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F van Kooten

Publications and source records attributed to F van Kooten.

At least 19 recordsLinked to original sources
PubMed2006

Randomized controlled trial of acetylsalicylic acid in aneurysmal subarachnoid hemorrhage: the MASH Study.

BACKGROUND AND PURPOSE: A previous systematic review of randomized trials suggested a positive effect of antiplatelet therapy in patients with aneurysmal subarachnoid hemorrhage (SAH). We performed a randomized controlled trial to assess whether acetylsalicylic acid (ASA) reduces the risk of delayed ischemic neurological deficit (DIND) in patients with SAH. METHODS: Criteria for inclusion were aneurysm treatment within 4 days after SAH. Trial medication (14 daily suppositories with 100 mg ASA or placebo) was started within 12 hours after aneurysm treatment. Analysis for the primary outcome event DIND was made according to the "on-treatment" principle and for the secondary outcome measures "poor outcome" and "nonexcellent outcome" according to the "intention-to-treat" principle. RESULTS: Inclusion was stopped after the second interim analysis, when 161 of the planned 200 patients were included, because by then the chances of a positive effect were negligible. At the final analysis, ASA did not reduce the risk of DIND (hazard ratio, 1.83; 95% CI, 0.85 to 3.9). The relative risk reduction for poor outcome was 21% (relative risk, 0.79; 95% CI, 0.38 to 1.6). CONCLUSIONS: ASA given after aneurysm treatment does not appreciably reduce the occurrence of DIND.

Aneurysm, Ruptured↗
PubMed2005

Efficacy of the epidural blood patch for the treatment of post lumbar puncture headache BLOPP: a randomised, observer-blind, controlled clinical trial [ISRCTN 71598245].

BACKGROUND: Post dural punction headache (PDPH) occurs in 10% to 40% of the patients who had a lumbar puncture. Its symptoms can be severe and incapacitating. The epidural blood patch is widely accepted as the treatment of choice for postdural puncture headache. Uncontrolled studies report rapid recovery after patching in 90% to 100% of treated patients. However, sufficient evidence from randomised, controlled clinical trials is lacking. METHODS: BLOPP (blood patch for post dural puncture headache) is a randomised, single centre, observer-blind clinical trial. Patients with PDPH for at least 24 hours and at most 7 days after lumbar puncture will be randomised to treatment with an epidural blood patch (EDBP) or to conventional treatment, i.e. 24 hours bed rest and ample fluid intake. PDPH 24 hours after treatment, classified on a 4-point scale (no, mild, moderate, severe) is the primary outcome. The secondary outcome is the presence of PDPH 7 days after treatment. We estimated that a sample size of 2 x 20 patients would provide us with a power of 80% to detect a relative reduction in number of patients with persisting PDPH after 24 hours of 50% at the usual significance level alpha = 5%, taking into account that in approximately 10% of the patients the PDPH will have resolved spontaneously after one day. DISCUSSION: The EDBP is accepted as the treatment of choice for PDPH although randomised, controlled data is scarce. Our randomised, observer-blind clinical trial enables us to compare the efficacy of two clinically practiced methods of PDPH treatment; EDBP versus conventional treatment, as they are applied in clinical practise.

Adolescent↗
PubMed2005

Magnesium sulfate in aneurysmal subarachnoid hemorrhage: a randomized controlled trial.

