029, respectively). CONCLUSIONS: A high lipid diet can significantly increase induction of CA formation. However, the lack of decreased induction in atorvastatin-treated animals suggests that high and low doses of atorvastatin do not inhibit the potential effects of hypercholesterolemia on CA formation. Further studies, such as those utilizing apolipoprotein E knockout mice, are necessary to elucidate the exact role of hypercholesterolemia in the pathophysiology of CA.

A Pressure Adjustment Protocol for Programmable Valves

OBJECTIVE: There is no definite adjustment protocol for patients shunted with programmable valves. Therefore, we attempted to find an appropriate method to adjust the valve, initial valve-opening pressure, adjustment scale, adjustment time interval, and final valve-opening pressure of a programmable valve. METHODS: Seventy patients with hydrocephalus of various etiologies were shunted with programmable shunting devices (Micro Valve with RICKHAM(R) Reservoir). The most common initial diseases were subarachnoid hemorrhage (SAH) and head trauma. Sixty-six patients had a communicating type of hydrocephalus, and 4 had an obstructive type of hydrocephalus. Fifty-one patients had normal pressure-type hydrocephalus and 19 patients had high pressure-type hydrocephalus. We set the initial valve pressure to 10-30 mmH2O, which is lower than the preoperative lumbar tapping pressure or the intraoperative ventricular tapping pressure, conducted brain computerized tomographic (CT) scans every 2 to 3 weeks, correlated results with clinical symptoms, and reset valve-opening pressures. RESULTS: Initial valve-opening pressures varied from 30 to 180 mmH2O (mean, 102 +/- 27.5 mmH2O). In high pressure-type hydrocephalus patients, we have set the initial valve-opening pressure from 100 to 180 mmH2O. We decreased the valve-opening pressure 20-30 mmH2O at every 2- or 3-week interval, until hydrocephalus-related symptoms improved and the size of the ventricle was normalized. There were 154 adjustments in 81 operations (mean, 1.9 times). In 19 high pressure-type patients, final valve-opening pressures were 30-160 mmH2O, and 16 (84%) patients' symptoms had nearly improved completely. However, in 51 normal pressure-type patients, only 31 (61%) had improved. Surprisingly, in 22 of the 31 normal pressure-type improved patients, final valve-opening pressures were 30 mmH2O (16 patients) and 40 mmH2O (6 patients). Furthermore, when final valve-opening pressures were adjusted to 30 mmH2O, 14 patients symptom was improved just at the point. There were 18 (22%) major complications : 7 subdural hygroma, 6 shunt obstructions, and 5 shunt infections. CONCLUSION: In normal pressure-type hydrocephalus, most patients improved when the final valve-opening pressure was 30 mmH2O. We suggest that all normal pressure-type hydrocephalus patients be shunted with programmable valves, and their initial valve-opening pressures set to 10-30 mmH2O below their preoperative cerebrospinal fluid (CSF) pressures. If final valve-opening pressures are lowered in 20 or 30 mmH2O scale at 2- or 3-week intervals, reaching a final pressure of 30 mmH2O, we believe that there is a low risk of overdrainage syndromes.

The Clinical Presentation and Treatment of Distal Posterior Inferior Cerebellar artery Aneurysms: Report on 2 cases / 대한뇌혈관외과학회지

Aneurysms arising from the posterior inferior cerebellar artery (PICA) are uncommon, with a reported incidence ranging between 0.5 and 2% of all the aneurysms in the brain. Most of them arise at the PICA origin from the vertebral artery, whereas distal PICA aneurysms are exceptional. We have experienced two consecutive cases of distal PICA aneurysms. Both patients were female and the first patient was 48 years old and the second patient was 60 years old. Cerebral angiography was performed immediately after admission and it showed an aneurysm located on the distal PICA. One patient was treated by a combined endovascular and surgical approach, and the other patient was treated by a surgical approach only. The former patient expired 8 days from the ictus. The latter patient had a good outcome during admission. Distal PICA aneurysms are exceptionally rare and they may be successfully treated with surgical or endovascular techniques. The therapeutic strategy, either surgical or endovascular, should be selected according to the condition of the patient and the arterial and aneurysmal morphology.

