Pediatric Acute Stroke Protocol Implementation and Utilization Over 7 Years

Imaging of Vertebral Artery Dissection in Children: An Underrecognized Condition with High Risk of Recurrent Stroke

Vertebral artery dissection (VAD) is a common cause of a rare condition, pediatric posterior circulation arterial ischemic stroke (PCAIS). VAD is clinically important due to the risk of multifocal and continuing infarcts from artery-to-artery thromboembolism, with the potential for occlusion of arteries that perfuse the brainstem. Early diagnosis is important, as recurrent stroke is a common effect of VAD in children. Although the relative efficacies of different treatment regimens for VAD in children remain unsettled, early initiation of treatment can mitigate the risk of delayed stroke. Clinical diagnosis of PCAIS may be delayed due to multiple factors, including nonspecific symptoms and the inability of younger patients to express symptoms. In fact, subacute or chronic infarcts are often present at initial imaging. Although the most common cause of isolated PCAIS is VAD, imaging of the cervical arteries has been historically underused in this setting. Cervical vascular imaging (MR angiography, CT angiography, and digital subtraction angiography) for VAD must be optimized to detect the sometimes subtle findings, which may be identified at initial or follow-up imaging. Osseous variants of the craniocervical junction and upper cervical spine and other extrinsic lesions that may directly injure the vertebral arteries or lead to altered biomechanics have been implicated in some cases. The authors review characteristic imaging features and optimized imaging of VAD and associated PCAIS and related clinical considerations. Identification of VAD has important implications for evaluation, treatment, and imaging follow-up, as this condition may result in progressive arteriopathy and recurrent stroke. © RSNA, 2023 Supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Stroke Diagnosis Protocol for Children With Ventricular Assist Devices

Ventricular assist devices (VADs) are increasingly used for end-stage heart failure in children. VAD-associated neurologic dysfunction, including stroke and intracranial hemorrhage, occurs in more than 20% of patients. Starting in 2019, we implemented a protocol to diagnose stroke in relation to VAD to facilitate treatment. A multidisciplinary approach was implemented including targeted education for providers. VAD goals, structured neurologic exam, and frequency of neuromonitoring were incorporated into daily rounds, tailored to patient's phase of recovery. A protocolized neurocritical team assessment was implemented. A VAD-specific stroke algorithm and order set were implemented to facilitate rapid neuroimaging. We performed a pre- and postimplementation analysis from 2015 to 2020. Forty-six patients had VADs placed, 25 preintervention, and 21 postintervention. We compared the number of patients evaluated for stroke, time to imaging, and documentation of last known normal exam. Preintervention, time to imaging was 7 hours, and documentation was inconsistent. Postintervention, time to imaging decreased to 2.8 hours ( p = 0.038) with universal documentation of last known normal ( p = 0.009). The use of head computerized tomographies decreased from 11 preintervention to three postintervention. Development of a VAD protocol decreased time to imaging for suspected stroke and reduced unnecessary imaging. Further studies are required to validate these data.

Stroke in the young

PURPOSE OF REVIEW

The purpose of this review is to review recent findings regarding stroke epidemiology, etiologies, and treatment in children and young adults.

RECENT FINDINGS

Incidence in young adults is increasing, and incidence, recurrence, and survival is worse in patients with cryptogenic stroke and in developing countries. Careful consideration of patent foramen ovale closure is now recommended in young adults with cryptogenic stroke. Thrombectomy has recently been extended to carefully selected children with acute ischemic stroke, and two recent publications strongly suggest that it can be beneficial for children. Sickle cell is also an important global contributor to stroke burden, but hydroxyurea can be a cost effective medication for stroke prevention in children. Recent advances in genetic testing and treatments may improve outcomes for patients with monogenic causes of stroke, such as deficiency of adenosine deaminase 2, hemophilia, and Fabry's disease.

