Etiology of stroke in children

Massive Chronic Hypernatremia Associated With Failure to Thrive in a Pediatric Patient

Hypernatremia is a severe, potentially life-threatening condition that can manifest with altered mental status, coma, seizure, and even death. Values above 190 mmol/L are seldom reported in young pediatric patients and often have poor outcomes. We present a case of severe chronic hypernatremia secondary to failure to thrive (FTT) in a toddler, which led to significant pathology including bilateral metabolic strokes. A 21-month-old female was found unresponsive and brought to the hospital. The patient's childhood was complicated by prematurity, poor weight gain, and persistent postprandial emesis. On examination, the patient was tachycardic and obtunded. Her weight was below the first percentile. Initial laboratory results showed a sodium level of 197 mmol/L with marked dehydration. Normal saline boluses were given followed by maintenance fluids with the goal of sodium decrementation by 0.5 mmol/hour; nephrology assisted with fluid and electrolyte correction calculations. Imaging revealed metabolic strokes involving the brainstem and thalami. During hospitalization, hypokalemia and hypophosphatemia complicated the treatment course. Over the next 21 days, electrolytes normalized. She tolerated nasogastric feeding, gradually improved as she gained weight, and was discharged. Chronic hypernatremia must be fixed judiciously as rapid correction can cause significant harm. This unusual case reminds providers that florid electrolyte dyscrasias may be secondary to FTT and can lead to significant neurological sequelae. Careful fluid selection and calculations should be performed in these cases. Chronic hypernatremia should be considered in children with FTT with altered mental status, and the gradual correction of electrolytes should be performed to minimize patient harm.

The Need to Look for Visual Deficit After Stroke in Children

Purpose: To evaluate the role of the ophthalmologist in the management of children with arterial stroke, at presentation and during follow-up.

Methods: This retrospective case series comprised children with arterial stroke who were followed for at least 12 months in a tertiary pediatric medical center in 2005–2016. Demographic data and findings on radiological neuroimaging and ophthalmological and neurological examination were retrieved from the medical files.

Results: The cohort included 26 children with stroke. Underlying disorders included metabolic syndrome (n = 5, 19.2%), cardiac anomaly or Fontan repair (n = 3 each, 11.5%), vascular anomaly (n = 3, 11.5%), head trauma with traumatic dissection (n = 3, 11.5%), and hypercoagulability (n = 1, 3.8%); in eight patients (30.8%), no apparent cause was found. Eleven patients (42.3%) had a non-ophthalmological neurological deficit as a result of the stroke. Eye examination was performed in nine patients (34.6%) during follow-up. Ophthalmological manifestations included hemianopic visual field defect in seven patients (7.7%) and complete blindness and poor visual acuity in one patient each (3.8%). At the last visit, no change in visual function was detected.

Conclusion: The variable etiology and presentation of pediatric stroke may mask specific visual signs. Children with arterial stroke should be referred for early ophthalmological evaluation and visual rehabilitation.

Presentation of Acute Childhood Stroke in a Tertiary Pediatric Emergency Department

OBJECTIVES

The aim was to describe clinical presentation, management, and outcomes of stroke in a tertiary emergency department (ED) of a developing country.

METHODOLOGY

Retrospective case series of patients aged 1 month to 18 years presenting to an ED with radiological confirmed acute stroke during a 7-year period were studied.

RESULTS

Ninety-five patients were identified. Twenty-five patients were excluded because of incomplete records (8) or not presenting via ED (17). Thirty-four (48.5%) were diagnosed with hemorrhagic stroke (HS), 30 (42.8%) with arterial ischemic stroke (AIS), and 6 (8.5%) with sinus venous thrombosis (SVT). Mean age was 5.3 years, and 55.3% were male. The median time from onset of symptoms to ED presentation was 24 hours (mean, 55 hours; interquartile range [IQR], 14-72) for AIS, 24 hours (mean, 46.9 hours; IQR, 9-48) for HS, and 120 hours (mean,112 hours; IQR, 72-168) for SVT. Congenital cardiac disease was the most common risk factor (9%). For AIS, the most common symptoms were focal numbness 56.6% (95% confidence interval [CI], 37.8%-75.4%), focal weakness 56.6% (95% CI, 37.8%-75.4%), and seizures 50% (95% CI, 31%-68.8%). For HS, the most common symptoms were headache 64.7% (95% CI, 47.7%-81.6%), vomiting 79.4 (95% CI, 65-93.7), and altered mental status 64.7% (95% CI, 47.7-81.6). Computed tomography scan was done in 100% of the patients and magnetic resonance imaging in 54%. Twenty-five (36%) patients were admitted to intensive care unit and required intubation. Long-term deficit was identified in 24 (36%) patients based on medium-term follow-up.

