Introduction: We present a first analysis of data from the diffusion tensor imaging (DTI) compone... more Introduction: We present a first analysis of data from the diffusion tensor imaging (DTI) component of the NIH MRI study of Normal Brain Development (PedsDTI). Although DTI studies of brain development are available in the literature, PedsDTI represents the largest prospective study on brain development performed to date in healthy children covering the entire age range of 0 to 22 years. DTI data from 498 scans in 274 unique subjects can be downloaded from the public data repository (NIH-pediatricMRI.org). Subjects were prospectively enrolled for the study in 5 centers across the US. All scanning was done without sedation, during natural sleep for the youngest children. An extensive set of neuropsychological data is also available in the data repository, allowing researchers to test hypotheses on structure/function relationships. In this report we present the construction of age specific brain atlases that will also be included in the data repository, and we study the feasibility of...
Perfusion-weighted imaging in adults with acute stroke often reveals hypoperfusion in the ischemi... more Perfusion-weighted imaging in adults with acute stroke often reveals hypoperfusion in the ischemic core and in a surrounding area of nondiffusion-restricted penumbral tissue. Perinatal stroke is common, but the perfusion pattern is rarely documented. We aimed to describe the perfusion pattern in newborns with perinatal stroke. Neonates with clinical features of acute stroke underwent magnetic resonance imaging. Perfusion data were obtained using pseudocontinuous arterial spin labeling. Strokes were classified as arterial, venous, or both. Core infarction was determined by the presence of restricted diffusion on diffusion-weighted imaging. Perfusion-weighted imaging and susceptibility-weighted imaging signal in the ischemic area were visually compared with the homologous region in the contralesional hemisphere. Electroencephalogram data were evaluated for seizure activity. In 25 neonates with acute stroke, 8 of 11 (73%) with arterial ischemic stroke demonstrated hyperperfusion, 1 of ...
MR diffusion-weighted imaging provides early demonstration of neonatal brain infarction. The evol... more MR diffusion-weighted imaging provides early demonstration of neonatal brain infarction. The evolution and limitations of diffusion-weighted imaging findings in newborns, however, have not been evaluated. Using line-scan diffusion imaging (LSDI), we investigated perinatal ischemic brain injury. Nineteen term newborns (age, 9 hours to 8 days; mean age, 2.6 days) with perinatal brain ischemia were evaluated using LSDI (1520/62.5/1 [TR/TE/excitations]) (b maximum = 750 s/mm2) and T1- and T2-weighted spin-echo (conventional) MR imaging. Follow-up examinations were performed in seven patients and autopsy in one. Apparent diffusion coefficients (ADCs) were measured in deep gray matter, white matter, the cortex, and focal lesions. Based on conventional MR imaging or pathologic findings, patients were divided into two groups. Group 1 (n = 12) had symmetric/diffuse injury consistent with global hypoperfusion. Group 2 (n = 7) had focal/multifocal injury suggesting cerebrovascular occlusion. A...
Inhibition of proliferative neointima formed by vascular smooth muscle cells is a potential targe... more Inhibition of proliferative neointima formed by vascular smooth muscle cells is a potential target in preventing angioplasty-induced restenosis. We have created a potent antiproliferative by fusing the active regions of the p27 and p16 cell cycle inhibitors. Intravascular delivery of a replication-deficient adenoviral vector (AV) encoding this p27-p16 fusion protein, named W9, inhibited balloon injury–induced neointimal hyperplasia in rabbit carotid arteries. In a therapeutically more relevant model, AV-W9 was delivered to balloon-injured porcine coronary arteries in vivo using an infusion catheter. Of the three coronary arteries, two were injured with a 15-mm balloon catheter and either were left untreated or were treated with 10 12 viral particles of either AV-W9 or a control null virus. AV-W9 treatment significantly inhibited neointimal hyperplasia in this porcine arterial balloon injury model compared with untreated or control virus–treated vessels. The average intimal area of t...
