MRI Vessel Wall Imaging after Intra-Arterial Treatment for Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Vessel wall imaging is increasingly performed in the diagnostic work-up of patients with ischemic stroke. The aim of this study was to compare vessel wall enhancement after intra-arterial thrombosuction with that in patients not treated with thrombosuction.

MATERIALS AND METHODS

From 2009 to 2017, forty-nine patients with an ischemic stroke underwent 7T MR imaging within 3 months after symptom onset as part of a prospective intracranial vessel wall imaging study. Fourteen of these patients underwent intra-arterial treatment using thrombosuction (intra-arterial treatment group). In the intra-arterial treatment group, vessel walls were evaluated for major vessel wall changes. All patients underwent pre- and postcontrast vessel wall imaging to assess enhancing foci of the vessel wall using coregistered subtraction images. A Wilcoxon signed rank test was performed to test for differences.

RESULTS

In the intra-arterial treatment group, 11 of 14 patients (79%) showed vessel wall enhancement compared with 17 of 35 patients without intra-arterial treatment (49%). In the intra-arterial treatment group, more enhancing foci were detected on the ipsilateral side (n = 18.5) compared with the contralateral side (n = 3, P = .005). Enhancement was more often concentric on the ipsilateral side (n = 8) compared with contralateral side (n = 0, P = .01). No differences were found in the group without intra-arterial treatment between the number and configuration of ipsilateral and contralateral enhancing foci.

CONCLUSIONS

Patients with intra-arterial treatment by means of thrombosuction showed more (concentric) enhancing foci of the vessel wall ipsilateral compared with contralateral to the treated artery than the patients without intra-arterial treatment, suggesting reactive changes of the vessel wall. This finding should be taken into account when assessing vessel wall MR images in patients with stroke.

Optimal cut-off criteria for duplex ultrasound compared with computed tomography angiography for the diagnosis of restenosis in stented carotid arteries in the international carotid stenting study

Introduction

Previous studies that reported duplex-ultrasound cut-off criteria, based on blood velocity parameters, for the degree of stenosis in a stented carotid artery were either retrospective, or the reference test was carried out only when a patient was suspected of having restenosis at duplex ultrasound, which is likely to have resulted in verification bias. We performed a prospective study of diagnostic accuracy to find new blood velocity cut-offs in duplex ultrasound for in-stent restenosis.

Patients and methods

Stented patients within the international carotid stenting study were eligible. Patients had a carotid computed tomography angiography in addition to routine duplex ultrasound performed at a yearly follow-up. Duplex-ultrasound bloodflow velocity parameters were compared to the degree of stenosis on computed tomography angiography. The results were analysed using receiver-operating-characteristic curves.

Results

We included 103 patients in this study. On computed tomography angiography, 30 (29.1%) patients had a 30%-49% in-stent restenosis, 21 (20.4%) patients had 50%-69% in-stent restenosis and 5 (4.9%) patients a ≥70% in-stent restenosis. The cut-off value ≥50% stenosis was a peak systolic velocity of 125 cm/s (sensitivity: 63% (95% CI: 41-79), specificity: 83% (95% CI: 72-90)).

Discussion

This study provides a level 2b evidence for new cut-off values for in-stent restenosis. Unfortunately, we could not say anything about severe stenosis because of the low number of severe stenosis after one year.

Conclusions

The 125 cm/s cut-off value on duplex ultrasound is lower than found in previous studies and equal to unstented arteries. Duplex-ultrasound measurements made in stented carotid arteries should not be corrected for the presence of a stent when determining the degree of stenosis.

The ThRombolysis in UnconTrolled Hypertension (TRUTH) protocol: an observational study on treatment strategy of elevated blood pressure in stroke patients eligible for IVT

BACKGROUND

Intravenous thrombolysis (IVT) with (recombinant) tissue plasminogen activator is an effective treatment in acute ischemic stroke. However, IVT is contraindicated when blood pressure is above 185/110 mmHg, because of an increased risk on symptomatic intracranial hemorrhage. In current Dutch clinical practice, two distinct strategies are used in this situation. The active strategy comprises lowering blood pressure with antihypertensive agents below these thresholds to allow start of IVT. In the conservative strategy, IVT is administered only when blood pressure drops spontaneously below protocolled thresholds. A retrospective analysis in two recent stroke trials showed a non-significant signal towards better functional outcome in the active group; robust evidence for either strategy, however, is lacking. We hypothesize that (I) the active strategy leads to a better functional outcome three months after acute ischemic stroke. Secondary hypotheses are that this effect occurs despite (II) increasing the number of symptomatic intracranial hemorrhages, and could be attributable to (III) a higher rate of IVT treatments and (IV) a shorter door-to-needle time.

METHODS AND DESIGN

The TRUTH is a prospective, observational, cluster-based, parallel group follow-up study; in which participating centers continue their current local treatment guidelines. Outcomes of patients admitted to centers with an active will be compared to those admitted to centers with a conservative strategy. The primary outcome is functional outcome on the modified Rankin Scale at three months. Secondary outcomes are symptomatic intracranial hemorrhage, IVT treatment and door-to-needle time. We based our sample size estimate on an ordinal analysis of the mRS with the "proportional odds" model. With the aforementioned signal observed in a recent retrospective study in these patients as an estimate of the effect size and with alpha 0 · 05, this analysis would have an 80 % power with a total number of 600 patients. Corrections for expected imbalance in group size and clustering effects resulted in a sample size of 1235 patients.

DISCUSSION

The TRUTH is the first large prospective study specifically studying IVT-candidates with elevated blood pressure, and has the potential to change clinical practice and optimize acute stroke care in these patients.

Effects of high-dose paracetamol on blood pressure in acute stroke

BACKGROUND

Early administration of paracetamol may improve outcome of patients with acute stroke and a baseline body temperature of 37°C or above by lowering body temperature and preventing fever. Besides its antipyretic effects, paracetamol may affect blood pressure through cyclooxygenase-2 inhibition. We therefore aimed to assess the effect of high-dose paracetamol on blood pressure in patients with acute stroke.

METHODS

We analyzed data of 540 patients admitted within 24 h of stroke onset who were randomized to treatment with either paracetamol (6 g daily) or placebo. Blood pressures were measured at 12, 24, and 48 h from the start of treatment. Changes in blood pressure from baseline in the two treatment groups and corresponding 95% confidence intervals (CI) were calculated with linear regression analysis. Adjustments for potential confounders were made with a multiple linear regression model.

RESULTS

Treatment with high-dose paracetamol was associated with a significant reduction in systolic blood pressure of 4.5 mm Hg (95% CI 0.6-8.5) at 12 h from the start of treatment. This effect was no longer present after 24 and 48 h.

CONCLUSION

High-dose paracetamol reduces not only body temperature but also systolic blood pressure in the first 12 h after start of treatment. Both effects may improve functional outcome after stroke, but this needs further study.

Vasodilatory capacity of the cerebral vasculature in patients with carotid artery stenosis

BACKGROUND AND PURPOSE

Impairment of the cerebral autoregulation is an important predictor of TIA and stroke in patients with an ICA stenosis. The autoregulative status can be assessed directly by measuring the vasodilatory capacity of the cerebral arteries. The aim of our study was to investigate the vasodilatory capacity of the proximal and distal cerebral vasculature in patients with an ICA stenosis and healthy control subjects by combining MRA with an acetazolamide provocation challenge.

MATERIALS AND METHODS

Fourteen functionally independent patients (mean age, 67.2 ± 8.7 years) with a symptomatic ICA stenosis and 19 healthy controls (mean age, 63.1 ± 7.2 years) were included. MRA was performed before and 20 minutes after intravenous administration of acetazolamide. The vasodilatory capacity of 11 proximal and distal cerebral vessels was assessed by measuring the increase in vessel diameter after acetazolamide.

RESULTS

In the hemisphere ipsilateral to the ICA stenosis, there was no increase in diameter after acetazolamide, whereas a significant increase was measured in the contralateral hemisphere for the A1 and A2 segments of the ACA, the pericallosal artery, and the BA. A significant diameter increase was measured in all except 1 vessel of the controls. The vasodilatory capacity was significantly lower ipsilateral to the ICA stenosis compared with the A1 segment of the ACA and the P2 segment of the PCA in the controls.

CONCLUSIONS

MRA combined with an acetazolamide provocation challenge can measure normal and impaired vasodilatory capacity of the cerebral vasculature.

Blunt traumatic carotid artery dissection still a pitfall? The rationale for aggressive screening

Introduction

The optimal diagnostic strategy for carotid dissection following blunt trauma is yet unclear. The rationale for aggressive screening will be discussed based on a consecutive case series of blunt traumatic carotid artery dissection (CAD).

Materials and methods

Five patients admitted to our level I trauma center developed severe complications as a consequence of blunt traumatic CAD. The diagnosis of CAD was delayed in all five patients until serious cerebral ischemia occurred. Despite the current awareness that CAD can result from blunt trauma, this type of injury is often overlooked. Clinical and radiological advances have considerably increased the knowledge of incidence and underlying mechanisms of traumatic CAD. This could have implications for case identification and the evaluation of treatment strategies in clinical trials in the future.

Conclusion

Screening may increase the rate of early CAD diagnosis, but it is unclear if screening will also result in early detection of a treatable lesion. Trials have to provide the answer to whether initiating therapy will lead to improvements in the outcome in traumatic CAD. We therefore believe that screening is a basic condition for initiation of future clinical trials.

Magnesium and headache after aneurysmal subarachnoid haemorrhage

BACKGROUND

In patients with aneurysmal subarachnoid haemorrhage (SAH), headache typically is severe and often requires treatment with opioids. Magnesium has analgesic effects in several conditions, but whether it reduces headache after SAH is unknown.

METHODS

In a cohort of 108 SAH patients included in the randomised controlled trial Magnesium in Aneurysmal Subarachnoid Haemorrhage-II (MASH-II), severity of headache was regularly assessed on an 11-point scale until day 10 after SAH. Headache was treated according to a standardised protocol with acetaminophen, codeine, tramadol or piritramide. Serum magnesium levels were assessed every other day. Differences in mean headache scores between patients with mean high (>1.0 mmol/l) and normal (< or =1.0 mmol/l) magnesium levels were analysed with a Student t test. Crude and adjusted ORs for the use of codeine, tramadol and piritramide for patients with high versus normal magnesium levels were calculated with logistic regression.

RESULTS

The 61 patients with high magnesium levels had lower mean headache scores (4.1) than the 47 patients with normal magnesium levels (4.9; mean difference, 0.8; 95% CI 0.1 to 1.6) and required less tramadol (adjusted OR, 0.3; 95% CI 0.1 to 0.7) or piritramide (adjusted OR 0.2; 95% CI 0.1 to 0.5). There were no differences in the use of acetaminophen or codeine.

CONCLUSION

In SAH patients, elevated serum magnesium levels are associated with slightly less severe headache and less frequent use of opioids. These data imply that intravenous magnesium therapy, besides a supposed beneficial effect on outcome, also provides pain relief for SAH patients, for whom it might also improve functional outcome.

VAST: Vertebral Artery Stenting Trial. Protocol for a randomised safety and feasibility trial

Background

Twenty to 30 percent of all transient ischaemic attacks and ischaemic strokes involve tissue supplied by the vertebrobasilar circulation. Atherosclerotic stenosis ≥ 50% in the vertebral artery accounts for vertebrobasilar stroke in at least one third of the patients. The risk of recurrent vascular events in patients with vertebral stenosis is uncertain and revascularisation of vertebral stenosis is rarely performed. Observational studies have suggested that the risk of subsequent stroke or death in patients with vertebrobasilar ischaemic events is comparable with that in patients with carotid territory events. Treatment of vertebral stenosis by percutaneous transluminal angioplasty has been introduced as an attractive treatment option. The safety and benefit of stenting of symptomatic vertebral stenosis as compared with best medical therapy alone remains to be elucidated in a randomised clinical trial.

