[Stroke in children and adolescents]

The occurrence of a stroke in children and adolescents constitutes a rare, critical event that is associated with substantial morbidity and mortality. In addition to the individual suffering for the young patient and the medical burden for the affected family, a stroke is also associated with high follow-up costs for the health system because of the necessary long-term rehabilitative treatment. Establishing an early and prompt diagnosis is of great therapeutic importance. Because of the rarity of the illness and the plethora of clinical manifestations, diagnosis is often delayed. The most frequent clinical presentation is an acute focal-neurological deficit, usually in the form of hemiparesis, but headache, seizures or alteration of consciousness may also be seen. Nowadays, the prompt performance of diffusion-weighted, blood-sensitive magnetic resonance imaging (MRI) constitutes the gold standard. The most relevant risk factors for the occurrence of a stroke in this age cohort are vasculopathies, infections, pathological cardiac conditions or coagulopathies. Recurrence of stroke is dependent on the underlying risk factors. In a substantial percentage of patients, residual neurological deficits are seen.Owing to a lack of randomized controlled trials in children and adolescents with stroke, the optimal treatment approach is still under debate. In addition to anti-platelet medication and heparinization, systematic intravenous thrombolysis and endovascular thrombectomy are other potentially effective treatment options. The long-term prognosis in children is dependent on establishing a correct, early diagnosis.

Patent foramen ovale and stroke in childhood: A systematic review of the literature

BACKGROUND

Stroke in association with a patent foramen ovale (PFO) may be due to paradoxical embolization via a right to left intracardiac shunt but the exact contribution of PFO to stroke or stroke recurrence in childhood remains unclear.

METHODS

To review the relationship of a PFO with stroke, and evaluate associated co-morbidities. An electronic database literature search of Pubmed, Cochrane and EMBASE was performed from January 2000-December 2014.

RESULTS

149 articles were retrieved, with overlap for diagnosis, management, treatment and outcome. 65 reports were utilized for the comprehensive review. Majority of childhood arterial ischemic stroke and transient ischemic attacks are associated with prothrombotic disorders or arteriopathy. Transthoracic echocardiography with a Valsalva maneuver is highly sensitive as a screening tool but may be falsely positive. Transthoracic echocardiography with color Doppler and a concurrent bubble contrast study are excellent for visualizing the atrial septum and PFO and identifying a right to left shunt. Current literature does not support PFO closure for cryptogenic stroke in young adults without an associated risk of thromboembolism.

CONCLUSIONS

High quality research in the pediatric population is lacking and most of the data is extrapolated from adults. Paradoxical embolism from a PFO as a cause of transient ischemic attack or stroke is a diagnosis of exclusion. PFO closure should be individualized based on significant shunting and risk factors such that maximum benefit is derived from the procedure. A young person with a PFO and stroke should be thoroughly investigated to rule out other etiologies.

Childhood infections and trauma as risk factors for stroke

Stroke is as common as brain tumor in children. The etiology of childhood arterial ischemic stroke (AIS) appears to be multifactorial, resulting from the interaction between genetic predisposition and environmental triggers. The risk factors for AIS in children are markedly different from the atherosclerotic risk factors in adults. Trauma and infections have been identified as associations in previous studies and are exposures of particular interest because of their increased prevalence in the children. The aim of this review article is to provide an overview of the research studies that have addressed the role of infections and trauma in pediatric AIS.

Endothelial injury in childhood stroke with cerebral arteriopathy: a cross-sectional study

OBJECTIVE

Circulating endothelial cells (CECs) and microparticles (MPs) have been reported to reflect endothelial injury, cellular activation, and MP-mediated thrombin generation. We tested the hypothesis that these indices differ between children with cerebral arteriopathy and arterial ischemic stroke (AIS) recurrence, and those with a single event.

METHODS

This was a single-center cross-sectional study of 46 children with AIS and cerebral arteriopathy matched with pediatric controls. AIS recurrence was defined as new acute neurologic deficit with radiologic evidence of further cerebral infarction. CECs and MPs were identified with immunomagnetic bead extraction and flow cytometry, respectively. MP function as assessed by thrombin generation was determined using a fluorogenic assay.

RESULTS

Ten children had AIS recurrence while 36 had a single AIS event. CECs were raised in children with recurrent AIS, compared to those with no recurrence (p = 0.0001), and in controls (p = 0.0001). Total circulating annexin V+ MPs were significantly greater in children with recurrence than in those with no recurrence (p = 0.0020). These MPs were of endothelial or platelet origin, and a subpopulation expressed tissue factor. Finally, MP-mediated thrombin generation was enhanced in children with recurrent AIS compared to those with no recurrence (p = 0.0001), providing a link between inflammation, endothelial injury, and increased thrombotic tendency.

