Long-Term Outcomes and Risk Factors Associated With Acute Encephalitis in Children

BACKGROUND

Factors associated with poor outcomes of children with encephalitis are not well known. We sought to determine whether electroencephalography (EEG) findings, magnetic resonance imaging (MRI) abnormalities, or the presence of seizures at presentation were associated with poor outcomes.

METHODS

A retrospective review of patients aged 0 to 21 years who met criteria for a diagnosis of encephalitis admitted between 2000 and 2010 was conducted. Parents of eligible children were contacted and completed 2 questionnaires that assessed current physical and emotional quality of life and neurological deficits at least 1 year after discharge.

RESULTS

During the study period, we identified 142 patients with an International Classification of Diseases 9th Revision diagnosis of meningitis, meningoencephalitis, or encephalitis. Of these patients, 114 met criteria for a diagnosis of encephalitis, and 76 of these patients (representing 77 hospitalizations) had complete data available. Forty-nine (64%) patients were available for follow-up. Patients admitted to the intensive care unit were more likely to have abnormal EEG results (P = .001). The presence of seizures on admission was associated with ongoing seizure disorder at follow-up. One or more years after hospitalization, 78% of the patients had persistent symptoms, including 35% with seizures. Four (5%) of the patients died. Abnormal MRI findings and the number of abnormal findings on initial presentation were associated with lower quality-of-life scores.

CONCLUSIONS

Encephalitis leads to significant morbidity and death, and incomplete recovery is achieved in the majority of hospitalized patients. Abnormal EEG results were found more frequently in critically ill children, patients with abnormal MRI results had lower quality-of-life scores on follow-up, and the presence of seizures on admission was associated with ongoing seizure disorder and lower physical quality-of-life scores.

Abstract 169: Clinical and Imaging Biomarkers of Childhood Arteriopathy: Results of the Vascular effects of Infection in Pediatric Stroke (VIPS) Study

Introduction: Childhood cerebral arteriopathies are heterogeneous and difficult to classify. Our goal was to identify clinical and imaging biomarkers associated with subtypes of childhood arteriopathy in order to facilitate their diagnosis and classification in both research and clinical settings.

Methods: From 2009-2014, the VIPS study enrolled 355 children (age 29d-18y) with arterial ischemic stroke. A neuroradiologist and pediatric vascular neurologist independently reviewed vascular imaging and clinical data to diagnose arteriopathy (none, possible, definite), and then classify arteriopathy subtype: arterial dissection, transient cerebral arteriopathy (TCA), moyamoya, and secondary vasculitis. Disagreements were resolved through discussion by a panel of two neuroradiologists and two pediatric vascular neurologists. We constructed multivariable logistic regression models to identify characteristics independently associated with each subtype.

Results: Of 127 cases with definite arteriopathy, 109 received a single arteriopathy subtype diagnosis (26 dissection, 25 TCA, 34 moyamoya, 15 secondary vasculitis, and 9 “other”), while 18 were of indeterminate subtype. There were no cases of primary vasculitis. Independent predictors of arteriopathy subtype are shown (Table). The association between black race and moyamoya is explained by sickle cell anemia. A banding pattern on the vascular imaging was pathognomonic of TCA. Moyamoya and vasculitis secondary to meningitis had similar distal internal carotid artery abnormalities, but lenticulostriate collaterals suggested moyamoya, and a decreased level of consciousness predicted secondary vasculitis.

Conclusions: The different subtypes of childhood arteriopathies are associated with typical clinical, parenchymal and vascular imaging features that can help narrow the differential diagnosis in pediatric stroke patients with vascular abnormalities.

Abstract TP405: Psychological Outcomes After Childhood Arterial Ischemic Stroke

Introduction: Previous research has broadly documented that emotional and behavioral difficulties are seen after pediatric stroke; however, global ratings are generally reported without comparison to age-based norms. Additionally, little is known about the discrete symptomatology exhibited by these children. Thus, the goal of the present study was to evaluate specific psychological symptoms following childhood arterial ischemic stroke (AIS).

Hypothesis: Children with AIS were predicted to have increased difficulties in both internalizing and externalizing symptoms compared to the normative sample. Age at AIS was anticipated to influence the presence of psychological symptoms, with internalizing symptoms occurring at higher levels when the AIS occurred at a later age.