Study objectives

The primary aim of the Vertebral Artery Stenting Trial (VAST) is to assess whether stenting for symptomatic vertebral artery stenosis ≥ 50% is feasible and safe. A secondary aim is to assess the rate of new vascular events in the territory of the vertebrobasilar arteries in patients with symptomatic vertebral stenosis ≥ 50% on best medical therapy with or without stenting.

Design

This is a randomised, open clinical trial, comparing best medical treatment with or without vertebral artery stenting in patients with recently symptomatic vertebral artery stenosis ≥ 50%. The trial will include a total of 180 patients with transient ischaemic attack or non-disabling ischaemic stroke attributed to vertebral artery stenosis ≥ 50%. The primary outcome is any stroke, vascular death, or non-fatal myocardial infarction within 30 days after start of treatment. Secondary outcome measures include any stroke or vascular death during follow-up and the degree of (re)stenosis after one year.

Discussion

Improvements both in imaging of the vertebral artery and in endovascular techniques have created new opportunities for the treatment of symptomatic vertebral artery stenosis. This trial will assess the feasibility and safety of stenting for symptomatic vertebral artery stenosis and will provide sufficient data to inform a conclusive randomised trial testing the benefit of this treatment strategy. The VAST is supported by the Netherlands Heart Foundation (2007B045; ISRCTN29597900).

Accuracy and inter-observer variation in the classification of dysarthria from speech recordings

BACKGROUND

Dysarthria may be classified as flaccid, spastic, ataxic, hypokinetic, choreatic, dystonic, or mixed. We hypothesized that in routine neurological practice the reliability and accuracy of perceptual analysis alone in the classification of dysarthria is low and that this classification is mainly based on the clinical context rather than on the perception of speech. We therefore studied the accuracy and the inter- observer agreement in the classification of dysarthrias on the basis of perceptual analysis alone.

METHODS

Seventy two neurologists and neurological trainees classified recorded speech samples of 100 patients as flaccid, spastic, ataxic, extrapyramidal, or mixed dysarthria, or as not dysarthric. All observers were blinded to the patients' final diagnosis, which was based on all clinical features and investigations. In the analysis the observers were arranged in eight groups of nine observers, or four paired groups with similar levels of clinical experience. Together, the observers in a given group rated all 100 recordings.

RESULTS

The accuracy of the classification was poor (35 % were classified correctly) and the inter-observer agreement between paired groups low (kappa 0.16 to 0.32). The level of experience in neurology did not have a significant influence.

CONCLUSION

Neurological trainees as well as experienced neurologists have great difficulty in identifying specific types of dysarthria on the basis of perceptual analysis alone. In clinical practice this probably means that most neurologists will classify dysarthria in the context of other features from neurological examination or ancillary investigations.

Familial occurrence of brain arteriovenous malformations: a systematic review

BACKGROUND

Brain arteriovenous malformations (BAVMs) are thought to be sporadic developmental vascular lesions, but familial occurrence has been described. We compared the characteristics of patients with familial BAVMs with those of patients with sporadic BAVMs.

METHODS

We systematically reviewed the literature on patients with familial BAVMs. Three families that were found in our centre were added. Age, sex distribution and clinical presentation of the identified patients were compared with those in population based series of patients with sporadic BAVMs. Furthermore, we calculated the difference in mean age at diagnosis of parents and children to study possible anticipation.

RESULTS

We identified 53 patients in 25 families with BAVMs. Mean age at diagnosis of patients with familial BAVMs was 27 years (range 9 months to 58 years), which was younger than in the reference population (difference between means 8 years, 95% CI 3 to 13 years). Patients with familial BAVMs did not differ from the reference populations with respect to sex or mode of presentation. In families with BAVMs in successive generations, the age of the child at diagnosis was younger than the age of the parent (difference between means 22 years, 95% CI 13 to 30 years), which suggests clinical anticipation.

CONCLUSIONS

Few patients with familial BAVMs have been described. These patients were diagnosed at a younger age than sporadic BAVMs whereas their mode of presentation was similar. Although there are indications of anticipation, it remains as yet unclear whether the described families represent accidental aggregation or indicate true familial occurrence of BAVMs.

Appreciation of the informed consent procedure in a randomised trial of decompressive surgery for space occupying hemispheric infarction

BACKGROUND AND AIM

As non-randomised studies have suggested that surgical decompression may reduce mortality in patients with space occupying hemispheric infarction, randomisation may be considered unethical in controlled trials testing this treatment strategy. We studied differences in recall of information and in appreciation of the informed consent procedure between representatives included in the Hemicraniectomy After Middle cerebral artery infarction with Life-threatening Edema Trial (HAMLET) and representatives of patients participating in the randomised trial of Paracetamol (Acetaminophen) In Stroke (PAIS).

METHODS

1 year after study inclusion, we contacted 30 consecutive representatives who had given informed consent for participation of their relative in HAMLET, and 30 for PAIS. Recall of trial details and appreciation of the informed consent procedure were investigated using standardised questionnaires and compared between the two groups.

RESULTS

All 30 PAIS representatives and 28 HAMLET representatives were interviewed. Participation of their relative in a clinical trial was remembered by 86% of HAMLET and 40% of PAIS representatives (p<0.001). HAMLET representatives remembered more trial details (effect of the treatment under study (61% vs 3%, p<0.001); randomised treatment allocation (71% vs 0%, p<0.001)). With respect to appreciation of the informed consent procedure, we found no differences between the groups: in each trial, four representatives (14% vs 13%) had considered the question of randomisation unacceptable.

CONCLUSIONS

Participation of patients in a randomised controlled trial of surgical decompression for space occupying infarction is generally considered acceptable by their representatives, and recall of trial details is better than in a trial in which less vital issues are at stake.

Anatomic Variations in the Circle of Willis in Patients with Symptomatic Carotid Artery Stenosis Assessed with Multidetector Row CT Angiography

PURPOSE

To assess the presence of anterior and posterior collateral pathways in the circle of Willis in patients with symptomatic carotid artery stenosis (SCAS) and to compare this to patients without carotid artery stenosis.

