Triaging transient ischemic attack and minor stroke patients using acute magnetic resonance imaging

We examined whether the presence of diffusion-weighted imaging (DWI) lesions and vessel occlusion on acute brain magnetic resonance images of minor stroke and transient ischemic attack patients predicted the occurrence of subsequent stroke and functional outcome. 120 transient ischemic attack or minor stroke (National Institutes of Health Stroke Scale < or = 3) patients were prospectively enrolled. All were examined within 12 hours and had a magnetic resonance scan within 24 hours. Overall, the 90-day risk for recurrent stroke was 11.7%. Patients with a DWI lesion were at greater risk for having a subsequent stroke than patients without and risk was greatest in the presence of vessel occlusion and a DWI lesion. The 90-day risk rates, adjusted for baseline characteristics, were 4.3% (no DWI lesion), 10.8% (DWI lesion but no vessel occlusion), and 32.6% (DWI lesion and vessel occlusion) (p = 0.02). The percentages of patients who were functionally dependent at 90 days in the three groups were 1.9%, 6.2%, and 21.0%, respectively (p = 0.04). The presence of a DWI lesion and a vessel occlusion on a magnetic resonance image among patients presenting acutely with a transient ischemic attack or minor stroke is predictive of an increased risk for future stroke and functional dependence.     

短暂性脑缺血发作病人脑循环中微栓子信号与脑卒中的危险性研究

目的 对短暂性脑缺血发作（TIAs)病人观察脑循环微栓子信号（MES）发生率及其发生脑卒中的危险率。方法 用经颅多普勒（TCD）监测TIAs病人双侧大脑中动脉（MCA）微栓子信号（MES）,并跟踪观察12个月。结果 25例短暂脑缺血发作病人有5例记录到MES（阳性率20％）,跟踪观察12个月,5例MES阳性病例中的3例（60％）发生脑梗死;而20例未记录到MES的病人中,仅有2例（10％）发展为脑梗死。结论 可检测到MES的TIAs病人发生梗死的危险性比无MES病人高。     

Prognosis of dolichoectasia in non-cardioembolic transient ischemic attack and minor stroke

Objectives This study aimed to estimate the prognosis of dolichoectasia in non-cardioembolic transient ischemic attack (TIA) and minor stroke patients.

Methods Data were derived from the imaging subgroup of patients in the Clopidogrel in High-risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) trial. Dolichoectasia was defined as ectasia (basilar artery diameter >4.5 mm) and dolichosis (either basilar artery bifurcation above the suprasellar cistern or lateral to the margin of the clivus or dorsum sellae). The prognosis included ischemic stroke recurrence and poor functional outcome (modified Rankin scale 2–6) at 12-month follow-up. The association of dolichoectasia with risk factors and prognosis of patients were assessed using multivariable Cox regression models.

Results Overall, 1089 patients with magnetic resonance images in the CHANCE trial were included in this subanalysis. A total of 98 (9.0%) patients were detected with dolichoectasia, and 106 (9.7%) patients had a recurrent ischemic stroke at 12 months. Small artery occlusion (SAO) was more prevalent in patients with dolichoectasia compared with those without dolichoectasia (29.6% vs. 22.7%, hazard ratio [HR] 2.87, 95% confidence interval [CI] 1.59–5.17, p < 0.001). However, multivariate analysis showed no association of dolichoectasia with 12-month recurrent stroke (9.2% vs. 9.8%, HR, 1.15; 95%CI, 0.32–4.12; p = 0.83) and poor functional outcome (7.6% vs. 8.4%, odds ratio, 1.22; 95%CI, 0.24–6.08; p = 0.81) in the current subgroup analysis.

Conclusions Dolichoectasia was significantly associated with SAO. There was no relationship between dolichoectasia and 12-month prognosis of patients with non-cardioembolic TIA or minor stroke.     

