Role of CT Angiography in Thrombolysis Decision-Making for Patients With Presumed Seizure at Stroke Onset

Diagnosis and Treatment of Poststroke Epilepsy: Where Do We Stand?

Purpose of Review

Stroke is the most common cause of seizures and epilepsy in older adults. This educational paper aims to give an update on current clinical aspects of diagnosis and treatment of poststroke epilepsy.

Recent Findings

Regarding epileptic seizures related to stroke, it is important to distinguish between acute symptomatic seizures and unprovoked seizures as they differ in their risk for seizure recurrence. In fact, after a single unprovoked poststroke seizure, a diagnosis of epilepsy can be made because there is a greater than 60% risk for further seizures. Clinical models that can predict the development of epilepsy after a stroke have been successfully established. However, treatment with anti-seizure medications is advised only after a first unprovoked poststroke seizure, as current treatments are not known to be effective for primary prevention. The management of poststroke epilepsy requires consideration of aspects such as age, drug-drug interactions and secondary vascular prophylaxis, yet evidence for the use of anti-seizure medications specifically in poststroke epilepsy is limited.

Summary

This text reviews the epidemiology and risk factors for poststroke epilepsy, explains the role of EEG and neuroimaging in patients with stroke and seizures and provides an overview on the clinical management of stroke-related acute symptomatic seizures and poststroke epilepsy.

Poststroke seizures as stroke mimics: Clinical assessment and management

Epileptic seizures with postictal negative symptoms represent 20% of all suspected strokes and should be considered in the differential diagnosis of stroke in any patient presenting with an acute neurological deficit, mostly in absence of convulsions. Seizures may also occur at stroke onset, and the latter need to be promptly recognized in order to timely administer reperfusion therapies and reduce the risk of irreversible brain injury. Neuroimaging is essential in differentiating between postictal negative symptoms and deficits due to stroke. After the acute phase, poststroke seizures may worsen or cause the reappearance of neurological deficits and consciousness impairment; they can be also misinterpreted as stroke recurrence and lead to delayed treatment with antiepileptic drugs. It is mandatory to maintain a low threshold for suspecting epileptic seizures, and require appropriate electroencephalographic and neuroimaging investigations to promptly ascertain the etiology of any unexplained change in the neurological status and provide the most adequate treatment. This article is part of the Special Issue "Seizures & Stroke".

Early seizures after ischemic stroke: focus on thrombolysis

INTRODUCTION

Stroke is a significant underlying cause of epilepsy. Seizures due to ischemic stroke (IS) are generally categorized into early seizures (ESs) and late seizures (LSs). Seizures in thrombolysis situations may raise the possibility of other etiology than IS.

AIM

We overtook a systematic review focusing on the pathogenesis, prevalence, risk factors, detection, management, and clinical outcome of ESs in IS and in stroke/thrombolysis situations. We also collected articles focusing on the association of recombinant tissue-type plasminogen activator (rt-PA) treatment and epileptic seizures.

RESULTS

We have identified 37 studies with 36,775 participants. ES rate was 3.8% overall in patients with IS with geographical differences. Cortical involvement, severe stroke, hemorrhagic transformation, age (<65 years), large lesion, and atrial fibrillation were the most important risk factors. Sixty-one percent of ESs were partial and 39% were general. Status epilepticus (SE) occurred in 16.3%. 73.6% had an onset within 24 h and 40% may present at the onset of stroke syndrome. Based on EEG findings seizure-like activity could be detected only in approximately 18% of ES patients. MRI diffusion-weighted imaging and multimodal brain imaging may help in the differentiation of ischemia vs. seizure. There are no specific recommendations with regard to the treatment of ES.

CONCLUSION

ESs are rare complications of acute stroke with substantial burden. A significant proportion can be presented at the onset of stroke requiring an extensive diagnostic workup.

Intravenous thrombolysis for suspected ischemic stroke with seizure at onset

OBJECTIVE

Seizure at onset (SaO) has been considered a relative contraindication for intravenous thrombolysis (IVT) in patients with acute ischemic stroke, although this appraisal is not evidence based. Here, we investigated the prognostic significance of SaO in patients treated with IVT for suspected ischemic stroke.