Background: Few data are available on the neuropsychological, behavioural, or structural brain im... more Background: Few data are available on the neuropsychological, behavioural, or structural brain imaging outcomes in adolescents who underwent corrective surgery in infancy for tetralogy of Fallot. Methods: In this single-centre cross-sectional study, we enrolled 91 adolescents (13–16 years old) with tetralogy of Fallot and 87 referent subjects. Assessments included tests of academic achievement, memory, executive functions, visual-spatial skills, attention, and social cognition, as well as brain magnetic resonance imaging. Results: Genetic abnormalities or syndromes were present in 25% of tetralogy of Fallot patients, who had markedly greater neuropsychological morbidities than did patients without a syndrome. However, even patients without a syndrome performed significantly worse than the referent group or population norms in all of the neuropsychological domains assessed. In multivariable regression in those without a genetic/phenotypic syndrome, the strongest predictors of adverse...
ObjectiveTo determine that children with arterial ischemic stroke (AIS) due to an identifiable ar... more ObjectiveTo determine that children with arterial ischemic stroke (AIS) due to an identifiable arteriopathy are distinct from those without arteriopathy and that each arteriopathy subtype has unique and recognizable clinical features.MethodsWe report a large, observational, multicenter cohort of children with AIS, age 1 month to 18 years, enrolled in the International Pediatric Stroke Study from 2003 to 2014. Clinical and demographic differences were compared by use of the Fisher exact test, with linear step-up permutation min-p adjustment for multiple comparisons. Exploratory analyses were conducted to evaluate differences between cases of AIS with and without arteriopathy and between arteriopathy subtypes.ResultsOf 2,127 children with AIS, 725 (34%) had arteriopathy (median age 7.45 years). Arteriopathy subtypes included dissection (27%), moyamoya (24.5%), focal cerebral arteriopathy–inflammatory subtype (FCA-i; 15%), diffuse cerebral vasculitis (15%), and nonspecific arteriopathy...
The Journal of allergy and clinical immunology, Jan 21, 2018
Deficiency of adenosine deaminase 2 is characterized by vasculitis, early-onset strokes, immunode... more Deficiency of adenosine deaminase 2 is characterized by vasculitis, early-onset strokes, immunodeficiency, and bone marrow failure. We describe a novel pathogenic mutation affecting a consensus N-linked glycosylation sequence and illustrate the essential role of glycosylation in the biology of ADA2.
Risk factors for pediatric stroke are poorly understood and require study to improve prevention. ... more Risk factors for pediatric stroke are poorly understood and require study to improve prevention. Total cholesterol and triglyceride values peak to near-adult levels before puberty, a period of increased stroke incidence. The role of lipids in childhood arterial ischemic stroke has been minimally investigated. We performed a cross-sectional analysis of lipid and Lp(a) concentrations in children with arterial ischemic stroke in the International Pediatric Stroke Study to compare the prevalence of dyslipidemia and high- or low-ranking lipid values in our dataset with reported population values. We analyzed sex, body mass index, race, ethnicity, family history, and stroke risk factors for associations with dyslipidemia, high non-high-density lipoprotein cholesterol, and hypertriglyceridemia. Compared with the National Health and Nutrition Examination Survey, a higher proportion of children ≥5 years with arterial ischemic stroke had dyslipidemia (38.4% versus 21%), high total cholesterol...
Midaortic syndrome (MAS) is a rare cause of severe childhood hypertension characterized by narrow... more Midaortic syndrome (MAS) is a rare cause of severe childhood hypertension characterized by narrowing of the abdominal aorta in children and is associated with extensive vascular disease. It may occur as part of a genetic syndrome, such as neurofibromatosis, or as consequence of a pathological inflammatory disease. However, most cases are considered idiopathic. We hypothesized that in a high percentage of these patients, a monogenic cause of disease may be detected by evaluating whole exome sequencing data for mutations in 1 of 38 candidate genes previously described to cause vasculopathy. We studied a cohort of 36 individuals from 35 different families with MAS by exome sequencing. In 15 of 35 families (42.9%), we detected likely causal dominant mutations. In 15 of 35 (42.9%) families with MAS, whole exome sequencing revealed a mutation in one of the genes previously associated with vascular disease (,,,, and). Ten of the 15 mutations have not previously been reported. This is the f...
