Cognitive impairment frequently co-occurs with type 2 diabetes but is often undiagnosed. Cognitive impairment affects self-management leading to treatment-related complications.
The aim of this study is to develop a stepped diagnostic procedure, consisting of a screening test complemented by an evaluation by a general practitioner (GP), to detect undiagnosed cognitive impairment in older people with type 2 diabetes.
The accuracy of two self-administered cognitive tests, the “Test Your Memory” (TYM) and “Self-Administered Gerocognitive Examination” (SAGE) alone, and in combination with an evaluation by a GP will be assessed. A diagnosis of mild cognitive impairment (MCI) or dementia at a memory clinic will serve as reference standard. This cognitive impairment in diabetes (Cog-ID) study will include 513 people from primary care facilities aged ≥70 with type 2 diabetes. The participants will first fill out the TYM and SAGE tests, followed by a standardized GP evaluation for cognitive impairment, including a mini mental state examination (MMSE). Subsequently, participants suspected of cognitive impairment (on either test or the GP assessment) and a random sample of 15% (65/435) of participants without suspected cognitive impairment will be referred to the memory clinic. At the memory clinic, a medical examination, neuropsychological examination, and magnetic resonance imaging (MRI) of the brain will be performed. Participants will also fill out questionnaires assessing health status and depressive symptoms at baseline and after 6 and 24 months.
This research obtained funding and ethical approval. Enrolment started in August, 2012, and all study-related activities will be completed in September, 2016.
With the results from this study, physicians will be able to detect cognitive impairment affecting type 2 diabetes patients through case-finding, and can use tailored care to reduce associated complications. Additionally, the results may stimulate discussions about cognitive impairment and whether early recognition is desirable.
type 2 diabetes mellitus; cognitive impairment; diagnostic procedure; screening; dementia; elderly
There is a marked lack of evidence on the optimal prevention of ischaemic stroke and other thromboembolic events in patients with non-valvular atrial fibrillation and a recent intracerebral haemorrhage during treatment with oral anticoagulation. These patients are currently treated with oral anticoagulants, antiplatelet drugs, or no antithrombotic treatment, depending on personal and institutional preferences.
Compared with warfarin, the direct oral anticoagulant apixaban reduces the risk of stroke or systemic embolism, intracranial haemorrhage, and case fatality in patients with atrial fibrillation. Compared with aspirin, apixaban reduces the risk of stroke or systemic embolism in patients with atrial fibrillation, and has a similar risk of intracerebral haemorrhage. Novel oral anticoagulants have not been evaluated in patients with atrial fibrillation and a recent intracerebral haemorrhage.
To inform a phase III trial, the phase II Apixaban versus Antiplatelet drugs or no antithrombotic drugs after anticoagulation-associated intraCerebral HaEmorrhage in patients with Atrial Fibrillation (APACHE-AF) trial aims to obtain estimates of the rates of vascular death or non-fatal stroke in patients with atrial fibrillation and a recent anticoagulation-associated intracerebral haemorrhage treated with apixaban and in those in whom oral anticoagulation is avoided.
APACHE-AF is a phase II, multicentre, open-label, parallel-group, randomised clinical trial with masked outcome assessment. One hundred adults with a history of atrial fibrillation and a recent intracerebral haemorrhage during treatment with anticoagulation in whom clinical equipoise exists on the optimal stroke prevention strategy will be enrolled in 14 hospitals in The Netherlands.
These patients will be randomly assigned in a 1:1 ratio to either apixaban or to avoiding oral anticoagulation. Patients in the control group may be treated with antiplatelet drugs at the discretion of the treating physician. The primary outcome is the composite of vascular death or non-fatal stroke during follow-up. We aim to include 100 patients in 2.5 years. All patients will be followed-up for the duration of the study, but at least for 1 year. Recruitment commenced in September 2014 and is ongoing. This trial is funded by the Dutch Heart Foundation (2012 T077) and ZonMW (015008048).
NTR4526 (16 April 2014).
Electronic supplementary material
The online version of this article (doi:10.1186/s13063-015-0898-4) contains supplementary material, which is available to authorized users.