CONCLUSIONS

The spectrum of stroke in a developing country was similar to published series from developed countries in terms of final diagnosis, risk factors, and delay to ED presentation, neuroimaging, and long-term neurodeficits. No tropical diseases were identified as risk factors.

Imaging of Pediatric Stroke

Despite being as common as brain tumors in children, lack of awareness of pediatric stroke presents unique challenges, both in terms of diagnosis and management. Due to diverse and overlapping risk factors, as well as variable clinical presentations, the diagnosis can be either missed or frequently delayed. Early recognition and treatment of pediatric stroke is however critical in optimizing long-term functional outcomes, reducing morbidity and mortality, and preventing recurrent stroke. Neuroimaging plays a vital role in achieving this goal. The advancements in imaging over the last two decades have allowed for multiple modality options for suspected stroke with more accurate diagnosis, as well as quicker turnaround time in imaging diagnosis, especially at primary stroke centers. However, with the multiple imaging possibilities, referring physicians can be overwhelmed with the best option for each clinical situation and what the literature recommends. Here the authors review the etiology of pediatric stroke in the settings of arterial ischemia, hemorrhage, and cerebral sinovenous thrombosis (CSVT), with emphasis on the best diagnostic tools available, including advanced imaging techniques.

[Neurological complications and outcomes of bacterial meningitis in children]

AIM

To analyze neurological complications and outcomes of bacterial meningitis (BM) in children.

MATERIAL AND METHODS

Fifty-five patients with BM, aged from 2 months to 12 years, were examined. Bacteriological study, clinical and biochemical blood tests and blood serology and cerebrospinal fluid (CSF) tests as well as serum molecular-genetic study were performed. Neuroimaging methods (neurosonography, computed (X-ray) tomography and brain magnetic resonance imaging) were used.

RESULTS AND СONCLUSION

A key role of generalized meningococcal infection in the development of BM in children was confirmed. Brain edema was an early and life-threatening complication of BM. It was found in 9% of the patients with meningococcal infection, 7.3% with pneumococcal meningitis and 3.6% with haemophilus meningitis. Changes in the brain structure were not found in 80% of the patients, in 20%, the residual stage of BM was characterized by cerebral destructive/proliferative or atrophic changes of different severity. The dissociation between clinical and neuroimaging parameters and poor outcomes of BM, related to the complicated premorbid state, concomitant somatic/neurological pathology, BM severity, late laboratory diagnosis and untimely etiotropic antibacterial treatment, were identified in 65.5%.

Are children with acute arterial ischaemic stroke eligible for hyperacute thrombolysis? A retrospective audit from a tertiary UK centre

AIM

The aim of this study was to evaluate the number of children with acute arterial ischaemic stroke (AIS) who would have been eligible for hyperacute thrombolysis in the authors' unit (Great Ormond Street Hospital, London, UK) and to identify barriers to this treatment.

METHOD

We compared the characteristics of children with a diagnosis of acute AIS, identified from neuroimaging databases, seen at our centre between January 2006 and December 2011. The criteria for hyperacute thrombolysis were predefined by us: age ≥8y; imaging-confirmed diagnosis of acute AIS and arrival at our centre within 6 hours of symptom onset; occluded major artery on computed tomography (CT) or magnetic resonance angiography; no contraindications. Factors that precluded therapy were examined.

RESULTS

Of a total of 107 children with acute AIS identified on MRI (n=64; 33 females, 31 males; median age 4y, range 1mo-17y) or CT databases (n=43; 14 females, 29 males; median age 1y, range 1mo-15y), none would have been eligible for hyperacute thrombolysis. The major barriers to this were (1) delayed diagnosis, (2) delayed transfer to the tertiary centre, (3) age, and (4) medical comorbidities. Of 107 children, three (2.8%) would have been eligible for thrombolysis if diagnosis and transfer had occurred in a timely manner. An additional 11 children (10.3%) would have been eligible if the age criterion was 28 days or more and if diagnosis and transfer had occurred promptly.

