Evaluation of Artificial Intelligence-Powered Identification of Large-Vessel Occlusions in a Comprehensive Stroke Center.

BACKGROUND AND PURPOSE: Artificial intelligence algorithms have the potential to become an important diagnostic tool to optimize stroke workflow. Viz LVO is a medical product leveraging a convolutional neural network designed to detect large-vessel occlusions on CTA scans and notify the treatment team within minutes via a dedicated mobile application. We aimed to evaluate the detection accuracy of the Viz LVO in real clinical practice at a comprehensive stroke center. MATERIALS AND METHODS: Viz LVO was installed for this study in a comprehensive stroke center. All consecutive head and neck CTAs performed from January 2018 to March 2019 were scanned by the algorithm for detection of large-vessel occlusions. The system results were compared with the formal reports of senior neuroradiologists used as ground truth for the presence of a large-vessel occlusion. RESULTS: A total of 1167 CTAs were included in the study. Of these, 404 were stroke protocols. Seventy-five (6.4%) patients had a large-vessel occlusion as ground truth; 61 were detected by the system. Sensitivity was 0.81, negative predictive value was 0.99, and accuracy was 0.94. In the stroke protocol subgroup, 72 (17.8%) of 404 patients had a large-vessel occlusion, with 59 identified by the system, showing a sensitivity of 0.82, negative predictive value of 0.96, and accuracy of 0.89. CONCLUSIONS: Our experience evaluating Viz LVO shows that the system has the potential for early identification of patients with stroke with large-vessel occlusions, hopefully improving future management and stroke care.

Plasma myeloperoxidase levels in acute brain ischaemia and high grade carotid stenosis.

BACKGROUND AND PURPOSE: Myeloperoxidase (MPO) is an important oxidative enzyme participating in different stages of cardiovascular disease and predicts prognosis. Little is known about its role in acute cerebrovascular events and carotid plaque vulnerability. In this study, the aim was to assess plasma MPO levels in acute stroke patients and their correlation to stroke severity and stroke outcome. METHODS: Plasma MPO levels were assessed in patients presenting with acute brain ischaemia within 36 h of symptom onset (n = 144, mean age 64.7 ± 11.6 years, 67% men) and in patients with moderate-to-severe carotid stenosis undergoing carotid artery stenting (n = 51, mean age 66.3 ± 8.4 years, 75% men). Patients presenting with acute brain ischaemia were assessed serially for stroke severity and disability. RESULTS: Plasma MPO concentrations (ng/ml) were associated with interleukin-6 (r = 0.38, P < 0.0001) and gender (median interquartile range) of 68.6 (49.8-107.0) vs. 59.7 (42.7-85.5) in women vs. men (P = 0.02). In acute brain ischaemia, MPO concentrations were associated with non-lacunar subtype (bottom, middle and top tertiles 37.5%, 71.7% and 71.7% respectively; P = 0.001), with stroke severity (baseline National Institutes of Health Stroke Scale score > 10, bottom, middle and top tertiles 6.3%, vs. 41.7% and 31.3%, respectively; P < 0.006) as well as with stroke severity at days 1-2, days 4-5 and at discharge (P < 0.05 for all), but less with disability at discharge (modified Rankin Scale score ≥ 2, 41.7% vs. 60.4% and 58.7% for the bottom, middle and top tertiles, respectively; P = 0.096). CONCLUSIONS: Amongst patients with acute brain ischaemia, plasma MPO concentrations were associated with stroke severity and non-lacunar subtype, but not with long-term functional disability.

A novel histochemical method for the visualization of thrombin activity in the nervous system.

Although thrombin has an important role in both central and peripheral nerve diseases, characterization of the anatomical distribution of its proteolytic activity has been limited by available methods. This study presents the development, challenges, validation and implementation of a novel histochemical method for visualization of thrombin activity in the nervous system. The method is based on the cleavage of the substrate, Boc-Asp(OBzl)-Pro-Arg-4MßNA by thrombin to liberate free 4-methoxy-2-naphthylamine (4MßNA). In the presence of 5-nitrosalicylaldehyde, free 4MßNA is captured, yielding an insoluble yellow fluorescent precipitate which marks the site of thrombin activity. The sensitivity of the method was determined in vitro using known concentrations of thrombin while the specificity was verified using a highly specific thrombin inhibitor. Using this method we determined the spatial distribution of thrombin activity in mouse brain following transient middle cerebral artery occlusion (tMCAo) and in mouse sciatic nerve following crush injury. Fluorescence microscopy revealed well-defined thrombin activity localized to the right ischemic hemisphere in cortical areas and in the striatum compared to negligible thrombin activity contralaterally. The histochemical localization of thrombin activity following tMCAo was in good correlation with the infarct areas per triphenyltetrazolium chloride staining and to thrombin activity measured biochemically in tissue punches (85 ± 35 and 20 ± 3 mU/ml, in the cortical and striatum areas respectively, compared to 7 ± 2 and 13 ± 2 mU/ml, in the corresponding contralateral areas; mean ± SEM; p<0.05). In addition, 24 h following crush injury, focal areas of highly elevated thrombin activity were detected in teased sciatic fibers. This observation was supported by the biochemical assay and western blot technique. The histochemical method developed in this study can serve as an important tool for studying the role of thrombin in physiological and pathological conditions.