Antiplatelet drugs; Apixaban; Atrial fibrillation; Intracerebral haemorrhage; Randomised controlled trial
A Transient Ischaemic Attack (TIA) bears a high risk of a subsequent ischaemic stroke. Adequate diagnosis of a TIA should be followed immediately by the start of appropriate preventive therapy, including antiplatelets. The diagnosis of a TIA based on symptoms and signs only is notoriously difficult and biomarkers of brain ischaemia might improve the recognition, and target management and prognosis of TIA patients. Our aim is to quantify the added diagnostic value of serum biomarkers of brain ischaemia in patients suspected of TIA.
Study design: a cross-sectional diagnostic accuracy study with an additional six month follow-up period.
Study population: 350 patients suspected of TIA in the primary care setting.
Patients suspected of a TIA will be recruited by at least 200 general practitioners (GPs) in the catchment area of seven TIA outpatient clinics willing to participate in the study. In all patients a blood sample will be drawn as soon as possible after the patient has contacted the GP, but at least within 72 h after onset of symptoms. Participants will be referred by the GP to the regional TIA outpatient clinic for additional investigations, including brain imaging. The ‘definite’ diagnosis (reference standard) will be made by a panel consisting of three experienced neurologists who will use all available diagnostic information and the clinical information obtained during the outpatient clinic assessment, and a six month follow-up period. The diagnostic accuracy, and value in addition to signs and symptoms of candidate serum biomarkers will be assessed in terms of discrimination with C statistics, and calibration with plots.
We aim to include 350 suspected cases, with 250 patients with indeed definite TIA (or minor stroke) according to the panel.
We hope to find novel biomarkers that will enable a rapid and accurate diagnosis of TIA. This would largely improve the management and prognosis of such patients.
ClinicalTrials.gov Identifier NCT01954329
TIA; Minor stroke; Diagnosis; Biomarkers
Patients who have suffered from cerebral ischemia have a high risk of recurrent vascular events. Predictive models based on classical risk factors typically have limited prognostic value. Given that cerebral ischemia has a heritable component, genetic information might improve performance of these risk models. Our aim was to develop and compare two models: one containing traditional vascular risk factors, the other also including genetic information.
Methods and Results
We studied 1020 patients with cerebral ischemia and genotyped them with the Illumina Immunochip. Median follow-up time was 6.5 years; the annual incidence of new ischemic events (primary outcome, n=198) was 3.0%. The prognostic model based on classical vascular risk factors had an area under the receiver operating characteristics curve (AUC-ROC) of 0.65 (95% confidence interval 0.61-0.69). When we added a genetic risk score based on prioritized SNPs from a genome-wide association study of ischemic stroke (using summary statistics from the METASTROKE study which included 12389 cases and 62004 controls), the AUC-ROC remained the same. Similar results were found for the secondary outcome ischemic stroke.
We found no additional value of genetic information in a prognostic model for the risk of ischemic events in patients with cerebral ischemia of arterial origin. This is consistent with a complex, polygenic architecture, where many genes of weak effect likely act in concert to influence the heritable risk of an individual to develop (recurrent) vascular events. At present, genetic information cannot help clinicians to distinguish patients at high risk for recurrent vascular events.
Patients with type 2 diabetes often show slowing of information processing. Disruptions in the brain white matter network, possibly secondary to vascular damage, may underlie these cognitive disturbances. The current study reconstructed the white matter network of 55 nondemented individuals with type 2 diabetes (mean age, 71 ± 4 years) and 50 age-, sex-, and education-matched controls using diffusion magnetic resonance imaging–based fiber tractography. Graph theoretical analysis was then applied to quantify the efficiency of these networks. Patients with type 2 diabetes showed alterations in local and global network properties compared with controls (P < 0.05). These structural network abnormalities were related to slowing of information processing speed in patients. This relation was partly independent of cerebrovascular lesion load. This study shows that the approach of characterizing the brain as a network using diffusion magnetic resonance imaging and graph theory can provide new insights into how abnormalities in the white matter affect cognitive function in patients with diabetes.
Stenosis of the internal carotid artery has been associated with cognitive impairment and decline. However, studies testing the effect of carotid revascularisation on cognition have had conflicting results. This may in part be explained by variation in the flow territory of the carotid artery. In 12 to 36% of the patients, the posterior cerebral artery is mainly or exclusively supplied by the internal carotid artery via a foetal-type posterior cerebral artery. In these patients, ipsilateral carotid artery stenosis is likely to result in a larger area with hypoperfusion than in case of a normal posterior cerebral artery. Patients with a foetal-type posterior cerebral artery could therefore benefit more from revascularisation. We compared the effects of carotid revascularisation on cognition between patients with a foetal-type and those with a normal posterior cerebral artery.
