Spontaneous intracranial haemorrhage in children: aetiology, presentation and outcome

Electrographic Seizures and Predictors of Epilepsy after Pediatric Arteriovenous Malformation Rupture

OBJECTIVE

To assess clinical and electroencephalogram (EEG) predictors of epilepsy and to describe the percentage of electrographic seizures (ES) and development of epilepsy among patients with spontaneous intracerebral hemorrhage (ICH) due to arteriovenous malformation (AVM) rupture.

STUDY DESIGN

Retrospective review of patients admitted to the pediatric intensive care unit with ICH secondary to AVM rupture over 11 years. Clinical variables were collected by review of the electronic medical record. Seizures were described as acute symptomatic (7 days after AVM rupture), subacute (7-30 days after AVM rupture) and remote (greater than 30 days after AVM rupture). Outcome metrics included mortality, and the development of epilepsy post discharge. Descriptive statistics were used.

RESULTS

Forty-three patients met inclusion criteria with a median age of 12.2 years (IQR 7.3-14.8) and 49% (21/43) were female. Sixteen percent (7/43) presented with a clinical seizure prior to EEG placement. EEG was performed in 62% (27/43) of patients; one had electrographic status epilepticus without clinical signs. Sixteen percent (7/43) of patients were diagnosed with epilepsy, with a median time to diagnosis of 1.34 years (IQR 0.55-2.07) after AVM rupture. One-year epilepsy free survival was 84% (95% CI 70%-98%) and two-year epilepsy free survival was 79% (95% CI 63%-95%) Remote seizures were associated with epilepsy (p<0.001), but acute symptomatic seizures were not (p=0.16).

CONCLUSIONS

EEG-confirmed seizures are uncommon in patients with ICH secondary to AVM rupture; however when identified, the seizure burden appears to be high. Patients with seizures 30 days after AVM rupture are more likely to develop epilepsy.

Endovascular Treatment of Brain Arteriovenous Malformations in Pediatric Patients: A Single Center Experience and Review of the Literature

BACKGROUND

 Brain arteriovenous malformations (bAVMs) are abnormal vascular connections with direct arteriovenous shunts, generally symptomatic in the adult life. However, a small number of bAVMs may manifest in pediatric patients, with higher bleeding risk and mortality rates when compared to adults. The purpose of this study is to review our experience with endovascular treatment of bAVMs in pediatric patients.

METHODS

 This is a retrospective analysis of all bAVMs in pediatric patients (0-18 years) who underwent diagnostic digital subtraction angiography (DSA) at our institution from January 2010 to June 2021.

RESULTS

 Twenty-six patients met the inclusion criteria, of which 12 underwent endovascular treatment. Treated patients had a mean age of 10.25 years and 58% were females. Complete angiographic exclusion was achieved in five (42%) patients with endovascular treatment. Five patients with residual bAVM after embolization needed adjuvant therapy with surgery (n = 3) or stereotactic radiosurgery (SRS; n = 2). Two patients are still undergoing embolization sessions. Procedure-related complications occurred in two patients (17%) and included small vessel perforation and an occipital ischemic stroke. Two patients showed bAVM recurrence on follow-up (17%) and subsequently underwent SRS (n = 1) or surgery (n = 1), both resulting in complete bAVM exclusion. All patients had a modified Rankin scale (mRS) score of 0 to 2 on follow-up.

CONCLUSION

 Our experience supports the effectiveness and safety of endovascular treatment of bAVM in selected pediatric patients. A multidisciplinary approach combining surgery and SRS is warranted to achieve higher complete bAVM obliteration rates. Long-term follow-up is important as these lesions may show recurrence over time, especially in the pediatric population.

Inhibition of endothelial histone deacetylase 2 shifts endothelial-mesenchymal transitions in cerebral arteriovenous malformation models

Cerebral arteriovenous malformations (AVMs) are the most common vascular malformations worldwide and the leading cause of hemorrhagic strokes that may result in crippling neurological deficits. Here, using recently generated mouse models, we uncovered that cerebral endothelial cells (ECs) acquired mesenchymal markers and caused vascular malformations. Interestingly, we found that limiting endothelial histone deacetylase 2 (HDAC2) prevented cerebral ECs from undergoing mesenchymal differentiation and reduced cerebral AVMs. We found that endothelial expression of HDAC2 and enhancer of zeste homolog 1 (EZH1) was altered in cerebral AVMs. These alterations changed the abundance of H4K8ac and H3K27me in the genes regulating endothelial and mesenchymal differentiation, which caused the ECs to acquire mesenchymal characteristics and form AVMs. This investigation demonstrated that the induction of HDAC2 altered specific histone modifications, which resulted in mesenchymal characteristics in the ECs and cerebral AVMs. The results provide insight into the epigenetic impact on AVMs.

Hypofractionated stereotactic radiotherapy in Spetzler Martin grades 4 and 5 arteriovenous malformations in the pediatric population: Is it a viable alternative?

OBJECTIVE

To analyze the outcomes of hypofractionated stereotactic radiotherapy (HFSRT) for Spetzler Martin grades 4 and 5 arteriovenous malformations (AVMs) in a pediatric population.

METHODS

Fourteen patients with Spetzler Martin (SM) grades IV and V large AVMs who underwent HFSRT between January 2013 and July 2019 were retrospectively reviewed. All patients received HFSRT at a dose of 30-36 Gy in 5 to 6 fractions. They were followed up annually with clinical and imaging assessments to evaluate obliteration rates.