INTERPRETATION

Although hyperacute thrombolysis is, as yet, an unproven treatment in childhood AIS, at least a subset of patients could potentially benefit. This audit has identified that clinical factors preclude treatment in a high percentage of children. Furthermore, in our specialist unit, without an emergency department, we identified major logistic barriers that will need to be addressed to enable access to hyperacute therapies. These results could inform future trial design and service delivery.

Stroke recurrence in children with congenital heart disease

OBJECTIVE

Pediatric arterial ischemic stroke (AIS) carries an important morbidity and mortality burden. Congenital heart disease (CHD) is among the most important risk factors for pediatric AIS. Data on stroke recurrence in childhood CHD are lacking, resulting in uncertainty regarding optimal strategies for preventing recurrence.

METHODS

In the Canadian Pediatric Ischemic Stroke Registry-Toronto site, we identified children (birth to 18 years) with CHD diagnosed with AIS during 1992-2008. Data were abstracted from both stroke and cardiac surgery databases. Time-dependent outcomes (death and recurrent stroke) following sentinel stroke were parametrically modeled in competing risk analysis. Factors predicting stroke recurrence in parametric survival models were sought in parametric survival model analyses using backward variable selection of variables.

RESULTS

A total of 135 patients (19 with recurrence, 116 without recurrence) were studied. In competing risk analysis, 10 years following sentinel stoke, 27% had experienced a stroke recurrence, 26% had died, and 47% were alive and free from recurrence. Stroke recurrence risk decreased over time from sentinel stroke. Approximately 50% of patients were receiving anticoagulation at recurrence. Significant factors associated with recurrence included the presence of a mechanical valve, prothrombotic condition, and an acute infection at the time of sentinel stroke. Hazard of mortality after recurrence was similar to mortality after sentinel stroke (hazard ratio, 1.3; p = 0.75).

INTERPRETATION

Stroke recurrence was relatively common in neonates and children with CHD. Identified groups of patients at increased risk may require more aggressive secondary prophylaxis, especially in the early poststroke period.

Thrombolytic therapy for acute stroke in a teenager

BACKGROUND

The importance of thrombolytic therapy within the first 3 hours of onset of symptoms of an acute stroke has been stressed, and in consequence, the diagnosis is most commonly made based on clinical grounds. Intracranial hemorrhage is the major life-threatening complication with the use of thrombolytic therapy. Because of the very small time window before administering thrombolytics, it is often not possible to investigate the unusual causes of a stroke that occurs most often in children.

OBJECTIVE

This study aimed to present the decision and risk of thrombolysis for an acute ischemic stroke in children.

CASE

A case of a teenager with an acute ischemic stroke who received thrombolysis and had resolution of symptoms.

CONCLUSIONS

Thrombolytic therapy is effective in acute ischemic strokes; however, in children, one must consider and exclude stroke mimickers and recognize that potentially life-threatening bleeding complicates the use of these medications.

Childhood moyamoya disease and moyamoya syndrome: a pictorial review

Moyamoya disease is an uncommon chronic cerebrovasculopathy, characterized by progressive stenosis of the terminal portion of the internal carotid artery and its main branches, in association with the development of compensatory collateral vessels at the base of the brain. The etiology is unknown, and was originally considered exclusive to East Asia, with particular prevalence in Japan. Moyamoya disease is increasingly diagnosed throughout the world, and represents an important cause of childhood stroke in Western countries. In some cases, similar angiographic features are evident in children with other medical conditions, such as sickle cell disease and Down syndrome. In these instances, the term "moyamoya syndrome" is used. Diagnosing the vasculopathy, excluding possible associated conditions, and planning treatment and follow-up imaging comprise important aspects of clinical management. We review the key imaging features of childhood moyamoya disease and syndrome, present examples of its associations, and discuss new neuroradiologic methods that may be useful in management.