METHODS

In this multicenter, IVT-registry-based study we assessed the association between SaO and symptomatic intracranial hemorrhage (sICH, European Cooperative Acute Stroke Study II definition), 3-month mortality, and 3-month functional outcome on the modified Rankin Scale (mRS) using unadjusted and adjusted logistic regression, coarsened exact matching, and inverse probability weighted analyses.

RESULTS

Among 10,074 IVT-treated patients, 146 (1.5%) had SaO. SaO patients had significantly higher National Institutes of Health Stroke Scale score and glucose on admission, and more often female sex, prior stroke, and prior functional dependence than non-SaO patients. In unadjusted analysis, they had generally less favorable outcomes. After controlling for confounders in adjusted, matched, and weighted analyses, all associations between SaO and any of the outcomes disappeared, including sICH (odds ratio [OR]_unadjusted = 1.53 [95% confidence interval (CI) = 0.74-3.14], OR_adjusted = 0.52 [95% CI = 0.13-2.16], OR_matched = 0.68 [95% CI = 0.15-3.03], OR_weighted = 0.95 [95% CI = 0.39-2.32]), mortality (OR_unadjusted = 1.49 [95% CI = 1.00-2.24], OR_adjusted = 0.98 [95% CI = 0.5-1.92], OR_matched = 1.13 [95% CI = 0.55-2.33], OR_weighted = 1.17 [95% CI = 0.73-1.88]), and functional outcome (mRS ≥ 3/ordinal mRS: OR_unadjusted = 1.33 [95% CI = 0.96-1.84]/1.35 [95% CI = 1.01-1.81], OR_adjusted = 0.78 [95% CI = 0.45-1.32]/0.78 [95% CI = 0.52-1.16], OR_matched = 0.75 [95% CI = 0.43-1.32]/0.45 [95% CI = 0.10-2.06], OR_weighted = 0.87 [95% CI = 0.57-1.34]/1.00 [95% CI = 0.66-1.52]). These results were consistent regardless of whether patients had an eventual diagnosis of ischemic stroke (89/146) or stroke mimic (57/146 SaO patients).

INTERPRETATION

SaO was not an independent predictor of poor prognosis. Withholding IVT from patients with assumed ischemic stroke presenting with SaO seems unjustified. ANN NEUROL 2019;86:770-779.

Stroke Chameleons and Stroke Mimics in the Emergency Department

PURPOSE OF REVIEW

We discuss the frequency of stroke misdiagnosis in the emergency department (ED), identify common diagnostic pitfalls, describe strategies to reduce diagnostic error, and detail ongoing research.

RECENT FINDINGS

The National Academy of Medicine has re-defined and highlighted the importance of diagnostic errors for patient safety. Recent rates of stroke under-diagnosis (false-negative cases, "stroke chameleons") range from 2-26% and 30-43% for stroke over-diagnosis (false-positive cases, "stroke mimics"). Failure to diagnosis stroke can preclude time-sensitive treatments and has been associated with poor outcomes. Strategies have been developed to improve detection of posterior circulation stroke syndromes, but ongoing work is needed to reduce under-diagnosis in other atypical stroke presentations. The published rates of harm associated with stroke over-diagnosis, particularly thrombolysis of stroke mimics, remain low. Additional strategies to improve the accuracy of stroke diagnosis should focus on rapid clinical reasoning in the time-sensitive setting of acute ischemic stroke and identifying imperfections in the healthcare system which may contribute to diagnostic error.

The prognosis of acute symptomatic seizures after ischaemic stroke

OBJECTIVE

Acute symptomatic seizure (AS) after ischaemic stroke is defined as a seizure occurring ≤7 days of the stroke. There remains a lack of information on the prognosis of AS after ischaemic stroke and how it should be treated.

METHODS

We prospectively recruited patients after their incidents of ischaemic stroke from a population-based stroke registry. Stroke aetiology was defined according to Trial-of-ORG-10172 in acute-stroke treatment (TOAST). Patients were examined for any transient complete-occlusion with recanalisation (TCOR) and haemorrhagic transformation. The seizure outcomes were (1) acute clustering of seizures ≤7 days, (2) seizure recurrence associated with stroke recurrence beyond the 7-day period and (3) unprovoked seizure (US) >7 days.