RESULTS

The median age at presentation was 15 years (range 8-21 years). Ten (71%) were SM grade 4 AVMs and the rest were SM grade 5 AVMs. The majority presented with headache (8 [57%]), and 3 (21%) presented with bleeding. The median nidus volume was 39.4 cc (IQR, 31.4-52.4). Two (14%) patients had infratentorial AVMs. All of them had deep venous drainage. The median clinical follow-up duration was 75 months (range 31-107 months). There was complete obliteration of the nidus in 3 (21%) patients with a median time to obliteration of 39 months. HFSRT resulted in a reduction of the AVM volume to 12 cc or less in nearly 70% of patients. None of the patients experienced re-bleeding. 79% reported an improvement in their symptoms.

CONCLUSION

HFSRT is a highly effective treatment for high-grade AVMs in children, which can result in either complete elimination or significant reduction of the nidus volume or make it suitable for additional treatment, such as single-session stereotactic radiosurgery (SRS).

Treatment of Brain Arteriovenous Malformations

Brain arteriovenous malformations (AVMs) are a rare entity of vascular anomalies, characteristic of anatomical shunting where arterial blood directly flows into the venous circulation. The main aim of the active treatment policy of brain AVMs is the prevention of haemorrhage. There are well-established treatment strategies that continually improve in their safety and efficacy, primarily due to the advances in imaging modalities, targeted and novel techniques, the development of alternative treatment approaches, and even better experience with the disease itself. There are interesting imaging novelties that may be prospectively applicable in the decision-making and planning of the most effective treatment approach for individual patients with intracranial AVM. Surgery is often considered the first-line treatment; however, each patient should be evaluated individually, and the risks of the active treatment policy should not overcome the benefits of the spontaneous natural history of the disease. All treatment modalities, i.e., surgery, radiosurgery, endovascular embolization, and observation, are justified but need to be meticulously selected for each individual patient in order to deliver the best treatment outcome. This chapter deals with historical and currently applied dogmas, followed by introductions of advances in each available treatment modality of AVM management.

Epidemiology, causes, and morbidities of stroke in the young

PURPOSE OF REVIEW

The purpose is to describe the latest research on epidemiology, causes, and morbidities of stroke in neonates and children.

RECENT FINDINGS

The global incidence of childhood stroke is approximately 2 per 100 000 person-years, which is significantly lower compared to neonates (20-40 per 100 000 live births) and adults (80-90 per 100 000 person-years). Placental abnormalities are a risk factor for perinatal stroke, although cause is usually multifactorial. In children, nonatherosclerotic arteriopathies and arteriovenous malformations are major causes of ischemic and hemorrhagic strokes, respectively. The perinatal period confers a high risk of stroke and can lead to long-term disability, including motor delay, cognitive or speech impairment, and epilepsy. Recent studies suggest that at least 50% of survivors of perinatal stroke have abnormal neurodevelopmental scores in long-term follow up. Childhood stroke is associated with significant morbidity, including epilepsy, motor impairments, and behavioral disability. Recent studies have also identified an association between pediatric stroke and behavioral disorders, such as attention deficit hyperactivity disorder and autism.

SUMMARY

Perinatal and childhood strokes are important causes of neurological morbidity. Given the low incidence of childhood stroke, prospective research studies on epidemiology, causes, and outcomes remain limited, highlighting the need for continued multisite collaborations.

The Role and Therapeutic Implications of Inflammation in the Pathogenesis of Brain Arteriovenous Malformations

Brain arteriovenous malformations (bAVMs) are focal vascular lesions composed of abnormal vascular channels without an intervening capillary network. As a result, high-pressure arterial blood shunts directly into the venous outflow system. These high-flow, low-resistance shunts are composed of dilated, tortuous, and fragile vessels, which are prone to rupture. BAVMs are a leading cause of hemorrhagic stroke in children and young adults. Current treatments for bAVMs are limited to surgery, embolization, and radiosurgery, although even these options are not viable for ~20% of AVM patients due to excessive risk. Critically, inflammation has been suggested to contribute to lesion progression. Here we summarize the current literature discussing the role of the immune system in bAVM pathogenesis and lesion progression, as well as the potential for targeting inflammation to prevent bAVM rupture and intracranial hemorrhage. We conclude by proposing that a dysfunctional endothelium, which harbors the somatic mutations that have been shown to give rise to sporadic bAVMs, may drive disease development and progression by altering the immune status of the brain.

Cases of acute hemiparesis in childhood

INTRODUCTION

Acute hemiparesis is an emergency of various etiologies and possible fatal outcome.

Neuromonitoring in Children with Cerebrovascular Disorders

BACKGROUND

Cerebrovascular disorders are an important cause of morbidity and mortality in children. The acute care of a child with an ischemic or hemorrhagic stroke or cerebral sinus venous thrombosis focuses on stabilizing the patient, determining the cause of the insult, and preventing secondary injury. Here, we review the use of both invasive and noninvasive neuromonitoring modalities in the care of pediatric patients with arterial ischemic stroke, nontraumatic intracranial hemorrhage, and cerebral sinus venous thrombosis.

METHODS

Narrative review of the literature on neuromonitoring in children with cerebrovascular disorders.

