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Background@#and Purpose The accurate prediction of functional outcomes in patients with acute ischemic stroke (AIS) is crucial for informed clinical decision-making and optimal resource utilization. As such, this study aimed to construct an ensemble deep learning model that integrates multimodal imaging and clinical data to predict the 90-day functional outcomes after AIS. @*Methods@#We used data from the Korean Stroke Neuroimaging Initiative database, a prospective multicenter stroke registry to construct an ensemble model integrated individual 3D convolutional neural networks for diffusion-weighted imaging and fluid-attenuated inversion recovery (FLAIR), along with a deep neural network for clinical data, to predict 90-day functional independence after AIS using a modified Rankin Scale (mRS) of 3–6. To evaluate the performance of the ensemble model, we compared the area under the curve (AUC) of the proposed method with that of individual models trained on each modality to identify patients with AIS with an mRS score of 3–6. @*Results@#Of the 2,606 patients with AIS, 993 (38.1%) achieved an mRS score of 3–6 at 90 days post-stroke. Our model achieved AUC values of 0.830 (standard cross-validation [CV]) and 0.779 (time-based CV), which significantly outperformed the other models relying on single modalities: b-value of 1,000 s/mm2 (P<0.001), apparent diffusion coefficient map (P<0.001), FLAIR (P<0.001), and clinical data (P=0.004). @*Conclusion@#The integration of multimodal imaging and clinical data resulted in superior prediction of the 90-day functional outcomes in AIS patients compared to the use of a single data modality.
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Ischemic stroke associated with pituitary apoplexy is an extremely rare but devastating complication. Arterial stenosis or occlusion due to direct compression secondary to acute expansion of the hemorrhagic pituitary adenoma may induce ischemic stroke. In case of presentation of diffusion-perfusion or diffusion-clinical mismatch, urgent tumor resection to decompress the involved arteries should be performed to salvage ischemic penumbra. If emergent surgery is not possible, other therapeutic options are needed to prevent the progression of cerebral ischemia. Herein, we report the case of successful revascularization achieved in a patient with ischemic stroke who underwent balloon angioplasty and stent placement for the non-atherosclerotic steno-occlusion of intracranial internal carotid artery due to pituitary apoplexy.
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Background@#and Purpose We aimed to develop a model predicting early recanalization after intravenous tissue plasminogen activator (t-PA) treatment in large-vessel occlusion. @*Methods@#Using data from two different multicenter prospective cohorts, we determined the factors associated with early recanalization immediately after t-PA in stroke patients with large-vessel occlusion, and developed and validated a prediction model for early recanalization. Clot volume was semiautomatically measured on thin-section computed tomography using software, and the degree of collaterals was determined using the Tan score. Follow-up angiographic studies were performed immediately after t-PA treatment to assess early recanalization. @*Results@#Early recanalization, assessed 61.0±44.7 minutes after t-PA bolus, was achieved in 15.5% (15/97) in the derivation cohort and in 10.5% (8/76) in the validation cohort. Clot volume (odds ratio [OR], 0.979; 95% confidence interval [CI], 0.961 to 0.997; P=0.020) and good collaterals (OR, 6.129; 95% CI, 1.592 to 23.594; P=0.008) were significant factors associated with early recanalization. The area under the curve (AUC) of the model including clot volume was 0.819 (95% CI, 0.720 to 0.917) and 0.842 (95% CI, 0.746 to 0.938) in the derivation and validation cohorts, respectively. The AUC improved when good collaterals were added (derivation cohort: AUC, 0.876; 95% CI, 0.802 to 0.950; P=0.164; validation cohort: AUC, 0.949; 95% CI, 0.886 to 1.000; P=0.036). The integrated discrimination improvement also showed significantly improved prediction (0.097; 95% CI, 0.009 to 0.185; P=0.032). @*Conclusions@#The model using clot volume and collaterals predicted early recanalization after intravenous t-PA and had a high performance. This model may aid in determining the recanalization treatment strategy in stroke patients with large-vessel occlusion.