Patients with symptomatic internal carotid artery stenosis ≥ 50%, enrolled in the International Carotid Stenting Study (ICSS) at a single centre, underwent detailed neuropsychological examinations before and 6 months after revascularisation. Cognitive test results were standardized into z-scores, from which a cognitive sumscore was calculated. The primary outcome was the change in cognitive sumscore between baseline and follow-up. Changes in cognitive sumscore were compared between patients with an ipsilateral foetal-type and those with a normal posterior cerebral artery, as assessed with CT or MR angiography.
Of 145 patients enrolled in ICSS at the centre during the study period, 98 had both angiography at baseline and neuropsychological examination at baseline and at 6-months follow-up. The cognitive sum score decreased by 0.28 (95% confidence interval, 0.10 to 0.45) in 13 patients with an ipsilateral foetal-type posterior cerebral artery and by 0.07 (95% CI, 0.002 to 0.15) in 85 patients with a normal posterior cerebral artery (mean difference, -0.20; 95% CI, -0.40 to -0.01). This did not change essentially after adjustment for baseline factors.
An ipsilateral foetal-type posterior cerebral artery appears to increase cognitive decline after carotid revascularisation. Our findings have to be reproduced in an independent study before further implications can be made.
Angioplasty and stenting; Carotid endarterectomy; Symptomatic carotid stenosis; Cognition; Circle of Willis
Prediction of clinical outcome in the acute stage of ischaemic stroke can be difficult when based on patient characteristics, clinical findings and on non-contrast CT. CT perfusion and CT angiography may provide additional prognostic information and guide treatment in the early stage. We present the study protocol of the Dutch acute Stroke Trial (DUST). The DUST aims to assess the prognostic value of CT perfusion and CT angiography in predicting stroke outcome, in addition to patient characteristics and non-contrast CT. For this purpose, individualised prediction models for clinical outcome after stroke based on the best predictors from patient characteristics and CT imaging will be developed and validated.
The DUST is a prospective multi-centre cohort study in 1500 patients with suspected acute ischaemic stroke. All patients undergo non-contrast CT, CT perfusion and CT angiography within 9 hours after onset of the neurological deficits, and, if possible, follow-up imaging after 3 days. The primary outcome is a dichotomised score on the modified Rankin Scale, assessed at 90 days. A score of 0–2 represents good outcome, and a score of 3–6 represents poor outcome. Three logistic regression models will be developed, including patient characteristics and non-contrast CT (model A), with addition of CT angiography (model B), and CT perfusion parameters (model C). Model derivation will be performed in 60% of the study population, and model validation in the remaining 40% of the patients. Additional prognostic value of the models will be determined with the area under the curve (AUC) from the receiver operating characteristic (ROC) curve, calibration plots, assessment of goodness-of-fit, and likelihood ratio tests.
This study will provide insight in the added prognostic value of CTP and CTA parameters in outcome prediction of acute stroke patients. The prediction models that will be developed in this study may help guide future treatment decisions in the acute stage of ischaemic stroke.
Stroke; Ischaemia; Infarct; Prediction; CT perfusion; CT angiography
Extracellular vesicles (EVs) and their protein levels have been identified as a potential risk marker for the development of vascular disease. In the present study, we assessed whether levels of four previously identified EV proteins (cystatin C, serpin G1, serpin F2 and CD14) are associated with cerebral white matter lesions (WMLs) and brain atrophy.
Cohort study; cross-sectional and prospective.
Single centre, secondary and tertiary setting.
1309 patients with manifest vascular disease from the Second Manifestations of ARTerial disease-MR (SMART-MR) study, of which 994 had successful brain MRI and EV protein level measurements.
WML and brain parenchymal fraction (BPF), as parameter for brain atrophy, at baseline and follow-up.
The relationship between EV protein levels and WML volume (expressed as log transformed percentage of intracranial volume) and BPF (expressed percentage of intracranial volume) on 1.5 T brain MRI was assessed with multivariable linear regression modelling. Subsequently, the relationship between baseline EV protein levels and progression of atrophy and WML was analysed in 534 patients, in whom a follow-up MRI was obtained after 4 years.