RESULTS

Neuroimaging, near-infrared spectroscopy, transcranial Doppler ultrasonography, continuous and quantitative electroencephalography, invasive intracranial pressure monitoring, and multimodal neuromonitoring may augment the acute care of children with cerebrovascular disorders. Neuromonitoring can play an essential role in the early identification of evolving injury in the aftermath of arterial ischemic stroke, intracranial hemorrhage, or sinus venous thrombosis, including recurrent infarction or infarct expansion, new or recurrent hemorrhage, vasospasm and delayed cerebral ischemia, status epilepticus, and intracranial hypertension, among others, and this, is turn, can facilitate real-time adjustments to treatment plans.

CONCLUSIONS

Our understanding of pediatric cerebrovascular disorders has increased dramatically over the past several years, in part due to advances in the neuromonitoring modalities that allow us to better understand these conditions. We are now poised, as a field, to take advantage of advances in neuromonitoring capabilities to determine how best to manage and treat acute cerebrovascular disorders in children.

Quantitative evaluation of the hemodynamic differences between ruptured and unruptured cerebral arteriovenous malformations using angiographic parametric imaging-derived radiomics features

PURPOSE

Imaging features of cerebral arteriovenous malformations (AVMs) are mainly interpreted according to demographic and qualitative anatomical characteristics. This study aimed to use angiographic parametric imaging (API)-derived radiomics features to explore whether these features extracted from digital subtraction angiography (DSA) were associated with the hemorrhagic presentation of AVMs.

METHODS

Patients with AVM were retrospectively evaluated. Among them, 80% were randomly assigned to a training dataset, and the remaining 20% were assigned to an independent test dataset. Radiomics features were extracted from DSA by API. Then, informative features were selected from radiomics features and clinical features using the Least Absolute Shrinkage and Selection Operator (LASSO) algorithm. A model was constructed based on the selected features to classify the dichotomous hemorrhagic presentation in the training dataset. The model performance was evaluated in the test dataset with confusion matrix-related metrics.

RESULTS

A total of 529 consecutive patients with AVMs between July 2011 and December 2020 were included in this study. After being selected by the LASSO algorithm and analyzed by multivariable logistic regression, three clinical features, namely, age (p = 0.01), nidus size (p < 0.001), and venous drainage patterns (p < 0.001), and four radiomics features were used to construct a model in the training dataset. On the independent test dataset, the model demonstrated a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 0.852, 0.844, 0.881, 0.809, and 0.849, respectively.

CONCLUSION

The radiomics features extracted from DSA by API could be potential indicators for the hemorrhagic presentation of AVMs.

Clinical features and outcome in pediatric arteriovenous malformation: institutional multimodality treatment

PURPOSE

Intracranial arteriovenous-malformation (AVM) is a relatively rare condition in pediatrics, yet is a major cause of spontaneous intracranial hemorrhage with a risk of fatal hemorrhage reported to be between 4 and 29%. Little is known about vessel morphology and optimum treatment modalities including multimodality combination therapy and prognosis in children.

METHODS

A retrospective review of all children presenting to our institution from 2006 to 2020 that had an AVM was undertaken.

RESULTS

A total of 50 children were identified with median age of 11 (range 1-16) years. The mean follow-up was 7.6 years. Forty-one children presented as an emergency and of those, 40 had hemorrhage identified on initial brain imaging. The average nidus size was 25 mm, drainage was superficial in 51% of cases, and located in eloquent cortex in 56%. The supplemental Spetzler-Martin grading indicated 78% (39/50) were grade 4 and above (moderate to high risk). Primary treatment modalities included embolization in 50% (25) or SRS in 30% (15) and surgery in 20% (10).The AVM was obliterated on follow-up DSA in 66% children. Three children had post-treatment hemorrhage, two related to embolization and one the day following SRS, giving a re-bleed rate of 6%. The GOSE was available for 32 children at long term follow and 94% had a good outcome (GOSE 5-8). Two children died due to acute hemorrhage (4%).

CONCLUSION

The majority of children with AVM present with hemorrhage. The rebleed rate during definitive treatment is low at 6% over the study period. The selective use of the 3 modalities of treatment has significantly reduced mortality and severe disability.

Natural history and treatment of deep-seated brain arteriovenous malformations in pediatric patients

OBJECTIVE

Pediatric deep brain arteriovenous malformations (bAVMs) represent a unique management challenge given their higher cumulative risk of hemorrhage as well as a higher risk of treatment. Better understanding of hemorrhage risk in this patient population will lead to a better decision-making process for patient management.

METHODS

The authors retrospectively reviewed their institutional bAVM database from 1990 to 2019 and included patients younger than 21 years who had deep-seated bAVMs. They present the annual hemorrhage risk, during the natural history and after treatment, and functional outcomes.

RESULTS

Thirty-one pediatric patients were included in this study (13 males and 18 females) with a mean age of 11.8 (SD 4.4) years. The most frequent presenting symptoms were headache (54.8%), weakness (38.7%), and seizure (22.6%). The mean follow-up duration was 13.14 (SD 12.5) years, during which 7 (22.6%) AVMs were obliterated, 10 (32.3%) individuals experienced hemorrhage, and the modified Rankin Scale score worsened in 8 (25.8%) patients. The annual natural history risk of hemorrhage was 3.24% per patient, and the overall annual hemorrhage risk after treatment was 1.98% per patient. In particular, the risk was reduced to 0.64% per patient in the stereotactic radiosurgery (SRS) group. Non-White race showed a trend of higher rupture at presentation (OR 5 [95% CI 0.84-41.68], p = 0.09). Female sex was associated with higher odds (OR 13.076 [95% CI 1.424-333.591], p = 0.048) and SRS was associated with lower odds (OR 0.122 [95% CI 0.011-0.862], p = 0.049) of follow-up hemorrhage.

