Publications by authors named "Bernard Timothy"

Intracranial steno-occlusive large vessel arteriopathies refer to abnormalities of the arterial wall that typically express luminal stenosis. Notably, some entities that can find themselves within this category may also express luminal dilation, and/or aneurysm formation as an alternative phenotype. Intracranial steno-occlusive large vessel arteriopathies are a leading cause of arterial ischemic stroke (AIS) in children, often progress, and can predispose to recurrent brain infarction.

View Article and Find Full Text PDF
Article Synopsis
  • The VIPS II study explored the link between varicella zoster virus (VZV) and childhood arterial ischemic stroke (AIS), focusing on vaccinated populations in North America and Australia.
  • Among 205 children with AIS, 97% showed prior VZV exposure, mostly through vaccination, with a small percentage demonstrating recent VZV reactivation before their stroke.
  • The findings suggest that recent VZV reactivation might be a trigger for childhood strokes, even in vaccinated individuals and without visible symptoms.
View Article and Find Full Text PDF

Introduction: At our institution, revascularization after indirect moyamoya surgery is routinely evaluated using magnetic resonance angiography (MRA) rather than catheter angiography. In this paper, we review how revascularization can be visualized on axial MRA and compare its visualization on MRA to that on catheter angiography. We also compare clinical outcomes of patients followed with routine postoperative MRA with outcomes of patients followed with routine catheter angiography.

View Article and Find Full Text PDF

Moyamoya arteriopathy is a condition where chronic, progressive stenosis of large intracranial arteries, primarily of the anterior circulation, results in ischemia and the growth of small, abnormal collateral vessels. There is increasing evidence that infectious pathologies, such as COVID-19, may serve as a sort of trigger, or "second hit," for the development of moyamoya arteriopathy. In this article, we present the case of a 13-year-old female with Down syndrome and unilateral moyamoya arteriopathy who developed contralateral internal carotid artery (ICA) dissection and thrombus in the setting of a positive COVID-19 test and subsequently developed rapidly progressive contralateral ICA and bilateral anterior cerebral artery (ACA) moyamoya-like stenosis.

View Article and Find Full Text PDF

Childhood stroke occurs from birth to 18 years of age, ranks among the top ten childhood causes of death, and leaves lifelong neurological impairments. Arterial ischemic stroke in infancy and childhood occurs due to arterial occlusion in the brain, resulting in a focal lesion. Our understanding of mechanisms of injury and repair associated with focal injury in the developing brain remains rudimentary.

View Article and Find Full Text PDF
Article Synopsis
  • DADA2 is a recessive disease leading to issues like systemic vasculitis and early-onset stroke, affecting both kids and adults, with over 35,000 cases globally and no current management guidelines.
  • The DADA2 Consensus Committee, including patient representatives and experts from 18 countries, created 32 consensus statements to improve diagnostic testing, screening, and treatment based on patient symptoms.
  • Early diagnosis and treatment of DADA2 are crucial, and these consensus statements aim to provide a structured approach for doctors in evaluating and managing the disease.
View Article and Find Full Text PDF

Objective: There has been increasing utilization of genetic testing for pediatric epilepsy in recent years. Little systematic data is available examining how practice changes have impacted testing yields, diagnostic pace, incidence of variants of uncertain significance (VUSs), or therapeutic management.

Methods: A retrospective chart review was performed at Children's Hospital Colorado from February 2016 through February 2020.

View Article and Find Full Text PDF

Up to more than half of previously healthy children presenting with their first arterial ischemic stroke have a cerebral arteriopathy. Cerebral arteriopathies during childhood can be congenital, reflecting abnormal vessel development, or acquired when caused by disruption of vascular homeostasis. Distinguishing different types of cerebral arteriopathies in children can be challenging but of great clinical value as they may dictate different disease and treatment courses, and clinical and radiologic outcomes.

View Article and Find Full Text PDF

Younger stroke patients may suffer worse outcomes than older patients; however, the extent to which age at stroke impacts remote areas of the brain remains unclear. The objective of this study was to determine thalamic volume changes ipsilateral to middle cerebral artery territory strokes based on age at acute ischemic stroke onset. Acute ischemic stroke patients <9 years, 9-18 years, and >18 years old were retrospectively recruited from a large quaternary care system.

View Article and Find Full Text PDF
Article Synopsis
  • Data from early in the pandemic showed that 0.62% of children hospitalized with COVID-19 experienced an acute arterial ischemic stroke (AIS), and researchers wanted to see if this percentage remained stable over time.
  • They surveyed 61 centers in 21 countries to gather data on the incidence of AIS in children with SARS-CoV-2 from June to December 2020, assessing the role of COVID-19 as a stroke risk factor.
  • Findings indicated that the risk of AIS in pediatric COVID-19 patients decreased to 0.32%, with SARS-CoV-2 identified as the main risk factor in a small number of cases, while elevated inflammatory markers were prevalent in those affected.
View Article and Find Full Text PDF

Ionogels are good candidates for flexible electronics owing to their excellent mechanical and electrical properties, including stretchability, high conductivity, and stability. In this study, conducting ionogels comprising a double network (DN) of poly(N-isopropylacrylamide-co-N,N'-diethylacrylamide)/chitosan which are further reinforced by the ionic and covalent crosslinking of the chitosan network by tripolyphosphate and glutaraldehyde, respectively, are prepared. Based on their excellent mechanical properties and high conductivity, the developed DN ionogels are envisioned as stretchable ionic conductors for extremely stretchable alternating-current electroluminescent (ACEL) devices.