The Neovascularization Effect of Bone Marrow Stromal Cells in Temporal Muscle after Encephalomyosynangiosis in Chronic Cerebral Ischemic Rats

OBJECTIVE: In Moyamoya disease, the primary goal of treatment is to improve collateral circulation through angiogenesis. In the present study, we obtained and sub-cultured bone marrow stromal cells (BMSCs) from rats without a cell-mediated immune response. Then, we injected the labeled BMSCs directly into adjacent temporal muscle during encephalomyosynangiosis (EMS). Three weeks after BMSC transplantation, we examined the survival of the cells and the extent of neovascularization. METHODS: We divided 20 rats into a BMSC transplantation group (n=12) and a control group (n=8). Seven days after the induction of chronic cerebral ischemia, an EMS operation was performed, and labeled BMSCs (1x106(6)/100 microliter) were injected in the temporal muscle for the transplantation group, while an equivalent amount of culture solution was injected for the control group. Three weeks after the transplantation, temporal muscle and brain tissue were collected for histological examination and western blot analysis. RESULTS: The capillary/muscle ratio in the temporal muscle was increased in the BMSC transplantation group compared to the control group, showing a greater increase of angiogenesis (p<0.05). In the brain tissue, angiogenesis was not significantly different between the two groups. The injected BMSCs in the temporal muscle were vascular endothelial growth factor (VEGF)-positive by immunofluorescence staining. In both temporal muscle and brain tissue, the expression of VEGF by western blot analysis was not much different between the two groups. CONCLUSION: During EMS in a chronic cerebral ischemia rat model, the injection of BMSCs resulted in accelerated angiogenesis in the temporal muscle compared to the control group.

Treatment of Superior Sagittal Sinus Dural Arteriovenous Fistula / 대한뇌혈관외과학회지

OBJECTIVE: Dural arteriovenous fistulas (dAVFs) at the superior sagittal sinus (SSS) are very rare. Endovascular treatment alone often fails to eliminate the fistula because of the midline location of the SSS, the eloquent venous drainage and the multiple bilateral arterial feeders. Surgical extirpation of dAVFs is not recommended in all cases because of the considerable risks involved. We report here on a case of dAVF at the SSS with patent sinus drainage and retrograde leptomeningeal venous drainage, and this was selectively disconnected using an aneurysmal clip under intraoperative Doppler monitoring. The neurological symptoms vanished during the 2 years of follow-up, and no further progression of the dAVF has been found. The methods of converting aggressive dAVFs to benign forms are relatively safe and simple. Therefore, this simple and effective method could be recommended for older aged patients with high intraoperative risk.

A New Method for Quantification of Ischemic Brain Lesion Using a Personal Computer and a Flatbed Scanner / 대한뇌혈관외과학회지

OBJECTIVE: Quantification of infarct size has been frequently used as an useful index to assess the focal cerebral ischemia models and therapeutic strategies. Currently-used image analysis systems require dedicated and expensive equipment to carry out this task. The planimeter method is time-consuming and complex. The first purpose of this study was to develop a new, low-cost and simple method to perform the image acquisition and analysis using flatbed color scanner and a commercial image processing software (Adobe Photoshop 6.0). The second purpose was to evaluate the accuracy and reproducibility of the new method. METHODS: Fifty-nine adult male Sprague-Dawley rats were sacrificed 24 hours following the focal cerebral ischemia. Hematoxylin-Eosin stain was used as a conventional staining method to differentiate ischemic damage from healthy brain tissue. Digital images were captured from the stained coronal sections using a flatbed color scanner and analyzed with a commercial image processing software. To evaluate the accuracy of the new method, the data obtained from the new procedure was correlated with those from a dedicated standard image analysis system and planimeter method. To evaluate the reproducibility, interobservor correlation coefficients were estimated. The correlation in the outcome of infarct size measurements between two different examiners and three different methods were evaluated using the Pearson's correlation coefficient and regression analysis. In each examiners, the data from three different methods were analyzed using nonparametric Freedman ANOVA. In each methods, the data from two different examiners were compared using Wilcoxon signed-rank test. RESULTS: The following results were obtained. 1. From the data taken by the two examiners, there was a close correlation in the outcome of infarct size measurement anong the new method, standard system method and planimeter method (P=0.0001). 2. There were no significant differences in the means of infarct size measurement among the three different methods in the results of examiner 1 and 2 (Freedman ANOVA, P>0.05). 3. A high agreement was obtained in measurement of the infarct size between two different examiners with the same source of samples. Using the Photoshop method, the correlation coefficient was 0.991 (P=0.0001). 4. In each methods, there were no significant differences in the means of infarct size measurement between two different examiners. Using the Photoshop method, results from examiner 1 and 2 were 27.33+/-4.18 mm2 and 27.35+/-4.14 mm2 respectively. Also there was no significant difference found by using Wilcoxon signed-rank test (P=0.95). CONCLUSIONS: These data demonstrated that ischemic lesion of focal cerebral ischemia in rats can be accurately and reproducibly quantified using this method. The low-cost and simplicity may facilitate the application of this method in measurement of ischemic brain damage.