RESULTS

104 patients (mean age 65 years/55% female) with AS after ischaemic stroke were identified (mean follow-up 6.17 years). Comparison of the group of patients with AS and those without seizures showed that patients with AS had significantly less large-vessel and small-vessel disease but more cardioembolisms (p<0.05) and a higher proportion of TCOR (p<0.01), multiple territory infarcts (p=0.007) and haemorrhagic transformations (p<0.01). Using Kaplan-Meier statistics, the risk of acute clustering of seizures ≤7 days was 22%, with a statistical trend for TCOR as a predictive factor (p=0.06). The risk of seizure recurrence associated with worsening/recurrence of stroke beyond 7 days was 13.5% at 2 years, 16.4% at 4 years and 18% at 8 years. Presence of >2 cardiovascular risk factors (p<0.05) and status epilepticus (P<0.05) are predictive risk factors on Cox regression model. The risk of US was 19% at 2 years, 25% at 4 years and 28% at 8 years with epileptiform EEG as a predictive factor (p<0.05).

CONCLUSIONS

Seizure recurrence following AS after ischaemic stroke may appear as acute clustering. Afterwards, seizures may occur as often with a recurrent stroke as without one within 4.2 years. We recommend the use of antiepileptic agents for up to 4 years if the underlying stroke aetiology cannot be fully treated.

Scientific Rationale for the Inclusion and Exclusion Criteria for Intravenous Alteplase in Acute Ischemic Stroke

Purpose—

To critically review and evaluate the science behind individual eligibility criteria (indication/inclusion and contraindications/exclusion criteria) for intravenous recombinant tissue-type plasminogen activator (alteplase) treatment in acute ischemic stroke. This will allow us to better inform stroke providers of quantitative and qualitative risks associated with alteplase administration under selected commonly and uncommonly encountered clinical circumstances and to identify future research priorities concerning these eligibility criteria, which could potentially expand the safe and judicious use of alteplase and improve outcomes after stroke.

Methods—

Writing group members were nominated by the committee chair on the basis of their previous work in relevant topic areas and were approved by the American Heart Association Stroke Council’s Scientific Statement Oversight Committee and the American Heart Association’s Manuscript Oversight Committee. The writers used systematic literature reviews, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and to indicate gaps in current knowledge and, when appropriate, formulated recommendations using standard American Heart Association criteria. All members of the writing group had the opportunity to comment on and approved the final version of this document. The document underwent extensive American Heart Association internal peer review, Stroke Council Leadership review, and Scientific Statements Oversight Committee review before consideration and approval by the American Heart Association Science Advisory and Coordinating Committee.

Results—

After a review of the current literature, it was clearly evident that the levels of evidence supporting individual exclusion criteria for intravenous alteplase vary widely. Several exclusionary criteria have already undergone extensive scientific study such as the clear benefit of alteplase treatment in elderly stroke patients, those with severe stroke, those with diabetes mellitus and hyperglycemia, and those with minor early ischemic changes evident on computed tomography. Some exclusions such as recent intracranial surgery are likely based on common sense and sound judgment and are unlikely to ever be subjected to a randomized, clinical trial to evaluate safety. Most other contraindications or warnings range somewhere in between. However, the differential impact of each exclusion criterion varies not only with the evidence base behind it but also with the frequency of the exclusion within the stroke population, the probability of coexistence of multiple exclusion factors in a single patient, and the variation in practice among treating clinicians.

Treatment of acute stroke: an update

Stroke is the second leading cause of global mortality after coronary heart disease, and a major cause of neurological disability. About 17 million strokes occur worldwide each year. Patients with stroke often require long-term rehabilitation following the acute phase, with ongoing support from the community and nursing home care. Thus, stroke is a devastating disease and a major economic burden on society. In this overview, we discuss current strategies for specific treatment of stroke in the acute phase, focusing on intravenous thrombolysis and mechanical thrombectomy. We will consider two important issues related to intravenous thrombolysis treatments: (i) how to shorten the delay between stroke onset and treatment and (ii) how to reduce the risk of symptomatic intracerebral haemorrhage. Intravenous thrombolysis has been approved treatment for acute ischaemic stroke in most countries for more than 10 years, with rapid development towards new treatment strategies during that time. Mechanical thrombectomy using a new generation of endovascular tools, stent retrievers, is found to improve functional outcome in combination with pharmacological thrombolysis when indicated. There is an urgent need to increase public awareness of how to recognize a stroke and seek immediate attention from the healthcare system, as well as shorten delays in prehospital and within-hospital settings.

