High residual platelet reactivity (HRPR) for adenosine diphosphate (ADP) stimuli is a determinant factor for long-term outcomes in acute ischemic stroke with anti-platelet agents: The meaning of HRPR after ADP might be more prominent in large atherosclerotic infarction than other subtypes of AIS.

High residual platelet activation (HRPA) after ADP stimuli has associated with recurrent vascular events in acute atherothrombosis with the use of antiplatelet agents (APAs). However, there has been little evidence supporting this association in acute ischemic stroke (AIS). In this study, we evaluated the influences of HRPR after ADP stimuli on the 1-year incidence of recurrent cardiovascular events and mortality in AIS with APAs. We conducted an observational, referral center cohort study on 968 AIS patients with APAs from January 2010 to December 2013 who were evaluated using optical platelet aggregometry (OPA). All patients received the dual APA combination of aspirin and clopidogrel or aspirin alone. We evaluated their platelet function 5 days after hospital admission using OPA. HRPR after ADP stimuli was defined as platelet aggregation of 70 % or greater according to OPA after 10 µM ADP stimuli. The primary endpoint was a composite of all causes of death, myocardial infarction, and stroke at the 1-year follow-up. The secondary endpoints were each component of the primary endpoint. The event rate of primary endpoint was 11.3 % (109/968). Its rate was significantly higher in the patients with HRPR (16.7 %) than in those without (9.7 %). HPRP was independently associated with the primary endpoint (OR = 1.97, CI 1.22-3.18, p < 0.01). According to the AIS subtype, the presence of HRPR was independently significant for the occurrence of the primary endpoint in the large artery atherosclerosis (LAA) subtype only (OR = 2.26, CI 1.15-4.45, p = 0.02). In this study, the presence of HRPR after ADP stimuli is associated with a poor long-term outcome after acute ischemic stroke. In particular, the influence of this factor might be more prominent in LAA compared with other types of AIS.

Impact of Prehospital Intervention on Delay Time to Thrombolytic Therapy in a Stroke Center with a Systemized Stroke Code Program.

BACKGROUND: The use of emergency medical services (EMS) and notification to hospitals by paramedics for patients with suspected stroke are crucial determinants in reducing delay time to acute stroke treatment. The aim of this study is to investigate whether EMS use and prehospital notification (PN) can shorten the time to thrombolytic therapy in a stroke center with a systemized stroke code program. METHODS: Beginning in January 2012, stroke experts in our stroke center received direct calls via mobile phone from paramedics prenotifying the transport of patients with suspected stroke. We compared baseline characteristics and prehospital/in-hospital delay time in stroke patients treated with intravenous recombinant tissue plasminogen activator for 44 months with and without EMS use and/or PN. RESULTS: Intravenous thrombolytic therapy was performed on 274 patients. Of those patients, 215 (78.5%) were transported to the hospital via EMS and 59 (21.5%) were admitted via private modes of transportation. The patients who used EMS had shorter median onset-to-arrival times (62 minutes versus 116 minutes, P < .001). There was no difference in in-hospital delay time between the 2 groups. In 28 cases (13%) of EMS transport, EMS personnel called the clinical staff to notify the incoming patient. Prenotification by EMS was associated with shorter median door-to-imaging time (9 minutes versus 12 minutes, P = .045) and door-to-needle time (20 minutes versus 29 minutes, P = .011). CONCLUSIONS: We found that EMS use reduces prehospital delay time. However, EMS use without prenotification does not shorten in-hospital processing time in a stroke center with a systemized stroke code program.

A systemized stroke code significantly reduced time intervals for using intravenous tissue plasminogen activator under magnetic resonance imaging screening.

BACKGROUND: A stroke code can shorten time intervals until intravenous tissue plasminogen activator (IV t-PA) treatment in acute ischemic stroke (AIS). Recently, several reports demonstrated that magnetic resonance imaging (MRI)-based thrombolysis had reduced complications and improved outcomes in AIS despite longer processing compared with computed tomography (CT)-based thrombolysis. METHODS: In January 2009, we implemented CODE RED, a computerized stroke code, at our hospital with the aim of achieving rapid stroke assessment and treatment. We included patients with thrombolysis from January 2007 to December 2008 (prestroke code period) and from January 2009 to May 2013 (poststroke code period). The IV t-PA time intervals and 90-day modified Rankin Scale (mRS) scores were collected. RESULTS: During the observation period, 252 patients used IV t-PA under the CODE RED (MRI based: 208; CT based: 44). The remaining 71 patients (MRI based: 53; CT based: 18) received it before the implementation of our stroke code. After implementation of CODE RED, door-to-image time, door-to-needle time, and the onset-to-needle time were significantly reduced by 11, 18, and 22 minutes in MRI-based thrombolysis. Particularly, the proportion of favorable outcome (mRS score 0-2) was significantly increased (from 41.5% to 60.1%, P = .02) in poststroke than in prestroke code period in MRI-based thrombolysis. However, in ordinal regression, the presence of stroke code showed just a trend for favorable outcome (odds ratio, .99-2.87; P = .059) at 90 days of using IV t-PA after correction of age, sex, and National Institutes of Health Stroke Scale. CONCLUSIONS: In this study, we demonstrated that a systemized stroke code shortened time intervals for using IV t-PA under MRI screening. Also, our results showed a possibility that a systemized stroke code might enhance the efficacy of MRI-based thrombolysis. In the future, we need to carry out a more detailed prospective study about this notion.