This study aimed to describe children with moyamoya disease from an international multicenter str... more This study aimed to describe children with moyamoya disease from an international multicenter stroke database, and explore risk factors for stroke recurrence. We reviewed data of children >28-days old with moyamoya disease enrolled in the International Pediatric Stroke Study from January 2003 to March 2013. A total of 174 children from 32 sites and 14 countries had moyamoya disease; median age 7.4 years, 49% male. Of these, 90% presented with ischemic stroke, 7.5% with transient ischemic attack, and 2.5% with hemorrhagic stroke. One-third of patients had moyamoya syndrome. Stroke recurrence was 20% over median follow-up of 13 months; 9% had multiple recurrences. Children treated with surgical revascularization were less likely to have stroke recurrence ( P = .046). Moyamoya disease accounted for 8% of arterial strokes in this international pediatric stroke registry. One-third of pediatric patients with moyamoya disease have an underlying syndromic condition. Surgical revasculariz...
To provide consensus-based, suggested imaging protocols to facilitate the accurate and timely dia... more To provide consensus-based, suggested imaging protocols to facilitate the accurate and timely diagnosis of a neonate with symptoms concerning for stroke. The Writing Group, an international collaboration of pediatric neurologists and neuroradiologists with expertise in perinatal and childhood stroke, participated in a series of pediatric stroke neuroimaging symposia. These discussions, in conjunction with extensive literature review, led to a consensus for imaging protocols to guide practitioners in the diagnosis of neonatal stroke subtypes as defined by the National Institute of Neurological Disorders and Stroke Common Data Elements. The epidemiology, clinical presentation, and associated risk factors for arterial ischemic stroke, cerebral sinovenous thrombosis, and hemorrhagic stroke are reviewed, with a focused discussion regarding the role of neuroimaging for each subtype. In a neonate with suspected stroke, magnetic resonance imaging is the preferred modality, given the lack of...
The purpose of this article is to aid practitioners in choosing appropriate neuroimaging for chil... more The purpose of this article is to aid practitioners in choosing appropriate neuroimaging for children who present with symptoms that could be caused by stroke. The Writing Group members participated in one or more pediatric stroke neuroimaging symposiums hosted by the Stroke Imaging Laboratory for Children housed at the Hospital for Sick Children in Toronto, Ontario, Canada. Through collaboration, literature review, and discussion among child neurologists with expertise diagnosing and treating childhood stroke and pediatric neuroradiologists and neuroradiologists with expertise in pediatric neurovascular disease, suggested imaging protocols are presented for children with suspected stroke syndromes including arterial ischemic stroke, cerebral sinovenous thrombosis, and hemorrhagic stroke. This article presents information about the epidemiology and classification of childhood stroke with definitions based on the National Institutes of Health Common Data Elements. The role of imaging...
To investigate the long-term impact of early-term birth (37-38 weeks' gestation) relative to ... more To investigate the long-term impact of early-term birth (37-38 weeks' gestation) relative to full-term birth (≥39 weeks' gestation) on neurodevelopmental and psychiatric outcomes in adolescents with single-ventricle congenital heart disease (CHD). This cross-sectional cohort study analyzed retrospective medical records from full term adolescents with single-ventricle CHD who underwent the Fontan procedure. Participants underwent neurodevelopmental and psychiatric evaluations, as well as structural brain magnetic resonance imaging. Early-term born adolescents were compared with full-term born adolescents using regression models with adjustments for family social status, birth weight, and genetic abnormality status. Medical and demographic risk factors were examined as well. Compared with the full-term group (n = 100), adolescents born early term (n = 33) scored significantly worse on daily-life executive functions, as measured by the Behavior Rating Inventory of Executive Fun...