Higher EV-cystatin C and EV-CD14 were significantly associated with larger WML volume (linear regression coefficient (95% CI) 0.10 log %/SD (0.04 to 0.17) and 0.14 log %/SD (0.07 to 0.20), respectively. Higher EV-CD14 was associated with more brain atrophy (–0.14%/SD; –0.27 to –0.01). Baseline EV-CD14 was significantly associated with increase of WMLs (0.11 log %/SD (0.04 to 0.18)). No relationship with EV-serpins was observed at baseline or at follow-up.
EV proteins cystatin C and CD14 are related to cerebral WMLs and the progression of brain atrophy in patients with manifest vascular disease, potentially identifying EVs in the aetiology of structural brain changes.
extracellular vesicles; White matter lesion; Brain atrophy
To examine whether type 2 diabetes is associated with microstructural abnormalities in specific cerebral white matter tracts and to relate these microstructural abnormalities to cognitive functioning.
RESEARCH DESIGN AND METHODS
Thirty-five nondemented older individuals with type 2 diabetes (mean age 71 ± 5 years) and 35 age-, sex-, and education-matched control subjects underwent a 3 Tesla diffusion-weighted MRI scan and a detailed cognitive assessment. Tractography was performed to reconstruct several white matter tracts. Diffusion tensor imaging measures, including fractional anisotropy (FA) and mean diffusivity (MD), were compared between groups and related to cognitive performance.
MD was significantly increased in all tracts in both hemispheres in patients compared with control subjects (P < 0.05), reflecting microstructural white matter abnormalities in the diabetes group. Increased MD was associated with slowing of information-processing speed and worse memory performance in the diabetes but not in the control group after adjustment for age, sex, and estimated IQ (group × MD interaction, all P < 0.05). These associations were independent of total white matter hyperintensity load and presence of cerebral infarcts.
Individuals with type 2 diabetes showed microstructural abnormalities in various white matter pathways. These abnormalities were related to worse cognitive functioning.
The aim of this randomised pilot study was to investigate the haemodynamic effects measured by oxygen-15 positron emission tomography (PET) of interventional treatment consisting of either endarterectomy or endovascular treatment of stenosed cerebropetal arteries, or tapering of antihypertensive medication in comparison with standard medical treatment alone in patients with symptomatic internal carotid artery (ICA) occlusion.
Twenty-three patients with symptomatic ICA occlusion underwent PET scanning at baseline and after 3 months. Twelve patients were randomised to intervention (either endarterectomy or endovascular treatment of stenosed cerebropetal arteries, or tapering of antihypertensive medication) and 11 to standard medical treatment alone. Primary outcome was a change in cerebral blood flow (CBF), cerebral blood volume (CBV) and/or oxygen extraction fraction (OEF) after 3 months measured by PET.
There were no differences in changes in CBF, CBV or OEF between the two groups. Only patients with compromised perfusion at presentation showed a borderline significant increase in CBF of 2.8 mL/min/100 mL (95% confidence interval 0.0 to 5.7) after intervention (n = 7).
This pilot study shows that in patients with symptomatic ICA occlusion, oxygen-15 PET did not detect differences in improvement of CBF, CBV or OEF between interventional and standard treatment.
Carotid artery diseases; Haemodynamics; Other cerebrovascular disease/stroke; PET
Background and Purpose
Good reliability of methods to assess the extent of ischemia in acute stroke is important for implementation in clinical practice, especially between observers with varying experience. Our aim was to determine inter- and intra-observer reliability of the 1/3 middle cerebral artery (MCA) rule and the Alberta Stroke Program Early CT Score (ASPECTS) for different CT modalities in patients suspected of acute ischemic stroke.
We prospectively included 105 patients with acute neurological deficit due to suspected acute ischemic stroke within 9 hours after symptom onset. All patients underwent non-contrast CT, CT perfusion and CT angiography on admission. All images were evaluated twice for presence of ischemia, ischemia with >1/3 MCA involvement, and ASPECTS. Four observers evaluated twenty scans twice for intra-observer agreement. We used kappa statistics and intraclass correlation coefficient to calculate agreement.
Inter-observer agreement for the 1/3 MCA rule and ASPECTS was fair to good for non-contrast CT, poor to good for CT angiography source images, but excellent for all CT perfusion maps (cerebral blood volume, mean transit time, and predicted penumbra and infarct maps). Intra-observer agreement for the 1/3 MCA rule and ASPECTS was poor to good for non-contrast CT, fair to moderate for CT angiography source images, and good to excellent for all CT perfusion maps.