Practice variation in neuroimaging to evaluate dizziness in the ED

BACKGROUND

The appropriate role of neuroimaging to evaluate emergency department (ED) patients with dizziness is not established by guidelines or evidence.

METHODS

We identified all adults with a triage complaint of dizziness who were evaluated at 20 EDs of a large Northern California integrated health care program in 2008. Using comprehensive medical records, we captured all head computed tomographies (CTs) or brain magnetic resonance images (MRIs) completed at presentation or within 2 days and all stroke diagnoses within 1 week. We assessed variation in neuroimaging use by site using a random-effects logistic model to account for differences in patient- (demographic and vascular risk factors) and site-level factors (volume, % patients with dizziness, and % patients with dizziness admitted) and linear regression to assess the relationship between neuroimaging rates and stroke diagnosis rates by site.

RESULTS

Of 378 992 patients seen in 2008, 20 795 (5.5%) had at least one ED visit for dizziness. Overall, 5585 patients (26.9%) had a head CT and 652 (3.1%) had a brain MRI. Between 21.8% and 32.8% of ED patients with dizziness at each site had a head CT (P<.001). For brain MRI, the range was 0.8% to 6.2%-a nearly 8-fold variation (P<.001) that persisted after adjustment for patient- and site-level factors. Higher neuroimaging rates did not translate into higher stroke diagnoses rates, with 0.7% to 2.5% of patients with dizziness diagnosed with stroke by site.

CONCLUSION

The use of neuroimaging for ED patients with dizziness varies substantially without an associated improvement in stroke diagnosis, which is identified only rarely.

Cerebral angiopathies as a cause of ischemic stroke in children: differential diagnosis and treatment options

BACKGROUND

Ischemic stroke in children can present with an epileptic seizure or be initially asymptomatic. The median time to diagnosis is 24 hours.

METHODS

This review is based on a selective literature search, with additional consideration of published guidelines and the authors' personal experience.

RESULTS

In Europe and the USA, the combined incidence of ischemic and hemorrhagic stroke in childhood is 2.5 to 10 per 100 000 children per year. 40% of ischemic strokes in childhood occur after an infectious illness or in association with a congenital heart defect, sickle-cell anemia, or a coagulopathy. Arterial dissection and chronic, progressive cerebral arteriopathies, particularly moyamoya disease, each account for up to 10% of childhood strokes. Magnetic resonance imaging can be used to demonstrate infarcts and to display the perfusion of ischemic areas and the surrounding brain tissue; arterial and venous occlusions can be defined more precisely. Children with arterial dissection, vasculitis, and para-infectious cerebral ischemia should be treated empirically, with medications and supportive care, according to the treatment plans developed for adults. For patients with moyamoya disease, surgical revascularization with extra-intracranial bypass techniques is recommended.

DISCUSSION

The current data provide an inadequate evidence base for the treatment of stroke in children. Potential revascularization or thrombolysis must be discussed individually in each case. For the treatment of temporary, para-infectious cerebral ischemia, hemodynamic optimization is an available option. Better evidence is needed regarding the surgical treatment of moyamoya disease.

Cerebral venous sinus thrombosis risk factors

Cerebral venous sinus thrombosis is an uncommon disease marked by clotting of blood in cerebral venous, or dural sinuses, and, in rare cases, cortical veins. It is a rare but potentially fatal cause of acute neurological deterioration previously related to otomastoid, orbit, and central face cutaneous infections. After the advent of antibiotics, it is more often related to neoplasm, pregnancy, puerperium, systemic diseases, dehydration, intracranial tumors, oral contraceptives, and coagulopathies are the most common causes, but in 30% of cases no underlying etiology can be identified. It has been found in association with fibrous thyroiditis, jugular thrombosis after catheterization, or idiopathic jugular vein stenosis. Other factors include surgery, head trauma, arterio-venous malformations, infection, paraneoplastic, and autoimmune disease. This article presents a comprehensive review of cerebral venous sinus thrombosis etiologies.