SUMMARY

Stroke in children and young adults is a morbid disease responsible for enormous indirect societal costs and a high burden of years with disability per affected patient. Recent advances have improved access to care for children with large vessel occlusion and adults with rare causes of stroke. Future research may bring effective treatments for other monogenic causes of stroke as well as increasing access to hyperacute therapies for young stroke patients.

Acute triage of childhood stroke in Denmark

Objective:

This 2-year observational study aimed to test the feasibility of implementing a pediatric stroke triage-setup that connected frontline providers with vascular neurologists and to examine final diagnoses in children triaged for suspected stroke.

Methods:

Prospective, consecutive registration of children with suspected stroke triaged by a team of vascular neurologists from Jan 1st, 2020 and through Dec 2021, Eastern Denmark (census 530,000 children). Based on the provided clinical information, the children were triaged to either assessment at the Comprehensive Stroke Center (CSC) in Copenhagen or to a pediatric department. All included children were retrospectively followed-up for clinical presentations and final diagnosis.

Results:

A total of 163 children with 166 suspected stroke events were triaged by the vascular neurologists. Cerebrovascular disease was present in 15 (9.0%) suspected stroke events; one child had intracerebral hemorrhage, one had subarachnoid hemorrhage, two children presented with three TIA events and nine children presented with 10 ischemic stroke events. Two children with ischemic stroke were eligible for acute revascularization treatment of which both were triaged to the CSC. The sensitivity of the triage by acute revascularization indication was 1.00 (95% confidence interval (95% CI): 0.15–1.00) and specificity 0.65 (95% CI: 0.57–0.73). Non-stroke neurological emergencies were present in 34 (20.5%) children, including seizures in 18 (10.8%) and acute demyelinating disorders in 7 (4.2%).

Conclusion:

Implementing regional triage-setup that connected frontline providers to vascular neurologists was feasible; this system was activated for the majority of children with ischemic stroke according to an expected incidence and led to identification of children eligible for revascularization treatments.

Imaging of Suspected Stroke in Children, From the AJR Special Series on Emergency Radiology

Pediatric stroke encompasses different causes, clinical presentations, and associated conditions across ages. Although it is relatively uncommon, pediatric stroke presents with poor short- and long-term outcomes in many cases. Because of a wide range of overlapping presenting symptoms between pediatric stroke and other more common conditions, such as migraine and seizures, stroke diagnosis can be challenging or delayed in children. When combined with a comprehensive medical history and physical examination, neuroimaging plays a crucial role in diagnosing stroke and differentiating stroke mimics. This review highlights the current neuroimaging workup for diagnosing pediatric stroke in the emergency department, describes advantages and disadvantages of different imaging modalities, highlights disorders that predispose children to infarct or hemorrhage, and presents an overview of stroke mimics. Key differences in the initial approach to suspected stroke between children and adults are also discussed.

Acute Hospital Management of Pediatric Stroke

The field of pediatric stroke has historically been hampered by limited evidence and small patient cohorts. However the landscape of childhood stroke is rapidly changing due in part to increasing awareness of the importance of pediatric stroke and the emergence of dedicated pediatric stroke centers, care pathways, and alert systems. Acute pediatric stroke management hinges on timely diagnosis confirmed by neuroimaging, appropriate consideration of recanalization therapies, implementation of neuroprotective measures, and attention to secondary prevention. Because pediatric stroke is highly heterogenous in etiology, management strategies must be individualized. Determining a child's underlying stroke etiology is essential to appropriately tailoring hyperacute stroke management and determining best approach to secondary prevention. Herein, we review the methods of recognition, diagnosis, management, current knowledge gaps and promising research for pediatric stroke.

Comparison of Arterial Ischemic and Hemorrhagic Pediatric Stroke in Etiology, Risk Factors, Clinical Manifestations, and Prognosis

BACKGROUND

Stroke is relatively rare in children but has a significant impact on long-term morbidity and mortality. There are limited data regarding the etiology, clinical manifestation, and prognosis of arterial ischemic stroke (AIS) and hemorrhagic stroke (HS) in children.