Methods: Participants were children ( n = 50, mean age = 12.1 years) who suffered an AIS during childhood (range = 1 month to 17.1 years). Parents completed the Child Behavior Checklist at least 10 months post-AIS (mean = 4.1 years). Children were divided into groups by age at AIS: early (<6 years), middle (6-10 years), or late (>10 years) childhood. Data were analyzed using one-sample t -tests and ANOVA.

Results: Children with AIS had significantly greater problems on the following DSM-oriented scales compared to the normative sample (all p -values < 0.01): Affective Problems, Anxiety Problems, Somatic Problems, Oppositional Defiant Problems, and Conduct Problems. There was a significant age-at-AIS effect on the Anxiety Problems subscale, F (2, 49) = 3.31, p = 0.05, such that the early childhood group had significantly higher levels of anxiety compared to the late childhood group.

Conclusions: Increased internalizing and externalizing symptoms were seen in children with AIS compared to the normative sample, and a higher percentage of children with AIS exceeded a clinically significant threshold in each domain. Contrary to expectations, children who had AIS at an earlier age showed greater number of anxiety symptoms relative to same-age peers. Possible mechanisms for the latter may include changes in family dynamics when young children suffer a neurological injury. These results support the need for careful psychological follow-up in this vulnerable population.

Moyamoya in a Patient with Smith-Magenis Syndrome

Occurrence of moyamoya syndrome in a patient with Smith-Magenis syndrome (SMS) has previously been reported once in a 10-year-old Asian female. We report a second case of moyamoya in a patient with SMS, in a now 25-year-old Asian female diagnosed with both conditions as a child. In addition to describing her medical and surgical history, we provide a detailed report of her omental transposition, in which the omental circulation was anastomosed to the superior thyroid artery and external jugular vein. To our knowledge, this is the first report of omental transposition for moyamoya in which omental vessels are anastomosed to vessels in the neck, as well as the second report of moyamoya in a patient with SMS.

Inter-Rater Reliability of the CASCADE Criteria: Challenges in Classifying Arteriopathies

BACKGROUND AND PURPOSE

There are limited data about the reliability of subtype classification in childhood arterial ischemic stroke, an issue that prompted the IPSS (International Pediatric Stroke Study) to develop the CASCADE criteria (Childhood AIS Standardized Classification and Diagnostic Evaluation). Our purpose was to determine the CASCADE criteria's reliability in a population of children with stroke.

METHODS

Eight raters from the IPSS reviewed neuroimaging and clinical records of 64 cases (16 cases each) randomly selected from a prospectively collected cohort of 113 children with arterial ischemic stroke and classified them using the CASCADE criteria. Clinical data abstracted included history of present illness, risk factors, and acute imaging. Agreement among raters was measured by unweighted κ statistic.

RESULTS

The CASCADE criteria demonstrated a moderate inter-rater reliability, with an overall κ statistic of 0.53 (95% confidence interval [CI]=0.39-0.67). Cardioembolic and bilateral cerebral arteriopathy subtypes had much higher agreement (κ=0.84; 95% CI=0.70-0.99; and κ=0.90; 95% CI=0.71-1.00, respectively) than cases of aortic/cervical arteriopathy (κ=0.36; 95% CI=0.01-0.71), unilateral focal cerebral arteriopathy of childhood (FCA; κ=0.49; 95% CI=0.23-0.76), and small vessel arteriopathy of childhood (κ=-0.012; 95% CI=-0.04 to 0.01).

CONCLUSIONS

The CASCADE criteria have moderate reliability when used by trained and experienced raters, which suggests that it can be used for classification in multicenter pediatric stroke studies. However, the moderate reliability of the arteriopathic subtypes suggests that further refinement is needed for defining subtypes. Such revisions may reduce the variability in the literature describing risk factors, recurrence, and outcomes associated with childhood arteriopathy.

Inflammatory Biomarkers in Childhood Arterial Ischemic Stroke: Correlates of Stroke Cause and Recurrence

BACKGROUND AND PURPOSE

Among children with arterial ischemic stroke (AIS), those with arteriopathy have the highest recurrence risk. We hypothesized that arteriopathy progression is an inflammatory process and that inflammatory biomarkers would predict recurrent AIS.

METHODS

In an international study of childhood AIS, we selected cases classified into 1 of the 3 most common childhood AIS causes: definite arteriopathic (n=103), cardioembolic (n=55), or idiopathic (n=78). We measured serum concentrations of high-sensitivity C-reactive protein, serum amyloid A, myeloperoxidase, and tumor necrosis factor-α. We used linear regression to compare analyte concentrations across the subtypes and Cox proportional hazards models to determine predictors of recurrent AIS.