Prognostic indicators for mortality in transient ischemic attack and minor stroke

In a prospective study, 129 consecutive patients with transient ischemic attacks (TIAs) and 80 consecutive patients with minor ischemic stroke, involving the carotid artery territory in both cases, were followed-up for six years from their inclusion during the period from January 1984 to October 1985. All patients were 40–80 years old at inclusion, the median age being 74 years in the TIA group and 76 years in the minor stroke group. Overall mortality in the TIA group was significantly higher than in the minor stroke group, [44%, (57/129) vs 20% (16/80), p<0.0006 after correction for age], and that in the general population of Malmö. Pre-existing vascular disease was slightly more prevalent in the TIA than in the minor stroke group [27% (35/129 vs 21% (17/80), NS]. Of the 19 patients with intermittent claudication, who all died [12 (63%) of them due to myocardial infarction (MI)], 18 belonged to the TIA group and only one to the minor stroke group. The respective frequencies of the putative risk factors in the TIA and minor stroke groups were 28% (36/129) vs 9% (7/80) for hypertension (p = 0.016), 9% (12/129) vs 6% (5/80) for diabetes mellitus (NS), and 8% (10/129) vs 9% (7/80) for cardiac arrhythmia (NS). Mortality due to MI was higher in the TIA than in the minor stroke group[24% (31/129) vs 6% (5/80), p = 0.001]. Of the minor stroke patients, none without vascular disease died of MI. Regarding the risk of death in the study population as a whole (i.e., both groups), mortality was greater among those with vascular disease than among those without [81% (42/52) vs 20% (31/157), p = 0.0001], the corresponding figures for death due to MI being 56% (29/52) vs 4% (7/157), p = 0.0001. All six patients with both vascular disease and hypertension died, five of them due to MI. Thus, both in the TIA and minor stroke groups, mortality was greatest among those with preexisting vascular disease. To significantly reduce mortality among TIA and minor stroke patients, it is suggested that very active measures need to be taken against cardiovascular disease.     

Silent stroke in patients with transient ischemic attack or minor ischemic stroke. The Dutch TIA Trial Study Group.

BACKGROUND AND PURPOSE: We studied silent stroke (i.e., infarcts on computed tomographic scan not related to later symptoms) in patients after transient ischemic attack or minor ischemic stroke. METHODS: Ours is a cross-sectional study of 2,329 patients who were randomized in a secondary prevention trial after transient ischemic attack or minor ischemic stroke and had no residual deficit after the qualifying event. RESULTS: Silent stroke was observed in 13% of the 2,329 patients. Lacunes formed 79%, cortical lesions 14%, and border zone lesions 7% of all silent strokes. Silent lacunes were most often located in the basal ganglia and symptomatic lacunes most often in the corona radiata. Age, hypertension, and current cigarette smoking were related to the presence of silent stroke. Silent stroke was equally common in different types of transient ischemic attack, including transient monocular blindness. Residual symptoms of any kind were more common in patients with silent stroke than in those without. CONCLUSIONS: Because only the sites of silent stroke infarcts differed slightly from those of symptomatic infarcts and the frequency of vascular risk factors was similar to that of symptomatic infarcts, silent stroke may have the same bearing on future risk as known prior stroke.     

Chronic blood hyperviscosity in subjects with acute stroke, transient ischemic attack, and risk factors for stroke

The origin and significance of blood hyperviscosity in subjects with acute stroke has been controversial. It has been argued that viscous abnormalities simply reflect either elevated hematocrit or an acute-phase response to the stroke itself. To address these issues, we measured the factors that determine blood viscosity in a cross-sectional study of 430 subjects, including 135 with acute stroke, 89 with acute transient ischemic attacks of the brain, 115 with recognized risk factors for stroke, and 91 healthy controls. The at-risk group was balanced with the acute stroke group for types of risk factors and medication usage, and all four groups were balanced for age. The viscosity of whole blood at low rates of shear and the plasma viscosity were significantly elevated in both groups with cerebrovascular symptoms and in the at-risk group compared with the healthy controls. The severity of hyperviscosity was stroke group greater than transient ischemic attack group greater than at-risk group greater than healthy controls. Increased viscosity of whole blood was associated with an elevated plasma fibrinogen concentration and with a decreased albumin/globulin ratio. This study provides evidence that blood hyperviscosity is present not only in subjects with acute brain infarction, but also in those with risk factors for stroke, and that these abnormalities are, to a considerable degree, chronic.     

The need for emergency treatment of transient ischemic attack and minor stroke

The risk of recurrent stroke following transient ischemic attack or minor stroke has recently been shown to be 5-10% at 1 week and 10-20% at 3 months, depending on study population and methods. This is considerably higher than previously estimated and current clinical guidelines reflect the need for rapid assessment although a wide variation in practice exists. Effective management of patients with transient ischemic attack or minor stroke, therefore, requires identification of individuals at the highest (and lowest) risk and initiation of appropriate secondary prevention. Risk can be stratified at initial presentation by the presence or absence of simple clinical features and following subsequent investigation. For transient ischemic attack patients, older age, diabetes, longer duration of symptoms and weakness or speech disturbance identify patients at highest risk, as does the presence of large artery atherosclerosis (mainly internal carotid artery stenosis) and lesions on diffusion-weighted magnetic resonance imaging. Strong evidence exists for the benefit of some early interventions (carotid endarterectomy and antiplatelet agents), but is circumstantial or awaited for others (statins and antihypertensives). In order for the public health challenge posed by transient ischemic attack and minor stroke to be met, considerable change is required in both public education (to ensure correct recognition of symptoms and swift presentation to medical attention) and the provision of clinical services to ensure the timely initiation of effective treatment.     

