Therapeutic approaches and advances in pediatric stroke

Hemostatic and Thrombotic Considerations in the Diagnosis and Management of Childhood Arterial Ischemic Stroke: A Narrative Review

Although rare in children, arterial ischemic stroke (AIS) is associated with increased mortality and neurological morbidity. The incidence of AIS after the neonatal period is approximately 1-2/100,000/year, with an estimated mortality of 3-7%. A significant proportion of children surviving AIS experience life-long neurological deficits including hemiparesis, epilepsy, and cognitive delays. The low incidence of childhood AIS coupled with atypical clinical-presentation and lack of awareness contribute to delay in diagnosis and consequently, the early initiation of treatment. While randomized-clinical trials have demonstrated the efficacy and safety of reperfusion therapies including thrombolysis and endovascular thrombectomy in appropriately-selected adult patients, similar data for children are unavailable. Consequently, clinical decisions surrounding reperfusion therapy in childhood AIS are either extrapolated from adult data or based on local experience. The etiology of childhood AIS is multifactorial, often occurring in the setting of both acquired and congenital risk-factors including thrombophilia. While multiple studies have investigated the association of thrombophilia with incident childhood AIS, its impact on stroke recurrence and therefore duration and intensity of antithrombotic therapy is less clear. Despite these limitations, a significant progress has been made over the last decade in the management of childhood AIS. This progress can be attributed to international consortiums, and in selected cohorts to federally-funded clinical trials. In this narrative review, the authors have systematically appraised the literature and summarize the hemostatic and thrombotic considerations in the diagnosis and management of childhood AIS focusing on the evidence supporting reperfusion therapies, relevance of thrombophilia testing, and duration and drug choices for secondary-prophylaxis.

Decompressive hemicraniectomy and duroplasty in toddlers and preschool children with refractory intracranial hypertension after unilateral hemispheric stroke

Objective

Life-threatening hemispheric stroke is associated with a high mortality and morbidity. Decompressive hemicraniectomy has been regarded as an effective treatment option for refractory intracranial hypertension. Here, we reported the clinical course of 5 children with decompressive craniectomy and duroplasty after non-traumatic refractory intracranial hypertension.

Methods

Four toddlers and one preschool-girl were included in this study; there were 3 boys and 2 girls with a mean age of 34.6 months (range 17-80). Decompressive craniectomy including duroplasty was performed in cases of dilatation of pupil size after intensified standard medical therapy had proven insufficient. All children had a Pediatric Glasgow Coma Scale score <8 at pre-operation state. The mean time-point of craniectomy after stroke attack was 12 hours (range 4-19).

Results

During the long-term follow-up period (mean 47.6 months), no children died. One year later, when we checked their Glasgow Outcome Scale scores, only one toddler received a score of 4 (moderate disability). But the others had good recoveries although they had minor physical or mental deficits. According to the Pediatric Cerebral Performance Category Scale, 4 children received a score of 2 (mild disability).

Conclusion

Despite our small cases, we suggest that decompressive hemicraniectomy and duroplasty is an acceptable and life-saving treatment for refractory intracranial hypertension after unilateral hemispheric stroke in toddlers and preschool children.

Perfusion CT in childhood stroke--initial observations and review of the literature

INTRODUCTION

To report the preliminary results of contrast-enhanced perfusion multi-detector CT for diagnoses of perfusion disturbances in children with clinical suspicion of stroke.

PATIENTS AND METHODS

Within the last two years emergency perfusion CT was performed in ten children (age: 8-17 years, male:female=3:7) for assessment of suspected childhood stroke. These intracranial perfusion CT, intracranial CT-digital subtraction angiography (CT-DSA) and extracranial CT-angiography (CTA) studies were retrospectively reviewed and compared with MRI, follow-up CT, catheter angiography and final clinical diagnosis. The total dose length product (DLP) for the entire examination was recorded. The image quality of perfusion CT-maps, CT-DSA and CTA were evaluated with a subjective three-point scale ranging from very good to non-diagnostic image quality rating perfusion disturbance, intracranial peripheral vessel depiction, and motion- or streak artifacts.