CONCLUSIONS

Given the substantial cumulative risk of lifelong hemorrhagic stroke in pediatric patients, timely definitive treatment is warranted. SRS may be beneficial when the risk-benefit profile is deemed acceptable.

Hemorrhagic stroke: Uncommon complication of diabetic ketoacidosis in pediatric patients

Diabetic ketoacidosis (DKA) is a well-known complication of type 1 diabetes mellitus. Diabetic ketoacidosis predisposes patients into devastating neurological complications. The most common neurologic complication is cerebral edema. Stroke either ischemic or hemorrhagic are uncommon complications of DKA with worse patient's outcome. Hemorrhagic stroke can manifest as subarachnoid or intraparenchymal hemorrhage. We present a 14-year-girl presented with DKA and complicated with both subarachnoid and intraparenchymal hemorrhages. Owing to early diagnosis and prompt treatment the patient had good outcome.

New aneurysm formation and regrowth associated with rebleeding of residual pediatric ruptured arteriovenous malformation: patient series

BACKGROUND

If complete obliteration of ruptured pediatric arteriovenous malformation (AVM) cannot be achieved, the appropriate follow-up duration and predictors of rebleeding remain unknown.

OBSERVATIONS

Pediatric patients with ruptured AVMs admitted to the authors' hospital within the past 30 years were evaluated. Rebleeding was confirmed in two patients. The first patient was a 5-year-old boy who experienced right thalamic hemorrhage. AVM was found in the bilateral thalamus and treated with stereotactic radiosurgery (SRS). New aneurysm formation and residual AVM regrowth were confirmed 21 years after the SRS. Eight months later, rebleeding occurred. The second patient was a 5-year-old boy who underwent removal of a left cerebellar hemorrhage and AVM. The residual AVM was treated with SRS. Residual AVM regrowth was detected at 6 years 7 months after SRS. Five months later, new aneurysm formation was confirmed. Two additional days later, rebleeding occurred.

LESSONS

New aneurysm formation and residual AVM regrowth may predict rebleeding and can occur >20 years after the initial rupture and treatment. If AVM obliteration is not achieved, long-term follow-up is needed, even in adulthood, with attention to new aneurysm formation and residual AVM regrowth. Further treatment is recommended if these findings are confirmed.

Closing the Gap in Pediatric Hemorrhagic Stroke: A Systematic Review

Pediatric hemorrhagic stroke (HS) accounts for a large proportion of childhood strokes, 1 of the top 10 causes of pediatric deaths. Morbidity and mortality lead to significant socio-economic and psychosocial burdens. To understand published data on recognizing and managing children with HS, we conducted a systematic review of the literature presented here. We searched PubMed, Embase, CINAHL and the Cochrane Library databases limited to English language and included 174 studies, most conducted in the USA (52%). Terminology used interchangeably for HS included intraparenchymal/intracranial hemorrhage, spontaneous ICH, and cerebrovascular accident (CVA). Key assessments informing prognosis and management included clinical scoring (Glasgow coma scale), and neuroimaging. HS etiologies reported were systemic coagulopathy (genetic, acquired pathologic, or iatrogenic), or focal cerebrovascular lesions (brain arteriovenous malformations, cavernous malformations, aneurysms, or tumor vascularity). Several scales were used to measure outcome: Glasgow outcome score (GOS), Kings outcome score for head injury (KOSCHI), modified Rankin scale (mRS) and pediatric stroke outcome measure (PSOM). Most studies described treatments of at-risk lesions. Few studies described neurocritical care management including raised ICP, seizures, vasospasm, or blood pressure. Predictors of poor outcome included ethnicity, comorbidity, location of bleed, and hematoma &gt;2% of total brain volume. Motor and cognitive outcomes followed independent patterns. Few studies reported on cognitive outcomes, rehabilitation, and transition of care models. Interdisciplinary approach to managing HS is urgently needed, informed by larger cohort studies targeting key clinical question (eg development of a field-guide for the clinician managing patients with HS that is reproducible internationally).

Long-term health-related quality of life in patients with ruptured arteriovenous malformations treated in childhood

OBJECTIVE

The aim of this study was to reveal the long-term health-related quality of life (HRQOL), educational level, and impact on occupation in 55 patients who experienced ruptured brain arteriovenous malformations (AVMs) that were treated during childhood.

METHODS

In 2016, questionnaires including the 15D instrument were sent to all living patients older than 18 years (n = 432) in the Helsinki AVM database. The cohort was further specified to include only patients with ruptured AVMs who were younger than 20 years at the time of diagnosis (n = 55). Educational level was compared with the age-matched general population of Finland. The mean 15D scores were calculated for independent variables (Spetzler-Ponce classification, admission age, symptomatic epilepsy, and multiple bleeding episodes) and tested using the independent-samples t-test or ANCOVA. Linear regression was used to create a multivariate model. Bonferroni correction was used with multiple comparisons.