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Background and Objectives@#Prior studies have shown that stroke patients treated with percutaneous left atrial appendage occlusion (LAAO) for non-valvular atrial fibrillation (NVAF) experience better outcomes than similar patients treated with warfarin. We investigated the impact of percutaneous left atrial appendage closure on post-stroke neurological outcomes in NVAF patients, compared with non-vitamin K antagonist oral anticoagulant (NOAC) therapy. @*Methods@#Medical records for 1,427 patients in multiple registries and for 1,792 consecutive patients at 6 Korean hospitals were reviewed with respect to LAAO or NOAC treatment.Stroke severity in patients who experienced ischemic stroke or transient ischemic attack after either treatment was assessed with modified Rankin Scale (mRS) scoring at hospital discharge and at 3 and 12 months post-stroke. @*Results@#mRS scores were significantly lower in LAAO patients at 3 (p<0.01) and 12 months (p<0.01) post-stroke, despite no significant differences in scores before the ischemic cerebrovascular event (p=0.22). The occurrences of disabling ischemic stroke in the LAAO and NOAC groups were 36.7% and 44.2% at discharge (p=0.47), 23.3% and 44.2% at 3 months post-stroke (p=0.04), and 13.3% and 43.0% at 12 months post-stroke (p=0.01), respectively.Recovery rates for disabling ischemic stroke at discharge to 12 months post-stroke were significantly higher for LAAO patients (50.0%) than for NOAC patients (5.6%) (p<0.01). @*Conclusions@#Percutaneous LAAO was associated with more favorable neurological outcomes after ischemic cerebrovascular event than NOAC treatment.
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Background@#and Purpose We aimed to develop a model predicting early recanalization after intravenous tissue plasminogen activator (t-PA) treatment in large-vessel occlusion. @*Methods@#Using data from two different multicenter prospective cohorts, we determined the factors associated with early recanalization immediately after t-PA in stroke patients with large-vessel occlusion, and developed and validated a prediction model for early recanalization. Clot volume was semiautomatically measured on thin-section computed tomography using software, and the degree of collaterals was determined using the Tan score. Follow-up angiographic studies were performed immediately after t-PA treatment to assess early recanalization. @*Results@#Early recanalization, assessed 61.0±44.7 minutes after t-PA bolus, was achieved in 15.5% (15/97) in the derivation cohort and in 10.5% (8/76) in the validation cohort. Clot volume (odds ratio [OR], 0.979; 95% confidence interval [CI], 0.961 to 0.997; P=0.020) and good collaterals (OR, 6.129; 95% CI, 1.592 to 23.594; P=0.008) were significant factors associated with early recanalization. The area under the curve (AUC) of the model including clot volume was 0.819 (95% CI, 0.720 to 0.917) and 0.842 (95% CI, 0.746 to 0.938) in the derivation and validation cohorts, respectively. The AUC improved when good collaterals were added (derivation cohort: AUC, 0.876; 95% CI, 0.802 to 0.950; P=0.164; validation cohort: AUC, 0.949; 95% CI, 0.886 to 1.000; P=0.036). The integrated discrimination improvement also showed significantly improved prediction (0.097; 95% CI, 0.009 to 0.185; P=0.032). @*Conclusions@#The model using clot volume and collaterals predicted early recanalization after intravenous t-PA and had a high performance. This model may aid in determining the recanalization treatment strategy in stroke patients with large-vessel occlusion.
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Background and Objectives@#Prior studies have shown that stroke patients treated with percutaneous left atrial appendage occlusion (LAAO) for non-valvular atrial fibrillation (NVAF) experience better outcomes than similar patients treated with warfarin. We investigated the impact of percutaneous left atrial appendage closure on post-stroke neurological outcomes in NVAF patients, compared with non-vitamin K antagonist oral anticoagulant (NOAC) therapy. @*Methods@#Medical records for 1,427 patients in multiple registries and for 1,792 consecutive patients at 6 Korean hospitals were reviewed with respect to LAAO or NOAC treatment.Stroke severity in patients who experienced ischemic stroke or transient ischemic attack after either treatment was assessed with modified Rankin Scale (mRS) scoring at hospital discharge and at 3 and 12 months post-stroke. @*Results@#mRS scores were significantly lower in LAAO patients at 3 (p<0.01) and 12 months (p<0.01) post-stroke, despite no significant differences in scores before the ischemic cerebrovascular event (p=0.22). The occurrences of disabling ischemic stroke in the LAAO and NOAC groups were 36.7% and 44.2% at discharge (p=0.47), 23.3% and 44.2% at 3 months post-stroke (p=0.04), and 13.3% and 43.0% at 12 months post-stroke (p=0.01), respectively.Recovery rates for disabling ischemic stroke at discharge to 12 months post-stroke were significantly higher for LAAO patients (50.0%) than for NOAC patients (5.6%) (p<0.01). @*Conclusions@#Percutaneous LAAO was associated with more favorable neurological outcomes after ischemic cerebrovascular event than NOAC treatment.