RESULTS

In nine of ten children perfusion CT showed no false positive or false negative results. In one of ten children suffering from migraine focal hypo-perfusion was read as perfusion impairment potentially indicating early stroke, but MRI and MRA follow-up were negative. Overall, perfusion-CT with CT-DSA was rated very good in 80% of cases for the detection of perfusion disturbances and vessel anatomy.

CONCLUSIONS

In comparison to standard CT, contrast-enhanced perfusion CT improves CTs' diagnostic capability in the emergency examination of children with a strong suspicion of ischemic cerebral infarction.

Seizures as a presenting symptom of acute arterial ischemic stroke in childhood

OBJECTIVES

To define the incidence of seizures as a presenting symptom of acute arterial ischemic stroke (AIS) in children and to determine whether younger age, infarct location, or AIS etiology were risk factors for seizure at AIS presentation.

STUDY DESIGN

Children aged 2 months to 18 years presenting with AIS between January 2005 and December 2008 were identified from a single center prospective pediatric stroke registry. Clinical data were abstracted, and a neuroradiologist reviewed imaging studies.

RESULTS

Among the 60 children who met our inclusion criteria, 13 experienced seizure at stroke presentation (22%). Median age was significantly younger in children who presented with seizures than in those who did not (1.1 years vs 10 years; P = .0009). Seizures were accompanied by hemiparesis in all patients. Three of 4 children with clinically overt seizures at presentation also had nonconvulsive seizures on continuous electroencephalography monitoring.

CONCLUSIONS

Twenty-two percent of children with acute AIS present with seizures. Seizures were always accompanied by focal neurologic deficits. Younger age was a risk factor for seizures at presentation. Seizure at presentation was not associated with infarct location or etiology. Nonconvulsive seizures may occur during the acute period.

Thrombotic disease in critically ill children

OBJECTIVES

To summarize a) epidemiology of arterial and venous thromboembolism, pulmonary embolism, and deep venous thrombosis in children; b) the risk factors for thrombosis in the pediatric intensive care unit; c) diagnostic techniques for arterial/venous thromboembolism; and d) the current recommendations for management and prevention of thromboembolic disease in critically ill children.

DATA SOURCE

Literature review, using National Library of Medicine PubMed and the following terms: arterial, venous thromboembolism; deep venous thrombosis; pulmonary embolism; thrombosis; as well as citations of interest from these articles.

STUDY SELECTION

Both pediatric and adult literature addressing thrombotic disease were reviewed.

DATA EXTRACTION AND SYNTHESIS

Articles were chosen for more extensive discussion when containing prospective studies, guidelines for practice, or data in critically ill patients. When data in children were unavailable, applicable data in adults were referenced. Due to the paucity of data in critically ill children, available adult and pediatric data were combined with institutional experience to provide suggestions for current practice and future inquiry.

CONCLUSIONS

Increasing awareness regarding the recognition and current approaches to management and prevention of thromboembolic disease in children is needed among pediatric intensivists, so outcome of these life-threatening processes might be improved.

Evaluation and management of stroke in the neonate

Ischemic perinatal stroke (IPS) occurs in 1 of 2300 to 5000 live births. It is an under-recognized cause of significant long-term disabilities, including hemiplegic cerebral palsy, epilepsy, cognitive delays, and behavioral impairments. The pathophysiology is complex and multifactorial, involving maternal, fetal, placental, and neonatal factors. Knowledge and interventions are emerging to facilitate early diagnosis and treatment of IPS. Early treatment may translate into improved long-term neurodevelopmental outcomes.