RESULTS

The mean follow-up time from diagnosis to survey was 24.2 (SD 14.7) years. The difference in the mean 15D scores between Spetzler-Ponce classes did not reach statistical significance. The youngest age group (< 10 years at the time of diagnosis) performed less well on the dimension of usual activities than the older patients. Symptomatic epilepsy significantly reduced the long-term HRQOL. Multiple hemorrhages significantly reduced the scores on three dimensions: mobility, speech, and sexual activity. In the regression model, symptomatic epilepsy was the only significant predictor for a lower 15D score. The educational level of the cohort was for the most part comparable to that of the general population in the same age group. AVM was the reason for early retirement in 11% of the patients, while lowered performance because of the AVM was reported by 37% of the patients.

CONCLUSIONS

Patients with ruptured AVMs treated in childhood can live an independent and meaningful life, even in the case of the highest-grade lesions. Symptomatic epilepsy significantly reduced the long-term HRQOL, highlighting the need for continuing support for these patients.

Comparison of Arterial Ischemic and Hemorrhagic Pediatric Stroke in Etiology, Risk Factors, Clinical Manifestations, and Prognosis

BACKGROUND

Stroke is relatively rare in children but has a significant impact on long-term morbidity and mortality. There are limited data regarding the etiology, clinical manifestation, and prognosis of arterial ischemic stroke (AIS) and hemorrhagic stroke (HS) in children.

OBJECTIVE

The aim of this study is to identify and compare etiology, risk factors, clinical manifestations, and prognostic outcomes between arterial ischemic and hemorrhagic pediatric stroke.

METHODS

We retrospectively reviewed all hospital medical records and pediatric neurology database of 83 children who were first diagnosed with AIS and HS at the Pediatric Department, Chiang Mai University Hospital, Chiang Mai, Thailand between January 1, 2009, and December 31, 2018. All children were from 1 month to 18 years old.

RESULTS

Fifty-one AIS (56%) and 32 (35.2%) HS were identified. The median age of onset was 6.9 years for AIS and 5.3 years for HS. Moyamoya disease/syndrome was the most common cause in AIS (21.6%). Rupture of cerebral arteriovenous malformation was the most common cause in HS (21.9%). More than one-third (39%) of children had multiple risk factors associated with stroke. Iron deficiency anemia was commonly found in children with AIS (39.2%). The majority of clinical presentations were hemiparesis (80.4%) for AIS and alteration of consciousness (68.8%) for HS. The median time to diagnosis exceeded 6 hours in both AIS and HS. The overall mortality rate of acute stroke was 5.1 per 100 person-years (95% confidence interval [CI], 2.9-9). The mortality rate was higher in HS compared with that in AIS with statistical significance (16.6; 95% CI, 8.9-30.8 vs 1.1%; 95% CI, 0.3-4.6 per 100 person-years). Thirty children (36.1%) developed epilepsy during the follow-up (median duration, 26 months). Recurrent stroke occurred in 1 child with AIS and 1 child with HS.

CONCLUSIONS

Moyamoya disease/syndrome and arteriovenous malformation rapture are the most common cause of AIS and HS, respectively. Iron deficiency anemia was commonly found in childhood AIS. The time to diagnosis in both AIS and HS was delayed. The mortality rate in HS was higher than in AIS. Neurological deficits are seen in 70% of childhood AIS during the follow-up. One-third of the children in our study developed epilepsy, which generally responds to a single antiseizure medication. The recurrence rate of childhood stroke was low compared with adult stroke.

Delayed recurrence of pediatric arteriovenous malformations after radiologically confirmed obliteration

OBJECTIVE

Arteriovenous malformations (AVMs) are a major cause of intracerebral hemorrhage in children, resulting in significant morbidity and mortality. Moreover, the rate of AVM recurrence in children is significantly higher than in adults. The aim of this study was to define the risk of delayed pediatric AVM (pAVM) recurrence following confirmed radiological obliteration. Further understanding of this risk could inform the role of long-term radiological surveillance.

METHODS

The authors conducted a retrospective review of ruptured and unruptured pAVM cases treated at a single tertiary care referral center between 1994 and 2019. Demographics, clinical characteristics, treatment modalities, and AVM recurrence were analyzed.

RESULTS

A total of 102 pediatric patients with intracranial AVMs, including 52 (51%) ruptured cases, were identified. The mean patient age at presentation was 11.2 ± 4.4 years, and 51 (50%) patients were female. The mean nidus size was 2.66 ± 1.44 cm. The most common Spetzler-Martin grades were III (32%) and II (31%). Stereotactic radiosurgery was performed in 69.6% of patients. AVM obliteration was radiologically confirmed in 68 (72.3%) of 94 patients with follow-up imaging, on angiography in 50 (73.5%) patients and on magnetic resonance imaging in 18 (26.5%). AVM recurrence was identified in 1 (2.3%) of 43 patients with long-term surveillance imaging over a mean follow-up of 54.7 ± 38.9 months (range 2-153 months). This recurrence was identified in a boy who had presented with a ruptured AVM and had been surgically treated at 5 years of age. The AVM recurred 54 months after confirmed obliteration on surveillance digital subtraction angiography. Two other cases of presumed AVM recurrence following resection in young children were excluded from recurrence analysis because of incomplete sets of imaging available for review.

CONCLUSIONS

AVM recurrence following confirmed obliteration on imaging is a rare phenomenon, though it occurs more frequently in the pediatric population. Regular long-term follow-up with dedicated surveillance angiography is recommended even after obliteration following resection.

