Stroke Of Undetermined Etiology Research Articles

Has the aetiology of ischaemic stroke changed in the past decades? Analysis and comparison of data from current and historical stroke databases

ObjectivesWe aimed to determine whether the aetiology of ischaemic stroke has changed in recent years and, if so, to ascertain the possible reasons for these changes. Patients and methodsWe analysed the epidemiological history and vascular risk factors of all patients diagnosed with ischaemic stroke at Complejo Hospitalario Universitario de Albacete (CHUA) from 2009 to 2014. Ischaemic stroke subtypes were established using the TOAST criteria. Our results were compared to data from the classic Stroke Data Bank (SDB); in addition, both series were compared to those of other hospital databases covering the period between the two. ResultsWe analysed 1664 patients (58% were men) with a mean age of 74 years. Stroke aetiology in both series (CHUA, SDB) was as follows: atherosclerosis (12%, 9%), small-vessel occlusion (13%, 25%), cardioembolism (32%, 19%), stroke of other determined aetiology (3%, 4%), and stroke of undetermined aetiology (40%, 44%). Sixty-three percent of the patients from the CHUA and 42% of the patients from the SDB were older than 70 years. Cardioembolic strokes were more prevalent in patients older than 70 years in both series. Untreated hypertension was more frequent in the SDB (SDB=31% vs CHUA=10%). The analysis of other databases shows that the prevalence of cardioembolic stroke is increasing worldwide. ConclusionsOur data show that the prevalence of lacunar strokes is decreasing worldwide whereas cardioembolic strokes are increasingly more frequent in both our hospital and other series compared to the SDB. These differences may be explained by population ageing and the improvements in management of hypertension and detection of cardioembolic arrhythmias in stroke units.

Microbubble signal and trial of org in acute stroke treatment (TOAST) classification in ischemic stroke

PurposeRight-to-left shunt (RLS) through a patent foramen ovale (PFO) is likely associated with ischemic stroke. Many studies have attempted to demonstrate the association between RLS and ischemic stroke. However, information on the association between the degree of RLS and the subtypes of ischemic stroke categorized by the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification is lacking. MethodThis was a retrospective study involving 508 patients with ischemic stroke who underwent a transcranial Doppler (TCD) microbubble test between 2013 and 2015. The degree of RLS was divided into 4 grades according to the microbubble signal (MBS) as follows: no MBS, grade 1; MBS < 20, grade 2; MBS > 20, grade 3; curtain sign, grade 4. The degree of RLS and the type of ischemic stroke as classified by TOAST were analyzed and compared with other clinical information and laboratory findings. ResultsThe higher RLS grade was associated with the cardioembolism (CE) and stroke of undetermined etiology (SUE), and the microbubble signals were inversely related with small vessel disease (SVD). An MBS higher than grade 3 showed a 2.95-fold higher association with SUE than large artery atherosclerosis (LAA), while grade 4 MBS revealed an approximately 8-fold higher association with SUE than LAA. ConclusionRLS identified by the TCD microbubble test was significantly and independently associated with cryptogenic ischemic stroke (negative evaluation). Subsequent studies are needed to determine the biologic relationship between RLS and ischemic stroke, particularly the cryptogenic subtype of ischemic stroke.

Embolic strokes of undetermined source in a cohort of Polish stroke patients

We aimed to provide a descriptive analysis of embolic stroke of undetermined etiology (ESUS) population based on a long-term prospective stroke registry. We retrospectively analyzed data collected in a detailed registry regarding consecutive patients admitted for first-ever ischemic stroke (IS) between January 2001 and December 2015. We used Org 10172 in Acute Stroke Treatment classification supplemented with ESUS criteria proposed by the Cryptogenic Stroke/ESUS International Working Group. Within the ESUS group, we additionally compared patients ≤ 60 and > 60 years of age. During the study period, there was a total of 3008 (1615 females and 1393 males) admissions of first-ever strokes. The most frequent cause was undetermined (38.7%), followed by cardioembolic (27.7%), large artery atherosclerosis (18.2%), small vessel disease (11.9%), and other determined (3.6%). We identified 326 patients as ESUS, which accounted for 10.8% of all strokes and 28% of strokes of undetermined etiology. ESUS patients were the youngest. Compared to all types of stroke but for those with small vessel disease, ESUS patients were most often independent before stroke and had the least severe neurological deficit at admission and the best outcome at discharge. ESUS patients ≤ 60 years were more frequently independent at discharge than ESUS patients > 60 years. Approximately 11% of patients from our registry met ESUS criteria. ESUS patients were younger when compared to all other stroke etiologies, suffered less severe strokes, and had more favorable outcome at discharge than other groups except for those with small vessel disease strokes.