Risk factors for arterial ischemic and hemorrhagic stroke in childhood

This study assessed potential etiologies of arterial ischemic stroke and hemorrhagic stroke among children of Mainland China. From January 1996-June 2006, 251 patients with consecutive childhood stroke (aged 1 month through 16 years) were admitted to Beijing Children's Hospital. Arterial ischemic stroke accounted for the majority of cases (62.5%). Idiopathic stroke (32.5%) was more common than cardiac stroke (8.9%), vascular or arteriopathic stroke (21.0%), hematologic disorder-associated stroke (10.8%), and other etiologies (26.8%). Vitamin K deficiency was a major etiology in 72 of 94 hemorrhagic strokes (76.6%), most of which occurred in breastfeeding infants (80.6%) and those who received no vitamin K after birth (73.6%). Arteriovenous malformation (6.4%) was a frequent etiology in the remaining hemorrhagic stroke cases. We found that ischemic stroke in children is more common than hemorrhagic stroke, and many cases of ischemic stroke are idiopathic. Vitamin K deficiency was a major etiology in these young infants who experienced hemorrhagic stroke.

Distribution of etiologies in patients above and below age 45 with first-ever ischemic stroke

BACKGROUND

There is limited information about distribution of etiologies of ischemic stroke in different age groups.

MATERIALS AND METHODS

In this study, we applied the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification in 87 patients aged < or = 45, and in 347 patients aged 46-60 years with first-ever ischemic stroke in order to follow the distribution of stroke etiologies in different age groups.

RESULTS

Traditional risk factors, except smoking and atrial fibrillation, were more frequent in older patients. The most frequent etiologies in the younger stroke patients (aged < or = 45) were 'other' than routine causes (26.4%), cardioembolism (22.4%) and 'idiopathic' strokes (20.7%), when no cause was found. In older patients (aged 46-60), small vessel disease (25.1%) and cardioembolism (22.2%) were the most frequent etiologies of stroke.

CONCLUSIONS

In stroke patients below the age of 45, the TOAST classification should be expanded to better classify the wide diversity of stroke etiologies. The relatively low frequency of routine stroke etiologies in patients aged < or = 45 can be explained by the significantly lower prevalence of traditional risk factors in these patients. In patients 46-60 years old, the TOAST classification is adequate in the characterization of ischemic stroke etiologies.

Stroke in the immature brain: review of pathophysiology and animal models of pediatric stroke

Pediatric stroke research presents many challenges. Relatively low incidence, need for age stratification, diverse etiologies, delays in diagnosis, lack of an established age-based stroke severity scale and outcome measures are only some of the issues that have prevented the implementation of clinical trials in infants and children with stroke. Experimental animal models of pediatric stroke, therefore, are critical to understanding the pathophysiology and management of ischemic brain damage in the immature brain, and provide the necessary platform for future clinical trials. In this review we discuss the pertinent clinical aspects of pediatric stroke, the pathophysiology of stroke in the developing brain and the animal models established to study basic mechanisms as well as translational issues in pediatric stroke.

Arterial ischemic stroke in childhood: risk factors and outcome in old versus new era

Risk factors of children with arterial ischemic stroke were retrospectively evaluated. The children were grouped according to values on developing diagnostic tools: 13 in the old era (1987-1994) and 18 in the new era (1995-2004). The old era battery included 5 tests: protein C, protein S, antithrombin, lupus anticoagulants, and anticardiolipin antibodies. The new era battery added 5 more tests: homocystine level, factor VIII level, mutations for factor V Leiden and prothrombin G20210A, and lipoprotein (a) level. At least 1 risk factor was found in 5 of 13 children (38.5%) in the old era and in 8 of 18 (44.4%) in the new era. The extended battery for prothrombotic disorders revealed 7 risk factors in 4 children (22.2%) in the new era, whereas the limited battery identified a single risk factor in 1 child (7.7%) in the old era. For the correct etiologic identification, prothrombotic risk factors should be extensively evaluated in patients with arterial ischemic stroke.

Diffusion-weighted MR imaging: pediatric clinical applications

We have summarized the diffusion-weighed imaging (DWI) findings in a number of different cerebral disorders. In many cases, DWI with the accompanying apparent diffusion coefficient (ADC) map provides additional useful information to the standard imaging sequences. Pathophysiologic mechanisms resulting in baseline normal ADC values and changes with disease processes are not well understood; therefore, caution should be used when prognosticating the outcome of regions with abnormal ADCs. DWI should be used as an adjunct to routine imaging and interpreted in the context of the routine imaging findings and clinical scenario. As our understanding of ADC mechanisms increases and we begin to incorporate information about tissue organization from diffusion tensor imaging or diffusion spectrum imaging, the role of these methods in clinical diagnosis should continue to increase.