Causes and Risk Factors of Pediatric Spontaneous Intracranial Hemorrhage—A Systematic Review

Previous studies suggest that the most common cause of spontaneous intracerebral hemorrhage in children and adolescents is arteriovenous malformations (AVMs). However, an update containing recently published data on pediatric spontaneous intracranial hemorrhages is lacking. The aim of this study is to systematically analyze the published data on the etiologies and risk factors of pediatric spontaneous intracranial hemorrhage. This systematic review was performed in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A search in PubMed, Embase, Scopus, Web of Science and Cochrane Library was conducted aiming for articles published in year 2000 and later, containing data on etiology and risk factors of spontaneous intracranial hemorrhages in unselected cohorts of patients aged between 1 month and 18 years. As a result, forty studies were eligible for data extraction and final analysis. These included 7931 children and adolescents with 4009 reported etiologies and risk factors. A marked variety of reported etiologies and risk factors among studies was observed. Vascular etiologies were the most frequently reported cause of pediatric spontaneous intracranial hemorrhages (n = 1727, 43.08% of all identified etiologies or risk factors), with AVMs being the most common vascular cause (n = 1226, 70.99% of all vascular causes). Hematological and systemic causes, brain tumors, intracranial infections and cardiac causes were less commonly encountered risk factors and etiologies.

Pediatric intracranial calcified arteriovenous malformation: A case report

Background:

Brain arteriovenous malformations (AVMs) are intracranial lesions that consist of a complex tangle of abnormal blood vessels. They can occasionally become hard and calcified. This may render these lesions difficult to resect and lead to neurological complications. There are very few reported cases of calcified brain AVMs in the literature.

Case Description:

We report the case of an 11-year-old patient who presented with headaches and seizures exacerbated in the past 3 months. Preoperative imaging confirmed a large, right parasagittal AVM, with significant internal calcifications seen on the computed tomography angiogram. We performed a successful microsurgical resection of the calcified AVM and confirmed the diagnosis on histopathological analysis.

Conclusion:

Dense internal calcifications within AVMs are a clinical rarity and can be challenging cases for microsurgical resection.

Cerebral vasospasm in children with subarachnoid hemorrhage: frequency, diagnosis, and therapeutic management

BACKGROUND

The present study explores the frequency, diagnostic approach, and therapeutic management of cerebral vasospasm in a cohort of children with moderate-to-severe traumatic and nontraumatic subarachnoid hemorrhage (SAH).

METHODS

This was a single-center retrospective study performed over a 10-year period, from January 2010 to December 2019. Children aged from one month to 18 years who were admitted to the pediatric or adult intensive care unit with a diagnosis of SAH were eligible. Cerebral vasospasm could be suspected by clinical signs or transcranial Doppler (TCD) criteria (mean blood flow velocity > 120 cm/s or an increase in mean blood flow velocity by > 50 cm/s within 24 h) and then confirmed on cerebral imaging (with a reduction to less than 50% of the caliber of the cerebral artery).

RESULTS

Eighty patients aged 8.6 years (3.3-14.8 years, 25-75th centiles) were admitted with an initial Glasgow Coma Scale score of 8 (4-12). SAH was nontraumatic in 21 (26%) patients. A total of 14/80 patients (18%) developed cerebral vasospasm on brain imaging on day 6 (5-10) after admission, with a predominance of nontraumatic SAH (12/14). The diagnosis of cerebral vasospasm was suspected on clinical signs and/or significant temporal changes in TCD monitoring (7 patients) and then confirmed on cerebral imaging. Thirteen of 14 patients with vasospasm were successfully treated using a continuous intravenous infusion of milrinone. The Pediatric Cerebral Performance Category score at discharge from the intensive care unit was comparable between children with vasospasm (score of 2 [1-4]) vs. children without vasospasm (score of 4 [2-4]) (p = 0.09).

CONCLUSIONS

These findings indicate that cerebral vasospasm exists in pediatrics, particularly after nontraumatic SAH. The use of TCD and milrinone may help in the diagnostic and therapeutic management of cerebral vasospasm.

Management and Outcome of Traumatic Intracerebral Hemorrhage in 79 Infants and Children from a Single Level 1 Trauma Center

OBJECTIVE

Traumatic brain injury is a leading form of pediatric trauma and a frequent cause of mortality and acquired neurological impairment in children. The aim of this study was to present the severity and outcomes of traumatic intracerebral bleeding in children and adolescence.

METHODS

Seventy-nine infants and children with intracerebral bleedings were treated between 1992 and 2020 at a single level 1 trauma center. Data regarding accident, treatment and outcomes were collected retrospectively. The Glasgow Outcome Scale was used to classify the outcome at hospital discharge and at follow-up visits. CT scans of the brain were classified according to the Rotterdam score.

RESULTS

In total, 41 (52%) patients with intracerebral bleedings were treated surgically, and 38 (48%) patients were treated conservatively; in 15% of the included patients, delayed surgery was necessary. Patients presenting multiple trauma (p < 0.04), higher ISS (p < 0.01), poor initial neurological status (p < 0.001) and a higher Rotterdamscore (p = 0.038) were significantly more often treated surgically. Eighty-three percent of patients were able to leave the hospital, and out of these patients, about 60% showed good recovery at the latest follow-up visit. Overall, 11 patients (14%) died.

CONCLUSION

The findings in this study verified intracerebral bleeding as a rare but serious condition. Patients presenting with multiple traumas, higher initial ISS, poor initial neurological status and a higher Rotterdamscore were more likely treated by surgery.

TRIAL REGISTRATION

(researchregistry 2686).