[An update on limitations of intravenous thrombolysis to treat acute ischemic stroke]

The benefit of intravenous thrombolysis with rt-pa has been demonstrated in acute ischemic stroke up to 4 h 30 after the first symptoms. The number of patients with stroke treated by rt-pa remains low at less than 5%. In the license of rt-pa in acute ischemic stroke, there are numerous contra-indications explained by the fear of cerebral hemorrhagic complications. These contra-indications are based on the first therapeutic trials published more than 15 years ago, but are not all evidence-based. Large post-marketing registers and new randomized trials have shown a favorable ratio benefit/risk of rt-pa in acute ischemic strokes in some classical contra-indications. Reconsidering some of the official contra-indications would increase the target population with treatable acute ischemic stroke using rt-pa to 20%.

The exact science of stroke thrombolysis and the quiet art of patient selection

The science of metric-based patient stratification for intravenous thrombolysis, revolutionized by the landmark National Institute of Neurological Disorders and Stroke trial, has transformed acute ischaemic stroke therapy. Recanalization of an occluded artery produces tissue reperfusion that unequivocally improves outcome and function in patients with acute ischaemic stroke. Recanalization can be achieved mainly through intravenous thrombolysis, but other methods such as intra-arterial thrombolysis or mechanical thrombectomy can also be employed. Strict guidelines preclude many patients from being treated by intravenous thrombolysis due to the associated risks. The quiet art of informed patient selection by careful assessment of patient baseline factors and brain imaging could increase the number of eligible patients receiving intravenous thrombolysis. Outside of the existing eligibility criteria, patients may fall into therapeutic 'grey areas' and should be evaluated on a case by case basis. Important factors to consider include time of onset, age, and baseline blood glucose, blood pressure, stroke severity (as measured by National Institutes of Health Stroke Scale) and computer tomography changes (as measured by Alberta Stroke Programme Early Computed Tomography Score). Patients with traditional contraindications such as wake-up stroke, malignancy or dementia may have the potential to receive benefit from intravenous thrombolysis if they have favourable predictors of outcome from both clinical and imaging criteria. A proportion of patients experience complications or do not respond to intravenous thrombolysis. In these patients, other endovascular therapies or a combination of both may be used to provide benefit. Although an evidence-based approach to intravenous thrombolysis for acute ischaemic stroke is pivotal, it is imperative to examine those who might benefit outside of protocol-driven practice.

Guidelines for the early management of patients with acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

The authors present an overview of the current evidence and management recommendations for evaluation and treatment of adults with acute ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators responsible for the care of acute ischemic stroke patients within the first 48 hours from stroke onset. These guidelines supersede the prior 2007 guidelines and 2009 updates.

METHODS

Members of the writing committee were appointed by the American Stroke Association Stroke Council's Scientific Statement Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Panel members were assigned topics relevant to their areas of expertise, reviewed the stroke literature with emphasis on publications since the prior guidelines, and drafted recommendations in accordance with the American Heart Association Stroke Council's Level of Evidence grading algorithm.

RESULTS

The goal of these guidelines is to limit the morbidity and mortality associated with stroke. The guidelines support the overarching concept of stroke systems of care and detail aspects of stroke care from patient recognition; emergency medical services activation, transport, and triage; through the initial hours in the emergency department and stroke unit. The guideline discusses early stroke evaluation and general medical care, as well as ischemic stroke, specific interventions such as reperfusion strategies, and general physiological optimization for cerebral resuscitation.

CONCLUSIONS

Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke remains urgently needed.

Thrombolytic therapy for acute ischaemic stroke: what can we do to improve outcomes?

Constant efforts are being made in the stroke community to aim for maximum benefit from thrombolytic therapy since the approval of intravenous recombinant tissue plasminogen activator (rt-PA; alteplase) for the management of acute ischaemic stroke. However, fear of symptomatic haemorrhage secondary to thrombolytic therapy has been a major concern for treating physicians. Certain imaging and clinical variables may help guide the clinician towards better treatment decision making. Aggressive management of some predictive variables that have been shown to be surrogate outcome measures has been related to better clinical outcomes. Achieving faster, safer and complete recanalization with evolving endovascular techniques is routinely practiced to achieve better clinical outcomes. Selection of an 'ideal candidate' for thrombolysis can maximize functional outcomes in these patients. Although speed and safety are the key factors in acute management of stroke patients, there must also be a systematic and organized pattern to assist the stroke physician in making decisions to select the 'ideal candidate' for treatment to maximize results.

Seven questions about stroke and epilepsy

Seizures and stroke are both common neurologic conditions, but when they occur in close temporal proximity they produce much more concern than either does alone. The stroke specialist (and the family) fear that convulsions will worsen the stroke because of acute hypertension and airway compromise, and the epileptologist is concerned that these acute seizures are the harbingers of later epilepsy. Other less commonly recognized but important aspects of this relationship are that subclinical seizures worsen some forms of stroke, and some anticonvulsants may have more adverse effects on stroke patients than they do in other groups. In surveying the connections between these two conditions, I have attempted to address seven questions. For some questions, there are data to help provide an answer; for others, there is only opinion; and for a maddening few, newer research is making older suggestions less certain.

Usefulness of CT angiography for therapeutic decision making in thrombolyzing intubated patients with suspected basilar artery thrombosis

BACKGROUND AND AIMS

Acute ischemic stroke (AIS) due to basilar artery thrombosis (BAT) causes high mortality and severe disability. Early neurological assessment and timely thrombolysis might improve outcome. BAT is difficult to diagnose due to wide spectrum of presentation and decreased conscious level. Emergency physicians often intubate BAT patients with airway compromise before arrival of stroke neurologist. We evaluated role of computerized tomography (CT) angiography (CTA) of brain and cervical arteries in early diagnosis of acute BAT in intubated patients and facilitating decision for thrombolysis.

METHODS

Consecutive AIS patients presenting between 2007 and 2009 within 6 hours of symptom onset, with sudden deterioration in conscious level and intubation before assessment by neurologist, were included. All patients underwent brain CT and CTA. Outcomes were assessed at 3 months.

RESULTS

Thrombolytic therapy, mainly intravenous tissue plasminogen activator (IV-TPA), was administered to 161 (8.4%) of 1,917 AIS patients during the study period. Acute BAT contributed 10.9% of our cohort. CTA was performed in 152 (94.4%) patients and the rest were excluded due to their impaired renal functions. Five patients (3 males, mean age 72 years) presenting with acute obtundation and airway compromise were intubated, sedated, and paralyzed before assessment by neurologist. CTA showed BAT in all. IV-TPA was initiated at 213 ± 59 minutes in 4 patients while 1 received intraarterial thrombolysis at 13 hours. There was no intracranial hemorrhage. Mean length of hospital stay was 11.8 days. Despite severe stroke at presentation, good functional recovery at 3 months (modified Rankin scale [mRS] 1) occurred in 2 patients; mRS 4 in 1, and 2 died.

CONCLUSION

In patients with BAT, intubated before assessment by neurologist, CTA might help in confirming the diagnosis and facilitating therapeutic decision making for initiating thrombolysis.

Hypoperfusion of an entire cerebral hemisphere - stroke or postictal deficit?

The clinical differential diagnosis between ischemic stroke and postictal deficit is sometimes challenging. If the clinical presentation is inconclusive, perfusion imaging can help to identify stroke patients for thrombolysis therapy. However, also epileptic phenomena may alter cerebral perfusion. Hypoperfusion spreading beyond the borders of cerebrovascular territories is usually considered suggestive of an etiology other than stroke. We present a patient whose clinical symptoms suggested a postictal deficit rather than an acute stroke. CT perfusion imaging showed hypoperfusion of the entire left cerebral hemisphere covering all vascular territories. CT angiography revealed occlusions in the ipsilateral internal carotid artery and in the circle of Willis as the cause of the global hypoperfusion. The patient was treated with i.v. thrombolysis and recovered with moderate disability. This is the first description of hyperacute ischemia of an entire cerebral hemisphere and its treatment with thrombolysis. It demonstrates the potential of modern neuroimaging in identifying atypically presenting strokes and shows that i.v. thrombolysis can be effectively and safely used to treat such potentially fatal insults.

[Difficult decisions in stroke therapy]

In numerous situations stroke physicians face a lack of evidence during their daily practice. In this report the authors address some of the difficult treatment decisions encountered in acute therapy and secondary prevention. Examples include off-label thrombolysis and prevention in high-risk situations. The available data from trials and registries are discussed, and personal views and recommendations are expressed.

Stroke during pregnancy: therapeutic options and role of percutaneous device closure

Percutaneous device closure of patent foramen ovale has developed into a therapeutic option for patients with presumed cryptogenic stroke. The appropriate use of these therapies relies on appropriate clinical assessment, as well as an understanding of the potential advantages of certain closure devices. Pregnancy is an uncommon scenario for stroke, but nonetheless represents a hypercoaguable state which may predispose to thromboembolism. We describe a case of stroke during pregnancy treated with percutaneous device closure; the role of, and alternatives to, device closure are discussed, as are specific issues related to device selection and the interventional procedure.

Top of the basilar syndrome in a young adult initially presenting with a convulsive seizure

A 23-year-old man was admitted to our hospital due to loss of consciousness and a generalized convulsive seizure. He was diagnosed as having primary epilepsy and treated with antiepileptic drugs. Emergency CT scan of the head showed no abnormality. However, MRI scan of the head several days after admission revealed fresh infarctions caused by occlusion of the basilar artery, i.e., "top of the basilar" syndrome. This case indicates the need for precise differential diagnosis of convulsive seizure in an emergency situation. It should also be borne in mind that basilar occlusion with 'onset seizure' can occur even in young adults who have no risk factors for stroke.

The MERCI Retrieval System for the Management of Acute Ischaemic Stroke – The NNI Singapore Experience

Introduction: Systemic and local intra-arterial thrombolysis in patients with large vessel ischaemic stroke is hampered by poor re-canalisation rates and risk of haemorrhage. The Merci Retrieval System is an endovascular device for removal of acute intracranial thrombus. We present our initial experience using this device in conjunction with existing thrombolytic therapy already in place in our institute. Materials and Methods: Prospective data in all patients presenting with large vessel ischaemic stroke treated using the Merci Retrieval System from July 2007 to March 2009 were analysed. Selection criteria for patients were similar to the multi- Merci trial of 2008. We compared re-canalisation rate, National Institutes of Health Stroke Score (NIHSS) and modified Rankin score (mRS) outcomes to the published trial results. Results: Seventeen patients were reviewed; none suffered immediate post-procedural complications. Fifteen underwent successful thrombus retrieval but in 2 cases the device failed due to technical considerations. Sites of vascular occlusion included: ICA/ICA-‘T’ junctions 27%, middle cerebral artery 13% and vertebrobasilar artery 60%. Of the 15 patients treated by MERCI with or without adjuvant thrombolytic therapy, complete re-canalisation was achieved in 60%, partial re-canalisation in 20%, partial re-canalisation with persistent distal vessel occlusion in 6% and failure of re-canalisation in 14%. Asymptomatic haemorrhage occurred in 33% and there was 1 death (6%) from symptomatic haemorrhage. Pre-treatment median NIHSS was 17.88 and 9.5 immediately post-treatment. Median mRS at 30 days was 2.6 for patients who achieved complete re-canalisation and 4.5 in failure or partial re-canalisation with or without persistent distal vessel occlusion. Conclusion: Re-canalisation rates using the Merci Retrieval System was comparable to the multi-Merci trial. Haemorrhagic complications and safety were also found to be satisfactory. Importantly, treatment success with eventual good clinical outcome hinges strongly on the ability of the device to achieve complete re-canalisation. Key words: Acute ischaemic stroke, Mechanical revascularisation, Thrombectomy, The Merci Retrieval System

[Computed tomography in acute ischemic stroke. Current developments compared with stroke MRI]

Modern multimodal acute stroke computed tomography (CT) includes noncontrast cranial CT (NCT), CT angiography (CTA), and CT perfusion imaging (CTP). Compared to stroke MRI, NCT is faster and easier. Multimodal CT can determine acute stroke etiology: Is arterial occlusion or intracerebal hemorrhage present? How extensive are the perfusion disturbance and infarct core, respectively? The information from NCT is sufficient for making acute stroke thrombolysis decisions within 4.5 h from symptom onset. The therapeutic effect of CTA and CTP--as well as acute stroke MRI--on improved functional outcome has still not been established.