Adenosine diphosphate-induced platelet aggregation might contribute to poor outcomes in atrial fibrillation-related ischemic stroke.

Systemic atherosclerosis is involved in ischemic damages and cardioembolism after atrial fibrillation (AF)-related ischemic stroke (IS). Platelet activation is a critical factor in systemic atherosclerosis; however, there is little information regarding the role of platelet activation on the outcome of AF-related IS. We investigated the relationship between adenosine diphosphate (ADP)-induced platelet aggregation and the long-term outcomes of AF-related IS. We studied 249 patients who were exclusively treated with anticoagulation therapy after they had experienced AF-related IS. We evaluated their platelet function 5 days after admission to the hospital by using an optic platelet aggregometer test. We also assessed the prognoses of patients 90 days after the AF-related IS. Our results showed that ADP-induced platelet aggregation was positively correlated with CHA2DS2-VASc scores (r = .285, P < .01). Totally, 107 (43.0%) patients had a poor outcome at 90 days after IS. Univariate analysis showed that the following factors significantly contribute to a poor outcome: older age (odds ratio [OR] = 1.07, confidence interval [CI] 1.04-1.10, P < .01), a history of stroke (OR = 3.24, CI 1.61-6.53, P < .01), high scores on the National Institutes of Health Stroke Scale (NIHSS; OR = 1.25, CI 1.18-1.32, P < .01), increased white blood cell counts (OR = 1.12, CI 1.02-1.24, P < .01), high CHA2DS2-VASc scores (≥5, OR = 7.31, CI 3.36-15.93, P = .025), and the highest tertile of ADP-induced platelet aggregation (≥72%, OR = 3.17, CI 1.67-5.99, P < .01). Of these factors, high NIHSS scores (OR = 1.27, CI 1.20-1.36, P < .01), high CHA2DS2-VASc scores (OR = 4.69, CI 1.21-18.14, P = .03), and the highest tertile of ADP-induced platelet aggregation (OR = 2.49, CI 1.17-5.27, P = .02) were independently associated with a poor outcome at 90 days after IS. Therefore, our results suggest that platelet activation might affect the outcome of AF-related IS.

Outcomes after tissue plasminogen activator administration under the drip and ship paradigm may differ according to the regional stroke care system.

The drip and ship paradigm for stroke patients enhances the rate of using intravenous tissue plasminogen activator (IVT) in community hospitals. The safety and outcomes of patients treated with IVT for acute ischemic stroke (AIS) under the drip and ship paradigm were compared with patients directly treated at a comprehensive stroke center in the Busan metropolitan area of Korea. This was a retrospective study of patients with AIS treated with IVT between January 2009 and January 2012. Information on patients' baseline characteristics, neuroimaging, symptomatic intracerebral hemorrhage (sICH), and outcome 90 days after using IVT was obtained from our stroke registry. We surveyed stroke neurologists regarding their pattern of post-thrombolysis care. During the observation periods, we selected 317 patients using IVT. Among these, 239 patients received IVT at our stroke center, and 78 were treated at 21 community hospitals under the drip and ship paradigm. Initial neurologic deficits and the size of ischemic lesions on magnetic resonance imaging were much more severe in patients treated with IVT under the drip and ship paradigm compared with patients treated at our comprehensive stroke center. The prevalence of a poor outcome (modified Rankin Scale score 3-6) 90 days after IVT was much higher in patients treated with the drip and ship paradigm than in those treated at our comprehensive stroke center. Regarding the occurrence of sICH, there was no significant difference between the 2 groups. The clinical characteristics and outcomes after using IVT under the drip and ship paradigm may differ greatly among stroke care systems.

Reduced rCBV ratio in perfusion-weighted MR images predicts poor outcome after thrombolysis in acute ischemic stroke.