Stroke in the very elderly: characteristics and outcome in patients aged ≥85 years with a first-ever ischemic stroke.

BACKGROUND: Epidemiological and clinical features of very elderly patients with stroke are still uncertain. Our aim was to study the patient characteristics and outcomes in the very elderly (aged ≥85 years) with a first-ever ischemic stroke in the National Acute Stroke Israeli Survey (NASIS) registry. METHODS: The NASIS registry is a nationwide prospective hospital-based study performed triennially (2004, 2007, 2010). Patients with ischemic stroke aged ≥85 years were compared with those 65-84 years old regarding their baseline characteristics, stroke severity, etiology of stroke and stroke outcomes. Logistic regression analyses were used to adjust for potential confounders. Stroke severity was determined according to the National Institute of Health Stroke Scale (NIHSS) score. RESULTS: The proportion of very elderly (≥85 years) patients among the NASIS population increased from 18.3% in 2004 to 19.9% in 2007 and 24.5% in 2010 (p for trend = 0.005). The percentage of women was higher in patients aged ≥85 years (p < 0.0001). Atrial fibrillation, congestive heart disease and prior disability were significantly more common, while diabetes, current smoking and dyslipidemia were less frequent in the very elderly. The very elderly presented with more severe strokes: 36.3% of the ≥85-year-old patients had an NIHSS score ≥11 compared with 22.0% in the younger age group (p < 0.05). CONCLUSIONS: There is an increasing proportion of very elderly subjects, mostly women, among first-ever ischemic stroke patients. Current information on age-specific aspects of stroke in the very elderly is crucial to set up successful prevention pathways and implementing well-organized stroke care for this population.

Off-hours admission for acute stroke is not associated with worse outcome--a nationwide Israeli stroke project.

BACKGROUND AND PURPOSE: Several studies reported worse outcome for stroke patients arriving on weekends. We compared working hours to off-work hours throughout the week as there is lack of experienced staff and special services during off-hours. METHODS: A nationwide stroke survey project on acute stroke was carried out in all acute care hospitals in Israel during 2004, 2007 and 2010 (2-month each). 'On-hours' were defined as regular Israel working hours and the rest, including holidays, were defined as 'off-hours'. The modified Rankin scale (mRS) at discharge was used for the main analysis on outcome. RESULTS: A total of 4827 acute strokes patients were analyzed (2139 arrived on-hours and 2688 during off-hours). 'Off-hours' patients were 1 year younger (mean 70 vs. 71 years in 'on-hours') had lower rates of prior cardiac interventions, but had higher admission blood pressure levels and had more intracerebral hemorrhages (ICH) (11% vs. 8% in 'on-hours' patients, P < 0.001). Death during hospitalization was recorded in 9% of 'off-hours' vs. 6% of 'on-hours' patient (P = 0.004). Controlling for age, blood pressure, stroke type, pre-stroke mRS, admission NIHSS, and thrombolysis, the relative odds of poor outcome (i.e. mRS ≥ 2) amongst 'off-hours' admissions compared to on-hours was 1.09 (95% CI: 0.92-1.30). Odds ratio amongst ischaemic stroke patients was 1.08 (95% CI: 0.88-1.33). CONCLUSIONS: Off-hours stroke admissions were associated with higher short-term mortality rate, probably due to a higher rate of ICH. After controlling for the latter and other potential confounders, 'off-hours' admissions were not different from 'on-hours' with respect to poor outcome.

Cerebral artery calcification in patients with acute cerebrovascular diseases: determinants and long-term clinical outcome.

