Jae-Hyung Choi

A Systemized Stroke Code Significantly Reduced Time Intervals for Using Intravenous Tissue Plasminogen Activator under Magnetic Resonance Imaging Screening

BACKGROUNDnA 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.nnnMETHODSnIn 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.nnnRESULTSnDuring 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.nnnCONCLUSIONSnIn 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.

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.

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

BACKGROUNDnThe 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.nnnMETHODSnBeginning 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.nnnRESULTSnIntravenous 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, Pu2009<u2009.001). 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, Pu2009=u2009.045) and door-to-needle time (20 minutes versus 29 minutes, Pu2009=u2009.011).nnnCONCLUSIONSnWe 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.

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.

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

OBJECTIVEnIn 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.nnnMETHODSnWe 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.nnnRESULTSnThe 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).nnnCONCLUSIONnThis 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.

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

We investigated the differences in determinant factors for functional outcomes between patients aged >80u2009years and those aged <80u2009years 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.

Pre-stroke glycemic control is associated with early neurologic deterioration in acute atrial fibrillation-related ischemic stroke

Background It has been suggested that AF-related ischemic stroke (IS) that is accompanied by atherosclerotic burden have poorer outcomes. The aim of this study was to investigate the importance of pre-stroke glycemic control (PSGC) on the early neurologic deterioration (END) of patients with acute AF-related IS. Methods We retrospectively recruited 121 patients with AF-related IS who also had Diabetes mellitus (DM). The HbA1C level was measured in all subjects. END was defined as an increase in the National Institute of Health Stroke Scale (NIHSS) score of 4 NIHSS points within 7 days of symptom onset compared to the initial NIHSS score. Results In this study, 20.7% (25 patients) were classified as having a poor PSGC status with a HbA1C level above 8.0%. In the univariate analysis, a poor PSGC status (p < 0.01), smoking (p = 0.01), severe neurologic deficits at admission (p = 0.01), and a larger size of ischemic lesions on DWI (p < 0.01) were associated with the occurrence of END. In the multivariate model, a poor PSGC status (p = 0.02) and larger size of ischemic lesions on MRI (p < 0.01) were independent predictors of END in acute AF-related IS. Conclusion The HbA1c level upon admission was independently associated with significant prediction of END in acute AF-related IS.

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 2u2005h 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 90u2005days 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 90u2005days 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.

Vasospastic Amaurosis Fugax Diagnosed by Cerebral Angiography

UNLABELLEDnWe report a case of recurrent monocular blindness presumed to be caused by vasospasm, demonstrated by digital subtraction angiography.nnnCASE REPORTnA 65-year-old man presented with recurrent visual loss in the left eye for 2 years. He had histories of hypertension, cigarette smoking, and May-Thurner syndrome. The symptom occurred variably from twice a day to once a week and usually lasted for 5 minutes. Brain magnetic resonance imaging, magnetic resonance angiography, and ophthalmologic evaluation did not reveal any abnormality. Cerebral digital subtraction angiography was performed. On the left internal carotid angiogram, vasospasm occurred in the cervical portion of the left internal carotid artery and, subsequently, the blood flow to the left ophthalmic artery diminished. This phenomenon was reproducible and, in the absence of vasospasm, the ophthalmic artery was well visualized with no steno-occlusive lesion. Examination of the carotid duplex showed diffuse luminal narrowing and increased flow velocities in the left cervical internal carotid artery without atherosclerotic plaque. Treatment was started with nimodipine, which markedly reduced the attacks.nnnCONCLUSIONnWe assumed that vasomotor instability, which made the vessels vulnerable to spasm, may have caused a recurrent ocular symptom in our patient.

The Processing Time for Recanalization and Size of Ischemic Lesions on DWI is Related With Complete Reperfusion After Mechanical Thrombectomy

Recent studies demonstrated that modified thrombolysis in cerebral infarction (TICI) 3 reperfusion have better functional outcomes than modified TICI 2b after mechanical thrombectomy in acute ischemic stroke with large vessel occlusion. The purpose of this study was to determine significant factors to forecast the presence of complete reperfusion after mechanical thrombectomy based on multimodal magnetic resonance imaging (MRI). We investigated 96 consecutive patients with acute large intracranial artery occlusion of anterior circulation who based on multimodal MRI. Also, we compared clinical and radiologic parameters between patients with modified TICI 3 and those with modified TICI 0-2b. Among 96 eligible subjects received mechanical thrombectomy, 39 patients (40.6%) showed complete reperfusion and 57 partial or nonreperfusion (mTICI 2b-26, mTICI 2a-9, mTICI 1-8, and mTICI 0-14) after mechanical thrombectomy. Patients with mTICI 3 had significantly smaller initial Diffusion weighted images (DWI) lesion volume (P < .01) and much shorter time interval from onset to reperfusion (P < .01) than those patients with mTICI (0-2b). In multivariate analysis, smaller initial DWI volume (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.23-2.57; P < .01) and faster reperfusion time (OR, 1.07; 95% CI 1.01-1.14; P = .015) had an independence significance for complete reperfusion after mechanical thrombectomy. In this study, the ischemic lesion volume on DWI and faster processing time are critical factor to predict the state of complete reperfusion after mechanical thrombectomy.