RESULTS

Median age at index stroke was 8.2 years (interquartile range, 3.6-14.3); serum samples were collected at median 5.5 days post stroke (interquartile range, 3-10 days). In adjusted models (including age, infarct volume, and time to sample collection) with idiopathic as the reference, the cardioembolic (but not arteriopathic) group had higher concentrations of high-sensitivity C-reactive protein and myeloperoxidase, whereas both cardioembolic and arteriopathic groups had higher serum amyloid A. In the arteriopathic (but not cardioembolic) group, higher high-sensitivity C-reactive protein and serum amyloid A predicted recurrent AIS. Children with progressive arteriopathies on follow-up imaging had higher recurrence rates, and a trend toward higher high-sensitivity C-reactive protein and serum amyloid A, compared with children with stable or improved arteriopathies.

CONCLUSIONS

Among children with AIS, specific inflammatory biomarkers correlate with cause and-in the arteriopathy group-risk of stroke recurrence. Interventions targeting inflammation should be considered for pediatric secondary stroke prevention trials.

Pediatric Cortical Vein Thrombosis: Frequency and Association With Venous Infarction

BACKGROUND AND PURPOSE

Cortical vein thrombosis (CVT) is an uncommon site of involvement in cerebral sinovenous thrombosis. Few reports have described pediatric CVT, and none has differentiated its unique attributes. This study assessed the clinical features and radiographic outcome of a cohort of children with cerebral sinovenous thrombosis, comparing those with CVT to those without CVT.

METHODS

Children diagnosed with cerebral sinovenous thrombosis were retrospectively reviewed and separated into 2 groups based on the presence or absence of cortical vein involvement.

RESULTS

Fifty patients met inclusion criteria, including 12 with CVT. The CVT group was more likely to present with seizure (P=0.0271), altered mental status (P=0.0271), and a family history of clotting disorder (P=0.0477). Acute imaging of the CVT group more commonly demonstrated concurrent superior sagittal sinus thrombosis (P=0.0024), parenchymal hemorrhage (P=0.0141), and restricted diffusion (P<0.0001). At follow-up, the CVT group more commonly showed headache, seizure, and focal neurological deficit (P=0.0449), and venous infarction (P=0.0007).

CONCLUSIONS

In our cohort, CVT was significantly associated with seizures at presentation, hemorrhage and restricted diffusion on acute imaging, as well as neurological disability and venous infarction at follow-up. Involvement of cortical veins in cerebral sinovenous thrombosis is associated with an increased risk of infarction and adverse outcome in children.

Preparing for a "Pediatric Stroke Alert"

BACKGROUND

Childhood arterial ischemic stroke is an important cause of morbidity and mortality in children. Hyperacute treatment strategies remain controversial and challenging, especially in the setting of increasingly proven medical and endovascular options in adults. Although national and international pediatric guidelines have given initial direction about acute therapy and management, pediatric centers have traditionally lacked the infrastructure to triage, diagnose, and treat childhood arterial ischemic stroke quickly.

METHODS

In the past 10 years, researchers in the International Pediatric Stroke Study and Thrombolysis in Pediatric Stroke study have initiated early strategies for establishing pediatric specific stroke alerts.

RESULTS

We review the rationale, process and components necessary for establishing a pediatric stroke alert.

CONCLUSION

Development of pediatric stroke protocols and pathways, with evidence-based acute management strategies and supportive care where possible, facilitates the evaluation, management, and treatment of an acute pediatric stroke.

Guidelines for Urgent Management of Stroke in Children

Stroke in children carries lasting morbidity. Once recognized, it is important to evaluate and treat children with acute stroke efficiently and accurately. All children should receive neuroprotective measures. It is reasonable to consider treatment with advanced thrombolytic and endovascular agents. Delivery of such care requires purposeful institutional planning and organization in pediatric acute care centers. Primary stroke centers established for adults provide an example of the multidisciplinary approach that can be applied to the evaluation and treatment of children who present with acute stroke. The organizational infrastructure of these centers can be employed and adapted for treatment of children with acute stroke. It is likely that care for children with acute stroke can best be delivered by regional pediatric primary stroke centers dedicated to the care of children with pediatric stroke.