Recent research has suggested that a perfusion-weighted image (PWI) relative cerebral blood volume (rCBV) map after acute ischemic stroke (AIS) provides information about the collateral circulation in the ischemic region. In this study, we demonstrate the usefulness of the rCBV ratio in PWI in predicting poor outcome after using IV t-PA in AIS. We recruited 58 stroke patients who were treated with IV t-PA after diagnostic magnetic resonance imaging (MRI). Poor outcome was defined as a Modified Rankin Scale (mRS) score >2 measured 90 days after ischemic insult. In total, 21 patients (36.2%) demonstrated poor outcome (i.e. mRS score 3-6). Poor outcome after t-PA correlated with age (p = 0.03), serum glucose level (p = 0.01), NIHSS (p = 0.05), and the presence of T-occlusion (p = 0.05). Poor outcome also correlated with diffusion-weighted MR images of the lesion volume (p < 0.01), lower rCBV ratio on PWI (p < 0.01), and non-recanalization (p < 0.01). Among these, non-recanalization (p < 0.01), reduced rCBV ratio on PWI (p < 0.01), age (p = 0.04), and serum glucose level (p = 0.01) had an independent significance for predicting it. This suggests that the rCBV ratio on PWI may be used to determine prognosis after thrombolysis in AIS.

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.

Patient Selection and Clinical Efficacy of Urgent Superficial Temporal Artery-Middle Cerebral Artery Bypass in Acute Ischemic Stroke Using Advanced Magnetic Resonance Imaging Techniques.

BACKGROUND: Selected patients with acute ischemic stroke might benefit from superficial temporal artery-middle cerebral artery (STA-MCA) bypass, but the indications for urgent STA-MCA bypass are unknown. OBJECTIVE: To report our experiences of urgent STA-MCA bypass in patients requiring urgent reperfusion who were ineligible for other reperfusion therapies, using advanced magnetic resonance imaging (MRI) techniques. METHODS: The inclusion criteria for urgent STA-MCA bypass were as follows: acute infarct volume <70 mL with a ratio of perfusion/diffusion lesion volume ≥1.2, and a regional cerebral blood volume ratio >0.85. From January 2013 to October 2015, 21 urgent STA-MCA bypass surgeries were performed. The control group included 19 patients who did not undergo bypass surgery mainly due to refusal of surgery or the decision of the neurologist. Clinical and radiological data were compared between the surgery and control group. RESULTS: The median age of the control group (70 years, interquartile range [IQR] 58-76) was higher than that of the surgery group (62 years, IQR 49-66), but the median preoperative diffusion and perfusion lesion volumes of the surgery group (13.8 mL, IQR 7.5-26.0 and 120.9 mL, IQR 84.9-176.0, respectively) were higher than those of the control group (5.6 mL, IQR 2.1-9.1 and 69.7 mL, IQR 23.9-125.3, respectively). Sixteen (76.2%) patients in the surgery group and 2 (10.5%) patients in the control group had favorable outcomes ( P < .001). Logistic regression analysis identified bypass surgery as the strongest predictive factor. CONCLUSION: STA-MCA bypass can be used as a therapeutic tool for acute ischemic stroke. Advanced MRI techniques are helpful for selecting patients and for decision making.

Relative CBV ratio on perfusion-weighted MRI indicates the probability of early recanalization after IV t-PA administration for acute ischemic stroke.

BACKGROUND: We hypothesized that the relative cerebral blood volume (rCBV) ratio on perfusion-weighted imaging (PWI) using MRI might serve as a predictor of early recanalization (ER) after intravenous tissue plasminogen activator (IV t-PA) administration for acute ischemic stroke. METHODS: Patients with acute middle cerebral artery (MCA) ischemic stroke (IS) were enrolled in the study. They were evaluated by MRI, including PWI and diffusion-weighted imaging, before administration of IV t-PA and underwent digital subtraction angiography (DSA) of the brain within 2 h after t-PA administration. We compared the rCBV ratio on PWI between patients with and without ER on DSA and investigated the proportion of patients with an excellent outcome at 90 days after t-PA administration (modified Rankin Scale score 0-1) among those with and without ER. RESULTS: 85 patients with acute MCA IS were included; 16 patients (18.8%) experienced ER on DSA after IV t-PA administration. Patients with ER more frequently had an excellent outcome at 90 days than those without ER. The rCBV ratio on PWI was higher in the ER group (1.01±0.21, p<0.01) than in the non-ER group (0.82±0.18). After adjusting for the presence of atrial fibrillation and the serum glucose level, the rCBV ratio on PWI (OR 1.07; 95% CI 1.02 to 1.12; p<0.01) was a significant independent indicator of ER. CONCLUSIONS: The results of this study suggest that the rCBV ratio on PWI might serve as a useful indicator of ER after IV t-PA administration.

Prognostic factors for long-term poor outcomes after acute ischemic stroke in very old age (>80 years) patients: Total cholesterol level might differently influence long-term outcomes after acute ischemic stroke at ages above 80 years.