View Article and Find Full Text PDF

Objective: Severe complications of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) include arterial ischemic stroke (AIS) in adults and multisystem inflammatory syndrome in children. Whether stroke is a frequent complication of pediatric SARS-CoV-2 is unknown. This study aimed to determine the proportion of pediatric SARS-CoV-2 cases with ischemic stroke and the proportion of incident pediatric strokes with SARS-CoV-2 in the first 3 months of the pandemic in an international cohort.

View Article and Find Full Text PDF

Objective: To 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.

Methods: We 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- adjustment for multiple comparisons.

View Article and Find Full Text PDF
Article Synopsis
  • - The study aimed to identify factors that influence recovery and outcomes in children following arterial ischemic stroke, particularly focusing on the role of age.
  • - It analyzed data from 587 pediatric patients over a two-year period, finding that younger children (ages 28 days to 1 year) had worse outcomes and a higher likelihood of developing new deficits compared to infants and older children.
  • - Overall, while many children show favorable recovery after stroke, significant neurological impairments remain common, highlighting the need for targeted treatments and better family guidance based on age-related risks.
View Article and Find Full Text PDF

We conducted a retrospective cohort study of 160 hospitalized children admitted for acute complicated sinusitis and compared children with S anginosus-associated infection to children with other or no pathogens identified. The incidence of S anginosus-associated infections increased 12% per year, and infections with S anginosus are associated with increased morbidity.

View Article and Find Full Text PDF

Background: Like adults, most children have lifelong morbidity after stroke. Revascularization therapies such as intravenous tissue plasminogen activator and mechanical thrombectomy may be options to decrease this morbidity in selected children, although currently there are no evidence-based recommendations to guide treatment. The utility and safety of mechanical thrombectomy in childhood stroke is unknown because of the lack of safety trials, case-controlled trials, and comprehensive retrospective studies.

View Article and Find Full Text PDF

Purpose- Much has transpired since the last scientific statement on pediatric stroke was published 10 years ago. Although stroke has long been recognized as an adult health problem causing substantial morbidity and mortality, it is also an important cause of acquired brain injury in young patients, occurring most commonly in the neonate and throughout childhood. This scientific statement represents a synthesis of data and a consensus of the leading experts in childhood cardiovascular disease and stroke.

View Article and Find Full Text PDF

Purpose: Recent evidence suggests that recovery from secondary neurodegeneration following arterial ischemic stroke (AIS) may be related to age at injury and site of occlusion. We conducted a study of hippocampal volume (HCV) in a cohort of pediatric patients with middle cerebral artery (MCA) territory AIS to determine whether HCV would be preserved in younger children as compared to older children.

Methods: This single-center, HIPAA-compliant retrospective study was approved by the institutional review board.

View Article and Find Full Text PDF

Background and Purpose- Focal cerebral arteriopathy (FCA)-a common cause of arterial ischemic stroke in previously healthy children-often progresses over days to weeks, increasing the risk of recurrent stroke. We developed a novel severity scoring system designed to quantify FCA progression and correlate with clinical outcomes. Methods- The VIPS study (Vascular Effects of Infection in Pediatric Stroke) prospectively enrolled 355 children with arterial ischemic stroke (2010-2014), including 41 with centrally confirmed FCA.

View Article and Find Full Text PDF

Ionogels are crosslinked polymer networks that swell in ionic liquids (ILs) and exhibit high conductivity and chemical stability. Combined with a representative thermally responsive polymer, poly(N-isopropylacrylamide) (PNIPAm), previously studied ionogels fulfilled the requirements for smart responsive materials, but their transition temperature in hydrophobic ILs exceeded that which could be used for practical applications. In this study, we prepared transition temperature tunable ionogels via copolymerization of NIPAm with solvatophilic N,N'-diethylacrylamide (NDEAm).

View Article and Find Full Text PDF

The current study focuses on the ability to improve cognitive function after stroke with interventions administered at delayed/chronic time points. In light of recent studies demonstrating delayed GABA antagonists improve motor function, we utilized electrophysiology, biochemistry and neurobehavioral methods to investigate the role of α5 GABAA receptors on hippocampal plasticity and functional recovery following ischemic stroke. Male C57Bl/6 mice were exposed to 45 min transient middle cerebral artery occlusion and analysis of synaptic and functional deficits performed 7 or 30 days after recovery.

View Article and Find Full Text PDF

Background And Purpose: Childhood arterial ischemic stroke is frequently associated with an intracranial arteriopathy that often progresses in the first 3 to 6 months post stroke. We hypothesized that children with enhancing arteriopathies on vessel wall imaging (VWI) would have a higher risk of arteriopathy progression than those without enhancement.

Methods: Our institutional radiographic database was searched for cases of childhood stroke with VWI.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF