Jakob Reith

Body temperature in acute stroke: relation to stroke severity, infarct size, mortality, and outcome

BACKGROUNDnIn laboratory animals, cerebral ischaemia is worsened by hyperthermia and improved by hypothermia. Whether these observations apply to human beings with stroke is unknown. We therefore examined the relation between body temperature on admission with acute stroke and various indices of stroke severity and outcome.nnnMETHODSnIn a prospective and consecutive study 390 stroke patients were admitted to hospital within 6 h after stroke (median 2.4 h). We determined body temperature on admission, initial stroke severity, infarct size, mortality, and outcome in survivors. Stroke severity was measured on admission, weekly, and at discharge on the Scandinavian Stroke Scale (SSS). Infarct size was determined by computed tomography. Multiple logistic and linear regression outcome analyses included relevant confounders and potential predictors such as age, gender, stroke severity on admission, body temperature, infections, leucocytosis, diabetes, hypertension, atrial fibrillation, ischaemic heart disease, smoking previous stroke, and comorbidity.nnnFINDINGSnMortality was lower and outcome better in patients with mild hypothermia on admission; both were worse in patients with hyperthermia. Body temperature was independently related to initial stroke severity (p < 0.009), infarct size (p < 0.0001), mortality (p < 0.02), and outcome in survivors (SSS at discharge) (p < 0.003). For each 1 degrees C increase in body temperature the relative risk of poor outcome (death or SSS score on discharge < 30 points) rose by 2.2 (95% CI 1.4-3.5) (p < 0.002).nnnINTERPRETATIONnWe have shown that, in acute human stroke, an association exists between body temperature and initial stroke severity, infarct size, mortality, and outcome. Only intervention trials of hypothermic treatment can prove whether this relation is causal.

Acute Stroke With Atrial Fibrillation: The Copenhagen Stroke Study

BACKGROUNDnAtrial fibrillation (AF) is a common arrhythmia and a major risk factor for stroke. Many physicians remain reluctant to provide stroke prevention by anticoagulant therapy especially for elderly individuals with AF. Using multivariate regression analyses, we studied the characteristics and the prognosis of stroke in patients with AF.nnnMETHODSnThe study is part of the Copenhagen Stroke Study, a prospective, community-based study of 1197 patients with acute stroke treated on a stroke unit from the time of acute admission to the end of rehabilitation. Initial stroke severity was measured by the Scandinavian Neurological Stroke Scale (SSS). Neurological and functional outcomes were evaluated by the SSS and the Barthel Index.nnnRESULTSnAF was diagnosed in 18% of the patients. AF increased steeply with age in the stroke population, from 2% in patients < 50 years old, 15% in patients in their 70s, and 28% in patients in their 80s, to 40% in patients > or = 90 years of age. In a multivariate analysis AF was associated with age (odds ratio [OR], 2.0 per 10-year increase; 95% confidence ratio [CI], 1.6 to 2.6), ischemic heart disease (OR, 3.4; 95% CI, 2.4 to 4.8), previous stroke (OR, 1.8; 95% CI, 1.2 to 2.6), and systolic blood pressure (OR, 0.93 per 10-mm Hg increases; 95% CI, 0.88 to 0.99), but not with sex, diabetes, hypertension, previous transient ischemic attack, or silent infarction on computed tomography. Patients with AF had a higher mortality rate (OR, 1.7; 95% CI, 1.2 to 2.5), longer hospital stays (50 days versus 40 days, P < .001), and a lower discharge rate to their own homes (OR, 0.60; 95% CI, 0.44 to 0.85). Neurological and functional outcomes were markedly poorer in patients with AF. Poorer outcome was exclusively explained by initially more-severe strokes.nnnCONCLUSIONSnStroke in patients with AF is generally more severe and outcome markedly poorer than in patients with sinus rhythm. This accentuates the importance of anticoagulant treatment of individuals with AF. A lower blood pressure in the acute stage of stroke may contribute to the increased stroke severity in patients with AF.

Feasibility and safety of inducing modest hypothermia in awake patients with acute stroke through surface cooling : A case-control study : the Copenhagen Stroke Study

Background and Purpose Hypothermia reduces neuronal damage in animal stroke models. Whether hypothermia is neuroprotective in patients with acute stroke remains to be clarified. In this case-control study, we evaluated the feasibility and safety of inducing modest hypothermia by a surface cooling method in awake patients with acute stroke. Methods We prospectively included 17 patients (cases) with stroke admitted within 12 hours from stoke onset (mean 3.25 hours). They were given hypothermic treatment for 6 hours by the “forced air” method, a surface cooling method that uses a cooling blanket with a flow of cool air (10°C). Pethidine was given to treat compensatory shivering. Cases were compared with 56 patients (controls) from the Copenhagen Stroke Study matched for age, gender, initial stroke severity, body temperature on admission, and time from stroke onset to admission. Blood cytology, biochemistry, ECGs, and body temperature were monitored during hypothermic treatment. Multiple regression analyses on outcome were performed to examine the safety of hypothermic therapy. Results Body temperature decreased from t0=36.8°C to t6=35.5°C (P <0.001), and hypothermia was present until 4 hours after therapy (t0=36.8°C versus t10=36.5°C;P =0.01). Mortality at 6 months after stroke was 12% in cases versus 23% in controls (P =0.50). Final neurological impairment (Scandinavian Stroke Scale score at 6 months) was mean 42.4 points in cases versus 47.9 in controls (P =0.21). Hypothermic therapy was not a predictor of poor outcome in the multivariate analyses. Conclusions Modest hypothermia can be achieved in awake patients with acute stroke by surface cooling with the “forced air” method, in combination with pethidine to treat shivering. It was not associated with a poor outcome. We suggest a large, randomized clinical trial to test the possible beneficial effect of induced modest hypothermia in unselected patients with stroke.