BACKGROUND AND PURPOSE: Magnesium reverses cerebral vasospasm and reduces infarct volume after experimental subarachnoid hemorrhage (SAH) in rats. We aimed to assess whether magnesium reduces the frequency of delayed cerebral ischemia (DCI) in patients with aneurysmal SAH. METHODS: Patients were randomized within 4 days after SAH. Magnesium sulfate therapy consisted of a continuous intravenous dose of 64 mmol/L per day, to be started within 4 days after SAH and continued until 14 days after occlusion of the aneurysm. The primary outcome DCI (defined as the occurrence of a new hypodense lesion on computed tomography compatible with clinical features of DCI) was analyzed according to the "on-treatment" principle. For the secondary outcome measures "poor outcome" (Rankin >3) and "excellent outcome" (Rankin 0), we used the "intention-to-treat" principle. RESULTS: A total of 283 patients were randomized. Magnesium treatment reduced the risk of DCI by 34% (hazard ratio, 0.66; 95% CI, 0.38 to 1.14). After 3 months, the risk reduction for poor outcome was 23% (risk ratio, 0.77; 95% CI, 0.54 to 1.09). At that time, 18 patients in the treatment group and 6 in the placebo group had an excellent outcome (risk ratio, 3.4; 95% CI, 1.3 to 8.9). CONCLUSIONS: This study suggests that magnesium reduces DCI and subsequent poor outcome, but the results are not yet definitive. A next step should be a phase III trial to confirm the beneficial effect of magnesium therapy, with poor outcome as primary outcome.

Brain Ischemia↗
PubMed2005

Diagnostic value of the Rotterdam-CAMCOG in post-stroke dementia.

BACKGROUND AND OBJECTIVE: Specific screening tests to detect post-stroke dementia are lacking. We recently reported that an adaptation of the Cambridge Cognitive Examination (CAMCOG), the Rotterdam-CAMCOG, had excellent sensitivity and specificity for detecting post-stroke dementia. In this study, we externally validated the diagnostic accuracy of the R-CAMCOG in a new, representative cohort of stroke patients. METHODS: The R-CAMCOG and an extensive neuropsychological examination were administered, independently of each other, in 121 patients aged 55 and over with a stroke in the preceding three to nine months. The gold standard diagnosis of dementia was based on the results of the extensive neuropsychological examination, clinical presentation, and information from a close relative, as well as DSM-IV criteria. RESULTS: Of the 121 patients, 35 had dementia (29%). The diagnostic accuracy at the pre-specified cut-off point of 33/34 was established through receiver operating characteristic (ROC) analyses (sensitivity 66%, specificity 94%). At a cut-off point of 36/37 sensitivity would be 83% and specificity 78%. CONCLUSION: The R-CAMCOG is a useful screening tool for post-stroke dementia in a clinical setting.

Aged↗
PubMed2000

The validity and reliability of signs of early infarction on CT in acute ischaemic stroke.

It has been suggested that subtle signs of early cerebral infarction on CT are important indicators of outcome and of the effect of thrombolytic treatment in acute ischaemic stroke. We studied these signs prospectively, in 260 patients with an anterior circulation stroke from a European-Australian randomised trial of lubeluzole in acute ischaemic stroke. Interobserver reliability was assessed by means of the chi statistic. The validity of the early signs was assessed by comparing the assessments of the first CT with another CT at 1 week after the onset of stroke, and with stroke outcome at 12 weeks. Each initial CT study was assessed by two of a group of five reviewers, who were blinded to each other's assessments and to the findings on the follow-up CT. The images were assessed twice, once without clinical information and again after disclosure of the side (left or right hemisphere) of the lesion. All reviewers were experienced clinicians with a special interest and training in vascular neurology and CT. The median time between stroke onset and the first CT was 3.2 h; 59% of the patients were imaged within 3 h and 77% within 6 h. More than half of the patients (52%) had a large middle cerebral artery territory (MCA) infarct on follow-up CT. Chance-adjusted interobserver agreement (chi) for any early infarct was 0.27 (95% confidence interval (CI): 0.15 to 0.39). Agreement (chi) on the extent of a middle cerebral artery (MCA) infarct and on the indication for treatment with recombinant tissue plasminogen activator (rt-PA) was fair: 0.37 and 0.35, respectively. Patients with early signs of an infarct of more than 1/3 of the MCA territory were more likely to have a large MCA infarct on follow-up CT (odds ratio 5.7, 95% confidence interval 2.8-11.5); the positive and negative predictive value of these signs was 81% and 57%, respectively. Chance-adjusted interobserver agreement on early, subtle signs of a large MCA territory infarct on CT by neurologists was thus no more than fair, and the accuracy of prediction of actual infarct size on the basis of these signs only moderate, under circumstances which resemble everyday clinical practice.

