Efficacy of Combining Proximal Balloon Guiding Catheter and Distal Access Catheter in Thrombectomy with Stent Retriever for Anterior Circulation Ischemic Stroke

OBJECTIVE: We evaluated efficacy of combining proximal balloon guiding catheter (antegrade flow arrest) and distal access catheter (aspiration at the site of occlusion) in thrombectomy for anterior circulation ischemic stroke. METHODS: We retrospectively analyzed 116 patients who underwent mechanical thrombectomy with stent retriever. The patients were divided by the techniques adopted, the combined technique (proximal balloon guiding catheter and large bore distal access catheter) group (n=57, 49.1%) and the conventional (guiding catheter with stent retriever) technique group (n=59, 50.9%). We evaluated baseline characteristics (epidemiologic data, clinical and imaging characteristics) and procedure details (the number of retrieval attempts, procedure time), as well as angiographic (thrombolysis in cerebral infarction (TICI) score, distal thrombus migration) and clinical outcome (National Institutes of Health Stroke Scale at discharge, modified Rankin Scale [mRS] at 3 months) of them. RESULTS: The number of retrieval attempts was lower (p=0.002) and the first-pass successful reperfusion rate was higher (56.1% vs. 28.8%; p=0.003) in the combined technique group. And the rate of final result of TICI score 3 was higher (68.4% vs. 28.8%; p<0.01) and distal thrombus migration rate was also lower (15.8% vs. 40.7%; p=0.021) in the combined technique group. Early strong neurologic improvement (improvement of National Institutes of Health Stroke Scale ≥11 or National Institutes of Health Stroke Scale ≤1 at discharge) rate (57.9% vs. 36.2%; p=0.02) and favorable clinical outcome (mRS at 3 months ≤2) rate (59.6% vs. 33.9%; p=0.005) were also better in the combined technique group. CONCLUSION: The combined technique needs lesser attempts, decreases distal migration, increases TICI 3 reperfusion and achieves better clinical outcomes.

Efficacy of Combining Proximal Balloon Guiding Catheter and Distal Access Catheter in Thrombectomy with Stent Retriever for Anterior Circulation Ischemic Stroke

OBJECTIVE: We evaluated efficacy of combining proximal balloon guiding catheter (antegrade flow arrest) and distal access catheter (aspiration at the site of occlusion) in thrombectomy for anterior circulation ischemic stroke.METHODS: We retrospectively analyzed 116 patients who underwent mechanical thrombectomy with stent retriever. The patients were divided by the techniques adopted, the combined technique (proximal balloon guiding catheter and large bore distal access catheter) group (n=57, 49.1%) and the conventional (guiding catheter with stent retriever) technique group (n=59, 50.9%). We evaluated baseline characteristics (epidemiologic data, clinical and imaging characteristics) and procedure details (the number of retrieval attempts, procedure time), as well as angiographic (thrombolysis in cerebral infarction (TICI) score, distal thrombus migration) and clinical outcome (National Institutes of Health Stroke Scale at discharge, modified Rankin Scale [mRS] at 3 months) of them.RESULTS: The number of retrieval attempts was lower (p=0.002) and the first-pass successful reperfusion rate was higher (56.1% vs. 28.8%; p=0.003) in the combined technique group. And the rate of final result of TICI score 3 was higher (68.4% vs. 28.8%; p<0.01) and distal thrombus migration rate was also lower (15.8% vs. 40.7%; p=0.021) in the combined technique group. Early strong neurologic improvement (improvement of National Institutes of Health Stroke Scale ≥11 or National Institutes of Health Stroke Scale ≤1 at discharge) rate (57.9% vs. 36.2%; p=0.02) and favorable clinical outcome (mRS at 3 months ≤2) rate (59.6% vs. 33.9%; p=0.005) were also better in the combined technique group.CONCLUSION: The combined technique needs lesser attempts, decreases distal migration, increases TICI 3 reperfusion and achieves better clinical outcomes.