Between observers with a different level of experience, agreement on the radiological diagnosis of cerebral ischemia is much better for CT perfusion than for non-contrast CT and CT angiography source images, and therefore CT perfusion is a very reliable addition to standard stroke imaging.
We examined whether patients with cerebral microbleeds on MRI, who started and continued antithrombotic medication for years, have an increased risk of symptomatic intracerebral haemorrhage (ICH).
Prospective cohort study.
Multicentre outpatient clinics in the Netherlands.
We followed 397 patients with newly diagnosed transient ischaemic attack (TIA) or minor ischaemic stroke receiving anticoagulants or antiplatelet drugs. 58% were men. The mean age was 65.3 years. 395 (99%) patients were white Europeans. MRI including a T2*-weighted gradient echo was performed within 3 months after start of medication. 48 (12%) patients had one or more microbleeds. They were followed every 6 months by telephone for a mean of 3.8 years.
Primary and secondary outcome measures
Primary outcome was a symptomatic ICH. Secondary outcome were all strokes, ischaemic stroke, myocardial infarct, death from all vascular causes, death from non-vascular causes and death from all causes.
Five patients (1%) suffered from a symptomatic ICH. One ICH occurred in a patient with microbleeds at baseline (adjusted HR 2.6, 95% CI 0.3 to 27). The incidence of all strokes during follow-up was higher in patients with than without microbleeds (adjusted HR 2.3, 95% CI 1.0 to 5.3), with a dose–response relationship. The incidences of ischaemic stroke, vascular death, non-vascular death and death of all causes were higher in patients with microbleeds, but not statistically significant.
In our cohort of patients using antithrombotic drugs after a TIA or minor ischaemic stroke, we found that microbleeds on MRI are associated with an increased risk of future stroke in general, but we did not find an increased risk of symptomatic ICH.
Oral Medicine; Stroke Medicine; Vascular Medicine
Vascular cognitive impairment is an umbrella term for cognitive dysfunction associated with and presumed to be caused by vascular brain damage. Autopsy studies have identified microinfarcts as an important neuropathological correlate of vascular cognitive impairment that escapes detection by conventional magnetic resonance imaging (MRI). As a frame of reference for future high-resolution MRI studies, we systematically reviewed the literature on neuropathological studies on cerebral microinfarcts in the context of vascular disease, vascular risk factors, cognitive decline and dementia. We identified 32 original patient studies involving 10,515 people. The overall picture is that microinfarcts are common, particularly in patients with vascular dementia (weighted average 62%), Alzheimer's disease (43%), and demented patients with both Alzheimer-type and cerebrovascular pathology (33%) compared with nondemented older individuals (24%). In many patients, multiple microinfarcts were detected. Microinfarcts are described as minute foci with neuronal loss, gliosis, pallor, or more cystic lesions. They are found in all brain regions, possibly more so in the cerebral cortex, particularly in watershed areas. Reported sizes vary from 50 μm to a few mm, which is within the detection limit of current high-resolution MRI. Detection of these lesions in vivo would have a high potential for future pathophysiological studies in vascular cognitive impairment.
cerebral microinfarct; cerebrovascular disease; dementia; MRI; neuropathology
Transcranial Doppler (TCD) CO2-reactivity and oxygen-15 positron emission tomography (PET) have both been used to measure the cerebral haemodynamic state in patients who may have a compromised blood flow. Our purpose was to investigate whether PET and TCD identify the same patients with an impaired flow state of the brain in patients with internal carotid artery (ICA) occlusion.
Patients with recent transient ischaemic attack or minor ischaemic stroke associated with ICA occlusion underwent TCD with measurement of CO2-reactivity and oxygen-15 PET within a median time interval of 6 days.
We included 24 patients (mean age 64 ± 10 years). Seventeen (71%) patients had impaired CO2-reactivity (≤20%), of whom six had absent reactivity (0%) or steal (<0%) in the hemisphere ipsilateral to the ICA occlusion. PET of the perfusion state of the hemisphere ipsilateral to the ICA occlusion demonstrated stage 1 haemodynamic compromise (decreased cerebral blood flow (CBF) or increased cerebral blood volume (CBV) without increased oxygen extraction fraction (OEF)) in 13 patients and stage 2 (increased OEF) in 2 patients. In 12 patients (50%), there was agreement between TCD and PET, indicating haemodynamic compromise in 10 and a normal flow state of the brain in 2 patients. There was no significant correlation between CO2-reactivity and CBF ipsilateral/contralateral hemispheric ratio (r = 0.168, p value = 0.432), OEF ratio (r = −0.242, p value = 0.255), or CBV/CBF ratio (r = −0.368, p value = 0.077).