MATERIALS AND METHODS

Multislice CT angiography was performed in 91 patients and 91 control subjects. Using consensus reading, 2 observers evaluated the presence and diameter of the anterior communicating artery (AcomA), the A1 segments of the anterior cerebral arteries, the posterior communicating arteries (PcomA) and the P1 segments of the posterior cerebral arteries. Anterior or posterior pathways were assumed to be present if the diameter of continuous arterial segments was >1 mm; both A1 segments and AcomA anterior, and ipsilateral P1 segment and PcomA posterior. Comparison between patients and controls was performed using the chi(2) test.

RESULTS

In the patients we found significantly more hypoplastic (<1 mm) or invisible A1 segments (16 and 14 vs. 4 and 1, respectively, p < 0.01). The AcomA was invisible in 4 patients versus 1 control. An isolated compromised anterior pathway and a combined compromised anterior and posterior pathway occurred more frequently in the patients as compared to the controls; 9 versus 1% (p < 0.01) and 26 versus 4% (p < 0.01).

CONCLUSION

A compromised anterior collateral pathway, usually combined with a compromised posterior pathway, occurs more frequently in patients with SCAS as compared to controls, which suggests a relation between symptomatic carotid stenosis and an incomplete circle of Willis.

[Stenting of symptomatic stenosis of the internal carotid artery is not preferred over endarterectomy at this time]

Carotid endarterectomy reduces the risk of stroke in patients with symptomatic internal carotid-artery stenosis of 50% or greater. Carotid-artery stenting may be an attractive alternative. Two randomised trials comparing carotid endarterectomy with stenting have recently been terminated prematurely. Reasons for termination included an excess in stroke and death after stenting, compared with carotid endarterectomy (the EVA-3S trial) and futility reasons and the absence of funding (the SPACE trial). Given that both trials failed to prove the non-inferiority of stenting compared with carotid endarterectomy in the first 30 days, the use of stenting should be restricted to patients with contraindications to surgery and those participating in randomised clinical trials.

Neuropsychological and neuroanatomical correlates of perseverative responses in subacute stroke

Patients with left-sided neglect frequently show repetitive behaviour on the ipsilesional side, such as re-markings on cancellation tasks or extensive elaboration on drawings. It is unclear whether these perseverative responses occur as a symptom of hemi-neglect or inattention in general, and/or whether they are related to anatomical brain correlates such as lesion location, lesion side or volume. In a first study, we examined the prevalence and neuropsychological correlates of perseverative responses in 206 subacute stroke patients and 63 healthy controls. Perseverative responses were considered present when there was at least one re-marking on the Star Cancellation, and both the degree and spatial distribution of re-markings were examined. A distinction was made between hemi-neglect and non-lateralized inattention. Spatial and verbal working memory were assessed with the Corsi Block Span and the Digit Span. Verbal and non-verbal executive function was assessed with the Visual Elevator and Letter Fluency. Stroke patients without inattention demonstrated re-markings that were related to executive performance, and the degree of perseveration was equally distributed across the sheet. Hemi-neglect patients but not patients with generalized inattention demonstrated more re-markings than controls, suggesting that a lateralized spatial attention bias triggers the perseverative responses. Patients with left and right hemi-neglect showed the same prevalence of perseveration, but the distribution of re-markings was more lateralized towards the ipsilesional side in patients with right-hemispheric stroke. The degree of perseveration in patients with hemi-neglect was related to the severity of the neglect. The goal of the second study on a subset of patients (n = 127) was to determine the neuroanatomical correlates of perseverative responses in the early phase of stroke. Lesion anatomy was administered by indicating involvement of frontal, parietal, temporal, occipital lobe, caudate nucleus, lenticular nucleus and/or thalamus. Lesion volume was calculated using a manual tracing technique. Lesion analyses indicated that perseverative behaviour is strongly associated with lesions involving the caudate nucleus or the lenticular nucleus, independent of lesion volume. The caudate nucleus was an important correlate of perseveration independent of the presence of hemi-neglect. No association was found between lesion side and perseverative responses, in contrast to previous studies. In conclusion, a stroke involving the basal ganglia and the presence of (left- or right-sided) hemi-neglect are two important associates of perseverative responses in the subacute phase of stroke.

Early cognitive impairment predicts long-term depressive symptoms and quality of life after stroke

OBJECTIVE

The aim of the present study was to examine the predictive value of cognitive impairment in the acute phase after stroke as a risk factor for long-term (six to ten months after stroke) depressive symptoms (DS) and a reduced quality of life (QOL), independent of demographic and neurological predictors.

METHODS

We evaluated 143 patients within the first 3 weeks post-stroke. Predictor variables included domain-specific cognitive function, demographic data, vascular risk factors, lesion characteristics, and clinical factors. Predictor variables associated with long-term DS (Montgomery Asberg Depression Rating Scale >or=7) and QOL (Stroke-Specific Quality of Life Scale) were identified with multiple logistic and linear regression.

RESULTS

Long-term DS were independently predicted by cognitive impairment at baseline, DS at baseline, female sex, diabetes mellitus, and previous TIA(s). Cognitive impairment, increasing age, and functional dependence predicted a reduced QOL, whereas hypercholesterolaemia predicted a better QOL. Among all cognitive disorders, unilateral neglect was the greatest risk factor for DS after 6 months, whereas a disorder in visual perception and construction affected QOL the most.

CONCLUSIONS

Cognitive impairment and vascular risk factors are important predictors of long-term DS and QOL after stroke. The prognostic value of cognition suggests a reactive component in the development or continuation of long-term DS.