Difference in Induction Rate of Experimental Cerebral Aneurysm According to High Salt, High Lipid and Normal Diet / 대한뇌혈관외과학회지

OBJECTIVE: An intracranial aneurysm is an important acquired cerebrovascular disease that can cause a catastrophic subarachnoid hemorrhage. Atherosclerosis is one of possible mechanism, but its contribution to aneurysm formation is unclear. Experimentally induced cerebral aneurysm rate by high lipid diet was evaluated and compared with high salt and normal diet to elucidate the role of lipid metabolism in the process of cerebral aneurysm formation. METHODS: Thirty-seven 7-week-old male Sprague-Dawley (SD) rats received a cerebral aneurysm induction procedure. The control animals (n=11) were fed a normal diet, and the experimental animals were fed a diet containing 8% salt (n=15) and high lipid (n=11) for three months. Three months after the operation, the rats were killed, their cerebral arteries were dissected, and the regions of the bifurcation of the right anterior cerebral artery-olfactory artery (ACA-OA) bifurcations were examined histologically and aneurysm induction rates among three groups were analysed. RESULTS: Average systolic blood pressures after 3 months feeding in three groups (high salt diet group, high lipid diet group and normal diet group) were 175.9+/-3.4 mmHg, 133.7+/-5.1 mmHg and 128+/-2.9 mmHg, respectively. The difference between high lipid group and normal diet group was not significant (P=0.215). The aneurysm induction rate in three group were 87%, 63% and 36%. The difference between high lipid diet group and normal diet group was significant (Pearson k2, P=0.029). CONCLUSIONS: High lipid diet significantly increase the cerebral aneurysm induction rate in experimentally induced cerebral aneurysm model of rats. That suggests a possible adverse role for hyperlipidemia leading to aneurysm formation. Further studies are necessary to elucidate the exact role of hyperlipidemia in the pathophysiology of cerebral aneurysm.

Apolipoprotein E Expression in Experimentally Induced Intracranial Aneurysms of RatsIntroduction

OBJECTIVE: An intracranial aneurysm is an important acquired cerebrovascular disease that can cause a catastrophic subarachnoid hemorrhage. Atherosclerosis is one of possible mechanism, but its contribution to aneurysm formation is unclear. Human apolipoprotein E(apoE) is best known for its arterial protection from atherosclerosis. In this study we observe apoE expression in experimental cerebral aneurysms of rats to elucidate the role of apoE in the process of cerebral aneurysm formation. METHODS: Twenty-four male 7-week-old Sprague-Dawley strain rats received a cerebral aneurysm induction procedure. One month(12) and three months(12) after the operation, the rats were killed, their cerebral arteries were dissected, and the regions of the bifurcation of the right anterior cerebral artery-olfactory artery (ACA-OA) bifurcations were examined histologically and immunohistochemically. RESULTS: In the 1 month group (n=12), the ACA-OA bifurcation showed no aneurysmal change in 7 rats and early aneurysmal change in 5 rats. In the 3 months group (n=12), the bifurcation showed no aneurysmal change in 2 rats and an advanced aneurysm in 10 rats. ApoE expression were in 3 specimen in early aneurysmal change, but not in advanced aneurysms. CONCLUSION: ApoE expression in early aneurysmal wall suggests a possible role for apoE in early events leading to aneurysm formation. Further studies are necessary to elucidate the exact role of apoE in the pathophysiology of cerebral aneurysm.

The Survival and Migration Pattern of the Bone Marrow Stromal Cells after Intracerebral Transplantation in Rats

OBJECTIVE: Bone marrow stromal cells (MSCs) are stem cells that can differentiate into chondrogenic, osteogenic, myogenic, adipogenic, and neurogenic cells according to the surrounding environment. Moreover, transplanted stem cells can migrate from the graft site in the recipient brain. The survival and migration patterns of the transplanted MSCs are investigated histologically. METHODS: Bone MSCs were harvested from adult Fisher rats and cultured for several passages. To identify cells derived from MSCs, 5microM bromodeoxyuridine (BrdU) was added to the medium 72 hours before transplantation. Bone MSCs were transplanted into the striatum of the recipient rat stereotactically. Test groups consisted of intracerebral transplantation of MSCs (n=6) and control-cultured medium alone (n=4). BrdU, hematoxylin and eosin staining were performed fourteen days after transplantation. RESULTS: More than 80% of the cultured MSCs showed reactivity to BrdU in vitro. Transplanted MSCs were found mainly around the injection route and migrated from the injection site about 1mm along the white matter. The corpus callosum clearly showed migration of MSCs. CONCLUSION: The results suggest that stem cells can be easily obtained from the adult bone MSCs and the transplanted MSCs can migrate from the grafted site. In such cases, the migration pattern of the grafted MSCs may be determined according to the recipient environment.