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@#Background: Early neurological deterioration is a critical determinant of functional outcome in patients with acute minor ischemic stroke. This study aimed to identify clinical predictors of early neurological deterioration in patients with acute minor ischemic stroke. Methods: A total of 739 patients who experienced acute minor ischemic stroke symptoms between January 2014 and December 2018 were enrolled in this study. All patients were presented within a 4.5-hour time window of stroke symptom onset. Early neurological deterioration was defined as an increment of at least one point in motor power or total National Institute of Health Stroke Scale (NIHSS) score deterioration ≥ 2 points within 3 days after admission. Unfavorable functional outcome was defined as a modified Rankin Scale score of ≥ 2 at 90 days after stroke onset. Demographic characteristics, risk factors for vascular diseases, stroke severity, stroke subtypes, and neuroimaging parameters were analyzed. Regression analysis was used to determine clinical predictors of early neurological deterioration. Results: Of the 739 patients, 78 (10.5%) patients had early neurological deterioration. Among the 78 patients with early neurological deterioration, 61 (78.2%) had unfavorable functional outcome at 90 days after stroke onset. In contrast, 131 of the remaining 661 (19.8%) patients without early neurological deterioration had unfavorable functional outcome. Multivariate analysis identified hemorrhagic transformation (odds ratio, 3.8; 95% confidence interval, 1.4-10.5; P = 0.010), higher NIHSS score at admission (odds ratio, 1.4; 95% confidence interval, 1.1-1.7; P = 0.003), arterial stenosis (odds ratio, 2.0; 95% confidence interval, 1.2-3.5; P = 0.014) and occlusion (odds ratio, 2.6; 95% confidence interval, 1.4-4.8; P = 0.004) in the territory of stroke as significant predictors of early neurological deterioration. Conclusions: The results of this study suggest that hemorrhagic transformation, higher NIHSS score at admission, and arterial steno-occlusive lesions in the territory of stroke are independent predictors of early neurological deterioration in patients with acute minor ischemic stroke.
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PURPOSE@#Many traumatic patients die from sepsis and multiple organ failure. Early recognition of post-traumatic sepsis in traumatic patients will help improve the prognosis. Recently, procalcitonin (PCT), macrophage migration inhibitory factor (MIF), and lactic acid have emerged as predictive factors. Our study aims to explore the significance of PCT, MIF and lactic acid as a predictor of posttraumatic-sepsis in trauma patients.@*METHODS@#This study was conducted on prospective observational study patients who visited an emergency medical center in a university hospital from March 2014 to February 2016. We measured the white blood cells, c-reactive protein (CRP), lactic acid, PCT, and MIF with serum taken from the patient's blood within 1 hour of the occurrence of the trauma. The definition of post-traumatic sepsis was defined as being part of systemic inflammation response syndrome criteria with infections within a week.@*RESULTS@#A total of 132 patients were analyzed, wherein 74 patients were included in the low injury severity score (ISS) group (ISS < 15) and 58 patients were included in the high ISS group (ISS ≥15). The mean PCT, MIF, and lactic acid levels were higher in the high ISS group (p < 0.05). Meanwhile, 38 patients were included in the early sepsis group and 94 patients were included in the non-sepsis group. The mean MIF levels were higher in the sepsis group than the non-sepsis group (p < 0.05) and there were no significant differences in the initial CRP, lactic acid, and PCT levels in these two groups.@*CONCLUSIONS@#MIF may be considered as a predictive factor for sepsis in trauma patients.