Comparative Analysis of Endovascular Stroke Therapy Using Urokinase, Penumbra System and Retrievable (Solitare) Stent

BACKGROUND: Higher reperfusion rates have been established with endovascular treatment for acute ischemic stroke patients. There are limited data on the comparative performance of mechanical thrombectomy devices. This study aimed to analyse the efficacy and safety of the stent retriever device (Solitaire stent) by comparing procedure time, angiographic outcome, complication rate and long term clinical outcome with previous chemical thrombolysis and mechanical thrombectomy using penumbra system. METHODS: A retrospective single-center analysis was undertaken of all consecutive patients who underwent chemical thrombolysis and mechanical thrombectomy using Penumbra or Solitaire stent retriever from March 2009 to March 2014. Baseline characteristics, rate of successful recanalization (modified Thrombolysis in Cerebral Infarction score 2b-3), symptomatic intracerebral hemorrhage, procedure time, mortality and independent functional outcomes (mRS < or =2) at 3 month were compared across the three method. RESULTS: Our cohort included 164 patients, mechanical thrombectomy using stent retriever device had a significant impact on recanalization rate and functional independence at 3 months. In unadjusted analysis mechanical thrombectomy using Solitaire stent retriever showed higher recanalization rate than Penumbra system and chemical thrombolysis (75% vs. 64.2% vs. 49.4%, p=0.03) and higher rate of functional independence at 3 month (53.1% vs. 37.7% vs. 35.4%, p=0.213). In view of the interrelationships between all predictors of variables associated with a good clinical outcome, when the chemical thrombolysis was used as a reference, in multiple logistic regression analysis, the use of Solitaire stent retriever showed higher odds of independent functional outcome [odds ratio (OR) 2.62, 95% confidence interval (CI) 0.96-7.17; p=0.061] in comparison with penumbra system (OR 1.57, 95% CI 0.63-3.90; p=0.331). CONCLUSION: Our initial data suggest that mechanical thrombectomy using stent retriever is superior to the mechanical thrombectomy using penumbra system and conventional chemical thrombolysis in achieving higher rates of reperfusion and better outcomes. Randomized clinical trials are needed to establish the actual benefit to specific patient populations.

Location and Characteristics of Warfarin Associated Intracranial Hemorrhage

OBJECTIVE: In the so-called primary intracerebral hemorrhage (ICH), lobar and deep ICH were mainly due to cerebral amyloid angiopathy and deep perforating arterial disease. Our aim was to identify specifics of warfarin associated ICH (WAICH) and to focus on differences in susceptibility to warfarin according to the underlying vasculopathies, expressed by ICH location. MATERIALS AND METHODS: We identified all subjects aged > or = 18 years who were admitted with primary ICH between January 1, 2007 and September 30, 2012. We retrospectively collected demographic characteristics, the presence of vascular risk factors and pre-ICH medication by chart reviews. We categorized ICH into four types according to location: lobar, deep, posterior fossa, and undetermined. We investigated characteristics (including hematoma volume and expansion) of ICH according to the location of ICH. RESULTS: WAICH accounted for 35 patients (5.6%) of 622 ICH cases. In WAICH, 13 patients (37.1%) had lobar ICH and 22 patients (60.0%) had non-lobar ICH. Compared to other locations of ICH, lobar ICH showed an excess risk of WAICH (OR 2.53, 95% CI 1.03-6.21, p = 0.042). The predictors of lobar location of ICH were warfarin (OR 2.29, 95% CI 1.05-5.04, p = 0.038) and diabetes mellitus (DM) (OR 0.54, 95% CI 0.29-0.98, p = 0.044). The lobar location of ICH showed significant association with larger hematoma volume (p = 0.001) and high ratio of hematoma expansion (p = 0.037) compared with other locations of ICH. CONCLUSION: In our study, warfarin showed significant association with lobar ICH and it caused larger hematoma volume and more expansion of hematoma in lobar ICH.

