Cancer and Tumor-Associated Childhood Stroke: Results From the International Pediatric Stroke Study

Generative Pre-trained Transformer for Pediatric Stroke Research: A Pilot Study

BACKGROUND

Pediatric stroke is an important cause of morbidity in children. Although research can be challenging, large amounts of data have been captured through collaborative efforts in the International Pediatric Stroke Study (IPSS). This study explores the use of an advanced artificial intelligence program, the Generative Pre-trained Transformer (GPT), to enter pediatric stroke data into the IPSS.

METHODS

The most recent 50 clinical notes of patients with ischemic stroke or cerebral venous sinus thrombosis at the UTHealth Pediatric Stroke Clinic were deidentified. Domain-specific prompts were engineered for an offline artificial intelligence program (GPT) to answer IPSS questions. Responses from GPT were compared with the human rater. Percent agreement was assessed across 50 patients for each of the 114 queries developed from the IPSS database outcome questionnaire.

RESULTS

GPT demonstrated strong performance on several questions but showed variability overall. In its early iterations it was able to match human judgment occasionally with an accuracy score of 1.00 (n = 20, 17.5%), but it scored as low as 0.26 in some patients. Prompts were adjusted in four subsequent iterations to increase accuracy. In its fourth iteration, agreement was 93.6%, with a maximum agreement of 100% and minimum of 62%. Of 2400 individual items assessed, our model entered 2247 (93.6%) correctly and 153 (6.4%) incorrectly.

CONCLUSIONS

Although our tailored generative model with domain-specific prompt engineering and ontological guidance shows promise for research applications, further refinement is needed to enhance its accuracy. It cannot enter data entirely independently, but it can be employed in tandem with human oversight contributing to a collaborative approach that reduces overall effort.

Risk factors for pediatric ischemic stroke and intracranial hemorrhage: A national electronic health record based study

Background

Stroke is an important cause of morbidity in pediatrics. Large studies are needed to better understand the epidemiology, pathogenesis and risk factors associated with pediatric stroke. Large administrative datasets can provide information on risk factors in perinatal and childhood stroke at low cost. The aim of this hypothesis-generating study was to use a large administrative dataset to assess for prevalence and odds-ratios of rare exposures associated with pediatric stroke.

Methods

The data for patients aged 0-18 with a diagnosis of either ischemic stroke or intracranial hemorrhage were extracted from the Cerner Health Facts EMR Database from 2000 to 2018. Prevalence of various possible risk factors for pediatric and adult stroke was assessed using ICD 9 and 10 codes. Odds ratios were calculated using a control group of patients without stroke.

Results

10,688 children were identified with stroke. 6339 (59 %) were ischemic and 4349 (41 %) were hemorrhagic. The most frequently identified risk factors for ischemic stroke across age groups were hypertension (29-44 %), trauma (19-33 %), and malignancy (11-24 %). The most common risk factors seen with hemorrhagic stroke were trauma (32-64 %), malignancy (5-19 %) and arrhythmia (9-12 %). Odds ratios across all age groups for dyslipidemia (17-64), hypertension (20-63), and tobacco exposure (3-59) were high in the ischemic stroke cohort.

Conclusion

This is the largest retrospective study of pediatric stroke of its kind from hospitals across the US in both academic and non-academic clinical settings. Much of our data was consistent with prior studies. ICD codes for tobacco exposure, hyperlipidemia, diabetes, and hypertension all had high odds ratios for stroke in children, which suggest a relationship between these conditions and pediatric stroke. However, ascertainment bias is a major concern with electronic health record-based studies. More focused study is needed into the role of these exposures into the pathogenesis of pediatric stroke.

How do children fare compared with adults? Comparing relative outcomes after thrombectomy for acute ischemic stroke due to large-vessel occlusion

OBJECTIVE

Safety and efficacy data for endovascular thrombectomy for acute ischemic stroke secondary to large-vessel occlusion in children are lacking compared with those for adults. We undertook an updated systematic review and meta-analysis of endovascular thrombectomy in children and compared their outcomes with adult data.

METHODS

We searched PubMed, Medline, and EMBASE databases to identify prospective and retrospective studies describing patients <18 years treated with endovascular thrombectomy for acute ischemic stroke due to large-vessel occlusion.