Adult↗
PubMed2000

A short screening instrument for poststroke dementia : the R-CAMCOG.

BACKGROUND AND PURPOSE: The CAMCOG is a feasible cognitive screening instrument for dementia in patients with a recent stroke. A major disadvantage of the CAMCOG, however, is its lengthy and relatively complex administration for screening purposes. We therefore developed the Rotterdam CAMCOG (R-CAMCOG), based on the original version. Our aim was to reduce the estimated administration time to 15 minutes or less and to retain or perhaps even improve its diagnostic accuracy. METHODS: We analyzed the item scores on the CAMCOG of 300 consecutive stroke patients, after exclusion of patients with a severe aphasia or lowered consciousness level, who were entered in the Rotterdam Stroke Databank. The diagnosis of dementia was made independent of the R-CAMCOG score, on the basis of clinical examination and neuropsychological test results. The R-CAMCOG was constructed in 3 steps. First, items with floor and ceiling effects were removed. Next, subscales with no additional diagnostic value were excluded. Finally, we removed items that did not contribute to the homogeneity of the subscales. The diagnostic accuracy of the R-CAMCOG and the original CAMCOG was determined by means of the area under the receiver operating characteristic (ROC) curve. RESULTS: In the 3 steps, the number of items was reduced from 59 to 25, divided over the subscales orientation, memory (recent, remote, and learning), perception, and abstraction. The subscale orientation did not reach significance in a logistic regression model but was included in the R-CAMCOG because of its high face validity in dementia screening. Internal validation with ROC analysis suggests that the R-CAMCOG and the CAMCOG are equally accurate in screening for poststroke dementia (area under the curve was 0.95 for both tests). CONCLUSIONS: The R-CAMCOG has overcome the disadvantages of the original CAMCOG. It is a promising, short, and easy-to-administer screening instrument for poststroke dementia. It seems to be sufficiently accurate for this purpose, but the test has yet to be validated in a separate, independent study.

Aged↗
PubMed1999

The diagnostic value of colour duplex ultrasound for symptomatic carotid stenosis in clinical practice.

We assessed the accuracy of colour duplex ultrasound for the detection of severe (70-99%) symptomatic carotid stenosis in a clinical setting, in order to assess whether it could make carotid angiography unnecessary. In 152 patients with a transient ischaemic attack or nondisabling ischaemic stroke in the carotid distribution, we compared the degree of colour duplex ultrasound stenosis with angiographic stenosis by receiver-operating-characteristic analysis. The angiograms were evaluated by blinded observers, and compared with routine reports of the colour duplex examination. We computed the sensitivity and specificity of colour duplex, and the number of angiograms and sonographic studies needed to prevent one stroke within 3 years, taking into account the risks of angiography, and the risks and efficacy of endarterectomy. The estimates were adjusted for nonverification bias. We found 34 patients (22%) with a severe (70-99%) symptomatic carotid stenosis. In 16 patients (11%) the symptomatic artery was occluded. The sensitivity and specificity of duplex ultrasound were 76% and 85%, respectively. The number of patients needed to undergo angiography to prevent one stroke was reduced from almost 200 to 33, when colour duplex was used as a preoperative examination. After adjustment for the effects of nonverification, the sensitivity dropped to 58% and the number of duplex studies needed to prevent one stroke would double. The number of angiograms needed after positive duplex sonography would be virtually unaffected. Were colour duplex sonography to have been the sole preoperative investigation, the number needed to diagnose to prevent one stroke within 3 years would be approximately 350, more than twice as many as with the combined diagnostic strategy. The diagnostic accuracy of colour duplex sonography in clinical practice seems less impressive than previous studies have suggested, but it remains an effective way to select patients for angiography. Its use as a single preoperative assessment cannot be recommended.