Introduction: We present a first analysis of data from the diffusion tensor imaging (DTI) compone... more Introduction: We present a first analysis of data from the diffusion tensor imaging (DTI) component of the NIH MRI study of Normal Brain Development (PedsDTI). Although DTI studies of brain development are available in the literature, PedsDTI represents the largest prospective study on brain development performed to date in healthy children covering the entire age range of 0 to 22 years. DTI data from 498 scans in 274 unique subjects can be downloaded from the public data repository (NIH-pediatricMRI.org). Subjects were prospectively enrolled for the study in 5 centers across the US. All scanning was done without sedation, during natural sleep for the youngest children. An extensive set of neuropsychological data is also available in the data repository, allowing researchers to test hypotheses on structure/function relationships. In this report we present the construction of age specific brain atlases that will also be included in the data repository, and we study the feasibility of...
Perfusion-weighted imaging in adults with acute stroke often reveals hypoperfusion in the ischemi... more Perfusion-weighted imaging in adults with acute stroke often reveals hypoperfusion in the ischemic core and in a surrounding area of nondiffusion-restricted penumbral tissue. Perinatal stroke is common, but the perfusion pattern is rarely documented. We aimed to describe the perfusion pattern in newborns with perinatal stroke. Neonates with clinical features of acute stroke underwent magnetic resonance imaging. Perfusion data were obtained using pseudocontinuous arterial spin labeling. Strokes were classified as arterial, venous, or both. Core infarction was determined by the presence of restricted diffusion on diffusion-weighted imaging. Perfusion-weighted imaging and susceptibility-weighted imaging signal in the ischemic area were visually compared with the homologous region in the contralesional hemisphere. Electroencephalogram data were evaluated for seizure activity. In 25 neonates with acute stroke, 8 of 11 (73%) with arterial ischemic stroke demonstrated hyperperfusion, 1 of ...
MR diffusion-weighted imaging provides early demonstration of neonatal brain infarction. The evol... more MR diffusion-weighted imaging provides early demonstration of neonatal brain infarction. The evolution and limitations of diffusion-weighted imaging findings in newborns, however, have not been evaluated. Using line-scan diffusion imaging (LSDI), we investigated perinatal ischemic brain injury. Nineteen term newborns (age, 9 hours to 8 days; mean age, 2.6 days) with perinatal brain ischemia were evaluated using LSDI (1520/62.5/1 [TR/TE/excitations]) (b maximum = 750 s/mm2) and T1- and T2-weighted spin-echo (conventional) MR imaging. Follow-up examinations were performed in seven patients and autopsy in one. Apparent diffusion coefficients (ADCs) were measured in deep gray matter, white matter, the cortex, and focal lesions. Based on conventional MR imaging or pathologic findings, patients were divided into two groups. Group 1 (n = 12) had symmetric/diffuse injury consistent with global hypoperfusion. Group 2 (n = 7) had focal/multifocal injury suggesting cerebrovascular occlusion. A...
Inhibition of proliferative neointima formed by vascular smooth muscle cells is a potential targe... more Inhibition of proliferative neointima formed by vascular smooth muscle cells is a potential target in preventing angioplasty-induced restenosis. We have created a potent antiproliferative by fusing the active regions of the p27 and p16 cell cycle inhibitors. Intravascular delivery of a replication-deficient adenoviral vector (AV) encoding this p27-p16 fusion protein, named W9, inhibited balloon injury–induced neointimal hyperplasia in rabbit carotid arteries. In a therapeutically more relevant model, AV-W9 was delivered to balloon-injured porcine coronary arteries in vivo using an infusion catheter. Of the three coronary arteries, two were injured with a 15-mm balloon catheter and either were left untreated or were treated with 10 12 viral particles of either AV-W9 or a control null virus. AV-W9 treatment significantly inhibited neointimal hyperplasia in this porcine arterial balloon injury model compared with untreated or control virus–treated vessels. The average intimal area of t...