Seizures in acute stroke: predictors and prognostic significance. The Copenhagen Stroke Study.

BACKGROUNDnDespite the common occurrence of seizures during the early phase of stroke (ES), the effect of ES on prognosis is not known. We determined the relationships between ES and stroke outcome and identified predictors of ES.nnnMETHODSnIn this community-based study, we prospectively and consecutively studied 1197 patients with acute stroke. We determined the number and type of seizures, initial stroke severity, infarct size, mortality, and outcome in survivors. Stroke severity was measured on admission, weekly, and at discharge using the Scandinavian Stroke Scale (SSS). Multiple logistic and linear regression outcome analyses included relevant confounders and potential predictors, including age, gender, stroke severity on admission, atrial fibrillation, ischemic heart disease, diabetes, blood glucose level on admission, claudication, and hypertension.nnnRESULTSnFifty patients (4.2%) had seizures within 14 days of the stroke. In the multivariate analyses, only initial stroke severity was related to ES; stroke type and lesion localization were not related. For each 10-point increase in stroke severity (SSS score), the relative risk of ES increased by a factor of 1.65 (95% confidence interval, 1.4 to 1.9) (P < .0001). ES did not influence the risk of death during hospital stay (P = .56). In survivors, ES was related to a better outcome, equivalent to an increased SSS score of 5.7 points (SE [b] = 1.8; P = .002).nnnCONCLUSIONSnThe decisive factor of ES was initial stroke severity. ES per se was not related to mortality. Surprisingly, in survivors, ES predicted a better outcome. We explain this finding by a relatively larger ischemic penumbra in patients who have an ES after a stroke.

Admission Body Temperature Predicts Long-Term Mortality After Acute Stroke The Copenhagen Stroke Study

Background and Purpose— Body temperature is considered crucial in the management of acute stroke patients. Recently hypothermia applied as a therapy for stroke has been demonstrated to be feasible and safe in acute stroke patients. In the present study, we investigated the predictive role of admission body temperature to the long-term mortality in stroke patients. Methods— We studied 390 patients with acute stroke admitted within 6 hours from stroke onset. Admission clinical characteristics (age, sex, admission stroke severity, admission blood glucose, cardiovascular risk factor profile, and stroke subtype) were recorded for patients with hypothermia (body temperature ≤37°C) versus patients with hyperthermia (body temperature >37°C). Univariately the mortality rates for all patients were studied by Kaplan-Meier statistics. To find independent predictors of long-term mortality for all patients, Cox proportional-hazards models were built. We included all clinical characteristics and body temperature as a continuous variable. Results— Patients with hyperthermia had more severe strokes and more frequently diabetes, whereas no difference was found for the other clinical characteristics. For all patients mortality rate at 60 months after stroke was higher for patients with hyperthermia (73 per 100 cases versus 59 per 10 cases, P =0.001). When body temperature was studied in a multivariate Cox proportional-hazards model, a 1°C increase of admission body temperature independently predicted a 30% relative increase (95% CI, 4% to 57%) in long-term mortality risk. For 3-month survivors we found no association between body temperature and long-term survival when studied in a multivariate Cox proportional hazard model (hazards ratio, 1.11 per 1°C; 95% CI, 0.82 to 1.52). Conclusion— Low body temperature on admission is considered to be an independent predictor of good short-term outcome. The present study suggests that admission body temperature seems to be a major determinant even for long-term mortality after stroke. Hypothermic therapy in the early stage in which body temperature is kept low for a longer period after ictus could be a long-lasting neuroprotective measure.