In patients with symptomatic ICA occlusion, identification of an impaired flow state of the brain by PET and TCD CO2-reactivity shows concordance in only half of the patients.
carotid artery disease; haemodynamic; PET; transcranial Doppler; stroke
The risk of deep vein thrombosis (DVT) after stroke is increased in patients with restricted mobility, a previous history of DVT, dehydration, or comorbidities such as malignant diseases or clotting disorders. Patients with an increased risk of DVT should receive prophylactic treatment. To reduce the chance of DVT, patients should be mobilized as soon as possible and should be kept well hydrated. Anti-embolism stockings cannot be recommended, because they have been demonstrated not useful for preventing DVT or pulmonary embolism in patients with stroke, and they are associated with a significantly increased risk of skin breaks. The usefulness of intermittent pneumatic compression is currently under study in a randomized clinical trial. Treatment with subcutaneously administered low-dose unfractionated heparin is preferred to unfractionated heparin and may be considered in patients with ischemic stroke if the risk of DVT is estimated to be higher than the risk of hemorrhagic complications. Aspirin may also be effective for patients with ischemic stroke who have contraindications to anticoagulants, although direct comparisons with anticoagulants are not available. In patients with intracerebral hemorrhage, low-dose subcutaneous low-molecular-weight heparin is probably safe after documentation of cessation of active bleeding, and may be considered on an individual basis after 3 to 4 days from stroke onset.
Type 2 diabetes is associated with a moderate degree of cerebral atrophy and a higher white matter hyperintensity (WMH) volume. How these brain-imaging abnormalities evolve over time is unknown. The present study aims to quantify cerebral atrophy and WMH progression over 4 years in type 2 diabetes.
RESEARCH DESIGN AND METHODS
A total of 55 patients with type 2 diabetes and 28 age-, sex-, and IQ-matched control participants had two 1.5T magnetic resonance imaging scans with a 4-year interval. Volumetric measurements of total brain, peripheral cerebrospinal fluid (CSF), lateral ventricles, and WMH were performed with k-nearest neighbor–based probabilistic segmentation. All volumes were expressed as percentage of intracranial volume. Linear regression analyses, adjusted for age and sex, were performed to compare brain volumes between the groups and to identify determinants of volumetric change within the type 2 diabetic group.
At baseline, patients with type 2 diabetes had a significantly smaller total brain volume and larger peripheral CSF volume than control participants. In both groups, all volumes showed a significant change over time. Patients with type 2 diabetes had a greater increase in lateral ventricular volume than control participants (mean adjusted between-group difference in change over time [95% CI]: 0.11% in 4 years [0.00 to 0.22], P = 0.047).
The greater increase in lateral ventricular volume over time in patients with type 2 diabetes compared with control participants shows that type 2 diabetes is associated with a slow increase of cerebral atrophy over the course of years.
Arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) with image acquisition at multiple inversion times is a noninvasive ASL technique able to compensate for spatial heterogeneities in transit times caused by collateral blood flow in patients with severe stenosis of the cerebropetal blood vessels. Our aim was to compare ASL-MRI and H215O positron emission tomography (PET), the gold standard for cerebral blood flow (CBF) assessment, in patients with a symptomatic internal carotid artery (ICA) occlusion. Fourteen patients (63±14 years) with a symptomatic ICA occlusion underwent both ASL-MRI and H215O PET. The ASL-MRI was performed using a pulsed STAR labeling technique at multiple inversion times within 7 days of the PET. The CBF was measured in the gray-matter of the anterior, middle and posterior cerebral artery, and white-matter. Both PET and ASL-MRI showed a significantly decreased CBF in the gray-matter of the middle cerebral artery in the hemisphere ipsilateral to the ICA occlusion. The average gray-matter CBF measured with ASL-MRI (71.8±4.3 mL/min/100 g) was higher (P<0.01) than measured with H215O PET (43.1±1.0 mL/min/100 g). In conclusion, ASL-MRI at multiple TIs is capable of depicting areas of regions with low CBF in patients with an occlusion of the ICA, although a systematic overestimation of CBF relative to H215O PET was noted.