Comparison of perfusion MRI by flow-sensitive alternating inversion recovery and dynamic susceptibility contrast in rats with permanent middle cerebral artery occlusion

We compared cerebral blood flow (CBF) parameters obtained by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) with those obtained by flow-sensitive alternating inversion recovery (FAIR) in brain regions with different perfusion levels in rats with permanent middle cerebral artery (MCA) occlusion. MCA occlusion was performed in 19 rats. T2-weighted MRI, FAIR and DSC-MRI were performed within 48 h after occlusion. CBF parameters were analyzed in regions of interest with either prolonged or less prolonged mean transit time (MTT). Ratios of ipsi- vs contralateral CBF values were calculated and tested for correlation and differences between FAIR and DSC-MRI. FAIR-aCBF ratios correlated significantly with DSC-rCBF ratios. The mean FAIR-aCBF ratio was significantly lower than mean DSC-rCBF ratio in the area with prolonged MTT. In the area with less prolonged MTT, the mean FAIR-aCBF ratio and mean DSC-rCBF values did not differ significantly. We conclude that FAIR correlates with DSC-MRI if perfusion is preserved. FAIR provides lower CBF values than DSC-MRI if perfusion is reduced and MTT is prolonged. This probable underestimation of perfusion may be caused by transit delays. Care should be taken when quantifying CBF with FAIR and when comparing the results of FAIR- and DSC-MRI in areas with hypoperfusion.

Applicability and relevance of models that predict short term outcome after intracerebral haemorrhage

OBJECTIVES

Several models for prediction of short term outcome after intracerebral haemorrhage (ICH) have been published, however, these are rarely used in clinical practice for treatment decisions. This study was conducted to identify current models for prediction of short term outcome after ICH and to evaluate their clinical applicability and relevance in treatment decisions.

METHODS

MEDLINE was searched from 1966 to June 2003 and studies were included if they met predefined criteria. Regression coefficients of multivariate models were extracted. Two neurologists independently evaluated the models for applicability in clinical practice. To assess clinical relevance and accuracy of each model, in a validation series of 122 patients the proportion with a >or=95% probability of death or poor outcome and the actual 30 day case fatality in these patients were calculated. Receiver operator characteristic (ROC) curves were computed for assessment of discriminatory power.

RESULTS

A total of 18 prognostic models were identified, of which 14 appeared easy to apply. In the validation series, the proportion of patients with a >or=95% probability of death or poor outcome ranged from 0% to 43% (median 23%). The 30 day case fatality in these patients ranged from 75% to 100% (median 93%). The area under the ROC curves ranged from 0.81 to 0.90.

CONCLUSIONS

Most models are easy to apply and can generate a high probability of death or poor outcome. However, only a small proportion of patients have such a high probability, and 30 day case fatality is not always correctly predicted. Therefore, current models have limited relevance in triage, but can be used to estimate the chances of survival of individual patients.

Early depressive symptoms after stroke: neuropsychological correlates and lesion characteristics

OBJECTIVE

To examine the relation between depressive symptoms and specific cognitive functions in patients with a recent stroke and to examine associations with lesion characteristics.

METHODS

We studied 126 of 183 consecutive patients within 3 weeks after a first-ever symptomatic stroke (mean interval, 8.3+/-4.3 days). Presence and severity of depressive symptoms was assessed with the Montgomery Asberg Depression Rating Scale. Neuropsychological functioning was examined by means of a detailed neuropsychological examination covering six cognitive domains. We included a healthy control group (N=75) to obtain normative data for the neuropsychological examination. Functional impairment was measured with the modified Barthel Index and the modified Rankin Scale. Symptomatic and preexistent lesion characteristics were determined on CT or MRI.

RESULTS

Of the included patients, 40% demonstrated mild and 12% moderate to severe depressive symptoms. Severity of depressive symptoms was related to lesion volume (p=0.008), functional impairment (all p<0.004), and degree of overall cognitive impairment (p=0.005). After adjustment for lesion size, a specific neuropsychological profile emerged in patients with moderate to severe depressive symptoms, affecting primarily memory, visual perception, and language (all p<0.05). No association was found between severity of depressive symptoms and lesion location, presence of preexistent lesions (white matter lesions and silent infarcts), and demographic factors (age, education, and gender).

CONCLUSIONS

Moderate or severe symptoms of depression in the early stage poststroke are associated with a specific pattern of cognitive impairment, lesion size, and functional status. We suggest that depressive symptoms early after stroke are, at least in part, a reactive phenomenon secondary to severe cognitive and functional deficits.

The prognostic value of domain-specific cognitive abilities in acute first-ever stroke

OBJECTIVE

To evaluate the prognostic value of domain-specific cognitive abilities in acute stroke with respect to long-term cognitive and functional outcome in addition to neurologic and demographic predictors.

METHODS

The authors evaluated 168 patients within the first 3 weeks after first-ever stroke. The prevalence of neuropsychological impairment was calculated vs 75 matched healthy controls. The authors also recorded demographic data, vascular risk factors, lesion characteristics, and clinical factors at admission. Independent predictor variables associated with long-term cognitive impairment (assessed with a follow-up neuropsychological examination) and functional impairment (assessed with the modified Barthel Index and the Frenchay Activities Index) were identified with stepwise multiple logistic regression. Areas under receiver operator characteristic curves were used to compare the predictive value of three models, i.e., a standard medical model, a purely cognitive model, and a model consisting of both medical and cognitive predictors.

RESULTS

Thirty-one percent of patients showed long-term cognitive impairment. Basic and instrumental ADL disturbances remained present in 19% and 24% of patients. Domain-specific cognitive functioning predicted cognitive and functional outcome better than any other variable. Moreover, the prediction of instrumental ADL functioning improved when cognitive predictors were added to the standard medical model (p < 0.05). Impairments in abstract reasoning and executive functioning were independent predictors of long-term cognitive impairment. Inattention and perceptual disorders were more important in predicting long-term functional impairment.

CONCLUSION

Domain-specific cognitive abilities in the early phase of stroke are excellent independent predictors of long-term cognitive and functional outcome.