Diagnostic Value of Thrombus Size on T2*-weighted Gradient Echo Imaging in Acute Middle Cerebral Artery Occlusion

OBJECTIVE: The T2*-weighted gradient echo image susceptibility vessel sign (GRE SVS) is a well-known indicator of intraluminal thrombi in acute cerebral infarction. The purpose of this study was to evaluate the relationships between thrombus size on GRE SVS and recanalization after intravenous administration of tissue plasminogen activator (IV-tPA). MATERIALS AND METHODS: Fifty five patients with GRE SVSs on the M1 were enrolled. Examination of magnetic resonance image (MRI), including diffusion weighted imaging and MR angiography, was performed within 20 minutes of admission. Thrombus size on GRE was calculated using the Picture Archiving and Communication System upon initial MRI. Recanalization was assessed with follow-up MRI or transfemoral cerebral angiography within 24 hours of treatment. RESULTS: The patient group consisted of 37 males and 18 females with an average age of 63.74 +/- 10.28 years (range: 43 - 77 years). The median NIHSS score was 13. Fifteen of these patients achieved recanalization (27.3%). The average thrombus cross-sectional area in the recanalization group was 38.54 +/- 20.27 mm2, and the corresponding size of the non-recanalization group was 53.38 +/- 24.77 mm2 (p = 0.043). In the receiver operator characteristic curve for thrombus cross-sectional area in relation to recanalization, the cut-off point was 47.28 mm2. The sensitivity at this cut-off point was 73.3%, the specificity was 60%, and the area under the curve was 0.687. CONCLUSION: Thrombus size on GRE is a simple diagnostic tool that can be easily measured, and thrombus size on GRE SVS was found to be associated with recanalization after IV-tPA.

Organized Comprehensive Stroke Center is Associated with Reduced Mortality: Analysis of Consecutive Patients in a Single Hospital / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: Organized inpatient stroke care is one of the most effective therapies for improving patient outcomes. Many stroke centers have been established to meet this need, however, there are limited data on the effectiveness of these organized comprehensive stroke center (CSC) in the real-world setting. Our aim is to determine whether inpatient care following the establishment of CSC lowers mortality of patients with acute ischemic stroke (AIS). METHODS: Based on a prospective stroke registry, we identified AIS patients hospitalized before and after the establishment of a CSC. We observed all-cause mortality within 30 days from time of admission. Logistic regression was used to determine whether the establishment of the CSC affects independently the 30-day all-cause mortality. RESULTS: A total of 3,117 consecutive patients with AIS were admitted within seven days after the onset of the symptoms. Unadjusted 30-day mortality was lower for patients admitted to our hospital after the establishment of the CSC than before (5.9% vs. 8.2%, P=0.012). Advanced age, female gender, previous coronary artery disease, non-smoking, stroke subtype, admission on a holiday, referral from other hospitals, high NIHSS on admission, and admission before the establishment of CSC were associated with increased 30-day stroke case fatality. After adjustment for these factors, stroke inpatient care subsequent to the establishment of the CSC was independently associated with lower 30-day mortality (OR, 0.57; 95% CI, 0.412-0.795). CONCLUSIONS: Patients treated after the establishment of a CSC had lower 30-mortality rates than ever before, even adjusting for the differences in the baseline characteristics. The present study reveals that organized stroke care in a CSC might improve the outcome after AIS.

Direct Relationship between Angiographic Characteristics of Carotid Atherosclerotic Plaque and Filling Defect in the Cerebral Protection Filters : Based on the Conventional Angiography

OBJECTIVE: Neurologic complications during carotid artery stenting (CAS) are usually associated with distal embolic event. These embolic incident during CAS are highly associated with the carotid plaque instability. The current study was undertaken to identify the angiographic characteristics of carotid plaque vulnerability, which was represented as filling defect in the cerebral protection filters during CAS. METHODS: A total of 107 patients underwent CAS with use of a distal protection filter. Angiographic carotid plaque surface morphology was classified as smooth, irregular, and ulcerated. To determine predictable factors of filling defect in the protection filters, 11 variables were retrospectively analyzed which might influence filling defect in the protection filters during CAS. RESULTS: Filling defects during CAS were presented in the 33 cerebral protection filters. In multivariate analysis, angiographic ulceration [odds ratio (OR), 6.60; 95% confidence interval (CI) : 2.24, 19.4; p=0.001], higher stenosis degree (OR, 1.06; 95% CI : 1.00, 1.12; p=0.039), and coexistent thrombus (OR, 7.58; 95% CI : 1.69, 34.05; p=0.08) were highly associated with filling defect in the cerebral protection devices during CAS. Among several variables, angiographic surface ulceration was the only significant factor associated with flow stagnation during CAS (OR, 4.11; 95% CI : 1.33, 12.72; p=0.014). CONCLUSION: Plaque surface morphology on carotid angiography can be a highly sensitive marker of plaque instability during CAS. The independent risk factors for filling defect in the filter devices during CAS were plaque ulceration, stenosis degree, and coexistent thrombus.