Managing stroke in children

The incidence of stroke in the pediatric population is estimated at between 2 and 3 per 100,000. Strokes are divided into ischemic or hemmorhagic categories, depending on whether the primary cause is obstruction or bleeding into the brain. Strokes may present with acute, recurrent, or evolving neurological deficits. There is a long and varied list of causes of stroke in children. The major causes of ischemic stroke are cardiac abnormalities and coagulation disorders. Cerebrovascular malformations account for the majority of hemmorhaghic strokes. The workup is guided by the initial history and imaging studies. Treatment is dependent on the specific risk factors identified, and outcome is dependent on the location and extent of the initial insult.

Pediatric stroke: the child is not merely a small adult

Arterial ischemic stroke and sinovenous thrombosis are a significant yet under-recognized causes of mortality and morbidity in the pediatric population. With increasingly complex etiologies yet urgency for rapid diagnosis and treatment, pediatric stroke teams likely will become the standard of care. A common terminology must be developed to avoid confusing types of acute cerebral insults--such as focal arterial ischemic stroke and global hypoxia and ischemia--that have different causes and pathophysiologic mechanisms of injury. Increased awareness of unique pediatric stroke subtypes, their clinical presentation, and their imaging findings will facilitate early identification and development of optimal treatment strategies.

Profile of pediatric hemiparesis

Our objective was to determine the clinical spectrum of pediatric hemiparesis by identifying the relative frequency of various diagnoses and comorbid conditions seen in these children. Case records of all patients with hemiparesis in a single practice over an 11-year period were reviewed with reference to clinical features, etiologic determination, and comorbid conditions. Ninety-two children were identified: 73 (79.3%) had a congenital hemiparesis and 19 (20.7%) had an acquired hemiparesis. An abnormal perinatal history (P = .003), prematurity (P = .016), and younger age at onset of symptoms (P < .001) were associated with a congenital hemiparesis. The overall etiologic yield was 83.7% (82.2% in the congenital and 89.5% in the acquired). The top four etiologic entities were cerebrovascular ischemia (40.2%), periventricular leukomalacia (18.5%), intracranial hemorrhage (16.3%), and cerebral dysgenesis (13%). Factors predictive of establishing an underlying etiology included birth prior to 34 weeks' gestation (P = .034), global developmental delay (P = .048), epilepsy (P = .024), and having appropriate imaging modalities (P = .001). Half of these children had a concurrent global developmental delay, associated epilepsy (odds ratio 3.67; 95% confidence interval 1.40-9.72), and prematurity (odds ratio 5.41; 95% confidence interval 1.56-18.80). A third of these children developed epilepsy. Multivariate predictive factors for epilepsy included global developmental delay (odds ratio 4.20; 95% confidence interval 1.44-12.27), cerebrovascular ischemia (odds ratio 5.10; 95% confidence interval 1.76-14.77), and term birth (odds ratio 3.87; 95% confidence interval 1.20-12.56). The majority of children with hemiparesis have a congenital etiology. The diagnostic yield is higher than previously reported; however, specific underlying etiologies need to be better determined. Comorbid conditions of global developmental delay and epilepsy have a high prevalence in this population, contributing to overall morbidity.

Pediatric stroke among Hong Kong Chinese subjects

BACKGROUND

The incidence of pediatric stroke was estimated to be 2.5 to 2.7 cases per 100,000 children per year in North America and 13 cases per 100,000 children per year in France. Stroke is among the top 10 causes of death among children in the United States, with the highest incidence in the first 1 year of life. The annual mortality rate was 0.34 deaths per 100,000 person-years, with an average of 244 deaths per year. Interethnic differences have been demonstrated to be important in pediatric stroke. However, most population-based studies on pediatric stroke were from Europe or North America, and there was a lack of data on the incidence of stroke among Chinese or Asian children. Whether the etiologic patterns and risk factors for death and morbidity among Chinese children with stroke were similar to those described for other ethnic groups was unknown.