Adult↗
PubMed1999

Increased platelet activation in the chronic phase after cerebral ischemia and intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Enhanced thromboxane (TX) biosynthesis has previously been reported in the acute phase after ischemic stroke. We investigated whether enhanced urinary excretion of 11-dehydro-TXB2, a noninvasive index of platelet activation, was present in the chronic phase after a transient ischemic attack (TIA) or stroke, including intracerebral hemorrhage. METHODS: We obtained a single urinary sample from 92 patients between 3 and 9 months after onset of stroke or TIA. The urinary excretion of the major enzymatic metabolite of TXA2, 11-dehydro-TXB2, was measured by a previously validated radioimmunoassay. The excretion rates were compared with those of 20 control patients with nonvascular neurological diseases. RESULTS: Urinary 11-dehydro-TXB2 averaged 294+/-139, 413+/-419, and 557+/-432 pmol/mmol creatinine for patients with TIA, ischemic stroke, and intracerebral hemorrhage, respectively; the values were higher in all subgroups (P<0.01) than that in control patients (119+/-66 pmol/mmol). Increased 11-dehydro-TXB2 excretion was present in 59% of all patients, in 60% (P<0.001) of patients with TIA, in 56% (P<0.001) of patients with ischemic stroke, and in 73% (P<0.001) of patients with intracerebral hemorrhage. Atrial fibrillation, no aspirin use, and severity of symptoms at follow-up contributed independently to the level of 11-dehydro-TXB2 excretion in a multiple linear regression analysis. CONCLUSIONS: Platelet activation is often present in patients in the chronic phase after stroke, including those with intracerebral hemorrhage. Persistent platelet activation, which is associated with atrial fibrillation and poor stroke outcome, can be substantially suppressed by aspirin treatment.

Brain Ischemia↗
PubMed1999

Increased thromboxane biosynthesis is associated with poststroke dementia.

BACKGROUND AND PURPOSE: It has been suggested that daily intake of aspirin is associated with a reduction of cognitive decline, both in normal and in demented subjects, but the mechanism is unclear. We have therefore studied the relationship between thromboxane (TX) A(2) biosynthesis, as reflected by the urinary excretion of 11-dehydro-TXB(2), and the presence of dementia in patients after acute stroke. METHODS: Patients from the Rotterdam Stroke Databank were screened for dementia between 3 and 9 months after stroke. Patients had a full neurological examination, neuropsychological screening, and, if indicated, extensive neuropsychological examination. Criteria used for the diagnosis of dementia were from the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (Revised). Urine samples were taken at the time of screening. Urinary 11-dehydro-TXB(2) was measured by means of a previously validated radioimmunoassay. RESULTS: Dementia was diagnosed in 71 patients, and urine samples were available for 62. Median value (range) of 11-dehydro-TXB(2) was 399 (89 to 2105) pmol/mmol creatinine for demented patients versus 273 (80 to 1957) for 69 controls with stroke but without dementia (P=0.013). No difference was found between 44 patients with vascular dementia, 404 (89 to 2105) pmol/mmol creatinine, and 18 patients with Alzheimer's disease plus cerebrovascular disease, 399 (96 to 1467) pmol/mmol creatinine (P=0.68). In a stepwise logistic regression analysis, in which possible confounders such as use of antiplatelet medication, cardiovascular risk factors, and type of stroke were taken into account, increased urinary excretion of 11-dehydro-TXB(2) remained independently related to the presence of dementia (OR 1.12, 95% CI 1.03 to 1.22 per 100 pmol/mmol creatinine). The difference in metabolite excretion rates between demented and nondemented patients was most prominent within the subgroup of ischemic stroke patients who received aspirin (P<0.01). CONCLUSIONS: Increased thromboxane biosynthesis in the chronic phase after stroke is associated with the presence of but not the type of poststroke dementia. It is particularly apparent in patients on aspirin, thereby suggesting the involvement of extraplatelet sources of TXA(2) production in this setting.