carotid artery; magnetic resonance imaging (MRI); MRI comparison with PET; MRI perfusion; positron emission tomography (PET)
Subfebrile temperature or fever is present in about a third of patients on the first day after stroke onset and is associated with poor outcome. However, the temporal profile of this association is not well established. We aimed to assess the relationship between body temperature on admission as well as the change in body temperature from admission to 24 h thereafter and functional outcome and death. We analyzed data of 1,332 patients admitted within 12 h of stroke onset. The relation between body temperature on admission or the change in body temperature from admission to 24 h thereafter (adjusted for body temperature on admission) on the one hand and unfavorable outcome (death, or a modified Rankin Scale score >2) at 3 months on the other were expressed as odds ratio per 1.0°C increase in body temperature. Adjustments for potential confounders were made with a multiple logistic regression model. No relation was found between admission body temperature and poor outcome (aOR 1.06; 95% CI 0.85–1.32) and death (aOR 1.23; 95% CI 0.95–1.60). In contrast, increased body temperature in the first 24 h after stroke onset was associated with poor outcome (aOR 1.30; 95% CI 1.05–1.63) and death (aOR 1.51; 95% CI 1.15–1.98). An early rise in body temperature rather than high body temperature on admission is a risk factor for unfavorable outcome in patients with acute stroke.
Stroke; Body temperature; Clinical outcome
To investigate the influence of internal carotid artery (ICA) stenosis on the distribution of blood flow to the caudate nucleus, lentiform nucleus, and thalamus.
We studied 18 healthy control subjects, 20 patients with a unilateral asymptomatic ICA stenosis, and 15 patients with a recently symptomatic unilateral ICA stenosis. The contribution of the ICAs and the basilar artery to the perfusion of the deep brain structures was assessed by perfusion territory selective arterial spin labeling (ASL) MRI. Differences were tested with a two-tailed Fishers’ exact test.
The caudate nucleus was predominantly supplied with blood by the ipsilateral ICA in all groups. In 4 of the 15 (27%) the symptomatic patients, the caudate nucleus partially received blood from the contralateral ICA, compared to none of the 18 healthy control subjects (p = 0.03). The lentiform nucleus and the thalamus were predominantly supplied with blood by the ipsilateral ICA and basilar artery respectively in all groups.
In patients with a symptomatic ICA stenosis, the caudate nucleus may be supplied with blood by the contralateral ICA more often than in healthy controls.
Magnetic resonance imaging; Cerebral hemodynamics; Perfusion; Basal ganglia; Carotid artery stenosis
We assessed test–retest variability of cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral metabolic rate of oxygen (CMRO2), and oxygen extraction fraction (OEF) measurements derived from dynamic 15O positron emission tomography (PET) scans.
In seven healthy volunteers, complete test–retest 15O PET studies were obtained; test–retest variability and left-to-right ratios of CBF, CBV, OEF, and CMRO2 in arterial flow territories were calculated.
Whole-brain test–retest coefficients of variation for CBF, CBV, CMRO2, and OEF were 8.8%, 13.8%, 5.3%, and 9.3%, respectively. Test–retest variability of CBV left-to-right ratios was <7.4% across all territories. Corresponding values for CBF, CMRO2, and OEF were better, i.e., <4.5%, <4.0%, and <1.4%, respectively.
The test–retest variability of CMRO2 measurements derived from dynamic 15O PET scans is comparable to within-session test–retest variability derived from steady-state 15O PET scans. Excellent regional test–retest variability was observed for CBF, CMRO2, and OEF. Variability of absolute CBF and OEF measurements is probably affected by physiological day-to-day variability of CBF.
Parametric; CBF; CMRO2; OEF; PET
Type 2 diabetes is known to be associated with decrements in memory and executive functions and information-processing speed. It is less clear, however, at which stage of diabetes these cognitive decrements develop and how they progress over time. In this study, we investigated cognitive functioning of patients with recent screen-detected type 2 diabetes, thus providing insight into the nature and severity of cognitive decrements in the early stage of the disease. Possible risk factors were also addressed.