Clinical neurological characteristics of ischemic stroke subtypes in acute phase

Objectives. The aim of the present study was to clarify clinical neurological characteristics and different ischemic stroke subtypes unfavorable course predictors in acute phase. Material and Methods. 482 patients with different ischemic stroke subtypes were observed. Among them there were 125 (25.9 %) with cardioembolic infarct (CEI), 119 (24.7 %) with large artery atherosclerosis (LAAS) infarct, 122 (25.3 %) with lacunar stroke (LAC), 116 (24.1 %) with stroke of undetermined etiology (UDE). The comparative analysis of clinical picture was performed. The predictors of unfavorable course of acute phase were established. Results. We have found out that severe neurological deficit, high mortality and the worst functional outcome during the first 14 days were observed in patients with CEI and LAAS. The highest frequency of early neurological deterioration (END) was detected at LAC (in 22.7 % of patients). There was a relationship between END and presence of transient ischemic attack (TIA) in past medical history, the level of systolic blood pressure (SBP) at the beginning of the disease and the degree of carotid arteries stenosis on the side of lesion. The patients with LAC had mild neurological deficit and better prognosis compared with other ischemic stroke subtypes. Among the clinical factors that have impact on the CEI, LAAS and UDE acute phase course were: the size of lesion, the level of consciousness on the 1st day, the baseline SBP, patient’s age. At LAAS, the presence of transient ischemic attack (TIA) in past medical history and low SBP in the onset of the disease (less than140 mm Hg) has an additional prognostic value for an unfavorable functional outcome. The severity of LAC in acute period depended on its localization and size. Localization of LAC in the internal capsule, thalamus and pons were characterized by the highest severity. Conclusions. Clinical neurological features of ischemic stroke depend on its subtype and have some prognostic value for the course of different ischemic stroke subtypes in acute phase.

Abstract 126: Relationship Between Visceral Infarction and Ischemic Stroke Subtype

Background: Most cryptogenic strokes are thought to have an embolic source. We sought to determine whether visceral infarcts, which are usually embolic, are associated with cryptogenic stroke. Methods: Among patients prospectively enrolled in the Cornell AcutE Stroke Academic Registry (CAESAR), we selected those with a contrast-enhanced abdominal computed tomography (CT) scan within 1 year of admission. Our primary predictor was stroke subtype, as adjudicated per the TOAST classification. Our outcome measure was renal or splenic infarction, as assessed by a single radiologist blinded to stroke subtype. We used Fisher’s exact test and multiple logistic regression to compare the prevalence of visceral infarcts among patients with cardioembolic stroke, stroke of undetermined etiology, and non-cardioembolic stroke (large- or small-vessel stroke). Results: Among 227 patients with a contrast-enhanced abdominal CT scan, 59 had a visceral infarct (35 with renal infarcts and 27 with splenic). The prevalence of visceral infarction was significantly different among patients with cardioembolic stroke (34.2%; 95% confidence interval [CI], 23.7-44.6%), stroke of undetermined etiology (23.9%; 95% CI, 15.0-32.8%), and stroke from large-artery atherosclerosis or small vessel-occlusion (12.5%; 95% CI, 1.8-23.2%) (P = 0.03). In multiple logistic regression models adjusted for demographics and vascular risk factors, we found significant associations with visceral infarction for both cardioembolic stroke (odds ratio [OR], 3.5; 95% CI, 1.2-9.9) and stroke of undetermined source (OR, 3.3; 95% CI, 1.1-10.5) as compared with the reference group of non-cardioembolic strokes. Conclusions: The prevalence of visceral infarction differs significantly across ischemic stroke subtypes. Cardioembolic and cryptogenic strokes were associated with a higher prevalence of visceral infarcts than non-cardioembolic strokes.