OBJECTIVE

The aim of this study is to identify and compare etiology, risk factors, clinical manifestations, and prognostic outcomes between arterial ischemic and hemorrhagic pediatric stroke.

METHODS

We retrospectively reviewed all hospital medical records and pediatric neurology database of 83 children who were first diagnosed with AIS and HS at the Pediatric Department, Chiang Mai University Hospital, Chiang Mai, Thailand between January 1, 2009, and December 31, 2018. All children were from 1 month to 18 years old.

RESULTS

Fifty-one AIS (56%) and 32 (35.2%) HS were identified. The median age of onset was 6.9 years for AIS and 5.3 years for HS. Moyamoya disease/syndrome was the most common cause in AIS (21.6%). Rupture of cerebral arteriovenous malformation was the most common cause in HS (21.9%). More than one-third (39%) of children had multiple risk factors associated with stroke. Iron deficiency anemia was commonly found in children with AIS (39.2%). The majority of clinical presentations were hemiparesis (80.4%) for AIS and alteration of consciousness (68.8%) for HS. The median time to diagnosis exceeded 6 hours in both AIS and HS. The overall mortality rate of acute stroke was 5.1 per 100 person-years (95% confidence interval [CI], 2.9-9). The mortality rate was higher in HS compared with that in AIS with statistical significance (16.6; 95% CI, 8.9-30.8 vs 1.1%; 95% CI, 0.3-4.6 per 100 person-years). Thirty children (36.1%) developed epilepsy during the follow-up (median duration, 26 months). Recurrent stroke occurred in 1 child with AIS and 1 child with HS.

CONCLUSIONS

Moyamoya disease/syndrome and arteriovenous malformation rapture are the most common cause of AIS and HS, respectively. Iron deficiency anemia was commonly found in childhood AIS. The time to diagnosis in both AIS and HS was delayed. The mortality rate in HS was higher than in AIS. Neurological deficits are seen in 70% of childhood AIS during the follow-up. One-third of the children in our study developed epilepsy, which generally responds to a single antiseizure medication. The recurrence rate of childhood stroke was low compared with adult stroke.

Zero-TE MRI: principles and applications in the head and neck

Zero echo-time (ZTE) MRI is a novel imaging technique that utilizes ultrafast readouts to capture signal from short-T2 tissues. Additional sequence advantages include rapid imaging times, silent scanning, and artifact resistance. A robust application of this technology is imaging of cortical bone without the use of ionizing radiation, thus representing a viable alternative to CT for both rapid screening and "one-stop-shop" MRI. Although ZTE is increasingly used in musculoskeletal and body imaging, neuroimaging applications have historically been limited by complex anatomy and pathology. In this article, we review the imaging physics of ZTE including pulse sequence options, practical limitations, and image reconstruction. We then discuss optimization of settings for ZTE bone neuroimaging including acquisition, processing, segmentation, synthetic CT generation, and artifacts. Finally, we examine clinical utility of ZTE in the head and neck with imaging examples including malformations, trauma, tumors, and interventional procedures.

Pediatric Acute Stroke Protocols in the United States and Canada

OBJECTIVE

To describe existing pediatric acute stroke protocols to better understand how pediatric centers might implement such pathways within the context of institution-specific structures.

STUDY DESIGN

We administered an Internet-based survey of pediatric stroke specialists. The survey included questions about hospital demographics, child neurology and pediatric stroke demographics, acute stroke response, imaging, and hyperacute treatment.

RESULTS

Forty-seven surveys were analyzed. Most respondents practiced at a large, freestanding children's hospital with a moderate-sized neurology department and at least 1 neurologist with expertise in pediatric stroke. Although there was variability in how the hospitals deployed stroke protocols, particularly in regard to staffing, the majority of institutions had an acute stroke pathway, and almost all included activation of a stroke alert page. Most institutions preferred magnetic resonance imaging (MRI) over computed tomography (CT) and used abbreviated MRI protocols for acute stroke imaging. Most institutions also had either CT-based or magnetic resonance-based perfusion imaging available. At least 1 patient was treated with intravenous tissue plasminogen activator (IV-tPA) or mechanical thrombectomy at the majority of institutions during the year before our survey.