Background: Few data are available on the neuropsychological, behavioural, or structural brain im... more Background: Few data are available on the neuropsychological, behavioural, or structural brain imaging outcomes in adolescents who underwent corrective surgery in infancy for tetralogy of Fallot. Methods: In this single-centre cross-sectional study, we enrolled 91 adolescents (13–16 years old) with tetralogy of Fallot and 87 referent subjects. Assessments included tests of academic achievement, memory, executive functions, visual-spatial skills, attention, and social cognition, as well as brain magnetic resonance imaging. Results: Genetic abnormalities or syndromes were present in 25% of tetralogy of Fallot patients, who had markedly greater neuropsychological morbidities than did patients without a syndrome. However, even patients without a syndrome performed significantly worse than the referent group or population norms in all of the neuropsychological domains assessed. In multivariable regression in those without a genetic/phenotypic syndrome, the strongest predictors of adverse...
ObjectiveTo determine that children with arterial ischemic stroke (AIS) due to an identifiable ar... more ObjectiveTo determine that children with arterial ischemic stroke (AIS) due to an identifiable arteriopathy are distinct from those without arteriopathy and that each arteriopathy subtype has unique and recognizable clinical features.MethodsWe report a large, observational, multicenter cohort of children with AIS, age 1 month to 18 years, enrolled in the International Pediatric Stroke Study from 2003 to 2014. Clinical and demographic differences were compared by use of the Fisher exact test, with linear step-up permutation min-p adjustment for multiple comparisons. Exploratory analyses were conducted to evaluate differences between cases of AIS with and without arteriopathy and between arteriopathy subtypes.ResultsOf 2,127 children with AIS, 725 (34%) had arteriopathy (median age 7.45 years). Arteriopathy subtypes included dissection (27%), moyamoya (24.5%), focal cerebral arteriopathy–inflammatory subtype (FCA-i; 15%), diffuse cerebral vasculitis (15%), and nonspecific arteriopathy...
The Journal of allergy and clinical immunology, Jan 21, 2018
Deficiency of adenosine deaminase 2 is characterized by vasculitis, early-onset strokes, immunode... more Deficiency of adenosine deaminase 2 is characterized by vasculitis, early-onset strokes, immunodeficiency, and bone marrow failure. We describe a novel pathogenic mutation affecting a consensus N-linked glycosylation sequence and illustrate the essential role of glycosylation in the biology of ADA2.
Risk factors for pediatric stroke are poorly understood and require study to improve prevention. ... more Risk factors for pediatric stroke are poorly understood and require study to improve prevention. Total cholesterol and triglyceride values peak to near-adult levels before puberty, a period of increased stroke incidence. The role of lipids in childhood arterial ischemic stroke has been minimally investigated. We performed a cross-sectional analysis of lipid and Lp(a) concentrations in children with arterial ischemic stroke in the International Pediatric Stroke Study to compare the prevalence of dyslipidemia and high- or low-ranking lipid values in our dataset with reported population values. We analyzed sex, body mass index, race, ethnicity, family history, and stroke risk factors for associations with dyslipidemia, high non-high-density lipoprotein cholesterol, and hypertriglyceridemia. Compared with the National Health and Nutrition Examination Survey, a higher proportion of children ≥5 years with arterial ischemic stroke had dyslipidemia (38.4% versus 21%), high total cholesterol...
Midaortic syndrome (MAS) is a rare cause of severe childhood hypertension characterized by narrow... more Midaortic syndrome (MAS) is a rare cause of severe childhood hypertension characterized by narrowing of the abdominal aorta in children and is associated with extensive vascular disease. It may occur as part of a genetic syndrome, such as neurofibromatosis, or as consequence of a pathological inflammatory disease. However, most cases are considered idiopathic. We hypothesized that in a high percentage of these patients, a monogenic cause of disease may be detected by evaluating whole exome sequencing data for mutations in 1 of 38 candidate genes previously described to cause vasculopathy. We studied a cohort of 36 individuals from 35 different families with MAS by exome sequencing. In 15 of 35 families (42.9%), we detected likely causal dominant mutations. In 15 of 35 (42.9%) families with MAS, whole exome sequencing revealed a mutation in one of the genes previously associated with vascular disease (,,,, and). Ten of the 15 mutations have not previously been reported. This is the f...