Cerebral CT angiography using a reduced dose of contrast material at high iodine concentration in combination with a saline flush

AIM

To determine whether cerebral computed tomography (CT) angiography with a 16-detector row system can be performed using a reduced dose of contrast material.

MATERIALS AND METHODS

Twenty-eight patients were assigned to one of four protocols: A=50 ml of 350 mg I/ml with a saline flush (SF, 40 ml); B=75 ml of 350 mg I/ml with an SF; C=75 ml of 350 mg I/ml without an SF; and D=100ml of 300 mg I/ml without an SF. The attenuation of the internal carotid, middle cerebral, and anterior cerebral arteries were measured. The demonstration of vessels was also assessed.

RESULTS

There were no significant attenuation differences of the arteries among the four groups, neither were any significant differences noted on the visual assessment.

CONCLUSIONS

By using a reduced dose (50 ml) at higher iodine concentration (350 mg I/ml) with an SF, CT angiograms comparable with those acquired with a standard dose and concentration can be obtained.

Multiphase CT angiography versus single-phase CT angiography: comparison of image quality and radiation dose

BACKGROUND AND PURPOSE

Conventional CT angiography (CTA) is acquired during only a short interval in the arterial phase, which limits its ability to evaluate the cerebral circulation. Our aim was to compare the image quality and radiation dose of conventional single-phase CTA (SP-CTA) with a multiphase CTA (MP-CTA) algorithm reconstructed from a perfusion CT (PCT) dataset.

MATERIALS AND METHODS

Fifty consecutive patients undergoing head CTA and PCT in 1 examination were enrolled. The PCT dataset was obtained with 40.0-mm-detector coverage, 5.0-mm axial thickness, 80 kilovolt peak (kVp), 180 mA, and 30 mL of contrast medium. MP-CTA was reconstructed from the same PCT dataset with an axial thickness of 0.625 mm by using a new axial reconstruction algorithm. A conventional SP-CTA dataset was obtained with 0.625-mm axial thickness, 120 kVp, 350 mA, and 60 mL of contrast medium. We compared image quality, vascular enhancement, and radiation dose.

RESULTS

SP-CTA and MP-CTA of 50 patients (male/female ratio, 31/19; mean age, 59.25 years) were analyzed. MP-CTA was significantly better than SP-CTA in vascular enhancement (P = .002), in the absence of venous contamination (P = .006), and was significantly higher in image noise (P < .001). MP-CTA used less contrast medium than SP-CTA and could demonstrate hemodynamic information. The effective dose of MP-CTA was 5.73 mSv, which was equal to that in conventional PCT, and it was 3.57 mSv in SP-CTA.

CONCLUSION

It is feasible that MP-CTA may provide both CTA and PCT results. Compared with SP-CTA, MP-CTA provides comparable image quality, better vascular enhancement, hemodynamic information, and more noise with less detail visibility with a lower tube voltage. The radiation dose of MP-CTA is higher than that of SP-CTA, but the dose can be reduced by altering the sampling interval.

MR imaging-based decision in thrombolytic therapy for stroke on awakening: report of 2 cases

Patients with stroke on awakening are denied the potential benefit of thrombolysis on the grounds that the onset time is unknown. Relying on clinical and MR imaging to indicate the most appropriate treatment could be more rational. We report 2 cases of stroke with unknown onset time. In both cases, anamnesis and MR imaging indicated that we might still be within 6 hours from stroke onset, with salvageable tissue. Arterial recanalization was successfully performed in both cases.

Seizure: an unusual primary presentation of type A aortic dissection

Aortic dissection is a potentially life-threatening condition that must be diagnosed early and accurately. Here we report a case of type A aortic dissection presenting with seizure and unconsciousness. We thought this rare manifestation should be reported because misdiagnosis of such cases could lead to disastrous results.