Abstract WMP72: The "Three Territory Sign": An Under-Recognized Radiographic Marker of Malignancy-Related Ischemic Stroke

Background: Multiple cerebral territory infarcts of undetermined origin are typically attributed to cardioembolism; and most frequently atrial fibrillation. However the significance of three territory involvement in association with malignancy is under-recognized. Objective: To highlight the “Three Territory Sign” (bilateral anterior and the posterior circulation DWI lesions), as a radiographic marker of stroke due to malignancy. Methods: We conducted a retrospective analysis of patients at our institution from Jan 2014-Jan 2016 who suffered an acute ischemic stroke with MRI-DWI. We identified all ischemic strokes of undetermined etiology in patients with known malignancy (60 patients) and patients with stroke, atrial fibrillation and no malignancy (167 patients). Patients with both atrial fibrillation and malignancy were excluded. All DWI images were reviewed for 3, 2, and 1 territory lesions. Fisher Exact tests were used to identify statistical significance between the two groups. Statistical significance was set at 0.05. Results: There was a significant association between both cohorts (malignancy vs. atrial fibrillation) and the number of territory infarcts found. While the number of 1 {71.6% (n=43) vs. 79% (n=132)} and 2 territory infarcts {10.0% (n=6) vs. 17. 4% (n=29)} were similar between the two groups, 3 territory infarcts were &gt; 5 times more frequent in malignancy as compared to atrial fibrillation {18.3% (n=11) vs. 3.5% (n=6)} ( p &lt; 0.002 ). Post-hoc pairwise comparisons using the Bonferroni correction for multiple tests support that the 3 territory pattern differs from both 1 territory ( p=0.0033 ) and 2 territory ( p =0.0037 ) patterns. Conclusion: Cerebral territory infarctions involving the bilateral anterior and posterior circulation are 5 times more frequent in malignancy-related ischemic stroke than atrial fibrillation. The “Three territory sign” is a robust marker of malignancy-related stroke and should prompt evaluation for malignancy after exclusion of other known causes.

When to Screen Ischaemic Stroke Patients for Cancer

Background and Purpose: Ischemic stroke can be the first manifestation of cancer and it is therefore important to ascertain which stroke patients should be considered for cancer-diagnostic investigations. We aimed to determine the frequency of active cancer in patients with acute ischemic stroke and to compare clinical findings in stroke patients with active cancer to ischemic stroke patients with no history of cancer. Finally, we aimed to develop a predictive and feasible score for clinical use to uncover underlying malignancy. Methods: All ischemic stroke patients admitted to the stroke unit in the Department of Neurology, Haukeland University Hospital were consecutively included in the Norwegian Stroke Research Registry (NORSTROKE). Stroke etiology was determined by the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. Data on cancer diagnoses was obtained from patients’ medical records and the Cancer Registry of Norway. Active cancer was defined as cancer diagnosis, metastasis of known cancer, recurrent cancer or receiving cancer treatment, all within 12 months before or after the index stroke. Based on variables independently associated with active cancer, a predictive score was developed using the area under the receiver operating characteristic (AUC-ROC) curves. Bayes’ theorem was used to calculate post-test probabilities of active cancer. Results: Of the 1,646 ischemic stroke patients included, 82 (5.0%) had active cancer. Increased D-dimer (OR = 1.1, 95% CI: 1.1–1.2, p = <0.001), lower Hb (OR = 0.6, 95% CI: 0.5–0.7, p = <0.001), smoking (OR = 2.2, 95% CI: 1.2–4.3, p = 0.02) and suffering a stroke of undetermined etiology (OR = 1.9, 95% CI: 1.1–3.3, p = 0.03) were factors independently associated with active cancer. These were included in the final predictive score which gave an AUC of 0.73 (95% CI: 0.65–0.81) in patients younger than 75 years of age. Assuming the prevalence of cancer to be 5%, the score shows that if a patient fulfills all 3 score points, the probability of active cancer is 53%. Conclusions: Active cancer was found in 5% of our ischemic stroke patients. We found that a clinical score comprising elevated D-dimer ≥3 mg/L, lower Hb ≤12.0 g/dL and previous or current smoking is feasible for predicting active cancer in ischemic stroke patients.

Intracranial Atherosclerosis is the Most Common Stroke Subtype: Ten-year Data from Hyderabad Stroke Registry (India).