BACKGROUND AND PURPOSE: Coronary artery calcium is an independent predictor of all-cause mortality. We sought to examine the determinants of intracranial cerebral artery calcification (CAC) and its association with long-term outcome in a large prospective cohort of stroke patients. METHODS: Consecutive patients hospitalized because of acute stroke (ischaemic and intracerebral hemorrhage) or TIA throughout a large medical center were systematically assessed and followed up for 1 year. Intracranial CAC was assessed from baseline brain CT blinded to clinical data. Patients were categorized to no, mild, and severe CAC according to their total CAC score. Determinants of CAC were studied with logistic regression analysis. Risk of death, Barthel Index ≤ 60 or death and living in a nursing facility or death were assessed. RESULTS: Amongst 1049 patients (mean age: 70 ± 13 years, 59% males) CAC was present in 727 (69%) patients. The main determinants of CAC were increasing age (OR 1.4, 95% CI 1.3-1.6, per 5 years), diabetes (OR: 2.1, 1.4-3.0), smoking (1.4, 1.0-2.2), hypertension (1.4, 1.0-2.1), and prior coronary heart disease (1.9, 1.3-2.9). CAC was associated with mortality and poor outcome amongst patients with ischaemic stroke; however, after adjusting for age and stroke severity, no significant association was observed. In patients with intracerebral hemorrhage, outcomes were not related to CAC. CONCLUSIONS: Intracranial CAC is highly prevalent in patients with acute stroke and its main determinants are older age, diabetes, smoking, hypertension, and prior coronary heart disease. Associations between CAC and mortality or poor functional outcome in the first year after ischaemic stroke are mainly age- and stroke severity-driven.

Ethnic variations in acute ischemic stroke: findings from the National Acute Stroke Israeli Survey (NASIS).

BACKGROUND: We intended to determine ethnic differences in the characteristics, management and outcome of acute ischemic stroke between the Israeli Arab and Jewish populations. METHODS: A national survey was conducted in 2004 at all 28 hospitals in Israel. Information on demographics, transportation, risk factors, clinical presentation, stroke severity, type and subtype, management and clinical outcome was obtained. Mortality during the 36 months after hospitalization was assessed by matching with national mortality data. RESULTS: Of the 1,540 patients, 169 (11%) were Arabs and 1,371 (89%) were Jews. The mean age of Arab patients was 9 years younger than in Jewish patients (63 ± 11 vs. 72 ± 12 years). Also, Arabs were more likely to be obese (OR = 1.72; 95% CI: 1.19-2.50) and have diabetes (OR = 1.41; 95% CI: 1.01-1.96), while Jews were more likely to have dyslipidemia (OR = 1.56; 95% CI: 1.11-2.17). A greater percentage of the Arab patients arrived at the hospital independently (OR = 3.85; 95% CI: 2.56-5.56) and were less likely to arrive within 3 h of symptom onset (OR = 2.33; 95% CI: 1.39-3.85). Arabs suffered increased rates of lacunar stroke (OR = 1.67; 95% CI: 1.14-2.43) and were discharged home more often (OR = 2.40; 95% CI: 1.35-4.25). No differences in severity of stroke, management, complications, disability or mortality were found between the 2 groups. CONCLUSIONS: The unique characteristics of the Arab and Jewish populations should be considered when planning stroke-care services and culturally oriented public education programs.

Derivation and validation of the prolonged length of stay score in acute stroke patients.

BACKGROUND: Length of stay (LOS) is the main cost-determining factor of hospitalization of stroke patients. Our aim was to derive and validate a simple score for the assessment of the risk of prolonged LOS for acute stroke patients in a national setting. METHODS: Ischemic stroke (IS) and intracerebral hemorrhage (ICH) patients in the National Acute Stroke Israeli Surveys (NASIS 2004 and 2007) were included. Predictors of prolonged LOS (LOS > or =7 days) in the NASIS 2004 (n = 1,700) were identified with logistic regression analysis and used for the derivation of the Prolonged Length of Stay (PLOS) score. The score was validated in the NASIS 2007 (n = 1,648). RESULTS: Median (interquartile range) LOS was 6 (3-10) days in the derivation cohort (42.3% prolonged LOS) and 5 (3-8) in the validation cohort (35.7% prolonged LOS). The derivation cohort included 54.8% men, 90.8% IS and 9.2% ICH, with a mean (SD) age of 71.2 (12.5) years. Stroke severity was the strongest multivariable predictor of prolonged LOS: odds ratio (95% confidence interval [CI]) increased from 2.6 (2.0-3.3) for NIH Stroke Scale score (NIHSS) 6-10 to 4.9 (3.0-8.0) for NIHSS 16-20, compared with NIHSS < or =5. Stroke severity and type, decreased level of consciousness on admission, history of congestive heart failure, and prior atrial fibrillation were used for the derivation of the PLOS score (c statistics 0.692, 95% CI 0.666-0.718). The score performed similarly well in the validation cohort (c statistics 0.680, 95% CI 0.653-0.707). CONCLUSION: A simple prolonged length of stay score, based on available baseline information, may be useful for tailoring policy aimed at better use of resources and optimal discharge planning of acute stroke patients.