Short-term risk and predictors of stroke after transient ischemic attack

BackgroundTransient ischemic attack (TIA) is a marker of stroke, especially in the early phase following this event. The aims of this study are to determine the short-term risk of stroke and to evaluate the independent predictors of stroke in patients with TIA who are hospitalized within 48 hours after symptom onset.MethodsDuring a 36-month period (beginning in November 2007), 3554 patients (mean age: 70.5 ± 13 years; 49.9% female; mean NIHSS score: 1.4 ± 2.5) from 15 hospitals suffering from TIA were prospectively evaluated.ResultsOf the 3554 patients, 43 (1.2%) suffered from stroke during hospitalization (6.5 ± 4.3 days). We identified the following independent predictors for stroke after TIA: male sex (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.3–5; P = 0.008), age ≥ 65 years (OR, 4.7; 95% CI, 1.4–15; P = 0.01), hyperlipidemia (OR, 2.4; 95% CI, 1.2–4.8; P = 0.015), and dysarthria (OR, 2; 95% CI, 1.1–5.0; P = 0.038).ConclusionPatient characteristics (male sex, age, and hyperlipidemia) and TIA symptom (dysarthria) may be useful in defining stroke after TIA in patients who were hospitalized with TIA.     

Long-term mortality and risk of stroke after transient ischemic attack

Background   Stroke and mortality rates in patients with transient ischemic attack (TIA) differ widely between community-based studies and research cohorts. Our aim therefore was to provide a reliable estimate for TIA patients treated in German neurology departments with an acute stroke unit. Methods   A total of 1951 consecutively admitted TIA patients were prospectively documented in 13 centers and 1480 (75.9 %) gave consent for long-term follow-up. During a mean follow-up of 23.4 months, we assessed recurrent cerebrovascular events and cause of death in 1448 patients via standardized telephone interview including confirmation of endpoint events by the treating physician. Results   Overall 94 patients (6.5 %) suffered a stroke and 118 patients (8.1 %) died, 21 due to stroke. The Kaplan-Meier estimate for stroke during the first year was 4.4 % (95 % CI 3.2–5.6 %) which corresponds to a relative risk of 9.5 (95 % CI 7.4–12.3) compared to the population-based stroke incidence in Germany. The annual rates after the first year were 2.2 % (95 % CI 1.7–2.7 %) for stroke and 3.2 % (95 % CI 2.7–3.8 %) for death. Independent predictors for stroke during follow-up were age and previous cerebrovascular events. The ABCD₂ score did not provide any meaningful prediction of stroke risk at 90 days. Conclusion   While the in-hospital risk of stroke was low, long-term stroke rates in our well-defined multicenter hospital-based cohort were comparable to a large randomized trial. In patients with a well-established diagnosis of TIA, only age and previous cerebrovascular events seem to constitute independent predictors for stroke during long-term follow-up. Participating Departments of Neurology (investigator): Ostalbklinikum Aalen (M. Heyden, MD), Klinikum Bernburg (M. Muller, MD), Krankenanstalten Gilead Bielefeld (C. Hagemeister, MD), Krankenhaus Buchholz (K. Luckner, MD), University of Essen (C. Weimar, MD), University of Freiburg (C. Fritzsch, MD), University of Greifswald (A. Khaw, MD), University of Hannover (K. Weissenborn, MC), Klinikum Heidenheim (S. Kaendler, MD), University of Jena (C. Terborg, MD), Krankenhaus Koln-Mehrheim (U. Frost, MD), University of Leipzig (D. Michalski, MD), Landesklinik Lubben (C. Rohrig, MD), University of Magdeburg (M. Goertler, MD), Ruppiner Kliniken Neuruppin (G. Zindler, MD), University of Rostock (A. Kloth, MD), Burgerhospital Stuttgart (T. Mieck, MD), University of Ulm (R. Huber, MD), Heinrich- Braun-Krankenhaus Zwickau (S. Grieshammer MD).