Aim:Limited data regarding stroke subtypes exist from South Asian countries. The aim of the study was to determine the pattern of ischemic stroke subtypes and their associated risk factors, in a 10-year long hospital-based registry in the South Indian city of Hyderabad.Materials and Methods:The Hyderabad stroke registry systematically collected clinical, radiological, and laboratory data of fully investigated consecutive stroke patients and studied pattern of ischemic stroke subtypes and their risk factor association.Results:The cohort comprised of 2642 patients: 2072 (78.4%) were ischemic and 570 (21.6%) were hemorrhagic strokes. In the ischemic stroke cohort, the mean age was 54.1 years and 1622 (78.3%) were men. The most common ischemic stroke subtype was large artery atherosclerosis (LAA) comprising 37.6% (n = 779), followed by small vessel occlusion comprising 19.9% (n = 413) and cardioembolism 11% (n = 228). Stroke of other determined etiologies constituted 4.2% (n = 86) and stroke of undetermined etiology was observed in 27.3%. Among patients with LAA, 610 (78.3%) patients had intracranial and 169 (21.7%) had extracranial disease as the underlying mechanism. Risk factor profile demonstrated that hyperlipidemia was significantly associated with LAA and ischemic heart disease with cardioembolic strokes.Conclusions:The study reveals a distinct pattern of ischemic stroke subtypes in the Indian context that has overlapping features of registries from West and East Asian countries. Both large artery and small vessel diseases are substantially represented with a predominance of intracranial atherosclerosis. The study results have significant implications for developing preventive and management strategies for stroke care and research in India.

Distinct predictive role of collateral status on clinical outcome in variant stroke subtypes of acute large arterial occlusion.

Clinical trials have shown that robust collateral flow has a relationship with good clinical outcome; however, different stroke subtypes were lumped together. This study explored the relationship between baseline collaterals and the onset-to-imaging time (OIT) and the correlation between pre-treatment collateral status and clinical outcome amongst different subtypes. Prospectively collected data from consecutive acute ischaemic stroke patients with acute middle cerebral artery occlusion who received reperfusion therapy were reviewed. The regional leptomeningeal score (20 points) was based on the scoring extent of contrast opacification in the six Alberta Stroke Program Early CT Score (ASPECTS) cortical regions (M1-6), parasagittal anterior cerebral artery territory and the basal ganglia by perfusion-derived dynamic four-dimensional computed tomography angiography (4D CTA). Stroke subtype was determined by the TOAST classification criteria. A 3-months modified Rankin Scale score of 0-2 was defined as a good outcome. The analysis included 158 patients: 30 (19.0%) patients had large artery atherosclerotic stroke (LAA), 87 (55.1%) cardioembolic stroke (CE) and 41 (25.9%) stroke of undetermined etiology. Baseline collateral was negatively correlated with OIT (P = 0.0205) in the CE group after adjusting for female sex, smoking, hyperlipidemia, baseline National Institutes of Health Stroke Scale (NIHSS) and baseline mismatch ratio, but not in the LAA group. Baseline collateral showed a strong relationship with good clinical outcome after adjusting for recanalization, baseline NIHSS, age and female sex (odds ratio 1.120, confidence interval 1.013-1.238, P = 0.027) in all patients and in the CE group (odds ratio 3.223, confidence interval 1.212-8.570, P = 0.019), but not in the LAA patients. Based on 4D CTA, sustained good leptomeningeal collaterals may predict good outcome in CE but not in LAA patients. Moreover, the extent of collaterals was associated with OIT in the CE patients, which indicates prompt reperfusion therapy in this group of patients.

Causes of Death in Different Subtypes of Ischemic and Hemorrhagic Stroke.

Causes of death in both ischemic stroke (IS) and hemorrhagic stroke (HS) subtypes are not comprehensively studied. Between 2008 and 2011, we enrolled 11 215 first-ever stroke patients from the Stroke Registry of Chang-Gung Healthcare System and linked these data to the national death registry. The main causes of death in each stroke subtype were assessed. Patients with HS had higher overall mortality than IS (32.0% vs 18.1%, P < .001). In IS subtypes, large-artery atherosclerosis plus cardioembolism had the worst mortality (40.7%, P < .001). Stroke was the leading cause of death in both IS and HS within the first year. Stroke remained the major cause of death in HS, but cancer was the leading cause of death in IS after the first year. After excluding the patients with previous cancer history, cancer was still an important cause of death in IS and HS, particularly in the IS subtypes of small vessel occlusion, stroke of undetermined etiology, and transient ischemic attack.