Aged↗
PubMed1998

Coagulation disorders in young adults with acute cerebral ischaemia.

We analysed the results of coagulation studies in an unselected series of young adults with acute cerebral ischaemia. Our aims were (a) to determine the prevalence of coagulation disorders among these patients, (b) to investigate the relation between the presence of coagulation abnormalities and large vessel disease or potential sources of cardiac embolism and (c) to evaluate the occurrence of thrombotic events in patients with or without coagulation disorders. One hundred and twenty consecutively admitted patients (53 men, 67 women, median age 38 years, range 15-45) who presented with acute cerebral infarction (n = 89) or a transient ischaemic attack (n = 31) were evaluated. Diagnostic studies consisted of electrocardiography, echocardiography, duplex scanning, and/or angiography. Coagulation studies included activity tests of protein S, protein C, antithrombin, plasminogen, measurement of immunoglobulin G (IgG) anticardiolipin antibodies (ACLA), and a dilute prothrombin assay. Initially, 30 patients had increased ACLA titres and 28 had an abnormal dilute prothrombin assay, suggesting lupus anticoagulant. Decreased protein S, protein C and antithrombin activity were detected in 20, 3 and 3 patients, respectively, excluding patients in whom the abnormalities could be explained by the use of medication, by pregnancy or puerperium. We detected a decreased activity of plasminogen in 5 patients. The disorders could be confirmed by a second assessment in only 2 patients with a protein S deficiency, in none of the patients with a protein C or antithrombin deficiency and in 1 patient with plasminogen deficiency. However, the abnormalities persisted in 19 of 21 patients with increased anticardiolipin IgG titres and in 9 of 20 patients with lupus anticoagulant. A confirmed coagulation disorder was not associated with stroke type or vascular risk factors, but it was more common among patients with large vessel disease (odds ratio: 3.8, 95% confidence interval (CI): 1.1-12.8). Sixteen patients had a recurrent thromboembolic event, but the risk of recurrence was not increased among patients with a confirmed coagulation disorder. Our results suggest that idiopathic coagulation disorders are found in about a quarter of young stroke patients. They are difficult to predict and probably interact with other risk factors.

Adolescent↗
PubMed1998

The Dutch Vascular Factors in Dementia Study: rationale and design.

Dementia is a rapidly increasing health problem in the industrialized countries. With the ageing of the population the number of demented persons increases both in relative and absolute terms. Obviously, there is a need for prevention and intervention strategies. We describe the methods and baseline findings of a large study aimed at identifying potentially modifiable vascular, thrombogenic, and metabolic determinants of dementia. The study population consists of subjects 55 years of age or older. Since the vascular wall of the cerebral vessels is different from that of the coronary or peripheral vessels, we formed three subgroups in which vascular risk factors for dementia are studied. Subjects with stroke were distinguished from subjects with coronary or peripheral artery disease, and from subjects without stroke or coronary or peripheral artery disease. To obtain a large enough number of subjects with stroke, cases and controls from a stroke registry were combined with cases and controls of a population-based study from the same region. For the diagnosis of dementia the DSM-III-R criteria were used. Extensive information on cardiovascular risk factors was collected, including indicators of atherosclerosis. Blood and urine were sampled to study platelet function and thrombogenic and metabolic factors. The study population consists of 7,466 subjects, of whom 300 were recruited from a hospital-based stroke registry. Coronary or peripheral artery disease was present in 956 subjects and stroke in 617. Dementia was present in 434 (5.8%) of all subjects. The prevalence of dementia was 3.0, 24.0, and 4.4% in subjects with a history of coronary or peripheral artery disease, a history of stroke, and subjects without a history of coronary or peripheral artery disease or stroke, respectively. The study will allow us to investigate the role of vascular factors in dementia, irrespective of its cause.

Adult↗
PubMed1998

The CAMCOG: a useful screening instrument for dementia in stroke patients.