OBJECTIVES

To calculate the incidence of stroke among Chinese children in Hong Kong and to examine the clinical spectrum, causes, patterns, risk factors, and outcomes of pediatric stroke among Chinese subjects.

METHODS

The population of Hong Kong was 6.7 million in 2001, and >98% of our population is Chinese in origin. In Hong Kong, public hospitals under the Hospital Authority provide >95% of the hospital service for the region. We identified children (>1 month to <15 years of age) who were admitted and given a discharge diagnosis of stroke from the Clinical Data Analysis and Reporting System, which is a centralized computerized database for all public hospitals. The discharge coding of stroke used codes from the International Classification of Diseases, 9th Revision, Clinical Modification. Only first admissions during the study period were included. We excluded any subsequent admissions by using multiple demographic characteristics of the patients. The incidence of pediatric stroke was estimated as the number of first hospitalizations divided by the person-years at risk. Since 1991, we had been collecting a database on pediatric stroke (ages of 1 month to 16 years) from a single center (the university-affiliated pediatric unit). The clinical presentation, causes, risk factors, and outcomes for those in the Hong Kong Children's Stroke Registry with follow-up data for > or =2 years were analyzed. Data on outcomes, in terms of survival and neurologic deficits, were studied. For survivors, neurologic deficits were defined as short-term if they resolved within 3 months and long-term if they persisted for >3 months. The severity of deficits was defined as mild when function was minimally affected and the patient remained independent in activities of daily living, moderate when the patient required supervision or partial assistance in activities of daily living or when the deficit caused delay in developmental milestones, and severe when the patient required total or near-total care in activities of daily living. Potential risk factors for death and poor neurologic outcomes, including gender, age at the time of stroke, clinical presentation, causes, and neuroimaging findings, were analyzed.

RESULTS

Using projections from census data in 2001, the number of children <15 years of age in Hong Kong from 1998 to 2001 was estimated to be 1,104100 to 1,158800, resulting in 4,545300 person-years. During the same period, 94 children with discharge coding of stroke were identified. Therefore, the estimated incidence of pediatric stroke between 1998 and 2001 was 2.1 cases per 100,000 children-years. The average number of new cases treated annually was 4.5 (0-15 cases/year). Fifty children (28 boys and 22 girls; male/female ratio: 1.27:1) were identified in the 11-year period. The mean age at presentation was 5.6 +/- 4.9 years. Thirty-six strokes (72%) were ischemic and 14 (28%) were hemorrhagic. Despite evaluation for possible underlying causes, 12% (6 cases) remained idiopathic. Eighteen patients with ischemic strokes had cerebral thrombosis, whereas 15 had cerebral embolism. We did not observe any case of sinovenous thrombosis. The 36 cases of ischemic stroke were subtyped according to vascular territories. Eleven cases had infarction involving the middle cerebral artery territory; 2 were limited to the cortical region, 3 were limited to subcortical structures such as the basal ganglia or internal capsule or both, and 6 had complete middle cerebral artery involvement, with cortical and subcortical stroke. Involvement of the anterior cerebral artery occurred in 2 cases, with involvement of cerebellar/basilar artery territories in another 2 cases. The remaining 15 cases had multiple sites of infarction. Three patients experienced secondary hemorrhagic transformation after the initial thrombotic event. Of the 14 patients with hemorrhagic strokes, only 1 had subarachnoid hemorrhage. All others had intracerebral bleeding, at single (N = 9) or multiple (N = 4) loci. Important causes included complications related to congenital heart diseases (N = 15, 30%), vascular diseases (N = 13, 26%), and hematologic diseases (N = 14, 28%). Six cases had no determined causes. One case involved mitochondrial encephalopathy with lactic acidosis and stroke-like episodes and constituted the only case with a metabolic cause. For the 7 patients for whom prothrombotic screening was performed, findings were negative. Seizures (52%) and hemiplegia (34%) were the most common presenting features. Other presenting clinical features included headaches (22%), decreased consciousness (30%), visual field defects (12%), dysphasia (10%), and lethargy (8%). Only 1 patient, with moyamoya disease, had a family history of stroke. The median follow-up time was 8.7 years (range: 2-12.4 years). Nine patients (18%) died, 5 with ischemic stroke and 4 with hemorrhagic stroke. Among the 5 cases of death with ischemic stroke, 3 involved hemorrhagic transformation before death. Seven patients (77%) died within 31 days (range: 2-31 days), whereas the other 2 died 6 months and 2.5 years after the episode. Recurrence occurred in 5 cases (10%). Long-term neurologic deficits occurred among 41% of survivors, including mental retardation (N = 11), epilepsy (N = 7), and hemiplegia (N = 10). The functional deficits were classified as severe in 7 cases, moderate in 3 cases, and mild in 7 cases, for patients with long-term neurologic deficits. Decreased levels of consciousness, hematologic causes, and hemorrhagic transformation (applicable only in ischemic stroke) were significant risk factors associated with high mortality rates. For the 41 patients who survived, the only significant risk factor for long-term neurologic deficits was seizures at the initial presentation. Other factors, such as gender, age, other clinical features, stroke type, vascular territory, other causes, and recurrence of stroke, were all insignificant for both death and long-term deficits. The 3 risk factors identified for death were analyzed in multivariate logistic regression analyses, with adjustment for the confounding variables, and only decreased levels of consciousness remained significant (odds ratio = 15.6).