HIV infection, hypercoagulability and ischaemic stroke in adults at the University Teaching Hospital in Zambia: a case control study

BackgroundIn Zambia, 14.2% of adults have HIV/AIDS. There has been a substantial and significant increase in patients hospitalized for ischaemic stroke with co-existing HIV infection. However, little is known about the mechanism of stroke in these HIV + ve patients let alone studied in our region. The aim of this pilot study was to explore the association of hypercoagulability state in HIV + ve patients with ischaemic stroke. This was achieved by comparing hypercoagulability state markers between HIV + ve ischaemic stroke patients with HIV-ve and HIV + ve patients with and without ischaemic stroke respectively.MethodsA matched case control study in which a total of 52 HIV + ve patients with ischaemic stroke were prospectively compared with control groups for the presence of protein S, protein C deficiencies and hyperhomocysteinaemia. The control groups comprised an equal number of consecutively matched for age and sex HIV-ve and HIV + ve patients with and without ischaemic stroke respectively. Data was analysed in contingency tables using Paired t- test, Chi square and conditional logistic regression.ResultsIschaemic stroke of undetermined aetiology occurred more frequently in HIV + ve compared to HIV-ve patients (p < 0.001). In addition, protein S deficiency and Hyperhomocysteinaemia were more prominent in HIV + ve than HIV-ve ischaemic stroke patients (P = 0.011). There was no difference in the presence of hyperhomocysteinaemia or protein S deficiency in HIV + ve patients with or without ischaemic stroke. Protein C deficiency was not noted to be significantly different between the cases and the two control arms.ConclusionProtein S deficiency and hyperhomocysteinaemia were associated with HIV infection, but not stroke in our study population. However, this is an area that requires extensive research and one that we cannot afford to ignore as it is an important bridge to all cardiovascular and cerebrovascular diseases.

Greater Risk of Stroke of Undetermined Etiology in a Contemporary HIV-Infected Cohort Compared with Uninfected Individuals

Although ischemic stroke risk is increased among people living with HIV infection, little is known about the epidemiology of ischemic stroke subtypes in contemporary HIV-infected cohorts. We examined the distribution of ischemic stroke subtypes among predominantly treated HIV-infected individuals to determine if and how the distribution differs from that of the general population. We studied 60 HIV-infected and 60 HIV-uninfected adults with a history of first-ever ischemic stroke between 2000 and 2012. Ischemic strokes were classified as 1 of 5 subtypes based on established criteria. We used multinomial logistic regression models to compare the relative frequency of ischemic stroke subtypes by HIV status. Large artery atherosclerosis (23%) and stroke of undetermined etiology (23%) were the most common stroke subtypes among HIV-infected individuals. The most recent plasma HIV viral load before the stroke event differed by subtype, with a median undetectable viral load for individuals with large artery stroke and stroke of undetermined etiology. Using cardioembolic stroke as the reference subtype, HIV-infected individuals were at higher proportional risk of stroke of undetermined etiology compared with uninfected individuals (relative risk ratio [RRR]: 8.6, 95% confidence interval [CI]: 1.2-63.7, P = .04). Among HIV-infected individuals with virologically suppressed infection, we observed a trend toward a greater proportion of strokes attributable to large artery atherosclerosis (RRR: 6.7, 95% CI: .8-57.9, P = .08). HIV-infected individuals may be at greater proportional risk of stroke of undetermined etiology compared with uninfected individuals. Further investigation is warranted to confirm this finding and determine underlying reasons for this greater risk.

Abstract TP210: Histopathological Evaluation of Thrombus in Acute Stroke and Correlation with Stroke Etiology