BACKGROUND AND PURPOSE: Most mental screening tests focus on the detection of cognitive deficits compatible with Alzheimer's disease. Stroke patients who develop a dementia syndrome, however, constitute a more heterogeneous group with both cortical and subcortical disturbances. We assessed the diagnostic accuracy of the CAMCOG (the cognitive and self-contained part of the Cambridge Examination for Mental Disorders of the Elderly) and the Mini-Mental State Examination (MMSE) for dementia in patients with a recent stroke. METHODS: In patients aged 55 and older who were admitted in the Rotterdam Stroke Databank, cognitive functioning was assessed between 3 and 9 months after the most recent stroke. The "gold standard" diagnosis of dementia was compatible with the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised. The CAMCOG and MMSE scores were obtained independent of the diagnostic procedure. RESULTS: Of 300 consecutive patients, 71 (23.7%) were demented. Sixteen severely demented patients could not be tested and were excluded. The CAMCOG and MMSE scores were significantly related to dementia (both P<0.0001) in a logistic regression model. Receiver operating characteristic analysis showed that the CAMCOG was a more accurate screening instrument (area under the curve for CAMCOG, 0.95; for MMSE, 0.90). Two other clinical variables independently improved the diagnostic accuracy of the MMSE and CAMCOG: patients with a left hemispheric lesion had a lower (odds ratio, 0.3; 95% confidence interval, 0.1 to 0.7), and patients with hemorrhagic stroke had a greater chance of being demented (odds ratio, 3; 95% confidence interval, 1 to 10). The effect of left hemispheric lesion as an independent diagnostic factor could not be explained by selection or its association with aphasia alone. CONCLUSIONS: The CAMCOG is a feasible instrument for use in patients with a recent transient ischemic attack or stroke. It is a more accurate screening tool for dementia than the MMSE, especially when type and site of stroke are taken into account.

Aged↗
PubMed1997

Interobserver agreement for 10% categories of angiographic carotid stenosis.

BACKGROUND AND PURPOSE: Although the reliability of the assessment of severe 70% to 99% carotid stenosis by carotid angiography has been proven excellent, this may not necessarily be the case for a more detailed classification of carotid stenoses by 10% categories. METHODS: Angiograms of the carotid arteries were assessed pairwise by three independent, experienced observers. The measurements of the degree of stenosis of both the carotid bifurcation and the internal carotid artery were made according to the European Carotid Surgery Trial method. Kappa statistics were used to assess the agreement beyond chance for severe (70% to 99%) carotid stenosis (kappa 1) and for 10% categories of carotid stenosis (kappa 2). The penalty scores were adjusted by weights for the relative difference in risk (RDR) of stroke in the ipsilateral carotid distribution between the 10% categories (kappa 3). An adjustment of the RDR method was made by assuming that only patients with a severe carotid stenosis would undergo surgery, and the penalty would be 0 if no disagreement would exist about the indication for surgery (kappa 4). An even further adjustment (kappa 5) was made by assuming that assessment of the rate of carotid stenosis by one or both observers would lead to different treatment recommendations in 50% of the cases, and accordingly the penalty for disagreement (RDR) was halved. RESULTS: One hundred twenty-one carotid bifurcations in 65 patients with a transient ischemic attack or nondisabling stroke were assessed. The intraclass correlation between the exact estimates of carotid stenosis was .90 (95% confidence interval, .85 to .92). The mean difference in stenosis between the two raters was 0.8% (95% confidence interval, -2.1% to 3.7%). kappa 1 to kappa 5 equaled 0.80, 0.40, 0.79, 0.91, and 0.92, respectively. CONCLUSIONS: Interobserver agreement for distinct 10% categories of angiographic carotid stenosis is moderate, but when realistic risk- and decision-based weights are used, agreement between experienced observers can be almost perfect.