CONCLUSION

Despite the wide spectrum of clinical and radiologic presentation of childhood AIS, indices of endothelial injury and cellular activation are different in patients with single and recurrent events. This novel approach has potential for furthering understanding of AIS pathophysiology and prognosis.

Antithrombotic therapy in neonates and children: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

Neonates and children differ from adults in physiology, pharmacologic responses to drugs, epidemiology, and long-term consequences of thrombosis. This guideline addresses optimal strategies for the management of thrombosis in neonates and children.

METHODS

The methods of this guideline follow those described in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.

RESULTS

We suggest that where possible, pediatric hematologists with experience in thromboembolism manage pediatric patients with thromboembolism (Grade 2C). When this is not possible, we suggest a combination of a neonatologist/pediatrician and adult hematologist supported by consultation with an experienced pediatric hematologist (Grade 2C). We suggest that therapeutic unfractionated heparin in children is titrated to achieve a target anti-Xa range of 0.35 to 0.7 units/mL or an activated partial thromboplastin time range that correlates to this anti-Xa range or to a protamine titration range of 0.2 to 0.4 units/mL (Grade 2C). For neonates and children receiving either daily or bid therapeutic low-molecular-weight heparin, we suggest that the drug be monitored to a target range of 0.5 to 1.0 units/mL in a sample taken 4 to 6 h after subcutaneous injection or, alternatively, 0.5 to 0.8 units/mL in a sample taken 2 to 6 h after subcutaneous injection (Grade 2C).

CONCLUSIONS

The evidence supporting most recommendations for antithrombotic therapy in neonates and children remains weak. Studies addressing appropriate drug target ranges and monitoring requirements are urgently required in addition to site- and clinical situation-specific thrombosis management strategies.

Pediatric neurocritical care

Pediatric neurocritical care is an emerging multidisciplinary field of medicine and a new frontier in pediatric critical care and pediatric neurology. Central to pediatric neurocritical care is the goal of improving outcomes in critically ill pediatric patients with neurological illness or injury and limiting secondary brain injury through optimal critical care delivery and the support of brain function. There is a pressing need for evidence based guidelines in pediatric neurocritical care, notably in pediatric traumatic brain injury and pediatric stroke. These diseases have distinct clinical and pathophysiological features that distinguish them from their adult counterparts and prevent the direct translation of the adult experience to pediatric patients. Increased attention is also being paid to the broader application of neuromonitoring and neuroprotective strategies in the pediatric intensive care unit, in both primary neurological and primary non-neurological disease states. Although much can be learned from the adult experience, there are important differences in the critically ill pediatric population and in the circumstances that surround the emergence of neurocritical care in pediatrics.

Challenges in the diagnosis and treatment of pediatric stroke

Stroke in children is rarely due to traditional stroke risk factors such as hypertension and diabetes. Rather, stroke in this patient group typically results from the simultaneous occurrence of multiple stroke risk factors, the presence of which necessitates a thorough evaluation to determine the cause of this disorder. Several challenges exist in the care of children with stroke. Of note, recognition of pediatric stroke onset by parents and caregivers is often delayed, highlighting the need for increased awareness of and education regarding this condition. Moreover, various neurological conditions resemble stroke in pediatric patients and a definite diagnosis of this disorder requires MRI; adding to the diagnostic challenge, young children may need to be sedated to undergo acute MRI. Perhaps the most significant challenge is the need for clinical research studies focusing on pediatric stroke treatment, so as to allow evidence-based treatment decision-making. A final challenge is the standardization of outcome assessment after stroke for a wide range of ages and developmental levels. In this Review, we examine recent findings and diagnostic issues pertaining to both arterial ischemic stroke and hemorrhagic stroke in children.

Diabetic ketoacidosis-associated stroke in children and youth

Diabetic ketoacidosis (DKA) is a state of severe insulin deficiency, either absolute or relative, resulting in hyperglycemia and ketonemia. Although possibly underappreciated, up to 10% of cases of intracerebral complications associated with an episode of DKA, and/or its treatment, in children and youth are due to hemorrhage or ischemic brain infarction. Systemic inflammation is present in DKA, with resultant vascular endothelial perturbation that may result in coagulopathy and increased hemorrhagic risk. Thrombotic risk during DKA is elevated by abnormalities in coagulation factors, platelet activation, blood volume and flow, and vascular reactivity. DKA-associated cerebral edema may also predispose to ischemic injury and hemorrhage, though cases of stroke without concomitant cerebral edema have been identified. We review the current literature regarding the pathogenesis of stroke during an episode of DKA in children and youth.