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PURPOSE: This study was performed to analyze the results from a 2016 three-day emergency medicine camp for premedical students. METHODS: The Public Relations Committee of Korea Emergency Medical Association planned the camp. We sent an official letter to 41 universities to recruit participants and create programs for three days. Questionnaires were prepared and analyzed before and after the camp. RESULTS: A total of 37 participants participated. There were three times more males than females. According to the recognition survey, knowledge (3.4±2.0 vs. 7.2±1.8) and preference (5.4±1.8 vs. 7.4±1.4) after the camp were better than before the camp (p<0.05). In detail, anxiety about funerals (3.5±2.5 vs. 2.4±2.8) and perception of the role (5.8±2.2 vs. 4.5±2.6) were improved (p<0.05). Worries regarding physical and psychological burden and danger were also greatly improved (p<0.05). The mean satisfaction was 8.6 points out of 10 points, according to the general survey. CONCLUSION: The three-day camp increased awareness of emergency medicine and improved their preferences.
Subject(s)
Female , Humans , Male , Anxiety , Education , Emergencies , Emergency Medicine , Korea , Public Relations , Schools, Medical , Students, Premedical , Surveys and QuestionnairesABSTRACT
Anti-Ma2-associated encephalitis is one of the paraneoplastic neurological syndromes. It has been shown to be associated with various neoplasms, mainly testicular, lung, and breast cancers. Most patients with anti-Ma2-associated encephalitis present limbic-diencephalic-brainstem dysfunctions such as seizure, mood disorder, excessive daytime sleepiness, and ophthalmoparesis. Some patients develop symptoms indicating the multifocal involvement of the limbic system, diencephalon, or brainstem. However, there are few case studies of anti-Ma2-associated encephalitis presenting as isolated hypersomnia. We report a case of anti-Ma2-associated encephalitis presenting as hypersomnia.
Subject(s)
Humans , Brain Stem , Breast , Diencephalon , Disorders of Excessive Somnolence , Encephalitis , Limbic System , Lung , Mood Disorders , Ophthalmoplegia , Paraneoplastic Syndromes , SeizuresABSTRACT
PURPOSE: Medical direction is an integral part of proper prehospital care, which is performed by EMS providers. In Gyunggi province, a number of measures have been implemented to improve the direct medical direction system. We aimed to report on the process and results of the newly implemented medical direction system. METHODS: This is a descriptive analysis of the newly implemented medical direction system for community EMS providers from June 2014 to October 2014. Direct medical direction was requested by emergency medical technicians (EMTs) during the study period, as follows: when a destination hospital was selected, EMTs requested medical direction from the physicians at the destination hospital. During the study period specially-trained advanced EMTs were permitted to perform intravenous (IV) access for fluid or glucose infusion without direct medical direction. EMTs were asked to complete records when they requested direct medical direction and performed IV access without medical direction. These records were collected and used in the analysis. RESULTS: Of 5949 direct medical direction requests, 5527 were analyzed; 2958 (53.5%) cases were requested to the destination hospitals, 2569 (46.5%) were requested to the centralized dispatch center. 'Patient evaluation' was the most common reason for EMTs to request medical direction to the destination hospitals (1680, 54.4%) and centralized dispatch center (980, 38.1%). EMTs' degree of satisfaction did not differ significantly between destination hospitals and the centralized dispatch center (4.12+/-0.82 and 4.09+/-0.84, p=0.053). IV access rate for hypotensive patients increased 6.1% during the study period compared to the same period of 2013 (17.6% and 11.5%, p<0.01). CONCLUSION: We found that it is feasible to request direct medical direction to the destination hospitals and perform IV access for fluid or glucose infusion without direct medical direction for specially-trained advanced EMTs. Continuing efforts to establish an optimized medical direction system would be required for proper pre-hospital care.
Subject(s)
Humans , Emergency Medical Service Communication Systems , Emergency Medical Services , Emergency Medical Technicians , Glucose , KoreaABSTRACT
PURPOSE: In this study, we investigated the stroke mechanism and the factors associated with ischemic stroke in patients with nonvalvular atrial fibrillation (NVAF) who were on optimal oral anticoagulation with warfarin. MATERIALS AND METHODS: This was a multicenter case-control study. The cases were consecutive patients with NVAF who developed cerebral infarction or transient ischemic attack (TIA) while on warfarin therapy with an international normalized ratio (INR) > or =2 between January 2007 and December 2011. The controls were patients with NVAF without ischemic stroke who were on warfarin therapy for more than 1 year with a mean INR > or =2 during the same time period. We also determined etiologic mechanisms of stroke in cases. RESULTS: Among 3569 consecutive patients with cerebral infarction or TIA who had NVAF, 55 (1.5%) patients had INR > or =2 at admission. The most common stroke mechanism was cardioembolism (76.0%). Multivariate analysis demonstrated that smoking and history of previous ischemic stroke were independently associated with cases. High CHADS2 score (> or =3) or CHA2DS2-VASc score (> or =5), in particular, with previous ischemic stroke along with > or =1 point of other components of CHADS2 score or > or =3 points of other components of CHA2DS2-VASc score was a significant predictor for development of ischemic stroke. CONCLUSION: NVAF patients with high CHADS2/CHA2DS2-VASc scores and a previous ischemic stroke or smoking history are at high risk of stroke despite optimal warfarin treatment. Some other measures to reduce the risk of stroke would be necessary in those specific groups of patients.