Abstract WMP104: Pediatric Cortical Vein Thrombosis: Frequency and Association With Venous Infarction

Introduction: Cortical vein thrombosis (CVT) is an uncommon site of involvement in cerebral sinovenous thrombosis (CSVT). Few reports have described pediatric CVT, and none have described its unique features. The aim of our study was to evaluate the clinical and radiographic features of a cohort of children with CSVT, comparing those with CVT to those without CVT.

Hypothesis: Children with CVT are more likely to experience acute restricted diffusion and chronic venous infarction, as compared to those without CVT.

Methods: Children diagnosed with CSVT from 2006 to 2014 were enrolled in a prospective cohort study at a single tertiary care center. Inclusion criteria comprised confirmation of CSVT on acute imaging with MRI/MRV or CTV, and availability of follow-up imaging at subacute and chronic time periods. Patients were separated into two groups: those with CVT (CVT group) and those without (non-CVT group). Patient demographics, clinical presentation, and imaging findings were collected and analyzed using a two-tailed Fisher's exact test. Scans were reviewed for clot location and parenchymal abnormalities.

Results: Fifty patients met inclusion criteria, including 12 with CVT. In both groups, children frequently presented with headache and focal neurological deficits. However, the CVT group was more likely to present with seizure (P = 0.0271), altered mental status (P = 0.0271), and a family history of clotting disorder (P = 0.0477). Acute imaging of the CVT group more commonly demonstrated concurrent superior sagittal sinus thrombosis (P = 0.0024) and restricted diffusion (P < 0.0001); and follow-up imaging in the CVT group more commonly showed venous infarction (P = 0.0007).

Conclusions: The presence of CVT in our pediatric CSVT cohort was significantly associated with seizures at presentation, venous-territory restricted diffusion on acute imaging, and venous infarction at follow up. While further work is needed to confirm our results, involvement of cortical veins in CSVT appears to be associated with an increased risk of infarction in children.

Cavernous Sinus Thrombosis in Children

Background and Purpose—

Cavernous sinus thrombosis (CST) is a rare life-threatening cerebrovascular disease known to cause carotid artery narrowing (CAN) and arterial ischemic stroke. The imaging features of CST and related complications have been reported in adults, but rarely in children.

Methods—

We performed a retrospective review of children with imaging confirmed CST from 2003 to 2014, describing presenting symptoms, imaging findings, and treatment.

Results—

Ten patients with CST were identified. All had CAN and 6 of 10 developed infarcts. Of 8 patients treated with anticoagulation therapy, 3 developed new infarcts. None required discontinuation of anticoagulation therapy because of bleeding. Visual impairment secondary to infectious neuritis was common. Imaging characteristics include cavernous sinus expansion, filling defects, restricted diffusion, arterial wall enhancement, empyema, superior ophthalmic vein enlargement and thrombosis, orbital cellulitis, and pituitary inflammation. CAN resolved in 60% of cases. Outcomes were mostly good, with a modified Rankin Scale score of ≤1 for 7 of 10 patients at discharge and 1 death.

Conclusions—

CAN and infarcts were common in this modest cohort of children with CST. Despite the high incidence of CAN and infarction, outcomes were often favorable. Although this is the largest cohort of childhood CST reported to date, large multicenter cohorts are needed to confirm our findings and determine the preferred therapeutic strategies for childhood CST.

Abstract T P364: Carotid Narrowing and Stroke in Childhood Cavernous Sinus Thrombosis

Introduction: Cavernous sinus thrombosis (CST) is a rare and potentially life-threatening disease in children. While the incidence of neurological complication is unknown, CST can cause carotid artery narrowing, carotid vasospasm, and/or ischemia. Given the lack of data regarding childhood CST, decisions about antithrombotic and antispasmodic management remain uncertain.

Hypothesis: We describe the clinical presentation, imaging findings, treatment and outcome of childhood CST at a tertiary care center, hypothesizing that carotid narrowing and stroke are common in this condition.

Methods: We performed a single-center retrospective review of children with imaging confirmed CST from 2003-2013. Clinical data were extracted from the electronic medical record and all available imaging reviewed by two neuroradiologists. Data was analyzed with descriptive statistics.

Results: Eight patients with childhood CST (Table 1) were identified. All had carotid artery narrowing and 63% (5/8) developed ischemia. The most common complication was visual impairment secondary to infectious neuritis. Of the seven patients treated with anticoagulation, three developed new ischemia on therapy. Similar results were seen with nimodipine therapy. Despite the high incidence of stroke, outcomes were generally good, with all but one patient attaining a mRS of ≤ 1at discharge.