Management of Aneurysms of the Proximal (A1) Segment of the Anterior Cerebral Artery

OBJECTIVE: Aneurysms originating from the proximal segment (A1) of the anterior cerebral artery are rare; however, because of their small size, the risk of injury of perforating arteries, and the location of the aneurysm in the surgical field, they are challenging to treat. We report on 15 patients with A1 aneurysms and review surgical views according to the direction of aneurysms. METHODS: Fifteen patients were diagnosed with A1 aneurysms and underwent surgical clipping or endovascular coiling at our institution between January 2006 and March 2012. We conducted a retrospective review of clinical and radiological features of all patients with A1 aneurysms. RESULTS: Nine patients underwent surgical clipping, and six patients received endovascular coiling. Six patients (40%) had multiple aneurysms. A1 aneurysms ranged in size from 1.5 to 8.2 mm, with an average size of 3.26 mm. Most A1 aneurysms (73%) had a posterior direction. In the surgical view, A1 aneurysms projecting posteriorly were located behind the A1 trunk. The A1 aneurysm projecting posteroinferiorly was completely eclipsed by the parent artery. In A1 aneurysms with a posterosuperior or superior direction, finding and clipping the aneurysm neck was relatively easy. Thirteen patients (87%) had an excellent outcome, one had moderate disability, and one died. CONCLUSION: A1 aneurysms have certain characteristics; small size, multiple aneurysms, and, usually, a posterior direction. A1 aneurysms with a posterosuperior or superior direction are relatively easy to assess, however, clipping of A1 aneurysms with a posterior or posteroinferior direction is more difficult. Endovascular coiling is an alternative therapeutic option when surgical clipping is expected to be difficult.

Ruptured Mycotic Aneurysm of the Distal Middle Cerebral Artery Manifesting as Subacute Subdural Hematoma

Mycotic aneurysms are rare inflammatory neurovascular lesions. Ruptured mycotic aneurysm manifesting as subdural hematoma is extremely rare. A 72-year-old male patient was admitted to our hospital with headache and drowsiness. Computer tomography (CT) of brain and CT angiography revealed subdural hematoma and an aneurysm located at the M4 segment of the left middle cerebral artery (MCA). Cerebral angiogram revealed 2 aneurysms; one located at the left distal MCA and the other at the bifurcation of left MCA. Laboratory studies showed leukocytosis and elevated inflammatory factors. The patent was treated with antibiotic therapy for 4 weeks. The follow-up CT and cerebral angiography showed that the mycotic aneurysm was completely resolved, and the patient was nearly free of symptoms.

Outcome Following Decompressive Craniectomy for Malignant Middle Cerebral Artery Infarction in Patients Older Than 70 Years Old

OBJECTIVE: Malignant middle cerebral artery (MCA) infarction occurs in 10% of all ischemic strokes and these severe strokes are associated with high mortality rates. Recent clinical trials demonstrated that early decompressive craniectomy reduce mortality rates and improves functional outcomes in healthy young patients (less than 61 years of age) with a malignant infarction. The purpose of this study was to assess the efficacy of decompressive craniectomy in elderly patients (older than 70 years of age) with a malignant MCA infarction. METHODS: Between February 2008 and October 2011, 131 patients were diagnosed with malignant MCA infarctions. We divided these patients into two groups: patients who underwent decompressive craniectomy (n = 58) and those who underwent conservative care (n = 73). A cut-off point of 70 years of age was set, and the study population was segregated into those who fell above or below this point. Mortality rates and functional outcome scores were assessed, and a modified Rankin Scale (mRS) score of > 3 was considered to represent a poor outcome. RESULTS: Mortality rates were significantly lower at 29.3% (one-month mortality rate) and 48.3% (six-month mortality rate) in the craniectomy group as compared to 58.9% and 71.2%, respectively, in the conservative care group (p or =70 years vs. < 70 years) did not statistically differ between groups for the six-month mortality rate (p = 0.137). However, the pre-operative National Institutes of Health Stroke Scale (NIHSS) score did contribute to the six-month mortality rate (p = 0.047). CONCLUSION: Decompressive craniectomy is effective for patients with a malignant MCA infarction regardless of their age. Therefore, factors other than age should be considered and the treatment should be individualized in elderly patients with malignant infarctions.