Kidney function is associated with the rate of cognitive decline in the elderly.

OBJECTIVE: We tested the hypothesis that impaired kidney function in the elderly is associated with a more rapid rate of cognitive decline. METHODS: Baseline serum was used to calculate estimated glomerular filtration rate (eGFR), using the Modification of Diet in Renal Disease formula, for 886 elderly without dementia participating in the Rush Memory and Aging Project, a prospective, observational cohort study. Kidney function was also dichotomized into impairment or no impairment based on eGFR < or >or=60 mL/min/1.73 m(2). Structured cognitive testing was performed at baseline and at annual evaluations, using a battery of 19 cognitive tests summarized into global cognition and 5 cognitive domains. RESULTS: In mixed-effects models adjusted for age, sex, and education, a lower eGFR at baseline was associated with a more rapid rate of cognitive decline (estimate 0.0008, SE <0.001, p = 0.017). The increased rate of cognitive decline associated with a 15-mL/min/1.73 m(2) lower eGFR at baseline (approximately 1 SD) was similar to the effect of being 3 years older at baseline. Impaired kidney function at baseline was associated with a more rapid rate of cognitive decline (estimate -0.028, SE <0.009, p = 0.003). The increased rate of cognitive decline associated with impaired kidney function at baseline was approximately 75% the effect of ApoE4 allele on the rate of cognitive decline. Baseline kidney function was associated with declines in semantic memory, episodic memory, and working memory but not visuospatial abilities or perceptual speed. CONCLUSION: Impaired kidney function is associated with a more rapid rate of cognitive decline in old age.

Increased insulin resistance and risk of incident cerebrovascular events in patients with pre-existing atherothrombotic disease.

BACKGROUND AND PURPOSE: Diabetes and the metabolic syndrome are known risk factors for ischaemic stroke. Our aim was to examine whether amongst patients with pre-existing atherothrombotic disease, increased insulin resistance is associated with incident cerebrovascular events. METHODS: Patients with stable coronary heart disease included in a secondary prevention trial were followed up for a mean of 6.2 years. Coronary heart disease was documented by a history of myocardial infarction > or =6 months and <5 years before enrollment and/or stable angina pectoris with evidence of ischaemia confirmed by ancillary diagnostic testing. Main exclusion criteria were insulin treated diabetes, hepatic or renal failure, and disabling stroke. Baseline insulin levels were measured in 2938 patients from stored frozen plasma samples and increased insulin resistance assessed using the homeostatic model assessment of insulin resistance (HOMA-IR), categorized into tertiles or quartiles. RESULTS: Crude rates of incident cerebrovascular events rose from 5.0% for HOMA-IR at the bottom tertile to 5.7% at the middle tertile, and 7.0% at the top tertile (P = 0.07). HOMA-IR at the top versus bottom tertile was associated with an unadjusted hazard ratio (HR) of 1.37 (95%CI, 0.94-1.98) and a 1-unit increase in the ln HOMA-IR was associated with a HR of 1.14 (95%CI, 0.97-1.35). In further analyses adjusting for potential confounders, or categorizing baseline HOMA-IR into quartiles, or excluding diabetic patients, we did not identify an increased risk for incident cerebrovascular events conferred by the top category. CONCLUSIONS: Increased insulin resistance did not predict incident cerebrovascular events amongst patients with pre-existing atherothrombotic disease.

Cerebral leukoaraiosis in patients with stroke or TIA: clinical correlates and 1-year outcome.