Background: While more endovascular treatments for acute stroke are being performed, few studies evaluate clot composition with variable results. We sought to evaluate the feasibility of collecting and analyzing the RBC to platelet ratios in clots, and correlated our findings with stroke etiology. Methods: This is an ongoing prospective study analyzing clots retrieved by mechanical thrombectomy in acute stroke patients at our institution. Retrieved clot material was fixed and cut at 4-m thickness. All clots were stained with hematoxylin-eosin to identify red blood cells (RBC’s), and antibodies for platelet glycoprotein IIIa with CD61 (LifeSpan Biosciences, Seattle, Washington) for platelets. Stained slides were scanned at 200x magnification by using a Scanscope XT digital scanner (Apergio, Vista, California). Image-J software (National Institutes of Health, Bethesda, Maryland) was used for semiquantitative analysis of percentage RBC’s and platelets. Correlation of RBC to Platelet ratios with stroke etiology was performed. Results: A total of 18 clots from 18 patients were analyzed. Stroke etiology was cardioembolic in 8, Large vessel atherosclerosis (LVA) in 5, undetermined in 3 and carotid dissection in 2. The mean RBC to platelet ratio was 0.51:1 in cardioembolic and 0.64:1 in LVA strokes. Patients with undetermined etiology had similar clot composition (0.53:1) to cardioembolic stroke. The highest RBC content was found in carotid dissection thrombus with a ratio of 1.73:1 as compared to other etiologies (p=0.01 cardioembolic, p=0.04 undetermined, p=0.02 LVA). Conclusion: In our study’s first phase, clot processing and analysis was found to be feasible. Although a high mean RBC content was found in carotid dissections and strokes of undetermined etiology had similar clot composition to cardioembolic stroke, ongoing collection and analysis will help support these findings.

Abstract WMP19: Identifying in vivo Luminal Thrombus Within 72 Hours After Stroke Onset: Interim Results of the Stroke Imaging Package Study

Background: The presence of luminal thrombus is associated with a high risk of stroke recurrence. Using high-resolution magnetic resonance imaging(HRMRI) and susceptibility-weighted imaging(SWI), luminal thrombus can be identified in vivo. We aimed to investigate the occurrence of luminal thrombus in patients with acute ischemic stroke. Methods: Patients with first ever stroke within 72 hours from onset, confirmed by diffusion weighted imaging, were recruited from 16 medical centers. Conventional MRI, magnetic resonance angiography, HRMRI (including 3-dimentional T1 images and 2-dimentional T2 images), and SWI were performed. Luminal thrombus was identified if isointense/hyperintense signals on 3-dimentional T1 images of HRMRI or susceptibility vessel sign on SWI were observed within the course of intracranial arteries. Results: Six hundred and one patients (70% male, mean age 61±16 years old, mean NIHSS 6± 5) were enrolled. Among them, 112 patients underwent recanalization therapies. Median time from symptom onset to MRI was 44 ± 20 hours. Luminal thrombus was identified in 138 (23%)patients. The occurrence rate of luminal thrombus was non-significantly different between the patients treated with and without recanalization therapies(16% vs.25%, p=0.054). Symptomatic luminal thrombus was more likely observed in large artery atherosclerosis stroke(121/240,50%) and cardicac stroke(11/36,31%) than other stroke subtypes (0/288 in lacunar stroke, 0/6 in stroke of undetermined etiology and 1/31 in cryptogenic stroke, P&lt;0.001). There were five patients with asymptomatic luminal thrombus irrelevant to ischemic lesions. Conclusions: Luminal thrombus is common in patients with acute ischemic stroke within 72 hours from onset. Further studies are required to clarify whether in vivo thrombus imaging can predict early stroke recurrence.

Diabetic patients are at a higher risk of lacunar infarction and dyslipidemia: results of a comparative pilot study from King Fahad Hospital of the University, Saudi Arabia.

Objective:To describe the various risk factors and identify the characteristics of ischemic stroke in diabetic patients.Method:A retrospective study carried out at King Fahd Hospital of the University in Al-Khobar, kingdom of Saudi Arabia from February 2010 to December 2015. Statistical analysis was performed by the Statistical Package for the Social Sciences (version 22.0, SPSS Inc, Chicago, IL, USA).Results:One hundred and twenty-seven diabetic patients with ischemic stroke were compared with 127 non-diabetics. Mean age was 61±13.6 (mean±SD) years for diabetics and 60±16.6 years for non-diabetics. There were 68.5% male in the diabetic group and 62.2% in the non-diabetic group. Small vessel occlusion was the most common subtype (41.7%) in diabetics and stroke of undetermined etiology (32%) in non-diabetics. Dyslipidemia was significantly more prevalent in diabetics as compared with non-diabetics.Conclusion:Our study found significant differences in characteristics of ischemic stroke in diabetics compared with non-diabetics with dyslipidemia, microangiopathy, and lacunar infarction being more frequent. Further epidemiological studies are required to understand the characteristics of strokes in diabetics.