The Evolution of Safe and Effective Coaguligands for Vascular Targeting and Precision Thrombosis of Solid Tumors and Vascular Malformations

In cardiovascular and cerebrovascular biology, control of thrombosis and the coagulation cascade in ischemic stroke, myocardial infarction, and other coagulopathies is the focus of significant research around the world. Ischemic stroke remains one of the largest causes of death and disability in developed countries. Preventing thrombosis and protecting vessel patency is the primary goal. However, utilization of the body’s natural coagulation cascades as an approach for targeted destruction of abnormal, disease-associated vessels and tissues has been increasing over the last 30 years. This vascular targeting approach, often termed “vascular infarction”, describes the deliberate, targeted delivery of a thrombogenic effector to diseased blood vessels with the aim to induce localized activation of the coagulation cascade and stable thrombus formation, leading to vessel occlusion and ablation. As systemic delivery of pro-thrombotic agents may cause consternation amongst traditional stroke researchers, proponents of the approach must suitably establish both efficacy and safety to take this field forward. In this review, we describe the evolution of this field and, with a focus on thrombogenic effectors, summarize the current literature with respect to emerging trends in “coaguligand” development, in targeted tumor vessel destruction, and in expansion of the approach to the treatment of brain vascular malformations.

Mortality and functional outcome after pediatric intracerebral hemorrhage: cohort study and meta-analysis

OBJECTIVE

The clinical outcome of pediatric intracerebral hemorrhage (pICH) is rarely reported in a comprehensive way. In this cohort study, systematic review, and meta-analysis of patients with pICH, the authors aimed to describe the basic clinical outcomes of pICH.

METHODS

Children who received treatment for pICH at the authors' institution were prospectively enrolled in the cohort in 2008; data since 2000 were retrospectively included, and data through October 2019 were analyzed. The authors then searched PubMed and conducted a systematic review of relevant articles published since 1990. Data from the identified populations and patients from the cohort study were pooled into a multicategory meta-analysis and analyzed with regard to clinical outcomes.

RESULTS

Among 243 children screened for inclusion, 231 patients were included. The median (IQR) age at ictus was 9.6 (4.6-12.5) years, and 128 patients (53%) were male. After a median (IQR) follow-up of 33 (13-63) months, 132 patients (57.4%) had a favorable clinical outcome, of whom 58 (44%) had no residual symptoms. Nineteen studies were included in the meta-analysis. Overall, the proportion of children with complete recovery was 27% (95% CI 19%-36%; Q = 49.6; I2 = 76%); of those with residual deficits, the complete recovery rate was 48.1% (95% CI 40%-57%; Q = 75.3; I2 = 81%). When pooled with the cohort study, the aggregate case-fatality rate at the last follow-up was 17.3% (95% CI 12%-24%; Q = 101.6; I2 = 81%).

CONCLUSIONS

Here, the authors showed that 1 in 6 children died after pICH, and the majority of children had residual neurological deficits at the latest follow-up. Results from the cohort study also indicate that children with vascular lesions as the etiology of pICH had significantly better clinical functional outcomes.

Deep medullary vein engorgement and superficial medullary vein engorgement: two patterns of perinatal venous stroke

Perinatal venous stroke has classically been attributed to cerebral sinovenous thrombosis with resultant congestion or thrombosis of the small veins draining the cerebrum. Advances in brain MRI, in particular susceptibility-weighted imaging, have enabled the visualization of the engorged small intracerebral veins, and the spectrum of perinatal venous stroke has expanded to include isolated congestion or thrombosis of the deep medullary veins and the superficial intracerebral veins. Congestion or thrombosis of the deep medullary veins or the superficial intracerebral veins can result in vasogenic edema, cytotoxic edema or hemorrhage in the territory of disrupted venous flow. Deep medullary vein engorgement and superficial medullary vein engorgement have characteristic findings on MRI and should be differentiated from neonatal hemorrhagic stroke.

Management of haemorrhagic stroke secondary to arteriovenous malformations in childhood

AIMS

The aim of this study is to describe the outcome and management of all children who have presented with haemorrhagic stroke (HS) secondary to an arteriovenous malformation (AVM) at a single UK centre over a 13-year period.

METHODS

All children with HS managed at our institution (2005-2018) were identified and those with underlying AVMs were studied. Clinical and imaging data were obtained from medical records. Outcome was scored using the Recovery and Recurrence Questionnaire.

RESULTS

Ninety-three children (median age 8.8 years; 56 males; 8 neonates) presented with both global and focal features (28 had Glasgow Coma Score < 8). Haemorrhage was intraparenchymal in 72; prior risk factors present in 14. An underlying vascular lesion was identified in 68/93, most commonly AVM (n = 48). A systemic cause was found in 10, cerebral venous thrombosis in three, and 9 remain unidentified despite neuroradiological investigation. Median follow-up was 2.4 years, six died, and one was lost to follow-up. Outcome was rated as good in 60/86. Of the 48 AVMs, 3 were Spetzler-Martin (SM) grade 1, 21 SM 2, 21 SM3 and 3 SM4. One patient was treated conservatively as the AVM was too high risk to treat. At follow-up, 19 with AVM were angiographically cured, all with low SM grade and with the use of a single modality in 9 cases (all low SM grade).

CONCLUSION

Although children with acute HS are extremely unwell at presentation, supportive care results in a good outcome in the majority. Complete obliteration for childhood AVMs is challenging even with low-grade lesions with multimodal treatment.