The time course of ischemic damage and cerebral perfusion in a rat model of space-occupying cerebral infarction

We aimed to establish a rat model of space-occupying hemispheric infarction to evaluate potential treatment strategies. For adequate timing of therapy in future experiments, we studied the development of tissue damage, edema formation, and perfusion over time with different MRI techniques. Permanent middle cerebral artery (MCA) occlusion was performed in 32 Fisher-344 rats. Forty-six MRI experiments including diffusion weighted (DW), T2-weighted (T2W), flow-sensitive alternating inversion recovery (FAIR) perfusion-weighted, and T1-weighted (T1W) imaging before and after gadolinium were performed at 1, 3, 8, 16, 24, and 48 h of ischemia. MCA occlusion consistently led to infarction of the complete MCA territory. Mortality was 75%. Lesion volumes as derived from apparent diffusion coefficient (ADC) and T2 maps increased to maximum values of 400+/-48 mm3 at 24 h and 420+/-54 mm3 at 48 h of ischemia, respectively. Midline shift peaked at 24 h. The area with diffusion-perfusion deficit decreased to a minimum at 24 h after onset of ischemia and perfusion of the contralateral hemisphere dropped at the same time point. Leakage of gadolinium through the blood-brain barrier in the entire infarct occurred within 3 h of ischemia. Permanent intraluminal MCA occlusion in Fisher-344 rats is an adequate model for space-occupying cerebral infarction. Rats may benefit from intervention aimed at reducing tissue shift and intracranial pressure (ICP), and at improving cerebral blood flow, if initiated before 24 h after MCA occlusion. The value of treatment modalities depending on an intact blood-brain barrier should be questioned.

Delayed decompressive surgery increases apparent diffusion coefficient and improves peri-infarct perfusion in rats with space-occupying cerebral infarction

BACKGROUND AND PURPOSE

There is no conclusive experimental support that decompressive surgery in late stages of space-occupying cerebral infarction will improve outcome. We studied the effects of delayed decompressive surgery on the development of tissue damage, edema formation, and cerebral perfusion with different MRI techniques in a rat model of space-occupying cerebral infarction.

METHODS

Permanent middle cerebral artery (MCA) occlusion was performed in 6 Fisher 344 rats. Decompressive surgery was performed 17 hours after the occlusion. Each animal was assessed before surgery and 2 and 4 hours after surgery by means, of diffusion-weighted T2-weighted, and flow-sensitive alternating inversion recovery perfusion-weighted MRI. Ischemic damage was also evaluated in hematoxylin-eosin-stained brain sections.

RESULTS

Lesion volume as derived from apparent diffusion coefficient (ADC) maps decreased from 522+/-98 mm3 before to 405+/-100 mm3 (P=0.016) 4 hours after decompressive surgery, whereas lesion volume from T2 maps increased from 420+/-66 mm3 before to 510+/-92 mm3 (P=0.048) 4 hours after decompressive surgery. Midline shift decreased from 1.4+/-0.1 mm to 0.5+/-0.2 mm (P=0.001). Blood flow in the noninfarcted area of the ipsilateral hemisphere improved from 25+/-9 mL/min/100 g of tissue to 38+/-9 mL/min/100 g of tissue (P=0.035). Despite the pseudonormalization of ADC, irreversible damage was found in the entire MCA territory on histological evaluation.

CONCLUSIONS

In rats with space-occupying cerebral infarction, delayed decompressive surgery leads to a decrease in lesion volume derived from ADC maps, which is probably because of an increase of extracellular water formation. There are no signs that this reflects rescue of ischemic tissue.

[Prevention of cardiovascular complications after a stroke or TIA: hypotensive and hypocholesterolemic therapy]

In patients who have recently had a TIA or stroke, the risk of new serious cardiovascular disease is decreased by the pharmacological reduction of the serum cholesterol level and blood pressure; this has been convincingly demonstrated by randomised clinical trials. There is sufficient evidence that cholesterol-lowering treatment is effective in patients with a TIA or cerebral infarction who have a total cholesterol > or = 3.5 mmol/l. The results from a trial in patients with only a TIA or a minor stroke will have to answer the question whether cholesterol-lowering treatment will be effective in patients > 80 years, and whether higher dosages of simvastatin will be more effective in these patients. Antihypertensive therapy is effective in preventing recurrent stroke and myocardial infarction in patients with a recent stroke or TIA. It is obvious that the treatment should be started with a diuretic and that a second agent should be added if necessary. On epidemiological grounds, vigorous treatment is also justified in patients with a normal or mildly elevated blood pressure; caution and a custom-tailored approach are essential, however, in each individual patient.

[Treatment of optic neuritis]

Optic neuritis manifests itself as a reversible loss of vision. It can be a clinically isolated incident or one of the (first) manifestations of multiple sclerosis (MS). Its differential diagnosis is extensive, and management of other disorders can differ radically. In a typical case, treatment with corticosteroids hastens recovery of vision but does not affect the eventual degree of recovery. There is a substantial risk of developing MS after isolated optic neuritis (approximately 50% within 20 years), especially if asymptomatic white matter lesions are found on MRI scanning of the brain. Intravenous treatment with methylprednisolone may delay the onset of MS somewhat, but after three years the benefit of this treatment is lost. Treatment with interferon beta-Ia in high-risk patients also slows down the progression to clinically definite MS, but the long-term benefits are uncertain. MR imaging of the brain has implications for prognosis but not for treatment.

[Surgical decompression in space-occupying cerebral infarct; notification of a randomized trial]

Patients with a hemispheric infarct and massive space-occupying brain oedema have a poor prognosis. Despite intensive conservative treatment, the case fatality rate may be as high as 80%, and most survivors are left severely disabled. Non-randomised studies suggest that decompressive surgery substantially reduces mortality and improves the functional outcome of survivors. The 'Hemicraniectomy after middle cerebral artery infarction with life-threatening edema trial' (HAMLET) is a newly-conceived randomised multi-centre clinical trial that compares the efficacy of decompressive surgery to improve functional outcome with that of conservative treatment in patients with space-occupying supratentorial infarction.