Conclusion: In childhood CST, carotid narrowing and arterial ischemic stroke appear to be common. While therapeutic interventions to prevent clot propagation and/or vasospasm did not prevent all new ischemia, they may have contributed to the prevention of medium/large ischemic events, which were uncommon in this series. Despite the high incidence of carotid vasospasm and stroke, outcomes were generally favorable. Large multicenter cohorts are needed to understand the preferred therapeutic strategies for childhood CST.

Abstract T MP62: Acute Infarct Volume in Perinatal Stroke Can Be Accurately Estimated by Measuring Residual Uninfarcted Tissue on Follow-up MRI

Introduction: Developing accurate measurements of infarct volume is vital to studying outcomes in Perinatal Arterial Ischemic Stroke (PAS). Methods for measuring Acute Infarct Volumes (aIV) are well established in PAS. However, techniques for measuring chronic infarct volume (cIV) in order to estimate aIV have not been validated and must account for changes in Total Brain Volume (TBV) over time, as well as contraction of the infarct. We compared two methods of measuring cIV, hypothesizing that cIV extrapolated from residual uninfarcted brain tissue volume would better estimate aIV than direct measurement of cIV.

Methods: Using modified manual segmentation techniques, two pediatric neuroradiologists independently measured the brain and infarct volumes of 10 PAS patients both on the acute (0-7 days old) and chronic (>3 months) MRIs. Volume measurements were averaged after high inter-rater reliability was established (ICC>0.9). We evaluated acute and chronic scans for changes in infarct anatomy, and excluded patients with bilateral infarctions. Method 1 for estimating cIV used a direct measurement of the infarct (figure). Method 2 extrapolated infarct volume from residual uninfarcted brain tissue (figure). The cIV for each method was then compared to the aIV.

Results: 3 patients with bilateral infarcts were excluded. Infarct anatomy between acute and chronic scans did not change for the 7 unilateral infarcts evaluated. In these 7 cases, the ICC comparing aIV and cIV from Method 1 was 0.507 (CI -0.120, 0.891), while the ICC comparing aIV and cIV from Method 2 was 0.964 (CI 0.821, 0.994). cIV’s from Method 1 were smaller than the aIV’s in all cases, despite stability of infarct anatomy.

Conclusions: In this pilot study measuring cIV in PAS, direct measurement of cIV likely underestimates volume because of contraction of infarcted tissue. In conclusion, extrapolation of cIV from measurement of residual uninfarcted tissue appears to accurately estimate aIV.

Moyamoya syndrome associated with Alagille syndrome: outcome after surgical revascularization

Vasculopathy is well-described in Alagille syndrome (ALGS); however, few data exist regarding neurosurgical interventions. We report 5 children with ALGS with moyamoya who underwent revascularization surgery. Postsurgical complications included 1 stroke and 1 death from thalamic hemorrhage. Global function improved in survivors. Revascularization is reasonably safe in patients with ALGS and may improve neurologic outcomes.

Abstract 19: Neurophysiological Responses Of Recovery In Pediatric Mice Compared To Adult Mice With Transient Focal Cerebral Ischemia

Introduction: Ischemic stroke is the fourth leading cause of death in the United States and is increasingly being recognized as a disease that occurs in people of all ages, not just the elderly. Studies suggest that the immature developing brain may have a greater degree of plasticity compared to the adult, thereby enhancing functional recovery to a greater extent during development.

Hypothesis: Pediatric mice exhibit greater recovery from hippocampal synaptic function following experimental stroke than adults.

Methods: Extracellular field recordings of CA1 neurons were performed in acute hippocampal slices prepared at 24 hrs, 7 or 30 days after recovery from middle cerebral artery occlusion (MCAO) and compared to sham control mice.

Results: In adult mice, hippocampal long-term potentiation (LTP) is impaired as early as 24 hrs after experimental stroke and remains impaired for at least 30 days in both the ipsilateral and contralateral, non-injured hemisphere. However, in pediatric mice, LTP is impaired as early as 24 hrs after MCAO and remained impaired in the ipsilateral side 7 days after MCAO, but recovered in the contralateral side at 7 days after MCAO. At day 30 post-stroke, pediatric mice display a full recovery of synaptic function in both hemispheres. Furthermore, significant experimental data is emerging demonstrating an imbalance between inhibitory and excitatory cortical pathways after ischemic stroke, suggesting that reducing GABAergic inhibitory transmission enhances recovery. To test this, hippocampal slices were incubated in L655,708 (100nM), an inverse agonist selective for α5 subunit-containing GABAA receptors. Our data shows that synaptic plasticity was rescued in both pediatric and adult mice in the presence of L655,708 at all-time points tested.