Adult↗
PubMed1997

Platelet activation and lipid peroxidation in patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: Both platelet activation and lipid peroxidation are potential sources of vasoactive eicosanoids that can be produced via the cyclooxygenase pathway, ie, thromboxane (TX) A2, or by free radical-catalyzed peroxidation of arachidonic acid, ie, isoprostanes. We investigated the biosynthesis of TXA2 and F2-isoprostanes, as reflected by the urinary excretion of 11-dehydro-TXB2 and 8-epi-prostaglandin (PG) F2 alpha respectively, in 62 consecutive patients (30 men, 32 women; mean age, 67 +/- 14 years) with acute ischemic stroke. METHODS: At least two consecutive 6-hour urine samples were obtained during the first 72 hours after onset of symptoms. Urinary eicosanoids were measured by previously described radioimmunoassays. RESULTS: Repeated periods of enhanced thromboxane biosynthesis were found in 52% of patients. Urinary 11-dehydro-TXB2 averaged 221 +/- 207 (mean +/- SD; n = 197; range, 13 to 967) pmol/mmol creatinine in 30 patients treated with cyclooxygenase inhibitors (mostly aspirin) at the time of study versus 392 +/- 392 (n = 186; range, 26 to 2533) in 32 untreated patients (P < .001). The corresponding values for 8-epi-PGF2 alpha excretion were 74 +/- 42 (range, 14 to 206) and 83 +/- 65 (range, 24 to 570) pmol/mmol creatinine (P > .05). The correlation between the two metabolites was moderate in both untreated patients (r = .41, P < .001) and patients with cyclooxygenase inhibitors (r = .31, P < .001). In a multiple regression analysis, increased thromboxane production was independently associated with severity of stroke on admission, atrial fibrillation, and treatment with cyclooxygenase-inhibiting drugs. CONCLUSIONS: We conclude that during the first few days after an acute ischemic stroke (1) platelet activation occurs repeatedly in a cyclooxygenase-dependent fashion; (2) platelet activation is not associated with concurrent changes in isoprostane biosynthesis; (3) platelet activation is independently associated with stroke severity and atrial fibrillation; and (4) isoprostane biosynthesis is largely independent of platelet cyclooxygenase activity.

Acute Disease↗
PubMed1996

Lipoprotein(a) in patients with acute cerebral ischemia.

BACKGROUND AND PURPOSE: In several cross-sectional studies, a high serum lipoprotein(a) [Lp(a)] level was found to be an independent risk factor for cerebral infarction. In a recent prospective study, however, no association was found between Lp(a) levels at baseline and future risk of stroke. Whether Lp(a) is a prognostic factor in a high-risk population of patients with acute ischemic stroke remains unclear. METHODS: We assessed Lp(a) level on admission to study its relationship with cardiovascular risk profile, stroke severity, and prognosis in 151 consecutive patients with acute cerebral ischemia. The mean follow-up period was 2.5 +/- 1.2 years. Lp(a) was measured by means of a solid-phase two-site immunoradiometric assay. RESULTS: Increased Lp(a) levels were found in 53 (35%) of the patients with cerebral ischemia. Median (5th and 95th percentile) values of Lp(a) were 191 (12 and 1539) mg/L and 197 (10 and 1255) mg/L for patients with transient ischemic attack and patients with ischemic stroke, respectively. No relationship was found between Lp(a) levels and stroke severity (P=.68) or the occurrence of vascular events during follow-up (P log rank=0.81). CONCLUSIONS: We conclude that Lp(a) is increased in about one third of patients with acute cerebral ischemia, but it does not appear to be associated with the cardiovascular risk profile, stroke characteristics, or the prognosis of such patients.

Acute Disease↗
PubMed1995

Comparison of CT in patients with cerebral ischaemia with or without non-rheumatic atrial fibrillation. European Atrial Fibrillation Trial and Dutch T I A Trial Study Groups.