Influence of Clinical and Anatomic Features on Treatment Decisions for Anterior Communicating Artery Aneurysms

OBJECTIVE: The purpose of this study was to analyze the clinical and anatomic features involved in determining treatment modalities for anterior communicating artery (AcoA) aneurysms. METHODS: The authors retrospectively evaluated 112 AcoA aneurysms with pretreatment clinical features including age, Hunt and Hess grade, medical or neurological comorbidity, and anatomical features including aneurysm size, neck size, dome-to-neck ratio, vessel incorporation, multiple lobulation, and morphologic scoring system. Post-treatment clinical results were classified according to the Glasgow Outcome Scale, and anatomic results in coiled patients were classified according to the modified Raymond scale. Using multivariate logistic regression, the probabilities for decision making between surgical clipping and coil embolization were calculated. RESULTS: Sixty-seven patients (60%) were treated with surgical clipping and 45 patients (40%) with endovascular coil embolization. The clinical factor significantly associated with treatment decision was age (> or =65 vs. or =2), presence of vessel incorporation, multiple lobulation, and morphologic score (> or =2 vs. 65 years) had significantly higher odds of being treated with coil embolization relative to clipping (adjusted OR=3.78; 95% CI, 1.39-10.3; p=0.0093) and higher morphological score patients (> or =2) had a higher tendency toward surgical clipping than endovascular coil embolization (OR=0.23; 95% CI, 0.16-0.93; p=0.0039). CONCLUSION: The optimal decision for treating AcoA aneurysms cannot be determined by any single clinical or anatomic characteristics. All clinical and morphological features need to be considered, and a collaborative neurovascular team approach to AcoA aneurysms is essential.

Endovascular Treatment and Microsurgical Treatment of Intracranial Aneurysms in the Elderly / 대한뇌혈관외과학회지

BACKGROUND: The prevalence of intracranial aneurysms in the elderly is increasing. However, most treatment strategies for the elderly is controversial and related research in the elderly has been insufficient. METHODS: Eighty-four patients > 65 years of age with intracranial aneurysms who received definitive treatment at our hospital between March 2007 and June 2010 were subjected to this study. Thirty-seven patients who had undergone endovascular treatment (EVT) were categorized into group I, while 47 patients who had undergone microsurgical treatment (MST) were categorized into group II. RESULTS: When the Glasgow Outcome Scale (GOS) score, which was independent to rupture, was evaluated at the time of discharge there was a trend of acquiring much better GOS scores (GOS> or =4) when the Hunt-Hess grade (HHG) is good (HHG< or =2) and the size of the aneurysm is small (<10 mm; p=0.001 [HHG] and p=0.000 [aneurysm size]). In the two groups in which EVT and MST were performed, the average values of the GOS scores by Student's t-test displayed a significant difference (4.54 [EVT] and 4.13 [MST], respectively, p=0.046). However, univariate and multivariate analyses were not statistically significant. CONCLUSION: If the clinical results are similar in the EVT and MST for intracranial aneurysms, then EVT is less invasive with less post-procedural complications would be considered with priority in elderly patients.

Clinical Features of Distal Anterior Cerebral Artery Aneurysm and Treatment Outcomes / 대한뇌혈관외과학회지