Conclusion: The present study demonstrates that transient focal ischemia causes functional impairment in the hippocampus at various time points after MCAO and that recovery of synaptic function is more robust in the young brain. In addition, we observed that excessive GABA activity may contribute to impaired synaptic function following ischemic injury, thus inhibition of specific GABA activity may provide a new therapeutic approach to improve functional recovery after stroke.

Out-of-pocket costs for childhood stroke: the impact of chronic illness on parents' pocketbooks

OBJECTIVE

Direct costs for children who had stroke are similar to those for adults. There is no information regarding the out-of-pocket costs families encounter. We described the out-of-pocket costs families encountered in the first year after a child's ischemic stroke.

METHODS

Twenty-two subjects were prospectively recruited at four centers in the United States and Canada in 2008 and 2009 as part of the "Validation of the Pediatric NIH Stroke Scale" study; families' indirect costs were tracked for 1 year. Every 3 months, parents reported hours they did not work, nonreimbursed costs for medical visits or other health care, and mileage. They provided estimates of annual income. We calculated total out-of-pocket costs in US dollars and reported costs as a proportion of annual income.

RESULTS

Total median out-of-pocket cost for the year after an ischemic stroke was $4354 (range, $0-$28,666; interquartile range, $1008-$8245). Out-of-pocket costs were greatest in the first 3 months after the incident stroke, with the largest proportion because of lost wages, followed by transportation, and nonreimbursed health care. For the entire year, median costs represented 6.8% (range, 0%-81.9%; interquartile range, 2.7%-17.2%) of annual income.

CONCLUSIONS

Out-of-pocket expenses are significant after a child's ischemic stroke. The median costs are noteworthy provided that the median American household had cash savings of $3650 at the time of the study. These results with previous reports of direct costs provide a more complete view of the overall costs to families and society. Childhood stroke creates an under-recognized cost to society because of decreased parental productivity.

Stroke in children with cardiac disease: report from the International Pediatric Stroke Study Group Symposium

BACKGROUND

Cardiac disease is a leading cause of stroke in children, yet limited data support the current stroke prevention and treatment recommendations. A multidisciplinary panel of clinicians was convened in February 2014 by the International Pediatric Stroke Study group to identify knowledge gaps and prioritize clinical research efforts for children with cardiac disease and stroke.

RESULTS

Significant knowledge gaps exist, including a lack of data on stroke incidence, predictors, primary and secondary stroke prevention, hyperacute treatment, and outcome in children with cardiac disease. Commonly used diagnostic techniques including brain computed tomography and ultrasound have low rates of stroke detection, and diagnosis is frequently delayed. The challenges of research studies in this population include epidemiologic barriers to research such as small patient numbers, heterogeneity of cardiac disease, and coexistence of multiple risk factors. Based on stroke burden and study feasibility, studies involving mechanical circulatory support, single ventricle patients, early stroke detection strategies, and understanding secondary stroke risk factors and prevention are the highest research priorities over the next 5-10 years. The development of large-scale multicenter and multispecialty collaborative research is a critical next step. The designation of centers of expertise will assist in clinical care and research.

CONCLUSIONS

There is an urgent need for additional research to improve the quality of evidence in guideline recommendations for cardiogenic stroke in children. Although significant barriers to clinical research exist, multicenter and multispecialty collaboration is an important step toward advancing clinical care and research for children with cardiac disease and stroke.

Arteriopathy diagnosis in childhood arterial ischemic stroke: results of the vascular effects of infection in pediatric stroke study

BACKGROUND AND PURPOSE

Although arteriopathies are the most common cause of childhood arterial ischemic stroke, and the strongest predictor of recurrent stroke, they are difficult to diagnose. We studied the role of clinical data and follow-up imaging in diagnosing cerebral and cervical arteriopathy in children with arterial ischemic stroke.