RESULTS

Eight pediatric studies were included (n = 192). Most patients were male (53.1 %), experienced anterior circulation large-vessel occlusion (81.8 %), and underwent endovascular thrombectomy by stent retreiver (70.7 %). The primary outcome was change in National Institutes of Health Stroke Scale score from presentation to 24 h after thrombectomy. Secondary outcomes included modified Rankin scale score improvement and 90-day score, recanalization rates, procedural complications, and mortality rates. After treatment, 88.5% of children had successful recanalization; the mean National Institutes of Health Stroke Scale score reduction was 7.37 (95 % CI 5.11-9.63, p < 0.01). The mean reduction of 6.87 (95 %CI 5.00-8.73, p < 0.01) for adults in 5 clinical trials (n = 634) was similar (Qb = 0.11; p = 0.74). Children experienced higher rates of good neurological outcome (76.1 % vs. 46.0 %, p < 0.01) and revascularization (88.5 % vs. 72.3 %, p < 0.01), fewer major periprocedural complications (3.6 % vs. 30.4 %, p < 0.01), and lower mortality (1.0 % vs. 12.9 %, p < 0.01).

CONCLUSIONS

Endovascular thrombectomy may be safe and effective treatment for acute ischemic stroke due to large-vessel occlusion in children. The aggregated data demonstrated high rates of revascularization, favorable long-term neurological outcomes, and low complication rates.

Stroke in the Developing Brain: Neurophysiologic Implications of Stroke Timing, Location, and Comorbid Factors

BACKGROUND

Pediatric stroke, which is unique in that it represents a static insult to a developing brain, often leads to long-term neurological disability. Neuroplasticity in infants and children influences neurophysiologic recovery patterns after stroke; therefore outcomes depend on several factors including the timing and location of stroke and the presence of comorbid conditions.

METHODS

In this review, we discuss the unique implications of stroke occurring in the fetal, perinatal, and childhood/adolescent time periods. First, we highlight the impact of the developmental stage of the brain at the time of insult on the motor, sensory, cognitive, speech, and behavioral domains. Next, we consider the influence of location of stroke on the presence and severity of motor and nonmotor outcomes. Finally, we discuss the impact of associated conditions on long-term outcomes and risk for stroke recurrence.

RESULTS

Hemiparesis is common after stroke at any age, although the severity of impairment differs by age group. Risk of epilepsy is elevated in all age groups compared with those without stroke. Outcomes in other domains vary by age, although several studies suggest worse cognitive outcomes when stroke occurs in early childhood compared with fetal and later childhood epochs. Conditions such as congenital heart disease, sickle cell disease, and moyamoya increase the risk of stroke and leave patients differentially vulnerable to neurodevelopmental delay, stroke recurrence, silent infarcts, and cognitive impairment.

CONCLUSIONS

A comprehensive understanding of the interplay of various factors is essential in guiding the clinical care of patients with pediatric stroke.

Stroke in Pediatric Cancer Patients: A Systematic Review

OBJECTIVE

Pediatric cancer patients have an increased risk of stroke. However, there is a knowledge gap regarding stroke in early stages of pediatric cancer. The objective of this project is to describe the current knowledge on stroke in pediatric cancer patients.

DESIGN

Systematic review.

MATERIALS AND METHODS

After Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines, literature search was conducted in PubMed, Cochrane, and Google Scholar from January 1, 1995, up to February 1, 2022.

RESULTS

A total of 3499 studies were identified, of which 8 met inclusion criteria. The incidence of stroke in pediatric cancer patients varied between 0.47% and 2.9%, and prevalence between 1% and 3%. The risk factors identified were leukemia diagnosis, cranial radiation, thrombocytopenia, coagulopathy, and infection. There was a higher rate of diagnosis with magnetic resonance imaging than with computed tomography scan. Treatment was inconsistent, and patients with cancer were less likely to receive antithrombotic treatment when compared with patients without cancer. The highest mortality was among hemorrhagic stroke. Recurrence rate was 5% to 19%.

CONCLUSIONS

The risk for stroke is increased in the pediatric cancer population and can lead to devastating results. The available reports include few patients, with heterogeneous cancer diagnoses and outcomes. Large-scale multicenter studies are needed, focusing on early diagnosis, risk factors, and management strategies of stroke in children with underlying cancer.