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Anticoagulants/adverse effects , Atrial Fibrillation/complications , Cardiovascular Diseases , Case-Control Studies , Cerebral Infarction/complications , Multivariate Analysis , Risk Factors , Stroke/etiology , Warfarin/adverse effectsABSTRACT
PURPOSE: In this study, we investigated the stroke mechanism and the factors associated with ischemic stroke in patients with nonvalvular atrial fibrillation (NVAF) who were on optimal oral anticoagulation with warfarin. MATERIALS AND METHODS: This was a multicenter case-control study. The cases were consecutive patients with NVAF who developed cerebral infarction or transient ischemic attack (TIA) while on warfarin therapy with an international normalized ratio (INR) > or =2 between January 2007 and December 2011. The controls were patients with NVAF without ischemic stroke who were on warfarin therapy for more than 1 year with a mean INR > or =2 during the same time period. We also determined etiologic mechanisms of stroke in cases. RESULTS: Among 3569 consecutive patients with cerebral infarction or TIA who had NVAF, 55 (1.5%) patients had INR > or =2 at admission. The most common stroke mechanism was cardioembolism (76.0%). Multivariate analysis demonstrated that smoking and history of previous ischemic stroke were independently associated with cases. High CHADS2 score (> or =3) or CHA2DS2-VASc score (> or =5), in particular, with previous ischemic stroke along with > or =1 point of other components of CHADS2 score or > or =3 points of other components of CHA2DS2-VASc score was a significant predictor for development of ischemic stroke. CONCLUSION: NVAF patients with high CHADS2/CHA2DS2-VASc scores and a previous ischemic stroke or smoking history are at high risk of stroke despite optimal warfarin treatment. Some other measures to reduce the risk of stroke would be necessary in those specific groups of patients.
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Anticoagulants/adverse effects , Atrial Fibrillation/complications , Cardiovascular Diseases , Case-Control Studies , Cerebral Infarction/complications , Multivariate Analysis , Risk Factors , Stroke/etiology , Warfarin/adverse effectsABSTRACT
No abstract available.
Subject(s)
Humans , Male , Clomiphene , Infertility , Sinus Thrombosis, IntracranialABSTRACT
The causes of ischemic stroke are widely diverse, ranging from large artery atherosclerosis to cardioembolism, and it is important to use preventive therapy toward the goal reducing the future risk of recurrent ischemic stroke, myocardial infarction, and vascular death. Antithrombotic therapy is one of the fundamental medical approaches for secondary prevention of ischemic stroke, which is broadly divided into two general categories, those that exert their effect via platelet inhibition (antiplatelet agents), and those that influence various factors in the clotting cascade (anticoagulants). In general, the clinical guidelines recommend antiplatelet agents for patients with non-cardioembolic stroke, while anticoagulants is indicated for patients with presumed or proven cardioembolic stroke. Many clinical trials have attempted to test the efficacy and safety of antithrombotics in ischemic stroke. This review will discuss on currently available antithrombotic agents that have demonstrated efficacy for secondary prevention of ischemic stroke.