Cryptogenic Stroke and Nonstenosing Intracranial Calcified Atherosclerosis

Because some cryptogenic strokes may result from large-artery atherosclerosis that goes unrecognized as it causes <50% luminal stenosis, we compared the prevalence of nonstenosing intracranial atherosclerotic plaques ipsilateral to cryptogenic cerebral infarcts versus the unaffected side using imaging biomarkers of calcium burden. In a prospective stroke registry, we identified patients with cerebral infarction limited to the territory of one internal carotid artery (ICA). We included patients with stroke of undetermined etiology and, as controls, patients with cardioembolic stroke. We used noncontrast computed tomography to measure calcification in both intracranial ICAs, including qualitative calcium scoring and quantitative scoring utilizing the Agatston-Janowitz (AJ) calcium scoring. Within subjects, the Wilcoxon signed-rank sum test for nonparametric paired data was used to compare the calcium burden in the ICA upstream of the infarction versus the ICA on the unaffected side. We obtained 440 calcium measures from 110 ICAs in 55 patients. Among 34 patients with stroke of undetermined etiology, we found greater calcium in the ICA ipsilateral to the infarction (mean Modified Woodcock Visual Scale score, 6.7 ± 4.6) compared with the contralateral side (5.4 ± 4.1) (P = .005). Among 21 patients with cardioembolic stroke, we found no difference in calcium burden ipsilateral to the infarction (6.7 ± 5.9) versus the contralateral side (7.3 ± 6.3) (P = .13). The results were similar using quantitative calcium measurements, including the AJ calcium scores. In patients with strokes of undetermined etiology, the burden of calcified intracranial large-artery plaque was associated with downstream cerebral infarction.

Carotid artery web and ischemic stroke: A case-control study.

To determine whether there is an association between carotid artery web and ischemic stroke. This was a single-center, age- and sex-matched, case-control study. Cases were consecutive patients with anterior circulation ischemic stroke of undetermined etiology (Trial of Org 10172 in Acute Stroke Treatment [TOAST] classification). Controls were consecutive patients with cerebral aneurysms, arteriovenous malformations, or primary intracerebral hemorrhages. Additional inclusion criteria were age <60 years and CT angiography of the neck. Two neuroradiologists diagnosed webs according to previously published criteria. One neuroradiologist also assessed for nonstenotic atherosclerotic plaque (carotid wall thickness ≥3 mm or intramural calcification). We used conditional logistic regression to estimate the odds ratio between carotid web and ischemic stroke and its 95% confidence interval. Fifty-three of 62 cases (85%) were matched by age (within 1 year) and by sex to 102 controls. There was a carotid web in 4 of 53 cases (9.4%) vs 1 of 102 controls (1.0%, odds ratio = 8.0, 95% confidence interval = 1.2-67, p = 0.032). There was no significant difference in the prevalence of nonstenotic carotid atherosclerotic plaque between the case and control groups. There was agreement on diagnosis of web for 163 of 164 patients (99%) and 7 of 8 webs (88%), and the Cohen κ for interobserver agreement was 0.93. There is an association between carotid artery web and ischemic stroke in patients who lack an alternative cause of stroke. Carotid web may be an underappreciated risk factor for stroke.

¿Se ha producido un cambio en la etiología del ictus isquémico en las últimas décadas? Análisis y comparación de una base de datos de ictus actual frente a las históricas

ObjectivesWe aimed to determine whether the aetiology of ischaemic stroke has changed in recent years and, if so, to ascertain the possible reasons for these changes. Patients and methodsWe analysed the epidemiological history and vascular risk factors of all patients diagnosed with ischaemic stroke at Complejo Hospitalario Universitario de Albacete (CHUA) from 2009 to 2014. Ischaemic stroke subtypes were established using the TOAST criteria. Our results were compared to data from the classic Stroke Data Bank (SDB); in addition, both series were compared to those of other hospital databases covering the period between the two. ResultsWe analysed 1664 patients (58% were men) with a mean age of 74 years. Stroke aetiology in both series (CHUA, SDB) was as follows: atherosclerosis (12%, 9%), small-vessel occlusion (13%, 25%), cardioembolism (32%, 19%), stroke of other determined aetiology (3%, 4%), and stroke of undetermined aetiology (40%, 44%). Sixty-three percent of the patients from the CHUA and 42% of the patients from the SDB were older than 70 years. Cardioembolic strokes were more prevalent in patients older than 70 years in both series. Untreated hypertension was more frequent in the SDB (SDB = 31% vs CHUA = 10%). The analysis of other databases shows that the prevalence of cardioembolic stroke is increasing worldwide. ConclusionsOur data show that the prevalence of lacunar strokes is decreasing worldwide whereas cardioembolic strokes are increasingly more frequent in both our hospital and other series compared to the SDB. These differences may be explained by population ageing and the improvements in management of hypertension and detection of cardioembolic arrhythmias in stroke units.