CONCLUSIONS

An acute stroke protocol is utilized in at least 41 pediatric centers in the US and Canada. Most acute stroke response teams are multidisciplinary, prefer abbreviated MRI over CT for diagnosis, and have experience providing IV-tPA and mechanical thrombectomy. Further studies are needed to standardize practices of pediatric acute stroke diagnosis and hyperacute management.

Childhood stroke

Stroke is an important cause of neurological morbidity in children; most survivors have permanent neurological deficits that affect the remainder of their life. Stroke in childhood, the focus of this Primer, is distinguished from perinatal stroke, defined as stroke before 29 days of age, because of its unique pathogenesis reflecting the maternal-fetal unit. Although approximately 15% of strokes in adults are haemorrhagic, half of incident strokes in children are haemorrhagic and half are ischaemic. The causes of childhood stroke are distinct from those in adults. Urgent brain imaging is essential to confirm the stroke diagnosis and guide decisions about hyperacute therapies. Secondary stroke prevention strongly depends on the underlying aetiology. While the past decade has seen substantial advances in paediatric stroke research, the quality of evidence for interventions, such as the rapid reperfusion therapies that have revolutionized arterial ischaemic stroke care in adults, remains low. Substantial time delays in diagnosis and treatment continue to challenge best possible care. Effective primary stroke prevention strategies in children with sickle cell disease represent a major success, yet barriers to implementation persist. The multidisciplinary members of the International Pediatric Stroke Organization are coordinating global efforts to tackle these challenges and improve the outcomes in children with cerebrovascular disease.

Acute ischemic stroke in childhood: a comprehensive review

This review provides an updated analysis of the main aspects involving the diagnosis and the management of children with acute ischemic stroke. Acute ischemic stroke is an emergency of rare occurrence in children (rate of incidence of 1/3500 live birth in newborns and 1-2/100,000 per year during childhood with peaks of incidence during the perinatal period, under the age of 5 and in adolescence). The management of ischemic stroke in the paediatric age is often challenging because of pleomorphic age-dependent risk factors and aetiologies, high frequency of subtle or atypical clinical presentation, and lacking evidence-based data about acute recanalization therapies. Each pediatric tertiary centre should activate adequate institutional protocols for the optimization of diagnostic work-up and treatments.Conclusion: The implementation of institutional standard operating procedures, summarizing the steps for the selection of candidate for neuroimaging among the ones presenting with acute neurological symptoms, may contribute to shorten the times for thrombolysis and/or endovascular treatments and to improve the long-term outcome. What is Known: •Acute ischemic stroke has a higher incidence in newborns than in older children (1/3500 live birth versus 1-2/100,000 per year). •Randomized clinical trial assessing safety and efficacy of thrombolysis and/or endovascular treatment were never performed in children What is New: •Recent studies evidenced a low risk (2.1% of the cases) of intracranial haemorrhages in children treated with thrombolysis. •A faster access to neuroimaging and hyper-acute therapies was associated with the implementation of institutional protocols for the emergency management of pediatric stroke.

Pediatric Thrombectomy: Design and Workflow Lessons From Two Experienced Centers

Endovascular thrombectomy has played a major role in advancing adult stroke care and may serve a similar role in pediatric stroke care. However, there is a need to develop better evidence and infrastructure for pediatric stroke care. In this work, we review 2 experienced pediatric endovascular thrombectomy programs and examine key design features in both care environments, including a formalized protocol and workflow, integration with an adult endovascular thrombectomy workflow, simplification and automation of workflow steps, pediatric adaptations of stroke imaging, advocacy of pediatric stroke care, and collaboration between providers, among others. These essential features transcend any single hospital environment and may provide an important foundation for other pediatric centers that aim to enhance the care of children with stroke.