Radiological strategy in acute stroke in children

The aim of the study was to estimate the preponderance of patterns of pediatric stroke, ischemic or hemorrhagic, their etiologies and the correct diagnostic protocol for acute management. Forty-one consecutive pediatric patients (age range 5-16 years) with an acute stroke observed in acute phase during a 10-year period, were retrospectively evaluated. Twenty-three patients underwent magnetic resonance imaging (MRI), 3 cases were studied by computed tomography (CT) without MRI, and 15 underwent both CT and MRI studies. In 9 cases, intra-arterial digital subtraction angiography (IADSA) was performed after non-invasive preliminary assessment. Seventeen hemorrhagic (41%) and 24 ischemic (59%) strokes were found. Among hemorrhagic forms, 5 cases were due to arteriovenous malformation (AVM), 7 to cavernoma, and 2 to aneurysm. Among ischemic forms, 2 were due to sickle-cell disease, 1 to hyperomocysteinemia, 1 to moyamoya syndrome, 1 to pseudoxantoma elasticum, 3 to prothrombotic state, 1 to Fabry's disease, 1 concomitant with CO intoxication, 5 to venous sinus thrombosis, and 4 to cardio-embolic state. Etiology remains unknown in 8 cases (20.5%). This study shows a moderate prevalence of ischemic over hemorrhagic strokes. Moreover, personal experience suggests that MRI is always more informative than CT and in selected cases should be the first-choice examination in the acute phase.

Ischemic stroke and excellent recovery after administration of intravenous tissue plasminogen activator

Intravenous tissue plasminogen activator has become a mainstream treatment for ischemic hyperacute stroke in the adult population. Its safety and efficacy remain undetermined in the pediatric population. We present a teenager who was hospitalized with left-sided paralysis, and with decreased sensations on the left side. Head computed tomography indicated hyperdensity in the middle cerebral artery region, which confirmed the diagnosis of acute ischemic stroke. Her score on the National Institutes of Health stroke scale was 11. She received intravenous tissue plasminogen activator without any complications. At a follow-up visit 5 months after the stroke, the patient manifested mild apraxia in her left hand and mild expressive amusia. This case underscores the need for emergency head imaging in the pediatric population to establish a diagnosis. The excellent recovery in our patient indicates the need to establish thrombolytic treatment as an option for acute stroke in pediatric populations. It also suggests that tissue plasminogen activator can be used safely and effectively, even in pediatric populations. However, further studies are needed to establish the adequate dosage and adverse-effect profile in pediatric populations.

Arterial ischemic stroke in children

Stroke in children is relatively rare. Advances in the clinical recognition and radiographic diagnosis of ischemic stroke have increased the frequency of the diagnosis in infants and children and have raised the need for immediate therapy. A vast amount of data has recently become available through basic research and neuroimaging techniques shedding new light on the chain of events that occur in ischemic stroke in animal models and in the adult population. Whether this new information can also be applied to the pediatric population remains to be seen, but it is likely that the active management of children with acute ischemic stroke in the near future will include brain protection, brain reperfusion, and prevention measures.

New pediatric model of ischemic stroke in infant piglets by photothrombosis: acute changes in cerebral blood flow, microvasculature, and early histopathology

BACKGROUND AND PURPOSE

The etiology and pathophysiology of acute ischemic stroke in children differ greatly from those in adults. The purpose of this study was to establish a new pediatric model of ischemic stroke in infant piglets for use in future studies of the response of the developing brain to focal ischemic injury.

METHODS

Ischemic stroke was produced in male infant piglets (2 to 4 weeks old) by photothrombotic occlusion of the middle cerebral artery. Regional cerebral blood flow was measured with radiolabeled microspheres up to 4 hours after occlusion. Early histopathology, including caspase-3 immunohistochemistry for apoptosis, was examined 4 hours after ischemia. The nature of the thrombus and its interaction with vascular endothelium were assessed by electron microscopy.