Advances in the Diagnosis and Treatment of Pediatric Arterial Ischemic Stroke

Though rare, stroke in infants and children is an important cause of mortality and chronic morbidity in the pediatric population. Neuroimaging advances and implementation of pediatric stroke care protocols have led to the ability to rapidly diagnose stroke and in many cases determine the stroke etiology. Though data on efficacy of hyperacute therapies, such as intravenous thrombolysis and mechanical thrombectomy, in pediatric stroke are limited, feasibility and safety data are mounting and support careful consideration of these treatments for childhood stroke. Recent therapeutic advances allow for targeted stroke prevention efforts in high-risk conditions, such as moyamoya, sickle cell disease, cardiac disease, and genetic disorders. Despite these exciting advances, important knowledge gaps persist, including optimal dosing and type of thrombolytic agents, inclusion criteria for mechanical thrombectomy, the role of immunomodulatory therapies for focal cerebral arteriopathy, optimal long-term antithrombotic strategies, the role of patent foramen ovale closure in pediatric stroke, and optimal rehabilitation strategies after stroke of the developing brain.

Stroke in Middle Eastern children with cancer: prevalence and risk factors

Objective

To determine the prevalence and to characterize the different types of strokes in children with cancer at the Children’s Cancer Center of Lebanon (CCCL), in addition to assess the factors and clinical findings leading to stroke in children.

Methods

We retrospectively reviewed the medical records and brain images (MRIs and CTs) of children admitted to the CCCL and diagnosed with cancer between years 2008 and 2017. Brain images were reviewed for the strokes’ onset, size, location, possible origin, its recurrence and type: intracranial hemorrhage (ICH), acute arterial ischemic stroke, and cerebral sinus venous thrombosis (CSVT) with and without venous infarct. Medical charts of the patients were reviewed for age, sex, their type of cancer, the treatment protocol they followed, and abnormal findings on their laboratory studies and neurological exams.

Results

Out of the 905 charts reviewed, twenty-seven children with variable types of cancer had strokes, with a prevalence of 2.9%. Their median age at cancer diagnosis was 9.4 (4.8-13.7) years and the median age at stroke onset was 10.6 (6.7-15.5) years. The median time between the cancer diagnosis and the stroke episode was 6 months. CSVT cases were the most common (60%) followed by acute arterial ischemic (22%) and hemorrhagic strokes (18%), with CSVT being the latest to occur. We observed that the different types of strokes were related to some types of cancer. Of the children that had acute arterial ischemic stroke in this cohort, 83% had brain tumors, of the children who had CSVT, 87.5% had leukemia, and of the children who had hemorrhagic stroke, 40% had leukemia. Neurological abnormalities were more prevalent in acute arterial ischemic stroke (80%). Patients with CSVT recovered better than those with other types of strokes. Strokes recurred in 60% of ischemic strokes. L-Asparaginase was significantly associated with CSVT.

Conclusions

The prevalence of strokes was 2.9% in children with cancer. We were able to identify factors related to the types of the stroke that occurred in children including the type and location of the cancer the type of treatment received, and stroke recurrence.

Pediatric Stroke: Overview and Recent Updates

Stroke can occur at any age or stage in life. Although it is commonly thought of as a disease amongst the elderly, it is important to highlight the fact that it also affects infants and children. In both populations, strokes have a high rate of morbidity and mortality. Arguably, it is more detrimental in the pediatric population given the occurrence at a younger age and therefore, a longer duration of disability, potentially over the entire lifespan. The high rate of morbidity and mortality in pediatrics is attributed to significant delays in diagnosis, as well as misdiagnosis. Acute stroke management is time dependent. Patients who receive acute treatment with either intravenous (IV) tissue plasminogen activator (tPA) or mechanical thrombectomy, have improved mortality and functional outcomes. Additionally, the earlier treatment is initiated, the higher the likelihood of preserving penumbra, restoring cerebral blood flow and potentially reversing symptoms, thereby limiting disability. Prompt identification is essential as it leads to improved patient care in such a narrow therapeutic window. It enhances the care received during hospitalization and reduces the risk of early stroke recurrence. Despite limited data and lack of large randomized clinical trials in pediatrics, both IV tPA and mechanical thrombectomy have been successfully used. Bridging the gap of acute stroke management in the pediatric population is an essential part of minimizing adverse outcomes. In this review, we discuss the epidemiology of pediatric stroke, the diverse etiologies, presentation as well as both acute and preventative management.