Subject(s)
Humans , Anticoagulants , Arteries , Atherosclerosis , Blood Platelets , Fibrinolytic Agents , Myocardial Infarction , Platelet Aggregation Inhibitors , Secondary Prevention , StrokeABSTRACT
BACKGROUND AND PURPOSE: Process improvement (PI) is an approach for enhancing the existing quality improvement process by making changes while keeping the existing process. We have shown that implementation of a stroke code program using a computerized physician order entry system is effective in reducing the in-hospital time delay to thrombolysis in acute stroke patients. We investigated whether implementation of this PI could further reduce the time delays by continuous improvement of the existing process. METHODS: After determining a key indicator [time interval from emergency department (ED) arrival to intravenous (IV) thrombolysis] and conducting data analysis, the target time from ED arrival to IV thrombolysis in acute stroke patients was set at 40 min. The key indicator was monitored continuously at a weekly stroke conference. The possible reasons for the delay were determined in cases for which IV thrombolysis was not administered within the target time and, where possible, the problems were corrected. The time intervals from ED arrival to the various evaluation steps and treatment before and after implementation of the PI were compared. RESULTS: The median time interval from ED arrival to IV thrombolysis in acute stroke patients was significantly reduced after implementation of the PI (from 63.5 to 45 min, p=0.001). The variation in the time interval was also reduced. A reduction in the evaluation time intervals was achieved after the PI [from 23 to 17 min for computed tomography scanning (p=0.003) and from 35 to 29 min for complete blood counts (p=0.006)]. CONCLUSIONS: PI is effective for continuous improvement of the existing process by reducing the time delays between ED arrival and IV thrombolysis in acute stroke patients.
Subject(s)
Humans , Blood Cell Count , Emergency Medical Services , Emergency Service, Hospital , Medical Order Entry Systems , Quality Improvement , Statistics as Topic , StrokeABSTRACT
OBJECTIVE: The purpose of this study is to demonstrate the technical feasibility and clinical efficacy of emergent carotid angioplasty and stenting (CAS) for acute stroke due to athero-thrombotic occlusion of the cervical internal carotid artery (ICA). METHODS: Review of medical records identified 17 patients who underwent emergent CAS for treatment of athero-thrombotic occlusion of the cervical ICA with acute stroke between 2009 and 2013. Eleven patients (64.7%) presented with concomitant intracranial artery occlusion, which was treated primarily by mechanical thrombectomy after CAS. RESULTS: Successful revascularization of the cervical ICA with emergent CAS was achieved in all patients. After CAS, intracranial recanalization with Thrombolysis in Cerebral Infarction > or =2b flow was achieved in four of the 11 patients (36.4%). The overall recanalization rate (cervical ICA and intracranial artery) was 10 of 17 patients (58.8%). Symptomatic intracranial hemorrhage occurred in two patients (11.8%), resulting in death. Ten patients (58.8%) showed improvement (decrease in NIHSS score of > or =4 points) at seven days after recanalization. Nine patients (52.9%) showed a favorable outcome (mRS < or =2) at the last follow-up. A favorable outcome (mRS < or =2) was obtained in four of the six patients with isolated cervical ICA occlusion (4/6, 66.7%) and five of 11 patients with intracranial tandem occlusion (5/11, 45.5%). CONCLUSION: Emergent CAS for acute stroke due to athero-thrombotic occusion of the cervical ICA showed a good technical feasibility and favorable clinical outcome.
Subject(s)
Humans , Angioplasty , Arteries , Carotid Artery, Internal , Cerebral Infarction , Follow-Up Studies , Intracranial Hemorrhages , Medical Records , Stents , Stroke , ThrombectomyABSTRACT
PURPOSE: Diffusion-weighted magnetic resonance (MR) image (DWI) has advantages for the assessment of acute stroke. However, false negative DWI findings in acute ischemic stroke have been reported. Our purpose was to estimate the rate of initial false negative DWI studies in acute ischemic stroke patients and to identify characteristics of false negative DWI stroke patients. METHODS: In this retrospective study from January 2010 to June 2011, acute ischemic stroke patients (within 6 hours after stroke onset) were enrolled. A total of 56 patients were included in this study. Cases with negative initial DWI findings, with an ischemic lesion visible on follow-up MR studies, were analyzed for times between the onset of symptoms and initial DWI, National Institute of Health Stroke Scale (NIHSS), and the location of the ischemic stroke lesion. RESULTS: We found seven cases (12.5%) of false negative initial DWI studies. The initial false negative DWI group had a significantly shorter time from the onset of symptoms to the initial DWI compared to the initial positive DWI group (p=0.011). The false negative group had a lower NIHSS without significance (p=0.091). CONCLUSION: A false-negative DWI study is not uncommon in the assessment of acute ischemic stroke. Thus, patients suspected of having a stroke should not be ruled out on the basis of a negative DWI, especially a suspected low NIHSS, for an early onset of symptoms.