Intravenous alteplase for stroke: beyond the guidelines and in particular clinical situations

BACKGROUND AND PURPOSE

Because of the risk of hemorrhage, especially in the brain, thrombolytic therapy with intravenous alteplase is restricted by guidelines, and only a small number of selected patients are being treated. Findings from metaanalyses, post hoc analyses of the randomized trials, and postlicensing experience suggest that more subjects, who otherwise have a poor predicted outcome without treatment, might benefit from intravenous alteplase. Summary of Review- There is a strong indication that treatment may still be beneficial beyond 3 hours up until 4.5 hours. The risk of symptomatic intracerebral hemorrhage is not increased in patients aged 80 years or older. Excluding patients with severe stroke or with early ischemic changes in more than one third of the middle cerebral artery territory on baseline CT scan is probably not necessary when treatment is started <3 hours of symptom onset. Patients with minor or improving symptoms can also benefit. Intravenous thrombolysis appears appropriate as first line therapy for posterior circulation stroke. Alteplase can be given to patients with cervical artery dissection, seizure at onset and evidence of acute ischemia on brain imaging, and after carefully weighing risk and benefit in pregnancy and during menstruation. There are anecdotal reports on its use in children, patients with recent myocardial infarction, cardiac embolus, intracranial aneurysm or arteriovenous malformation, prior stroke and recent surgery. There appears to be a substantially increased risk of symptomatic cerebral hemorrhage in hyperglycemic stroke patients. The combined intravenous and intraarterial approach to recanalization appears safe and is currently under investigation in a randomized trial.

CONCLUSIONS

This document does not intend to change the guidelines but reviews the literature on the use of intravenous alteplase for stroke beyond guidelines and in particular conditions.

Guidelines for the Early Management of Adults With Ischemic Stroke

Purpose— Our goal is to provide an overview of the current evidence about components of the evaluation and treatment of adults with acute ischemic stroke. The intended audience is physicians and other emergency healthcare providers who treat patients within the first 48 hours after stroke. In addition, information for healthcare policy makers is included.

Methods— Members of the panel were appointed by the American Heart Association Stroke Council’s Scientific Statement Oversight Committee and represented different areas of expertise. The panel reviewed the relevant literature with an emphasis on reports published since 2003 and used the American Heart Association Stroke Council’s Levels of Evidence grading algorithm to rate the evidence and to make recommendations. After approval of the statement by the panel, it underwent peer review and approval by the American Heart Association Science Advisory and Coordinating Committee. It is intended that this guideline be fully updated in 3 years.

Results— Management of patients with acute ischemic stroke remains multifaceted and includes several aspects of care that have not been tested in clinical trials. This statement includes recommendations for management from the first contact by emergency medical services personnel through initial admission to the hospital. Intravenous administration of recombinant tissue plasminogen activator remains the most beneficial proven intervention for emergency treatment of stroke. Several interventions, including intra-arterial administration of thrombolytic agents and mechanical interventions, show promise. Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke is needed.

Guidelines for the early management of adults with ischemic stroke: a guideline from the American Heart Association/American Stroke Association Stroke Council, Clinical Cardiology Council, Cardiovascular Radiology and Intervention Council, and the Atherosclerotic Peripheral Vascular Disease and Quality of Care Outcomes in Research Interdisciplinary Working Groups: the American Academy of Neurology affirms the value of this guideline as an educational tool for neurologists

PURPOSE

Our goal is to provide an overview of the current evidence about components of the evaluation and treatment of adults with acute ischemic stroke. The intended audience is physicians and other emergency healthcare providers who treat patients within the first 48 hours after stroke. In addition, information for healthcare policy makers is included.

METHODS

Members of the panel were appointed by the American Heart Association Stroke Council's Scientific Statement Oversight Committee and represented different areas of expertise. The panel reviewed the relevant literature with an emphasis on reports published since 2003 and used the American Heart Association Stroke Council's Levels of Evidence grading algorithm to rate the evidence and to make recommendations. After approval of the statement by the panel, it underwent peer review and approval by the American Heart Association Science Advisory and Coordinating Committee. It is intended that this guideline be fully updated in 3 years.

RESULTS

Management of patients with acute ischemic stroke remains multifaceted and includes several aspects of care that have not been tested in clinical trials. This statement includes recommendations for management from the first contact by emergency medical services personnel through initial admission to the hospital. Intravenous administration of recombinant tissue plasminogen activator remains the most beneficial proven intervention for emergency treatment of stroke. Several interventions, including intra-arterial administration of thrombolytic agents and mechanical interventions, show promise. Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke is needed.