Time-Dependent Endovascular Treatment Effect According to Collateral Status in Basilar Artery Occlusion

Prior studies on anterior circulation stroke have demonstrated that the benefits of endovascular treatment (EVT) may be absent in patients with poor collaterals. Our study focused on patients with basilar artery occlusion (BAO) to investigate time-dependent EVT effects according to the posterior circulation collateral score (PC-CS). The BASILAR study was a nationwide prospective Chinese registry of consecutive BAO patients. Patients were divided into groups receiving standard medical therapy alone (SMT group) or SMT plus EVT (EVT group). Restricted cubic spline analyses (RCSA) were performed to explore the nonlinear and linear relationships between EVT time and outcomes for different PC-CS. We included 828 patients with acute BAO. Compared with the poor collateral (PC-CS 0-3), the adjusted odds ratio of favorable outcome was 1.311 in patients with moderate (PC-CS 4-5) (95% CI, 0.781-2.201) and 1.899 with good (PC-CS 6-10) collateral (1.125-3.207) for EVT. RCSA revealed that in patients with PC-CS 0-3, the favorable outcome probability after EVT significantly decreased to 10% within 6 h and stabilized thereafter (Pnonlinearity = 0.035), while in patients with moderate and good collateral, the probability was maintained at approximately 30% and 40% respectively, even beyond 6 h (all Pnonlinearity > 0.05). Among patients with BAO, good collateral circulation was independently associated with improved outcomes along with the usage of thrombectomy. Patients with poor collaterals should receive EVT as early as possible, especially within 6 h of symptom onset, while the time window may be extended in patients with moderate and good collaterals. Unique identifier: ChiCTR1800014759.

Increased admission and fasting glucose are associated with unfavorable short-term outcome after intra-arterial treatment of ischemic stroke in the MR CLEAN pretrial cohort

BACKGROUND

Limited data are available on the impact of fasting glucose on outcome after intra-arterial treatment (IAT). We studied whether hyperglycemia on admission and impaired fasting glucose (IFG) are associated with unfavorable outcome after IAT in acute ischemic stroke.

METHODS

Patients were derived from the pretrial registry of the MR CLEAN-trial. Hyperglycemia on admission was defined as glucose>7.8mmol/L, IFG as fasting glucose>5.5mmol/L in the first week of admission. Primary effect measure was the adjusted common odds ratio (acOR) for a shift in the direction of worse outcome on the modified Rankin Scale at discharge, estimated with ordinal logistic regression, adjusted for common prognostic factors.

RESULTS

Of the 335 patients in which glucose on admission was available, 86 (26%) were hyperglycemic, 148 of the 240 patients with available fasting glucose levels (62%) had IFG. Median admission glucose was 6.8mmol/L (IQR 6-8). Increased admission glucose (acOR 1.2, 95%CI 1.1-1.3), hyperglycemia on admission (acOR 2.6, 95%CI 1.5-4.6) and IFG (acOR 2.8, 95%CI 1.4-5.6) were associated with worse functional outcome at discharge.

CONCLUSION

Increased glucose on admission and IFG in the first week after stroke onset are associated with unfavorable short-term outcome after IAT of acute ischemic stroke.

Comparison of CTA- and DSA-Based Collateral Flow Assessment in Patients with Anterior Circulation Stroke

BACKGROUND AND PURPOSE

Collateral flow is associated with clinical outcome after acute ischemic stroke and may serve as a parameter for patient selection for intra-arterial therapy. In clinical trials, DSA and CTA are 2 imaging modalities commonly used to assess collateral flow. We aimed to determine the agreement between collateral flow assessment on CTA and DSA and their respective associations with clinical outcome.

MATERIALS AND METHODS

Patients randomized in MR CLEAN with middle cerebral artery occlusion and both baseline CTA images and complete DSA runs were included. Collateral flow on CTA and DSA was graded 0 (absent) to 3 (good). Quadratic weighted κ statistics determined agreement between both methods. The association of both modalities with mRS at 90 days was assessed. Also, association between the dichotomized collateral score and mRS 0-2 (functional independence) was ascertained.

RESULTS

Of 45 patients with evaluable imaging data, collateral flow was graded on CTA as 0, 1, 2, 3 for 3, 10, 20, and 12 patients, respectively, and on DSA for 12, 17, 10, and 6 patients, respectively. The κ-value was 0.24 (95% CI, 0.16-0.32). The overall proportion of agreement was 24% (95% CI, 0.12-0.38). The adjusted odds ratio for favorable outcome on mRS was 2.27 and 1.29 for CTA and DSA, respectively. The relationship between the dichotomized collateral score and mRS 0-2 was significant for CTA (P = .01), but not for DSA (P = .77).