CONCLUSIONS

The incidence of stroke among Chinese children was slightly lower than that in Europe or North America. The etiologic pattern was different in our cohort, and there was no sickle cell anemia, thrombophilia, or sinovenous thrombosis. Despite these differences, however, mortality and long-term neurologic deficit rates were similar.

Antithrombotic drug treatment of pediatric patients with ischemic stroke

Causes of stroke in children include congenital heart malformations, sickle cell disease, infections, and metabolic disorders. Up to 80% of children with ischemic stroke have cerebrovascular disease, and case control studies demonstrate an association of ischemic stroke in children with hereditary prothrombotic risk factors. There have been no randomized, clinical trials for primary prevention, short-term treatment, or secondary prevention of pediatric ischemic stroke. Treatment recommendations are based on small case series or case reports, and have mainly been adapted from adult stroke studies. Antiplatelet agents (e.g. aspirin [acetylsalicylic acid]) and heparins (e.g. low molecular weight heparin), have been used on an individual patient basis. Warfarin is administered in children with cardioembolic stroke, arterial dissection, or persistent hypercoagulable states. Alteplase has been used in a few patients within 3 hours of the onset of symptoms. In each patient treated the benefit of anticoagulation has to be weighed up against the individual bleeding risk.

Time lag to diagnosis of stroke in children

OBJECTIVE

Strokes occur rarely in children, and the causes are different from those in adults. Frequently, more than 1 cause is found. The consequences are lifelong significant disability in a majority of cases. Children who are younger than 18 years have not been included in therapeutic trials of thrombolytic or neuroprotective agents. We evaluated whether children who receive a diagnosis of stroke meet a major inclusion criterion for such trials, namely time to diagnosis of <3 to 6 hours.

METHODS

Prospective documentation and retrospective chart review was conducted of children who were 0 to 18 years and carried a diagnosis of stroke during the last 2 years in the hospital database, including children who presented with either ischemic or hemorrhagic strokes.

RESULTS

Forty-seven events were encountered in 41 children. Twelve neonates with stroke, diagnosed in the neonatal period, were excluded from the subsequent analysis. In the remaining 29 children, the mean age at presentation was 8.67 years. Accurate time records were available in 24 children. In this group, 28 events were recorded. Time from clinical onset to first medical contact averaged 28.5 hours, and the time to diagnosis of stroke averaged 35.7 hours. We subsequently separated between children with ischemic (21 documented events) and hemorrhagic strokes (7 documented events), because the presentation and the intervention options are different.

CONCLUSIONS

Stroke in children is rarely diagnosed in the time frame of 3 to 6 hours. Given the causes and outcome of stroke in children, this age group might benefit from thrombolysis and from neuroprotective therapy, yet the long delay in diagnosis in this age group excludes most cases from being considered for such treatments. This situation should encourage attempts to increase public and professional awareness of stroke in children and of the potential value of early diagnosis and treatment, preferably by broadening current educational efforts to all age groups.