[Treatment of stroke by reducing the body temperature; 'Paracetamol (acetaminophen) in stroke' (PAIS): start of a clinical trial]

Subfebrile temperatures and fever in acute stroke are associated with poor functional outcome. A 1 degree C rise in body temperature may double the risk of a poor outcome in patients who are admitted within 12 hours from the onset of symptoms. Two randomised double-blind clinical trials in patients with acute ischaemic stroke have shown that treatment with a daily dose of 6 g paracetamol results in a small but rapid and potentially worthwhile reduction of 0.3 degree C (95% CI: 0.1-0.5) in body temperature. It has been hypothesized that early antipyretic therapy reduces the risk of death or dependency in patients with acute stroke, even if they are normothermic. For this reason, a multicentre, randomized, double-blind clinical trial comparing high-dose paracetamol with placebo in 2500 patients has been launched. This study has been named 'Paracetamol (acetaminophen) in stroke' (PAIS). The primary outcome is death or dependency at three months. The study protocol is simple, and the amount of data to be gathered is limited. The trial will run for four years.

Timing of the effect of acetaminophen on body temperature in patients with acute ischemic stroke

The authors assessed the time of onset of the hypothermic effect of acetaminophen in 102 patients with acute ischemic stroke. These patients were randomized to treatment with either 1000 mg of acetaminophen (n = 52) or placebo (n = 50), given six times daily. Treatment with high-dose acetaminophen resulted in a 0.26 degrees C (95% CI 0.07 to 0.46 degrees C) lower mean body temperature than placebo treatment within 4 hours. This effect remained present throughout the next 20 hours. A large phase III trial seems warranted.

The effect of tirilazad mesylate on infarct volume of patients with acute ischemic stroke

The authors investigated whether the lack of effect of tirilazad on clinical outcome in patients with acute ischemic stroke is explained by failure of tirilazad to reduce infarct volume. Overall, tirilazad had no significant effect on infarct volume. In the subgroups of male patients and of those with a cortical infarct, tirilazad significantly reduced infarct volume. These effects were reduced to nonsignificant trends after adjustment for imbalances in baseline characteristics. In conclusion, early treatment of patients with tirilazad has no effect on infarct volume.

Effect of paracetamol (acetaminophen) on body temperature in acute ischemic stroke: a double-blind, randomized phase II clinical trial

BACKGROUND AND PURPOSE

Body temperature is a strong predictor of outcome in acute stroke. However, it is unknown whether antipyretic treatment leads to early and clinically worthwhile reduction of body temperature in patients with acute stroke, especially when they have no fever. The main purpose of this trial was to study whether early treatment of acute ischemic stroke patients with acetaminophen (paracetamol) reduces body temperature.

METHODS

Seventy-five patients with acute ischemic stroke confined to the anterior circulation were randomized to treatment with either 500 mg (low dose) or 1000 mg (high dose) acetaminophen or with placebo, administered as suppositories 6 times daily during 5 days. Body temperatures were measured with a rectal electronic thermometer at the start of treatment and after 24 hours and with an infrared tympanic thermometer at 2-hour intervals during the first 24 hours and at 6-hour intervals thereafter. The primary outcome measure was rectal temperature at 24 hours after the start of treatment.

RESULTS

Treatment with high-dose acetaminophen resulted in 0.4 degrees C lower body temperatures than placebo treatment at 24 hours (95% CI 0.1 degrees C to 0.7 degrees C). The mean reduction from baseline temperature with high-dose acetaminophen was 0.3 degrees C (95% CI 0 degrees C to 0.6 degrees C) higher than that in placebo-treated patients. Treatment with low-dose acetaminophen did not result in lower body temperatures. After 5 days of treatment, no differences in temperature were found between the placebo and the high- or low-dose acetaminophen groups.

CONCLUSIONS

Treatment with a daily dose of 6000 mg acetaminophen may result in a small, but potentially beneficial, decrease in body temperature shortly after ischemic stroke, even in normothermic and subfebrile patients. Further studies should determine whether this effect is reproducible and whether early reduction of body temperature leads to improved outcome.

[Intravenous thrombolytic therapy: ideal treatment for acute ischemic stroke]

In four patients with symptoms of presumed acute ischaemic stroke intravenous treatment with recombinant tissue plasminogen activator (rtPA) was considered. Two patients indeed received rtPA within 3 hours after onset of symptoms. One of them, a 55-year-old woman, recovered and was able to resume her job as a teacher four months later. The other patient, a 38-year-old man, had a severe bleeding complication that could be stopped, but the patient died several days later because of the massive stroke. The third patient, an 82-year-old woman, could not be treated with rtPA because the time of onset of neurological deficit was uncertain. Nevertheless, she recovered well from her hemiplegia after a few days. The fourth patient, a 24-year-old woman, did not receive rtPA because her symptoms were thought to be the result of a psychogenic disorder. Intravenous thrombolysis increases the risk of intracranial haemorrhage, but should be considered a useful treatment for ischaemic stroke provided there is no doubt about this diagnosis and treatment with rtPA can be started within 3 hours of onset of the neurological deficit.

Correlation between tissue depolarizations and damage in focal ischemic rat brain

Ischemia-induced depolarizations may play a key role in the development of cerebral ischemic injury. Our goal was to assess the relationship between tissue depolarizations and tissue damage in focal ischemia. We performed multi-electrode cortical direct current (DC) potential recording and, subsequently, diffusion-weighted and T(2)-weighted magnetic resonance imaging (MRI) in rats after i) cortical application of KCl, and ii) permanent and transient middle cerebral artery (MCA)-occlusion in rats. Cortical KCl application induced 10.0+/-2.2 transient negative DC potential shifts per h on the ipsilateral hemisphere (i.e. cortical spreading depressions) (n=4). During 6 h of permanent MCA-occlusion (n=9) 1-10 DC potential shifts were observed, dependent on the brain location. Anoxic depolarization developed in the ischemic core. Outside ischemic areas DC potential shifts resembled cortical spreading depressions. Depolarizations in cortical ischemic borderzones were also transient, but generally long-lasting. Reperfusion induced 1 (n=5) or 3 h (n=6) after MCA-occlusion resulted in repolarization in 2.9+/-1.5 min. Ischemic lesion volumes after 7 h, calculated from diffusion-weighted and T(2)-weighted MR images, correlated significantly with total depolarization time in cortical perifocal zones (R=0.741, p<0.05), but not with the number of depolarizations. The extent of ischemic damage, as measured from alterations in the water diffusion coefficient and T(2), was also significantly related to the total time of depolarization (R=0.762 and 0.738, respectively, p<0.01). We conclude that early ischemic tissue injury is related to the total duration of tissue depolarization and not to the frequency of depolarizations.