AIM: We investigated the differences in determinant factors for functional outcomes between patients aged >80 years and those aged <80 years after acute ischemic stroke (AIS). In particular, we would like to know the differential impacts of initial total cholesterol (TC) levels between the two groups. METHODS: We defined a poor outcome as 3-6 modified Rankin Scale 90 days after AIS. RESULTS: In the present study, 2772 participants were enrolled. Among them, 374 patients (13.5%) were aged >80 years, and 1061 patients had a poor outcome 90 days after AIS. The proportion was significantly higher in patients aged >80 years than in those aged <80 years after AIS. Regarding factors relating to poor outcomes, previous history of stroke, stroke severity and stroke subtypes of ischemic stroke were independent factors in patients aged <80 years, and the stroke severity and initial TC level independently influenced the outcome for patients aged >80 years. In particular, risk of poor outcome adjusted for age, stroke severity and subtypes of ischemic stroke for patients (OR [95% CI]) in the first quartile range (≤157 mg%) were 2.21 (1.06-4.62), in the third quartile range (184-210 mg%) 2.76 (1.27-6.01) and in the fourth quartile range (≥211 mg%) 2.75 (1.21-6.24) compared with those in the second quartile range (158-183 mg%) in patients aged >80 years. CONCLUSIONS: There were also some differences in related factors regarding occurrences of poor outcome between the two groups. In particular, the initial TC level might play a crucial role for the outcome after AIS in the very old population.

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 ≤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 ≥ 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 mm(2), and the corresponding size of the non-recanalization group was 53.38 ± 24.77 mm(2) (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 mm(2). 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.

Direct access to a hospital offering intravenous thrombolysis therapy improves functional outcome of acute ischemic stroke patients.

Referral from other hospitals is one of the primary causes of delayed thrombolysis therapy after acute ischemic stroke (AIS). We aimed to evaluate whether direct access to a hospital offering intravenous thrombolysis therapy was associated with good functional outcome in AIS patients treated with thrombolysis. We enrolled patients who received intravenous thrombolysis within 3 hours of symptom onset at our stroke center. We divided these patients into two groups: those with a direct admission to our stroke center and those with indirect admission by referral from other community hospitals. We investigated onset-to-door time and onset-to-recombinant tissue plasminogen activator (rtPA) time according to admission mode. We then assessed the association between a direct admission and favorable outcome at 90 days. A total of 232 patients (mean age of 66.6 years, median National Institutes of Health Stroke Scale score of 10) were included. A total of 48.7% of AIS patients treated with intravenous thrombolytic therapy were transferred from other hospitals. Patients who were directly admitted to our stroke center had a shorter onset-to-door time (61 versus 120 minutes, p<0.001) and onset-to-rtPA time (103 versus 155 minutes, p<0.001) than those referred from other hospitals. Direct admission was associated with a good outcome with an odds ratio of 2.03 (95% confidence interval 1.051-3.917, p=0.035), after adjusting for baseline variables. Thrombolysis after direct admission to a hospital offering intravenous thrombolysis therapy could shorten onset-to-rtPA time and improve stroke outcome in patients with AIS.

The rCBV ratio on perfusion-weighted imaging reveals the extent of blood flow on conventional angiography after acute ischemic stroke.

OBJECTIVE: In this study, we evaluated the relationship between the rCBV (regional cerebral blood flow volume) ratio on perfusion-weighted imaging (PWI) and the extent of collateral flow on conventional angiography. METHODS: We recruited 98 patients with AIS (within 24h after ischemic events). All the patients were evaluated by MRI, including PWI and diffusion-weighted imaging (DWI), and underwent digital subtraction angiography (DSA) of the brain. We hypothesized that the rCBV ratio on PWI could reveal the extent of the blood flow and predict early neurological deterioration (END) within 7 days after AIS. RESULTS: The rCBV ratio on PWI was significantly correlated with its extent on DSA (p<0.01). During the observation period, 24 patients (24.5%) experienced END. The univariate analysis revealed that severe neurological deficit at admission (p<0.01), the volume of the ischemic lesion on DWI (p<0.01), poor blood flow on DSA (p<0.01), the presence of DPM (p=0.05) and a low rCBV ratio on PWI (p<0.01) were related to END occurrence. The multivariate analysis showed that the presence of a low rCBV ratio on PWI was independently significant as a correlate of END (OR, 5.64; 95% CI, 1.68-18.90; p<0.01). CONCLUSION: This study shows that the rCBV ratio on PWI may be a useful tool to reveal the status of blood flow after AIS. Moreover, the extent of collateral flow may be an important parameter that subtly influences the fate of DPM in AIS.

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.

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.

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

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.

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 < 0.001, p = 0.007). Age (≥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.