Gadolinium Enhancement in Intracranial Atherosclerotic Plaque and Ischemic Stroke: A Systematic Review and Meta-Analysis.

BackgroundGadolinium enhancement on high‐resolution magnetic resonance imaging (MRI) has been proposed as a marker of inflammation and instability in intracranial atherosclerotic plaque. We performed a systematic review and meta‐analysis to summarize the association between intracranial atherosclerotic plaque enhancement and acute ischemic stroke.Methods and ResultsWe searched the medical literature to identify studies of patients undergoing intracranial vessel wall MRI for evaluation of intracranial atherosclerotic plaque. We recorded study data and assessed study quality, with disagreements in data extraction resolved by a third reader. A random‐effects odds ratio was used to assess whether, in any given patient, cerebral infarction was more likely in the vascular territory supplied by an artery with MRI‐detected plaque enhancement as compared to territory supplied by an artery without enhancement. We calculated between‐study heterogeneity using the Cochrane Q test and publication bias using the Begg‐Mazumdar test. Eight articles published between 2011 and 2015 met inclusion criteria. These studies provided information about plaque enhancement characteristics from 295 arteries in 330 patients. We found a significant positive relationship between MRI enhancement and cerebral infarction in the same vascular territory, with a random effects odds ratio of 10.8 (95% CI 4.1–28.1, P<0.001). No significant heterogeneity (Q=11.08, P=0.14) or publication bias (P=0.80) was present.ConclusionsIntracranial plaque enhancement on high‐resolution vessel wall MRI is strongly associated with ischemic stroke. Evaluation for plaque enhancement on MRI may be a useful test to improve diagnostic yield in patients with ischemic strokes of undetermined etiology.

Stroke etiologic subtype may influence the rate of hyperdense middle cerebral artery sign disappearance after intravenous thrombolysis.

Disappearance of hyperdense middle cerebral artery sign (HMCAS) on non-contrast brain computed tomography (CT) scan is a reliable sign of arterial recanalization after intravenous (IV) thrombolysis for ischemic stroke. We aimed to assess whether stroke etiologic subtype may influence the rate of HMCAS disappearance and the clinical outcome after IV thrombolysis. We conducted a retrospective analysis of data prospectively collected from 1031 consecutive stroke patients treated with IV thrombolysis. Outcome measures were HMCAS disappearance on follow-up CT scan within 22-36h of IV thrombolysis, neurologic improvement (NIH Stroke Scale [NIHSS] ≤4 points from baseline or NIHSS score of 0) at 7days, and modified rankin scale (mRS) ≤1 at 3months. Of 256 patients with HMCAS on admission CT scan, 125 had a cardioembolic stroke, 67 a stroke due to large-artery atherosclerosis (LAA), 58 a stroke of undetermined etiology, and six a stroke secondary to carotid artery dissection. HMCAS disappearance occurred in 145 (56.6%) patients, neurologic improvement in 122 (55.0%) patients, and mRS ≤1 in 64 (32.8%) patients. Compared with cardioembolic stroke patients, patients with stroke due to LAA had lower odds ratios (OR) for HMCAS disappearance (OR 0.29, 95% CI 0.15-0.58, p<0.001), neurologic improvement (OR 0.42, 95% CI 0.22-0.82, p=0.011), and mRS ≤1 (OR 0.18, 95% CI 0.06-0.52, p=0.002). No significant differences in outcome measures were found between cardioembolic strokes and strokes of undetermined etiology. This study suggests that stroke due to LAA is associated with lower rates of HMCAS disappearance, neurologic improvement, and mRS ≤1 after IV thrombolysis, compared with cardioembolic stroke.