BACKGROUND AND PURPOSE: Cerebral leukoaraiosis is frequently observed in patients with acute stroke, but its clinical consequences on functional recovery remain incompletely defined. We evaluated the clinical correlates of leukoaraiosis, and its association with stroke-outcome in a cohort of consecutively hospitalized patients. METHODS: One-thousand twenty-four consecutive patients with acute stroke or transient ischemic attack (TIA) undergoing brain CT were included in this single-center study. Patients were systematically evaluated at hospitalization and followed-up for 1 year. Mortality, functional outcome, quality of life (QoL), psychological distress, community integration, and patient perception of recovery were evaluated by leukoaraiosis severity. Adjusted ORs (95%CI) were calculated. RESULTS: Moderate/severe leukoaraiosis was diagnosed in 177 patients (17.3%) and mild leukoaraiosis in 362 patients (35.3%). After 1 year, adjusted ORs for moderate/severe leukoaraiosis compared with no leukoaraiosis were 2.0 (95%CI 1.1-4.0) for Barthel Index

Burden of stroke in Israel.

Stroke is the third most common cause of death in Israel, similar to the United States and Europe. A decline in stroke mortality rates for the Israeli population is evident in the last decades. However, stroke is still a major health and economical burden in Israel and has recently been recognized by the Israeli health-care policy planners as a top priority disease. Action plans are being taken in order to establish a comprehensive infrastructure for the treatment of acute stroke patients.

Interleukin-6 and soluble intercellular adhesion molecule-1 in acute brain ischaemia.

Inflammation plays a critical role in the pathogenesis of atherothrombosis. Our aim was to examine the association between plasma concentrations of inflammatory biomarkers and severity and outcome of acute brain ischaemia. Plasma samples were collected within 36 h of symptom onset in patients with acute brain ischaemia, and assessed by conventional ELISA kits for concentration of interleukin-6 (IL-6) and soluble intercellular adhesion molecule-1 (sICAM-1). Patients were assessed serially for stroke severity (National Institute of Health stroke scale) and outcome during follow-up (modified Rankin Scale, mRS; and Stroke Impact Scale-16, SIS). Patients (n = 113, 65% men, mean age 64 +/- 12 years) had a mean IL-6 concentrations of 5.1 +/- 5.0 pg/ml and sICAM-1 of 377 +/- 145 ng/ml. IL-6, but not sICAM-1, concentrations were strongly associated with stroke severity (P < 0.01 at all serial assessments). Ln-transformed IL-6 levels (per 1 SD) were associated with disability (mRS > or = 2, OR = 1.7; 95% CI 1.1-3.0) and poor physical function (SIS < or = 85, OR = 1.7; 95% CI 1.0-2.8). Further adjustment for baseline stroke severity, however, eliminated these associations. Our results suggest that high plasma concentrations of the inflammatory biomarker IL-6 but not sICAM-1 are associated with stroke severity and poorer functional outcome. IL-6 does not add, however, additional prognostic information for stroke outcome beyond that conveyed by the stroke severity.

Aspirin responsiveness in acute brain ischaemia: association with stroke severity and clinical outcome.

PURPOSE: Platelets play a critical role in the pathogenesis of acute brain ischaemia. We studied the association between the degree of inhibition of platelet function by aspirin (ASA) and the severity and outcome of acute brain ischaemia. METHODS: Platelet responsiveness to ASA was assessed in patients with acute brain ischaemia, treated with ASA since hospital admission. The degree of ASA responsiveness was assessed by optical aggregometry and categorized into patients with good response, partial response and complete unresponsiveness to ASA (good responders, partial responders and non-responders, respectively). An additional evaluation of responsiveness to ASA was performed by Impact-R (cone and platelet analyzer). Patients underwent serial clinical assessment during hospitalization, at discharge and during follow-up. RESULTS: Among 105 patients (mean age 63 +/- 12 years; 66% men), impaired ASA responsiveness at baseline as assessed by aggregometry was associated with increased stroke severity at baseline, unfavourable clinical course, and poor functional outcome during follow-up (p < 0.05 for all). Age-adjusted odds ratios in non-responders compared to good responders were 9.8 for severe stroke on admission (95% CI 2.8-34.9), 3.1 for lack of early clinical improvement (95% CI 1.1-8.8) and 8.6 for poor functional outcome during follow-up (95% CI 2.4-30.4). Less robust trends were observed with the Impact-R. CONCLUSIONS: Impaired responsiveness to ASA in acute brain ischaemia is common and is associated with worse neurological deficits at stroke onset, early clinical deterioration and poorer functional outcome. The clinical significance of these findings requires further evaluation in larger longitudinal studies.

C-reactive protein distribution and correlates among men and women with chronic coronary heart disease.