METHODS

Vascular effects of infection in pediatric stroke, an international prospective study, enrolled 355 cases of arterial ischemic stroke (age, 29 days to 18 years) at 39 centers. A neuroradiologist and stroke neurologist independently reviewed vascular imaging of the brain (mandatory for inclusion) and neck to establish a diagnosis of arteriopathy (definite, possible, or absent) in 3 steps: (1) baseline imaging alone; (2) plus clinical data; (3) plus follow-up imaging. A 4-person committee, including a second neuroradiologist and stroke neurologist, adjudicated disagreements. Using the final diagnosis as the gold standard, we calculated the sensitivity and specificity of each step.

RESULTS

Cases were aged median 7.6 years (interquartile range, 2.8-14 years); 56% boys. The majority (52%) was previously healthy; 41% had follow-up vascular imaging. Only 56 (16%) required adjudication. The gold standard diagnosis was definite arteriopathy in 127 (36%), possible in 34 (9.6%), and absent in 194 (55%). Sensitivity was 79% at step 1, 90% at step 2, and 94% at step 3; specificity was high throughout (99%, 100%, and 100%), as was agreement between reviewers (κ=0.77, 0.81, and 0.78).

CONCLUSIONS

Clinical data and follow-up imaging help, yet uncertainty in the diagnosis of childhood arteriopathy remains. This presents a challenge to better understanding the mechanisms underlying these arteriopathies and designing strategies for prevention of childhood arterial ischemic stroke.

Etiology and treatment of arterial ischemic stroke in children and young adults

OPINION STATEMENT

Stroke is the second leading cause of death worldwide (Go et al. Circulation 129:e28-292, 2014) and is a major cause of morbidity and mortality. Compared with older adults, arterial ischemic stroke (AIS) is relatively uncommon in children and young adults, comprising 5-10 % of all stroke (Biller Nat Rev Cardiol 6:395-97, 2009), but is associated with significant cost. In contrast to the declining overall incidence of stroke, some early studies suggest that the rate of stroke hospitalizations in children and young adults is rising (George et al. Ann Neurol 70:713-21, 2011; Kissela et al. Stroke 41:e224, 2010; Nguyen-Huynh et al. Stroke 43, 2012), emphasizing the importance of understanding the similarities and differences in etiology and treatment of AIS across the age spectrum. Among the most common causes of AIS in children are cardioembolism (often related to congenital heart disease), cervicocephalic arterial dissections, focal arteriopathy of childhood and several genetic and metabolic disorders, such as sickle cell disease (SCD). AIS in young adults is less well understood, but likely overlaps in etiology with both children and older adults. Young adults with AIS often have classic atherosclerotic risk factors similar to older adults, but are also more likely to have thrombophilias, cervicocephalic arterial dissections and cardioembolism, similar to children with AIS. Since little evidence exists regarding both acute treatment and secondary prevention after AIS in children and young adults, standard treatment practices are mainly extrapolated from research done in older adults. In most cases we recommend treating young adults per the guidelines published by the American Heart Association for adults with stroke (Jauch et al. Stroke 44:870-947, 2013; Kernan et al. Stroke 45:2160-2236, 2014) and children per the equivalent guidelines regarding pediatric stroke (Roach et al. Stroke 39:2644-91, 2008). It is also important in children and young adults to consider less common structural, metabolic and genetic risk factors for stroke, which may require more specific treatment. Other standard risk factors for stroke, including hypertension, hyperlipidemia and diabetes mellitus should also be addressed, but are less likely in children and young adults. Given the lack of data and possibility of rare underlying etiologies such as Antiphospholipid Antibody Syndrome or Ehlers-Danlos syndrome, we recommend including multiple specialists in the care of these patients, such as hematologists and vascular neurologists.

Emergence of the primary pediatric stroke center: impact of the thrombolysis in pediatric stroke trial

BACKGROUND AND PURPOSE

In adult stroke, the advent of thrombolytic therapy led to the development of primary stroke centers capable to diagnose and treat patients with acute stroke rapidly. We describe the development of primary pediatric stroke centers through preparation of participating centers in the Thrombolysis in Pediatric Stroke (TIPS) trial.

METHODS

We collected data from the 17 enrolling TIPS centers regarding the process of becoming an acute pediatric stroke center with capability to diagnose, evaluate, and treat pediatric stroke rapidly, including use of thrombolytic therapy.

RESULTS

Before 2004, <25% of TIPS sites had continuous 24-hour availability of acute stroke teams, MRI capability, or stroke order sets, despite significant pediatric stroke expertise. After TIPS preparation, >80% of sites now have these systems in place, and all sites reported increased readiness to treat a child with acute stroke. Use of a 1- to 10-Likert scale on which 10 represented complete readiness, median center readiness increased from 6.2 before site preparation to 8.7 at the time of site activation (P≤0.001).