CONCLUSIONS

Commonly applied collateral flow assessment on CTA and DSA showed large differences, indicating that these techniques are not interchangeable. CTA was significantly associated with mRS at 90 days, whereas DSA was not.

Safety of intra-arterial treatment in acute ischaemic stroke patients on oral anticoagulants. A cohort study and systematic review

BACKGROUND AND PURPOSE

An elevated international normalized ratio (INR) of >1.7 is a contraindication for the use of intravenous thrombolytics in acute ischaemic stroke. Local intra-arterial therapy (IAT) is considered a safe alternative. The safety and outcome of IAT were investigated in patients with acute ischaemic stroke using oral anticoagulants (OACs).

METHODS

Data were obtained from a large national Dutch database on IAT in acute stroke patients. Patients were categorized according to the INR: >1.7 and ≤1.7. Primary outcome was symptomatic intracerebral hemorrhage (sICH), defined as deterioration in the National Institutes of Health Stroke Scale score of ≥4 and ICH on brain imaging. Secondary outcomes were clinical outcome at discharge and 3 months. Occurrence of outcomes was compared with risk ratios and corresponding 95% confidence intervals. Further, a systematic review and meta-analysis on sICH risk in acute stroke patients on OACs treated with IAT was performed.

RESULTS

Four hundred and fifty-six patients were included. Eighteen patients had an INR > 1.7 with a median INR of 2.4 (range 1.8-4.1). One patient (6%) in the INR > 1.7 group developed a sICH compared with 53 patients (12%) in the INR ≤ 1.7 group (risk ratio 0.49, 95% confidence interval 0.07-3.13). Clinical outcomes did not differ between the two groups. Our meta-analysis showed a first week sICH risk of 8.1% (95% confidence interval 3.9%-17.1%) in stroke patients with elevated INR treated with IAT.

CONCLUSION

The use of OACs, leading to an INR > 1.7, did not seem to increase the risk of an sICH in patients with an acute stroke treated with IAT.

High versus standard clopidogrel loading in patients undergoing carotid artery stenting prior to cardiac surgery to assess the number of microemboli detected with transcranial Doppler: results of the randomized IMPACT trial

AIM

The aim of this study was to compare the effects of 300 mg or 600 mg clopidogrel loading dose, prior to carotid artery stenting (CAS) on the number of transcranial Doppler (TCD)-detected microembolic signals (MES) and to investigate the relationship between the magnitude of platelet reactivity and MES.

METHODS

In this prospective randomized, double-blind study, 35 consecutive asymptomatic patients (17.1% females), scheduled for CAS and cardiac surgery were included. The primary endpoint was the number of TCD-detected MES. The secondary endpoints were the absolute magnitude of on-treatment platelet reactivity and the adverse cerebral events. Negative binomial regression to find predictors for sum of single emboli, the student's t-test to assess the association between platelet function tests and randomized dose of 300 mg or 600 mg clopidogrel, and the R2 calculation for the assessment of the association between platelet function tests and embolic load, were used.

RESULTS

No statistically significant difference in the number of TCD-detected MES, in the sum of all the single emboli or showers and platelet aggregation measurements between the two groups was observed (aggregometry: 21.7±18.3 versus 23±18%, P=0.8499 and 45.8±17.5 versus 46.5±14.5%, P=0.9003) (verifyNow P2Y12 assay: 231±93 PRU versus 222±86 PRU, P=0.7704). In one patient a transient ischemic attack occurred.

CONCLUSION

A loading dose of 300 mg of clopidogrel in combination with aspirin is as effective as 600 mg of clopidogrel in achieving adequate platelet inhibition and preventing periprocedural events in asymptomatic patients undergoing CAS prior to cardiac surgery.

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).

Embolization of pulmonary arteriovenous malformations and decrease in prevalence of migraine

OBJECTIVE

To determine if embolization of pulmonary arteriovenous malformations (PAVMs) decreases the occurrence of migraine.

METHODS

All 105 patients with hereditary hemorrhagic telangiectasia (HHT), minimum age 16 years, who underwent an embolization of PAVM in our hospital between June 1995 and April 2004, were included in this study. A structured headache questionnaire was sent to all patients and focused on two periods: 1 year before and at least 6 months after embolization. Two independent neurologists diagnosed migraine according to the International Headache Society criteria.

RESULTS

Eighty-four patients (80%) sent back the questionnaire (mean age 47.8 +/- 15.1 years, 51 female). Median follow-up time was 48 months (first quartile: 23 months; third quartile: 66 months). The overall prevalence of migraine decreased from 45.2% before to 34.5% after embolization (p = 0.01). The prevalence of migraine with aura decreased from 33.3% before to 19.0% after embolization (p = 0.002). The severity of headache attacks decreased in patients who still had migraine (p = 0.15) or migraine with aura after embolization (p = 0.11).

CONCLUSION

Embolization of pulmonary arteriovenous malformations in patients with hereditary hemorrhagic telangiectasia seems to be related to a decrease in prevalence of migraine, suggesting that the presence of a right-to-left shunt rather than the localization of this shunt plays a causative role in the pathogenesis of migraine.

Outcome in patients with basilar artery occlusion treated conventionally

BACKGROUND

Most data on the outcome of basilar artery occlusion are from recent case series of patients treated with intra-arterial thrombolysis. The limited knowledge on the outcome after a conventional treatment approach comes from a few small case series of highly selected patients.

OBJECTIVE

To provide more data on the outcome of conventional treatment.

METHODS

Data were analysed on patients from three centres with symptomatic basilar artery occlusion treated conventionally. Conventional therapy was defined as treatment with antiplatelets, anticoagulation, or both.

RESULTS

Data were available on 82 patients. The case fatality was 40%. Among survivors, 65% remained dependent (Rankin score 4-5). Patients younger than 60 years (odds ratio = 3.1 (95% confidence interval, 1.0 to 9.5)) and those with a minor stroke (OR = 3.1 (1.0 to 9.6)) were more likely to have a good outcome (Rankin score 0-3). Patients with a progressive stroke were less likely to have a good outcome (OR = 0.3 (0.08 to 1.2)) than patients with a maximum deficit at onset or fluctuating symptoms at presentation.

CONCLUSIONS

Conventional treatment of symptomatic basilar artery occlusion is associated with a poor outcome in almost 80% of patients, which emphasises the importance of the search for a more effective treatment approach.

[Chronic daily headaches caused by too much caffeine]

Caffeine dependence is a frequent cause of chronic daily headache. This condition was diagnosed in three men aged 33, 35 and 26 years, respectively, and two women aged 67 and 44 years, respectively. As little as 100 mg caffeine may be enough to cause the headache, i.e. the equivalent of one cup of coffee, one bar of dark chocolate, 2 cups of tea or 2 tablets of an analgesic-coffee combination preparation. The therapy consists of discontinuing the caffeine consumption. Assessment of caffeine use is an important part of the headache anamnesis, especially in the case of morning or weekend headaches, unexplained increase in frequency and duration of episodes, a decreased response to headache medication or chronic daily headache.

[Acute language disorder in elderly patients: ischemic or epileptic origin?]

Acute language disorder is highly suggestive of cerebrovascular disease, but when accompanied by behavioral disturbance, particularly in elderly patients, it may express a different etiology. Six women aged 71 to 84 years presented with a mild behavioral disturbance followed by a language disorder that included fluent dysphasia, paraphasia, dysnomia, perseveration, and impaired understanding of complex orders. They fully recovered within 24 h. MR-imaging, including diffusion-weighted sequences in five of them, showed no acute lesions. EEG showed epileptogenic waveforms in three cases and slow waves in the other three, in a location that included the left temporal region. These findings disappeared in subsequent controls. All of these tests were performed during the acute episode or up to 72 h after onset. No patient has presented a new episode so far. The high sensitivity of new neuroimaging techniques forces the search for non-vascular etiologies in those patients in which no structural lesions that could account for the symptoms can be demonstrated. EEG can be useful in the diagnosis of some of these stroke mimics. Acute language disorders accompanied by disturbed behavior in the elderly may reflect a partial seizure of the temporal lobe.

Diffusion-weighted MRI in acute lacunar syndromes. A clinical-radiological correlation study

BACKGROUND AND PURPOSE

Clinical-radiological correlation studies in lacunar syndromes have been handicapped by the low sensitivity of CT and standard MRI for acute small-vessel infarction and their difficulty in differentiating between acute and chronic lesions.

METHODS

We prospectively studied 43 patients presenting with a classic lacunar syndrome using diffusion-weighted MRI, a technique with a high sensitivity and specificity for acute small-vessel infarction.