OBJECTIVE: Distal anterior cerebral artery (DACA) aneurysms are relatively uncommon and surgical management presents some unique technical difficulties. We retrospectively reviewed our experience with 35 DACA aneurysm cases, their clinical features and treatment outcomes to assess the characteristics and treatment outcomes of DACA aneurysms. MATERIALS AND METHODS: The medical records of 33 patients with 35 ruptured and unruptured DACA aneurysms were reviewed. Of these, 29 had undergone surgery and four were treated by coil embolization at our institution between September 1992 and January 2010. The clinical presentation, radiologic features and surgical and endovascular treatment outcomes were analyzed. RESULTS: In our series, the incidence of DACA aneurysms was 35 of 1106 (3.1%) aneurysms. The most common location of these 35 aneurysms was the bifurcation of the pericallosal and callosomarginal arteries (51%). Multiple aneurysms were found in nine patients (27%) and associated vascular anomalies such as azygous anterior cerebral artery and Moyamoya disease were found in six patients (18%). Ninety four percent of the aneurysms were less than 10 mm in diameter. Twenty nine patients were treated by surgical clipping and four patients were treated by coil embolization. Premature rupture of aneurysms and mortality or morbidity directly related to the aneurysmal surgery or endovascular treatments were not observed. CONCLUSION: DACA aneurysms have a tendency to rupture before becoming large or giant in size. We achieved favorable outcomes (modified Rankin Scale <4) in 29 of the 33 patients with a tailored surgical approach and coil embolization. Therefore, DACA aneurysms should be treated aggressively even if they are <10 mm in diameter and early surgery can reduce the rate of rebleeding.

Prehospital Notification from the Emergency Medical Service Reduces the Transfer and Intra-Hospital Processing Times for Acute Stroke Patients

BACKGROUND AND PURPOSE: There is little information available about the effects of Emergency Medical Service (EMS) hospital notification on transfer and intrahospital processing times in cases of acute ischemic stroke. METHODS: This study retrospectively investigated the real transfer and imaging processing times for cases of suspected acute stroke (AS) with EMS notification of a requirement for intravenous (IV) tissue-type plasminogen activator (t-PA) and for cases without notification. Also we compared the intra-hospital processing times for receiving t-PA between patients with and without EMS prehospital notification. RESULTS: Between December 2008 and August 2009, the EMS transported 102 patients with suspected AS to our stroke center. During the same period, 33 patients received IV t-PA without prehospital notification from the EMS. The mean real transfer time after the EMS call was 56.0+/-32.0 min. Patients with a transfer distance of more than 40 km could not be transported to our center within 60 min. Among the 102 patients, 55 were transferred via the EMS to our emergency room for IV t-PA. The positive predictive value for stroke (90.9% vs. 68.1%, p=0.005) was much higher and the real transfer time was much faster in patients with an EMS t-PA call (47.7+/-23.1 min, p=0.004) than in those without one (56.3+/-32.4 min). The door-to-imaging time (17.8+/-11.0 min vs. 26.9+/-11.5 min, p=0.01) and door-to-needle time (29.7+/-9.6 min vs. 42.1+/-18.1 min, p=0.01) were significantly shorter in the 18 patients for whom there was prehospital notification and who ultimately received t-PA than in those for whom there was no prehospital notification. CONCLUSIONS: Our results indicate that prehospital notification could enable the rapid dispatch of AS patients needing IV t-PA to a stroke centre. In addition, it could reduce intrahospital delays, particularly, imaging processing times.

Treatment of the Posterior Circulation Aneurysms / 대한뇌혈관외과학회지

OBJECTIVE: Endovascular treatment is now accepted as an initial treatment modality, especially in cases of posterior circulation aneurysms. The purpose of this study was to review the treatment outcomes and to emphasize the necessity of maintaining the surgical ability for posterior circulation aneurysms. METHODS: During the past 10 years, 570 patients have been treated for cerebral aneurysms at our institute. Among these patients, 34 harbored posterior circulation aneurysms. From January 2004 to June 2008, 13 of the 34 patients were treated by endovascular coiling. We retrospectively reviewed the clinical outcome, cerebral angiograms, and other radiological imagings through a comparative study of the pre- and post-endovascular treatment periods. RESULTS: Overall, 9 (69.2%) of the pre-endovascular treatment period group and 20 (95.2%) of the endovascular treatment period group had good outcomes. The mean post-operative hospital days for these groups were 38.6 and 21.1, respectively. Patients in the endovascular treatment period group had shorter post-operative hospital periods and better outcomes than those in the pre-endovascular treatment period group. CONCLUSION: It is recommended that multimodality treatment involving microsurgical clipping and endovascular coiling is used to obtain better results in the treatment of posterior circulation aneurysms. These results suggest that although the trend toward endovascular treatment as the initial aneurysm therapy for posterior circulation aneurysms is also enhancing, it might be necessary to maintain the surgical ability for posterior circulation aneurysm.

Recent Epidemiological Trends of Stroke

OBJECTIVE: Rapid increase in aged population and westernization of lifestyle have modified epidemiological status of stroke. The purpose of this study is to analyze changing trends of stroke epidemiology in South Korea. METHODS: We reviewed retrospectively medical records of 1,124 cases diagnosed as stroke among 54,534 patients who visited the Emergency Medical Center at our hospital from January 1994 to December 1996 (Group A). Also, we evaluated 1,705 cases diagnosed as stroke among 55,381 patients who visited to the same hospital from January 2003 to December 2005 (Group B). The variable features of stroke, such as age, sex, seasonal variation and distribution of stroke subtypes were studied by comparing group A with B. RESULTS: In group A, hemorrhagic stroke (67.9%) was more prevalent than ischemic stroke (32.1%). However, group B showed that the ratio of hemorrhagic stroke (40.3%) to ischemic stroke (59.6%) has been reversed. The highest incidence of stroke was noted in their sixties and seventies of age in group B, which was older than that of group A. In group A, male ischemic stroke (IS) patients outnumbered female patients (1.26:1). Moreover, this gender disproportion became higher in group B (1.53:1). In group A, the number of male intracerebral hermorrhage (ICH) patients were similar to that of female patients (0.97:1). However, male ICH patients outnumbered female patients in group B (1.23:1). As for subarachnoid hemorrhage (SAH), female patients outnumbered male patients more than two-fold in both groups. Both groups showed that the occurrence of ischemic stroke was highest in summer, but that of hemorrhagic stroke was the highest in winter. CONCLUSION: This study showed the changing trends of stroke in its distribution of subtypes. Multicenter prospective study using stroke registry would be required for the determination of national epidemiologic trends.

Predisposing Factors Related to Shunt-Dependent Chronic Hydrocephalus after Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE: Hydrocephalus is a common sequelae of aneurysmal subarachnoid hemorrhage (SAH) and patients who develop hydrocephalus after SAH typically have a worse prognosis than those who do not. This study was designed to identify factors predictive of shunt-dependent chronic hydrocephalus among patients with aneurysmal SAH, and patients who require permanent cerebrospinal fluid diversion. METHODS: Seven-hundred-and-thirty-four patients with aneurysmal SAH who were treated surgically between 1990 and 2006 were retrospectively studied. Three stages of hydrocephalus have been categorized in this paper, i.e., acute (0-3 days after SAH), subacute (4-13 days after SAH), chronic (> or =14 days after SAH). Criteria indicating the occurrence of hydrocephalus were the presence of significantly enlarged temporal horns or ratio of frontal horn to maximal biparietal diameter more than 30% in computerized tomography. RESULTS: Overall, 66 of the 734 patients (8.9%) underwent shunting procedures for the treatment of chronic hydrocephalus. Statistically significant associations among the following factors and shunt-dependent chronic hydrocephalus were observed. (1) Increased age (p < 0.05), (2) poor Hunt and Hess grade at admission (p < 0.05), (3) intraventricular hemorrhage (p < 0.05), (4) Fisher grade III, IV at admission (p < 0.05), (5) radiological hydrocephalus at admission (p < 0.05), and (6) post surgery meningitis (p < 0.05) did affect development of chronic hydrocephalus. However the presence of intracerebral hemorrhage, multiple aneurysms, vasospasm, and gender did not influence on the development of shunt-dependent chronic hydrocephalus. In addition, the location of the ruptured aneurysms in posterior cerebral circulation did not correlate with the development of shunt-dependent chronic hydrocephalus. CONCLUSION: Hydrocephalus after aneurysmal SAH seems to have a multifactorial etiology. Understanding predisposing factors related to the shunt-dependent chronic hydrocephalus may help to guide neurosurgeons for better treatment outcomes.

The Role of Aquaporin-4 in Cerebral Edema Formation after Focal Cerebral Ischemia in Rats

OBJECTIVE: To elucidate the role of aquaporin-4(AQP4) in cerebral edema formation, we studied the expression and subcellular localization of AQP4 in astrocytes after focal cerebral ischemia. METHODS: Cerebral ischemia were induced by permanent middle cerebral artery(MCA) occlusion in rats and estimated by the discoloration after triphenyltetrazolium chloride(TTC) immersion. Change of AQP4 expression were evaluated using western blot. Localization of AQP4 was assessed by confocal microscopy and its interaction with alpha-syntrophin was analyzed by immunoprecipitation. RESULTS: After right MCA occlusion, the size of infarct and number of apoptotic cells increased with time. The ratio of GluR1/GluR2 expression also increased during ischemia. The polarized localization of AQP4 in the endfeet of astrocytes contacting with ventricles, vessels and pia mater was changed into the diffuse distribution in cytoplasm. The interactions of AQP4 and Kir with alpha-syntrophin, an adaptor of dystrophin complex, were disrupted by cerebral ischemia. CONCLUSION: The deranged spatial buffering function of astrocytes due to mislocalized AQP4/Kir4.1 channel as well as increased assembly of Ca2+ permeable AMPA receptors might contribute to the development of edema formation and the excitotoxic neuronal cell death during ischemia.

Elastin Degradation and Collagen III Deficiency in the Superficial Temporal Arteries of Patients with Intracranial Aneurysms

OBJECTIVE: We present the difference of histopathologic changes of the internal elastic lamina (IEL) and collagen III in the superficial temporal artery (STA) between aneurysmal patients and non-aneurysmal patients. Also, the pathologic data with clinical features by comparative methods to validate the risk factor of the intracranial aneurysm are presented. METHODS: Samples of the STA were harvested form 38 patients including aneurysmal and non-aneurysmal patients undergoing craniotomy. Paraffin-embedded sections were examined, using hematoxylin and eosin, van Giebson and mouse anti-collagen III staining techniques. Histopathological observations were analysed and correlated with clinical features such as presence of aneurysm, hypertension, age, and sex. RESULTS: Twenty-seven patients had the intracranial aneurysm. Of these 24 patients were 50 years old or older. Nineteen patients had a history of hypertension. Twenty patients were female. Histopathological study demostrated the derangement of IEL and the deficiency of type III collagen were prominent in aneurysmal patients (p<0.05). Fifty years old or older patients did not show correlation with the deficiency of type III collagen, but with the derangement of IEL (p<0.05). The female sex was not correlated with the derangement of IEL but with the deficiency of type III collagen (p<0.05). However, Hypertension was not correlated with these pathologic data. CONCLUSION: Patients with intracranial aneurysms have severe histopathologic changes of the arterial wall showing the derangement of IEL and the deficiency of type III collagen. In the clinico-pathologic study, the advanced age and female sex were considered as risk factors of the intracranial aneurysm.

Endothelial Cell Products as a Key Player in Hypoxia-Induced Nerve Cell Injury after Stroke

OBJECTIVE: Activated endothelial cells mediate the cascade of reactions in response to hypoxia for adaptation to the stress. It has been suggested that hypoxia, by itself, without reperfusion, can activate the endothelial cells and initiate complex responses. In this study, we investigated whether hypoxia-induced endothelial products alter the endothelial permeability and have a direct cytotoxic effect on nerve cells. METHODS: Hypoxic condition of primary human umbilical vein endothelial cells(HUVEC) was induced by CoCl2 treatment in culture medium. Cell growth was evaluated by 3,4,5-dimethyl thiazole-3,5-diphenyl tetrazolium bromide (MTT) assay. Hypoxia-induced products (IL-1beta, TGF-beta1, IFN-gamma, TNF-alpha, IL-10, IL-6, IL-8, MCP-1 and VEGF) were assessed by enzyme-linked immunosorbent assay. Endothelial permeability was evaluated by Western blotting. RESULTS: Prolonged hypoxia caused endothelial cells to secrete IL-6, IL-8, MCP-1 and VEGF. However, the levels of IL-1, IL-10, TNF-alpha, TGF-beta, IFN-gamma and nitric oxide remained unchanged over 48 h hypoxia. Hypoxic exposure to endothelial cells induced the time-dependent down regulation of the expression of cadherin and catenin protein. The conditioned medium taken from hypoxic HUVECs had the cytotoxic effect selectively on neuroblastoma cells, but not on astroglioma cells. CONCLUSION: These results suggest the possibility that endothelial cell derived cytokines or other secreted products with the increased endothelial permeability might directly contribute to nerve cell injury followed by hypoxia.