Inhibition of iron-dependent and ischemia-induced brain damage by the alpha-tocopherol analogue MDL 74,722

Free radical-induced lipid peroxidation is an important factor in the pathogenesis of ischemic brain damage. We studied the effects of the alpha-tocopherol analogue MDL 74,722 on iron-dependent lipid peroxidation and infarct volume after transient focal cerebral ischemia. The effects of MDL 74,722 on iron-induced lipid peroxidation were tested in cerebellar granule cell cultures by means of a thiobarbituric acid reactive substances (TBARS) assay. The absorbance resulting from mitochondrial reduction of 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) was taken as a measure of cell viability. Besides, in male Wistar rats the left middle cerebral artery (MCA) was occluded for 3 h by means of an intraluminal filament. Rats were treated with vehicle (n = 19) or MDL 74,722 (n = 17), administered intravenously for 3 h in a dose of 2 mg/(kg.h), starting 105 min after MCA occlusion. Infarct volume was measured in coronal brain sections stained with hematoxylin and eosin. In cerebellar granule cell cultures, MDL 74,722 resulted in a dose-dependent inhibition of TBARS formation and prevention of cell toxicity. The compound reduced infarct volume after transient occlusion of the MCA in rats by 49%. It is concluded that MDL 74,722 is a potent inhibitor of lipid peroxidation and reduces infarct volume by about one half, even when treatment is delayed. This contributes to its potential clinical usefulness.

Dietary vitamin E levels affect outcome of permanent focal cerebral ischemia in rats

BACKGROUND AND PURPOSE

A supraphysiological amount of vitamin E in the standard diet of laboratory animals may provide partial protection against cerebral ischemic damage in stroke models. The aim of the present study was to test the effect of dietary vitamin E on infarct volume in rats subjected to permanent focal cerebral ischemia.

METHODS

Male Wistar rats were raised on a vitamin E-deficient diet (n=10) or a control diet containing 62.7 mg vitamin E/kg (n=11) for 13 to 16 weeks, from the age of 3 weeks. The left middle cerebral artery (MCA) was permanently occluded by means of an intraluminal silicone-coated 3-0 suture. Blood flow in the left MCA territory was measured before and after occlusion with laser Doppler flowmetry. The area of infarction was measured in hematoxylin-eosin-stained brain sections by means of an image analysis system. The investigator was not aware of the vitamin E status of the rats.

RESULTS

Blood flow in the left MCA territory in the second half hour after occlusion was 43+/-17% and 42+/-17% (mean+/-SD) of the baseline value in control and vitamin E-deficient rats, respectively. The mean infarct volume, measured after 48 hours of survival, was 61+/-19 mm3 in control rats and 137+/-76 mm3 in vitamin E-deficient rats (P=0.037).

CONCLUSIONS

After permanent focal cerebral ischemia, the infarct is larger in vitamin E-deficient rats than in rats raised on a diet with the usual, supraphysiological amount of vitamin E. This may have consequences for cerebral ischemia studies with experimental animals.

Complications of acute ischaemic stroke

Neurological, cardiac, and systemic complications during the first days to weeks after ischaemic stroke can cause substantial morbidity and mortality. The reported 30-day case fatality rate for cerebral infarction varies between 10 and 17%. The incidence and effects of the various complications vary with time after stroke: transtentorial herniation and other cerebral complications prevail during the 1st week, whereas medical complications are more prominent in the weeks thereafter. Many complications are treatable, and some are preventable. The goal of this report is to provide information on their incidence, consequences, and management.

Dynamics of cerebral tissue injury and perfusion after temporary hypoxia-ischemia in the rat: evidence for region-specific sensitivity and delayed damage

BACKGROUND AND PURPOSE

Selective regional sensitivity and delayed damage in cerebral ischemia provide opportunities for directed and late therapy for stroke. Our aim was to characterize the spatial and temporal profile of ischemia-induced changes in cerebral perfusion and tissue status, with the use of noninvasive MRI techniques, to gain more insight in region-specific vulnerability and delayed damage.

METHODS

Rats underwent 20 minutes of unilateral cerebral hypoxia-ischemia (HI). We performed combined repetitive quantitative diffusion-weighted, T2-weighted, and dynamic susceptibility contrast-enhanced MRI from before HI to 5 hours after HI. Data were correlated with parallel blood oxygenation level-dependent MRI and laser-Doppler flowmetry. Finally, MRI and histology were done 24 and 72 hours after HI.

RESULTS

Severe hypoperfusion during HI caused acute reductions of the apparent diffusion coefficient (ADC) of tissue water in the ipsilateral hemisphere. Reperfusion resulted in dynamic perfusion alterations that varied spatially. The ADC recovered completely within 1 hour in the hippocampus (from 0.68 +/- 0.07 to 0.83 +/- 0.09 x 10[-3] mm2/s), cortex (from 0.56 +/- 0.06 to 0.77 +/- 0.07 x 10[-3] mm2/s), and caudate putamen (from 0.58 +/- 0.06 to 0.75 +/- 0.06 x 10[-3] mm2/s) but only partially or not at all in the thalamus (from 0.65 +/- 0.07 to 0.68 +/- 0.12 x 10[-3] mm2/s) and substantia nigra (from 0.80 +/- 0.08 to 0.76 +/- 0.10 x 10[-3] mm2/s). Secondary ADC reductions, accompanied by significant T2 elevations and histological damage, were observed after 24 hours. Initial and secondary ADC decreases were observed invariably in the hippocampus, cortex, and caudate putamen and in approximately 70% of the animals in the thalamus and substantia nigra.

CONCLUSIONS

Region-specific responses and delayed ischemic damage after transient HI were demonstrated by MRI. Acute reperfusion-induced normalization of ADCs appeared to poorly predict ultimate tissue recovery since secondary, irreversible damage developed eventually.