RESULTS

Severe ischemia (0 to 15 mL/100 g per min) occurred rapidly in 1.4+/-0.2 g of tissue at 15 minutes and increased to 2.4+/-0.7 g at 4 hours. Similarly, moderate ischemia (16 to 30 mL/100 g per min) was measured in 1.2+/-0.3 g of tissue at 15 minutes and increased to 2.0+/-0.6 g at 4 hours. These regional cerebral blood flow values represent ischemic levels of blood flow in 20% to 25% of the volume of the ischemic hemisphere at 4 hours after ischemia. Ischemic infarction occurred in both gray and white matter, and cerebral microvessels in the ischemic hemisphere contained large numbers of inflammatory leukocytes. Caspase-3-positive cells were few in number and were found in the periphery of the infarct; cell death appeared to occur primarily by necrosis rather than apoptosis at 4 hours. Electron microscopy revealed a pure platelet thrombus firmly attached to the vascular endothelium, which in some areas appeared to be detached from the basement membrane.

CONCLUSIONS

Ischemic stroke can be produced in infant piglets by middle cerebral artery photothrombosis. The stroke involved both gray and white matter and exhibited a robust inflammatory component. The mean infarct volume determined histopathologically amounted to 9.6+/-2.4% of the affected (ipsilateral) hemisphere, which was correlated well with the mass equivalent of tissue (12.0+/-3.5%), in which severe declines in regional cerebral blood flow were observed at 4 hours.

Quantified Corticospinal Tract Diffusion Restriction Predicts Neonatal Stroke Outcome

Background and Purpose— Neonatal arterial ischemic stroke occurs in ≥1:4000 births. Many children experience motor deficits but acute predictors of outcome are lacking. Diffusion-weighted MRI changes in descending corticospinal tracts remote from arterial ischemic stroke may represent pre-Wallerian degeneration. We verify and quantify this signal and correlate it with motor outcome.

Methods— Fourteen neonates with acute arterial ischemic stroke and ≥12 months follow-up with the Pediatric Stroke Outcome Measure were included. Quantitative measurements of descending corticospinal tracts diffusion-weighted MRI signal were developed using Image J software.

Results— Ipsilesional descending corticospinal tract diffusion-weighted MRI signal was abnormal in 10 neonates with decreased apparent diffusion coefficients ( P <0.001). Poor outcome correlated with: (1) percentage of peduncle ( P =0.002); (2) length of descending corticospinal tracts P <0.001); and (3) volume of descending corticospinal tracts ( P =0.002). None of: (1) any peduncle; (2) any posterior limb of the internal capsule; or (3) infarct volume correlated with outcome. All children without descending corticospinal tracts signal had normal outcome. Chronic Wallerian degeneration was seen in all children with hemiparesis. Software-assisted analysis was superior to visual inspection with excellent reliability (intra-class correlation coefficient ≥0.9).

Conclusion— Descending corticospinal tracts diffusion-weighted MRI signal is predictive of motor outcome from neonatal arterial ischemic stroke. This accurate, reliable, and simple tool will impact decision making in acute neonatal stroke.

Ischemic stroke complicating pediatric cardiovascular disease

BACKGROUND

After a year of unsuccessful treatment for hypertension, a young boy underwent a stenting procedure for aortic hypoplasia and awoke with hemiparesis and language deficits.

INVESTIGATIONS

Neuroimaging, echocardiography, craniocervical vascular imaging and prothrombotic testing.

DIAGNOSIS

Procedure-related acute arterial ischemic stroke and malignant cerebral edema with herniation.

MANAGEMENT

Anticoagulation with heparin, seizure prophylaxis and neuroprotective care, including external cooling for hyperthermia. Medical management of increased intracranial pressure and hemicraniectomy at 48 h for malignant cerebral edema. Treatment of deep vein thrombosis with inferior vena cava filter was also required. Long term treatments included extensive rehabilitation, aspirin, antiepileptics, antidyskinetics, antidepressants, antihypertensives and cosmetic skull reconstruction.