RESEARCH DESIGN AND METHODS
Included in this study were 183 diabetic patients from a previously established study cohort and 69 control subjects. A full neuropsychological assessment, addressing six cognitive domains, was made for each participant. Raw test scores were standardized into z scores per domain and compared between the groups. Possible risk factors for cognitive decrements were examined with multivariate linear regression.
Relative to scores for the control group, mean z scores were between 0.01 and 0.2 lower in the diabetic group across all domains, but after adjustment for differences in IQ between patients and control subjects, only memory performance was significantly reduced (mean difference −0.15 [95% CI −0.28 to −0.03]). A history of macrovascular disease and current smoking were significant determinants of slower information-processing speed in patients with diabetes.
This study shows that modest cognitive decrements are already present at the early stage of type 2 diabetes. A history of macrovascular disease and smoking are significant risk factors for some early decrements.
Information on the prognosis of patients with transient ischaemic attack or moderately disabling ischaemic stroke associated with bilateral internal carotid artery (ICA) occlusion is scarce. We prospectively studied 57 consecutive patients (46 men; mean age 60 ± 9 years) with bilateral ICA occlusion who had presented with unilateral transient or moderately disabling cerebral or retinal ischaemic symptoms. We determined the long-term risk of recurrent ischaemic stroke and the composite outcome of stroke, myocardial infarction or vascular death. Four patients had a recurrent ischaemic stroke during a mean follow-up of 5.9 years, resulting in an annual stroke rate of 1.2% (95% confidence interval (CI) 0.3–3.1). Risk factors for recurrent ischaemic stroke could not be identified. Eighteen patients suffered a stroke, myocardial infarction or vascular death, resulting in an annual rate for major vascular events of 5.3% (95% CI 3.1–8.3). Age and a history of ischaemic heart disease were significant risk factors for future vascular events. Patients with transient or moderately disabling symptoms of cerebral or retinal ischaemia associated with bilateral ICA occlusion have a relatively low risk of recurrent ischaemic stroke. Although this study was not designed to compare conservative treatment with surgical intervention, the favourable outcome suggests that a policy of medical therapy and control of risk factors may be justified in these patients.
Carotid artery diseases; Stroke; Collateral circulation; Follow-up studies
The Paracetamol (Acetaminophen) In Stroke (PAIS) study is a phase III multicenter, double blind, randomized, placebo-controlled clinical trial of high-dose acetaminophen in patients with acute stroke. The trial compares treatment with a daily dose of 6 g acetaminophen, started within 12 hours after the onset of symptoms, with matched placebo. The purpose of this study is to assess whether treatment with acetaminophen for 3 days will result in improved functional outcome through a modest reduction in body temperature and prevention of fever.
The previously planned statistical analysis based on a dichotomization of the scores on the modified Rankin Scale (mRS) may not make the most efficient use of the available baseline information. Therefore, the planned primary analysis of the PAIS study has been changed from fixed dichotomization of the mRS to a sliding dichotomy analysis.
Instead of taking a single definition of good outcome for all patients, the definition is tailored to each individual patient's baseline prognosis on entry into the trial.
The protocol change was initiated because of both advances in statistical approaches and to increase the efficiency of the trial by improving statistical power.
Current Controlled Trials [ISCRTN74418480]
Delirium is a common disorder in the early phase of stroke. Given the presumed cholinergic deficiency in delirium, we tested treatment with the acetylcholinesterase inhibitor rivastigmine.
This pilot study was performed within an epidemiological study. In 527 consecutive stroke patients presence of delirium was assessed during the first week with the confusion assessment method. Severity was scored with the delirium rating scale (DRS). Sixty-two patients developed a delirium in the acute phase of stroke. Only patients with a severe and persistent delirium (defined as a DRS of 12 or more for more than 24 hours) were enrolled in the present study. In total 26 fulfilled these criteria of whom 17 were treated with orally administered rivastigmine with a total dose between 3 and 12 mg a day. Eight patients could not be treated because of dysphagia and one because of early discharge.
No major side effects were recorded. In 16 patients there was a considerable decrease in severity of delirium. The mean DRS declined from 14.8 on day one to 8.5 after therapy and 5.6 after tapering. The mean duration of delirium was 6.7 days (range; 2–17).
Rivastigmine is safe in stroke patients with delirium even after rapid titration. In the majority of patients the delirium improved after treatment. A randomized controlled trial is needed to establish the usefulness of rivastigmine in delirium after stroke.
Nederlands Trial Register NTR1395