What Determines Good Recovery in Patients With the Most Severe Strokes? The Copenhagen Stroke Study

BACKGROUND AND PURPOSEnEven patients with the most severe strokes sometimes experience a remarkably good recovery. We evaluated possible predictors of a good outcome to search for new therapeutic strategies.nnnMETHODSnWe included the 223 patients (19%) with the most severe strokes (Scandinavian Stroke Scale score <15 points) from the 1197 unselected patients in the Copenhagen Stroke Study. Of these, 139 (62%) died in the hospital and were excluded. The 26 survivors (31%) with a good functional outcome (Barthel Index >/=50 points) were compared with the 58 survivors (69%) with a poor functional outcome (Barthel Index <50 points). The predictive value of the following factors was examined in a multivariate logistic regression model: age; sex; a spouse; work; home care before stroke; initial stroke severity; blood pressure, blood glucose, and body temperature on admission; stroke subtype; neurological impairment 1 week after onset; diabetes; hypertension; atrial fibrillation; ischemic heart disease; previous stroke; and other disabling disease.nnnRESULTSnDecreasing age (odds ratio [OR], 0.50 per 10-year decrease; 95% CI, 0.25 to 0.99; P=0.04), a spouse (OR, 3.1; 95% CI, 1.1 to 8. 8; P=0.03), decreasing body temperature on admission (OR, 1.8 per 1 degrees C decrease; 95% CI, 1.1 to 3.1; P=0.01), and neurological recovery after 1 week (OR, 3.2 per 10-point increase in Scandinavian Stroke Scale score; 95% CI, 1.1 to 7.8; P=0.01) were all independent predictors of good functional outcome.nnnCONCLUSIONSnPatients with the most severe strokes who achieve a good functional outcome are generally characterized by younger age, the presence of a spouse at home, and early neurological recovery. Body temperature was a strong predictor of good functional outcome and the only potentially modifiable factor. We suggest that a randomized controlled trial be undertaken to evaluate whether active reduction of body temperature can improve the generally poor prognosis of patients with the most severe strokes.

Leukocytosis in acute stroke: Relation to initial stroke severity, infarct size, and outcome: The copenhagen stroke study*

UNLABELLEDnLeukocytosis is a common finding in the acute phase of stroke. A detrimental effect of leukocytosis on stroke outcome has been suggested, and trials aiming at reducing the leukocyte response in acute stroke are currently being conducted. However, the influence of leukocytosis on stroke outcome has not been clarified.nnnMETHODSnIn 763 unselected patients with stroke admitted within 24 hours from onset, we prospectively studied the relation between leukocyte count and outcome considering relevant confounders and predictors such as initial stroke severity, risk factor profile, body temperature, and infection.nnnRESULTSnUnivariate, leukocyte count on admission was significantly related to initial stroke severity (assessed by the Scandinavian Stroke Scale), lesion size on computed tomography, mortality, and outcome in survivors. However, multivariate regression analysis revealed that only the relation between leukocytosis and initial stroke severity was independent of other factors, whereas the relations found univariately between leukocytosis and lesion size, mortality, and outcome in survivors disappeared when initial stroke severity was included in the multivariate model.nnnCONCLUSIONnLeukocytosis on admission was related to initial stroke severity but not to outcome. Leukocyte count on admission seems merely to reflect initial stroke severity and is most likely a stress response with no independent influence on outcome. Our study may suggest that attempts aimed merely at lowering leukocyte count in peripheral circulating blood in the acute phase of stroke cannot be expected to improve outcome.

Potentially Reversible Factors during the Very Acute Phase of Stroke and Their Impact on the Prognosis: Is There a Large Therapeutic Potential to Be Explored?

In the Copenhagen Stroke Study, we evaluated the combined impact on stroke outcome of potentially treatable factors such as acute body temperature, blood glucose, and stroke in progression. The patients were stratified into two groups: (1) patients with ‘good’ prognostic parameters (body temperature on admission ≤37.0°C and plasma glucose on admission ≤6.5 mmol/l and who did not develop stroke in progression) and (2) patients with correspondingly ‘poor’ prognostic parameters. A poor outcome was observed in 4% of the patients with good prognostic parameters versus in 49% of the patients with poor prognostic parameters (p < 0.01). In the multivariate analysis which also included stroke severity, blood glucose contributed significantly to poor outcome with an odds ratio (OR) of 1.2/1.0 mmol/l increase, body temperature with an OR of 2.2/1°C increase, and stroke in progression with an OR of 2.9. However, the combined effect of all three factors was more than additive with an OR of 10.0 (95% CI 1.5–56; p < 0.01). We have shown that in human stroke a strong and more than additive association exists between potentially reversible parameters and outcome. Intervention trials can prove whether these marked relations are causal.

Carotid Doppler - costs and need after stroke or TIA.

Objectives– To estimate the need for and the costs of carotid Doppler and carotid endarterectomy after stroke or TIA in non‐selected hospitalized patients. Material and methods– During 25 months hospitalized patients with stroke or TIA, in whom carotid endarterectomy could be relevant, were examined with carotid Doppler. If a significant stenosis was found, they were further evaluated for surgery. Based on our results, the requirement for future carotid endarterectomy and Doppler screening was estimated, and the costs of the procedures calculated. Results– Among 1351 patients 703 were screened with carotid Doppler. Forty‐five had severe (70–99%) stenosis of the relevant carotid artery. Only 3 were operated on. The future costs of screening were estimated under different assumptions. Conclusion– Carotid endarterectomy is expensive due to the large number of patients screened with carotid Doppler per operated patient. A careful clinical selection of patients for screening is necessary.