RESULTS

All patients were scanned within 6 days of stroke onset. An acute infarction was identified in all patients. Pure motor stroke was associated with lesions in the posterior limb of the internal capsule (PLIC), pons, corona radiata, and medial medulla; ataxic hemipareses with lesions in the PLIC, corona radiata, pons, and insular cortex; sensorimotor stroke with lesions in the PLIC and lateral medulla; dysarthria-clumsy hand syndrome with lesions in the PLIC and caudate nucleus; and pure sensory stroke with a lesion in the thalamus. Supratentorial lesions extended into neighboring anatomic structures in 48% of the patients.

CONCLUSIONS

Lacunar syndromes can be caused by lesions in a variety of locations, and specific locations can cause a variety of lacunar syndromes. Extension of lesions into neighboring structures in patients with lacunar syndromes appears to be more frequent than previously described in studies using CT and standard MRI.

Diffusion-weighted MR of acute cerebral infarction: comparison of data processing methods

BACKGROUND AND PURPOSE

Some investigators have proposed that either calculated diffusion trace images or apparent diffusion coefficient (ADC) maps, which require imaging with multiple diffusion sensitivities and/or postacquisition image processing, are essential for the accurate interpretation of diffusion-weighted images in acute stroke because of the possible pitfalls of regional diffusion anisotropy, magnetic susceptibility artifacts, and confounding T2 effects, all of which alter signal on diffusion-weighted MR images. The purpose of our study was to compare the sensitivity, specificity, and accuracy of simple, orthogonal-axis diffusion-weighted imaging for the diagnosis of early cerebral infarction with three other sets of postacquisition-processed images: isotropic diffusion-weighted, diffusion trace-weighted, and diffusion trace images.

METHODS

Twenty-six consecutive adult patients with signs and symptoms consistent with a clinical diagnosis of early cortical and/or subcortical cerebral infarction and 17 control subjects were studied with multisection, single-shot, spin-echo echo-planar diffusion-weighted imaging at 1.5 T to generate a set of three orthogonal-axis diffusion-weighted images. Isotropic diffusion-weighted, diffusion trace-weighted, and diffusion trace (mean ADC) images were then generated off-line and all four sets of images were interpreted blindly by two neuroradiologists.

RESULTS

The average sensitivity, specificity, and accuracy for the orthogonal-axis diffusion-weighted images were 98.1%, 97.1%, and 97.7%, respectively. The average sensitivity, specificity, and accuracy for isotropic diffusion-weighted images were 88.5%, 100%, and 93% respectively. The average sensitivity, specificity, and accuracy for diffusion trace-weighted images were 82.7%, 73.6%, and 79.1%, respectively. The average sensitivity, specificity, and accuracy for diffusion trace images were 50.0%, 85.3%, and 64.0%, respectively.

CONCLUSION

Orthogonal-axis diffusion-weighted images have the highest sensitivity and accuracy and very high specificity for early cerebral infarction. Our data contradict the contention that quantitative diffusion maps, requiring imaging with multiple diffusion sensitivities and/or subsequent image processing, are necessary for clinical stroke imaging.

Diffusion-weighted MRI in acute subcortical infarction

BACKGROUND AND PURPOSE

Conventional imaging lacks sensitivity and specificity for the detection of early subcortical cerebral infarction. The purposes of our study were (1) to determine the accuracy of diffusion-weighted (DW) MRI for early subcortical infarction and (2) to determine the efficacy of DW MRI for differentiating acute from nonacute subcortical infarctions when conventional MR demonstrates multiple infarctions.

METHODS

Thirty-nine patients with clinically diagnosed acute subcortical infarction and 17 control subjects were imaged with both conventional and DW MRI from 7 hours to 4 days (mean, 2.0 days) after onset of symptoms. All images were read blinded to specific clinical findings. In all cases, the precise neuroanatomic locations of lesions were noted. These lesions were subsequently correlated by an experienced stroke neurologist to determine whether their locations correlated to the patients' symptoms.

RESULTS

The accuracy of DW MRI for acute subcortical infarction was 94.6%. In 4 of 39 cases, the acute infarction was not detected on conventional MRI. In 24 of 39 cases, conventional MRI showed the acute lesion as well as multiple other subcortical lesions. In each of these 24 cases, the DW MRI showed a single lesion to be acute, and in all 24 cases, that lesion corresponded to the patients' acute symptoms.

CONCLUSIONS

DW MRI has very high accuracy for acute subcortical infarction and can differentiate acute from nonacute lesions. These data have significant implications in guiding patient management and patient selection for clinical trials.