CONCLUSIONS

Before preparing for TIPS, centers interested in pediatric stroke had not developed systematic strategies to diagnose and treat acute pediatric stroke. TIPS trial preparation has resulted in establishment of pediatric acute stroke centers with clinical and system preparedness for evaluation and care of children with acute stroke, including use of a standardized protocol for evaluation and treatment of acute arterial stroke in children that includes use of intravenous tissue-type plasminogen activator.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01591096.

Abstract 42: Chronic Endothelial Activation in Childhood Arterial Ischemic Stroke

Objective: Despite evidence suggesting that arterial inflammation plays a role in the pathophysiology of childhood arterial ischemic stroke (AIS), relatively little is known about inflammatory induced coagulation and/or endothelial activation. The object of this study was to compare biomarkers of coagulation activation [D-dimer and thrombin-antithrombin complex (TAT)] and endothelial activation [Plasminogen activator inhibitor-1 (PAI-1) and von Willebrand factor antigen (vWF Ag)] in children with AIS as compared to healthy pediatric controls.

Methods: Sixty patients with childhood AIS (ages 28 days to 19 years) were enrolled in a prospective six-center study. Biomarker samples were collected in the acute (0-3 weeks post-AIS) and chronic (> 3 months post-AIS) timeframes. Healthy pediatric controls were enrolled at the central site. Biomarker differences by group were examined using t-test, chi-square, and, if demographics differed, regression models.

Results: Age and gender were similar in all case and control groups, except age in acute vWF Ag and D-dimer populations [mean (SD): vWF Ag age = 9.3 yrs. (5.2), control age = 6.9 yrs. (4.3), P=0.007 ; D-Dimer age = 9.4 yrs. (5.2), control age = 7.3 yrs. (4.3), P=0.032 ]. All acute biomarkers were significantly elevated in cases as compared to healthy controls, while only markers of endothelial activation remained significantly elevated in cases during the chronic phase (PAI-1 P=0.0014 ; vWF Ag P=0.0002 ; Table).

Conclusion: Children with AIS have increased levels of endothelial and coagulation activation during the acute phase following stroke, while endothelial biomarkers remain elevated beyond 3 months. These results suggest that endothelial activation persists into the chronic phase of childhood AIS. Future studies with larger cohorts and stroke subtype analysis are needed to evaluate the use of endothelial biomarkers as surrogates of ongoing disease and recurrence risk.

The methylenetetrahydrofolate reductase polymorphism (MTHFR c.677C>T) and elevated plasma homocysteine levels in a U.S. pediatric population with incident thromboembolism

OBJECTIVE

Elevated plasma homocysteine (tHcy) and the MTHFR c.677C>T variant have been postulated to increase the risk of venous thromboembolism (VTE), although mechanisms and implications to pediatrics remain incompletely understood. The objectives of this study were to determine the prevalences of elevated tHcy and MTHFR variant in a pediatric population with VTE or arterial ischemic stroke (AIS), and to determine associations with thrombus outcomes.

STUDY DESIGN

Subjects were enrolled in an institution-based prospective cohort of children with VTE or AIS. Inclusion criteria consisted of objectively confirmed thrombus, ≤21years at diagnosis, tHcy measured and MTHFR c.677C>T mutation analysis. Clinical and laboratory data were collected. Frequencies for elevated tHcy and MTHFR variant were compared with NHANES values for healthy US children and also between study groups (VTE vs AIS, provoked vs idiopathic) and by age.

RESULTS

The prevalences of hyperhomocysteinemia or MTHFR variant were not increased in comparison to NHANES. tHcy did not differ between those with wild-type MTHFR versus either c.677C>T heterozygotes or homozygotes. There was no association between tHcy or MTHFR variant and thrombus outcomes.

CONCLUSION

In this cohort of US children with VTE or AIS, neither the prevalence of hyperhomocysteinemia nor that of MTHFR variant was increased relative to reference values, and adverse thrombus outcomes were not definitively associated with either. While it is important to consider that milder forms of pyridoxine-responsive classical homocystinuria will be detected only by tHcy, we suggest that routine testing of MTHFR c.677C>T genotype as part of a thrombophilia evaluation in children with incident thromboembolism is not warranted until larger studies have been performed in order to establish or refute a link between MTHFR and adverse outcomes.