In an attempt to distinguish between the CT characteristics of strokes of presumed cardioembolic origin and strokes caused by arterial disease, a comparison was made between the baseline CT of two prospective cohorts of patients with transient ischaemic attack or minor ischaemic stroke, with (n = 985) or without (n = 2987) non-rheumatic atrial fibrillation (NRAF). Of the patients with NRAF 54% had evidence of cerebral infarction v 41% of the controls (patients with sinus rhythm (SR); odds ratio (OR) 1.7; 95% confidence interval (95% CI) 1.4-1.9). Patients with NRAF more often had multiple infarcts (OR 1.4; 95% CI 1.1-1.8), and more often infarcts that were not related to current neurological symptoms (OR 1.5; 95% CI 1.2-1.8). For symptomatic infarcts, patients with NRAF more often had cortical end zone infarcts (OR 3.1; 95% CI 2.6-3.8) and cortical border zone infarcts (OR 1.9; 95% CI 1.3-2.9) than patients with SR. Conversely, symptomatic small deep infarcts (lacunae) were more often seen in patients with SR (OR 3.9; 95% CI 2.8-5.4). Multivariate analyses showed that all these findings were independent of differences in baseline characteristics between the two study groups. The CT characteristics overlapped and did not allow a reliable distinction between cardioembolic and atherosclerotic causes of stroke in patients with NRAF.

Aged↗
PubMed1994

Evidence for episodic platelet activation in acute ischemic stroke.

BACKGROUND AND PURPOSE: Enhanced thromboxane biosynthesis has previously been reported in patients with acute ischemic stroke. In this study we examined the time course of thromboxane biosynthesis after the onset of symptoms in 13 patients with acute cerebral infarction. METHODS: We obtained five to eight consecutive 6-hour urine samples from each of these 13 patients within the first 48 hours after onset of symptoms to study the dynamics of platelet activation in this setting. The urinary excretion of the major enzymatic metabolite of thromboxane B2, 11-dehydro-thromboxane B2, was measured by a previously validated radioimmunoassay. The excretion rate was compared with that of 20 control patients with nonvascular neurological diseases. RESULTS: Eleven patients (85%) had at least one value exceeding 2 SD of the control mean (251 pmol/mmol creatinine). The proportion of samples with an elevated 11-dehydro-thromboxane B2 level was markedly similar in each of the eight 6-hour collection periods (mean, 52 +/- 8%; range, 40% to 67%). In 4 patients (31%) the excretion rate was elevated in all measurements obtained. In the 11 patients with enhanced thromboxane biosynthesis, no uniform pattern of changes over time in metabolite excretion emerged, with 3 patients having peak values at 0 to 12 hours, 3 at 12 to 24 hours, 3 at 24 to 36 hours, and 2 at 36 to 48 hours. The level and dynamics of 11-dehydro-thromboxane B2 excretion were related neither to the neurological symptoms nor to the type or site of the cerebral ischemia. CONCLUSIONS: We conclude that episodes of platelet activation occur repeatedly during the first 48 hours after the onset of symptoms of an acute ischemic stroke. Given its apparent dynamic nature, this ongoing process may be amenable to pharmacologic modulation.

Adult↗
PubMed1993

Hyperglycemia in the acute phase of stroke is not caused by stress.

BACKGROUND AND PURPOSE: Hyperglycemia in the acute phase of stroke is associated with poor outcome. Whether hyperglycemia in nondiabetic stroke patients is caused by stress is controversial. METHODS: We studied glucose levels and glycosylated hemoglobin in 91 consecutive patients with acute stroke admitted within 24 hours after onset of symptoms. In 27 unselected patients we also measured catecholamines on days 1 and 3 after onset. RESULTS: Hyperglycemia was found in 39 (43%) of the patients, 55% of whom either had diabetes mellitus or latent diabetes; the others had idiopathic hyperglycemia. Norepinephrine levels were associated with the severity of the stroke (P = .005) and with hypertension (P = .03) but not with glucose levels, irrespective of whether or not the patients had diabetes. CONCLUSIONS: We conclude that hyperglycemia in the acute phase of stroke cannot be explained by increased stress.

Aged↗