BACKGROUND: C-reactive protein (CRP) elevated in inflammation is associated with atherosclerotic disease. We describe the distribution of CRP and its association with coronary heart disease (CHD) risk factors in a large CHD patient group. METHODS: This analysis comprises 2,723 male and 256 female CHD patients, included in the Bezafibrate Infarction Prevention (BIP) study. High sensitive CRP levels were determined in frozen plasma samples. RESULTS: CRP distribution, was normalized upon log transformation. Levels among women were higher than in men in the entire group (4.4 vs. 3.5 mg/l) and in each age group. Co-morbidities, smoking, lower education level, and use of cardiovascular drugs, were associated with elevated CRP levels in both sexes. The correlation between CRP and body mass index (BMI), insulin and glucose was stronger among women. The explained variability in CRP level was larger in women (20%) compared to men (13%). Among women, BMI explained 10% of CRP variability, whereas the contribution of each variable among men was significantly smaller. CONCLUSIONS: Among men and women with CHD, CRP level was correlated with traditional risk factors and to a lesser degree to manifestation of CHD. BMI is the main contributor to CRP variability, explained by these factors among women.

Relation between the metabolic syndrome and ischemic stroke or transient ischemic attack: a prospective cohort study in patients with atherosclerotic cardiovascular disease.

BACKGROUND AND PURPOSE: The combination of risk factors known as the metabolic syndrome is receiving increased attention, but prospective data on the syndrome's association with ischemic cerebrovascular events are scarce. We explored the relation of metabolic syndrome versus frank diabetes with first-ever ischemic stroke or transient ischemic attack (TIA) in a large cohort of patients with atherosclerotic cardiovascular disease. METHODS: Patients with coronary heart disease, screened for a clinical trial, underwent an extensive medical evaluation and follow-up for cerebrovascular disease over 4.8 to 8.1 years. National Cholesterol Education Program Adult Treatment Panel III criteria were used to define the metabolic syndrome, with body mass index substituted for waist circumference. Patients with previously diagnosed diabetes or with a fasting plasma glucose level >125 mg/dL (> or =7.0 mmol/L) were considered diabetic. RESULTS: The study sample comprised 14,284 patients, of which 3703 (26%) fulfilled the criteria for the metabolic syndrome without diabetes and 3500 others (25%) the criteria for diabetes. Adjusting for stroke risk factors, patients with the metabolic syndrome without diabetes exhibited a 1.49-fold increased odds for ischemic stroke or TIA (95% confidence interval [CI], 1.20 to 1.84), whereas those with frank diabetes had a 2.29-fold increased odds (95% CI, 1.88 to 2.78). The relative odds for ischemic stroke or TIA, associated with presence of the metabolic syndrome per se, were 1.39 (95% CI, 1.10 to 1.77) in men but 2.10 (95% CI, 1.26 to 3.51) in women. Although all components of the metabolic syndrome were associated with increased risk for ischemic stroke or TIA, impaired fasting glucose and hypertension were the strongest predictors of risk. CONCLUSIONS: The presence of the metabolic syndrome, even without diabetes, in patients with pre-existing atherosclerotic vascular disease identifies patients at increased risk for ischemic stroke or TIA. The suggestion of more pronounced risk associated with the metabolic syndrome in women deserves further assessment in other cohorts.

Triggering risk factors for ischemic stroke: a case-crossover study.

BACKGROUND: While vascular risk factors for stroke are well established, little is known about factors that may precipitate the acute event. In this study the authors investigated the association between exposure to seven potential triggers during waking hours and acute onset of ischemic stroke. METHODS: In a case-crossover study, 200 consecutive stroke patients were interviewed 1 to 4 days after the event using a validated questionnaire. Reported exposure to potential triggers including negative and positive emotions, anger, sudden posture changes as response to a startling event, heavy physical exertion, heavy eating, and sudden temperature changes during a 2-hour hazard period prior to stroke onset were compared to the same period during the preceding day and to average exposures in the last year. RESULTS: Seventy-six patients (38%) reported exposure to at least one of the study triggers during the 2-hour hazard period. For all factors combined, the OR was 8.4 (95% CI 4.5 to 18.1). The OR for negative emotions was 14.0 (95% CI 4.4 to 89.7), for anger 14.0 (95% CI 2.8 to 253.6), and for sudden changes in body posture in response to a startling event 24.0 (95% CI 5.1 to 428.9). It is important to interpret the reported ORs as estimates of a short-term 2-hour period relative risk and not as cumulative risks. CONCLUSIONS: Negative emotions, anger, and sudden changes in body posture in response to a startling event appear to be independent triggers for ischemic stroke.