This study aimed to describe children with moyamoya disease from an international multicenter str... more This study aimed to describe children with moyamoya disease from an international multicenter stroke database, and explore risk factors for stroke recurrence. We reviewed data of children >28-days old with moyamoya disease enrolled in the International Pediatric Stroke Study from January 2003 to March 2013. A total of 174 children from 32 sites and 14 countries had moyamoya disease; median age 7.4 years, 49% male. Of these, 90% presented with ischemic stroke, 7.5% with transient ischemic attack, and 2.5% with hemorrhagic stroke. One-third of patients had moyamoya syndrome. Stroke recurrence was 20% over median follow-up of 13 months; 9% had multiple recurrences. Children treated with surgical revascularization were less likely to have stroke recurrence ( P = .046). Moyamoya disease accounted for 8% of arterial strokes in this international pediatric stroke registry. One-third of pediatric patients with moyamoya disease have an underlying syndromic condition. Surgical revasculariz...
To provide consensus-based, suggested imaging protocols to facilitate the accurate and timely dia... more To provide consensus-based, suggested imaging protocols to facilitate the accurate and timely diagnosis of a neonate with symptoms concerning for stroke. The Writing Group, an international collaboration of pediatric neurologists and neuroradiologists with expertise in perinatal and childhood stroke, participated in a series of pediatric stroke neuroimaging symposia. These discussions, in conjunction with extensive literature review, led to a consensus for imaging protocols to guide practitioners in the diagnosis of neonatal stroke subtypes as defined by the National Institute of Neurological Disorders and Stroke Common Data Elements. The epidemiology, clinical presentation, and associated risk factors for arterial ischemic stroke, cerebral sinovenous thrombosis, and hemorrhagic stroke are reviewed, with a focused discussion regarding the role of neuroimaging for each subtype. In a neonate with suspected stroke, magnetic resonance imaging is the preferred modality, given the lack of...
The purpose of this article is to aid practitioners in choosing appropriate neuroimaging for chil... more The purpose of this article is to aid practitioners in choosing appropriate neuroimaging for children who present with symptoms that could be caused by stroke. The Writing Group members participated in one or more pediatric stroke neuroimaging symposiums hosted by the Stroke Imaging Laboratory for Children housed at the Hospital for Sick Children in Toronto, Ontario, Canada. Through collaboration, literature review, and discussion among child neurologists with expertise diagnosing and treating childhood stroke and pediatric neuroradiologists and neuroradiologists with expertise in pediatric neurovascular disease, suggested imaging protocols are presented for children with suspected stroke syndromes including arterial ischemic stroke, cerebral sinovenous thrombosis, and hemorrhagic stroke. This article presents information about the epidemiology and classification of childhood stroke with definitions based on the National Institutes of Health Common Data Elements. The role of imaging...
To investigate the long-term impact of early-term birth (37-38 weeks' gestation) relative to ... more To investigate the long-term impact of early-term birth (37-38 weeks' gestation) relative to full-term birth (≥39 weeks' gestation) on neurodevelopmental and psychiatric outcomes in adolescents with single-ventricle congenital heart disease (CHD). This cross-sectional cohort study analyzed retrospective medical records from full term adolescents with single-ventricle CHD who underwent the Fontan procedure. Participants underwent neurodevelopmental and psychiatric evaluations, as well as structural brain magnetic resonance imaging. Early-term born adolescents were compared with full-term born adolescents using regression models with adjustments for family social status, birth weight, and genetic abnormality status. Medical and demographic risk factors were examined as well. Compared with the full-term group (n = 100), adolescents born early term (n = 33) scored significantly worse on daily-life executive functions, as measured by the Behavior Rating Inventory of Executive Fun...
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