Hypertension and childhood stroke

Cerebrovascular disease (stroke) is one of the ten leading causes of death in children and adolescents. Multiple etiologies, from arteriopathies to prothrombic states, can cause stroke in youth. In adult stroke, hypertension has been shown to be the single most important modifiable risk factor. Although hypertension has not been strongly identified as a risk factor in childhood stroke to date, there is preliminary evidence that suggests that hypertension may also be associated with stroke in children. In this review, we summarize the literature that may link hypertension to stroke in the young. We have identified a series of barriers and limitations in the fields of pediatric hypertension and pediatric neurology that might explain why hypertension has been overlooked in childhood stroke. We suggest that hypertension may be a relevant risk factor that, alone or in combination with other multiple factors, contributes to the development of stroke in children. Currently, there are no consensus guidelines for the management of post-stroke hypertension in children. Thus, we recommend that blood pressure be assessed carefully in every child presenting with acute stroke in order to better understand the effects of hypertension in the development and the outcome of childhood stroke. We suggest a treatment algorithm to help practitioners manage hypertension after a stroke.

Intracerebral Nontraumatic Hemorrhagic Stroke in Children: Case Series and Literature Review

Pediatric stroke is an event caused by disturbance of cerebral circulation that occurs in individuals between 28 days and 18 years of age. Although an uncommon event, pediatric stroke still carries significant morbidity and mortality. Unlike adults, causes of pediatric stroke are various and include vascular, infectious, hematologic, neoplastic, and toxic etiologies. Clinical presentation of nontraumatic intracerebral hemorrhages in older children is similar to adults, however in neonates and infants signs and symptoms can be more subtle, especially with smaller hemorrhages. Management of nontraumatic intracerebral hemorrhage consists of stabilizing the patient, management of the hemorrhage itself, and reduction of the rebleeding risk. Even so, when child reaches a medical care, morbidity and mortality rates are still high. We described a case series of pediatric patients with intracerebral nontraumatic hemorrhagic stroke from different etiologies. Although increasingly recognized, such situations are still poorly described in children and our report offers a good overview on this topic.

Etiology of intracerebral hemorrhage in children: cohort study, systematic review, and meta-analysis

OBJECTIVE

Understanding the etiological spectrum of nontraumatic pediatric intracerebral hemorrhage (pICH) is key to the diagnostic workup and care pathway. The authors aimed to evaluate the etiological spectrum of diseases underlying pICH.

METHODS

Children treated at the authors' institution for a pICH were included in an inception cohort initiated in 2008 and retrospectively inclusive to 2000, which was analyzed in October 2019. They then conducted a systematic review of relevant articles in PubMed published between 1990 and 2019, identifying cohorts with pICH. Identified populations and patients from the authors' cohort were pooled in a multicategory meta-analysis.

RESULTS

A total of 243 children with pICH were analyzed in the cohort study. The final primary diagnosis was an intracranial vascular lesion in 190 patients (78.2%), a complication of a cardiac disease in 17 (7.0%), and a coagulation disorder in 14 (5.8%). Hematological and cardiological etiologies were disproportionately more frequent in children younger than 2 years (p < 0.001). The systematic review identified 1309 children in 23 relevant records pooled in the meta-analysis. Overall, there was significant heterogeneity. The dominant etiology was vascular lesion, with an aggregate prevalence of 0.59 (95% CI 0.45-0.64; p < 0.001, Q = 302.8, I2 = 92%). In 18 studies reporting a detailed etiological spectrum, arteriovenous malformation was the dominant etiology (68.3% [95% CI 64.2%-70.9%] of all vascular causes), followed by cavernoma (15.7% [95% CI 13.0%-18.2%]).

CONCLUSIONS

The most frequent etiology of pICH is brain arteriovenous malformation. The probability of an underlying vascular etiology increases with age, and, conversely, hematological and cardiac causes are dominant causes in children younger than 2 years.

Vessel Enlargement in Development and Pathophysiology

From developmental stages until adulthood, the circulatory system remodels in response to changes in blood flow in order to maintain vascular homeostasis. Remodeling processes can be driven by de novo formation of vessels or angiogenesis, and by the restructuration of already existing vessels, such as vessel enlargement and regression. Notably, vessel enlargement can occur as fast as in few hours in response to changes in flow and pressure. The high plasticity and responsiveness of blood vessels rely on endothelial cells. Changes within the bloodstream, such as increasing shear stress in a narrowing vessel or lowering blood flow in redundant vessels, are sensed by endothelial cells and activate downstream signaling cascades, promoting behavioral changes in the involved cells. This way, endothelial cells can reorganize themselves to restore normal circulation levels within the vessel. However, the dysregulation of such processes can entail severe pathological circumstances with disturbances affecting diverse organs, such as human hereditary telangiectasias. There are different pathways through which endothelial cells react to promote vessel enlargement and mechanisms may differ depending on whether remodeling occurs in the adult or in developmental models. Understanding the molecular mechanisms involved in the fast-adapting processes governing vessel enlargement can open the door to a new set of therapeutical approaches to be applied in occlusive vascular diseases. Therefore, we have outlined here the latest advances in the study of vessel enlargement in physiology and pathology, with a special insight in the pathways involved in its regulation.

Neurovascular disease and syndromes: Diagnosis and therapy in children

The pediatric neurovascular disease runs the chronologic spectrum with dramatic changes in the presentation, evaluation, and treatment from the prenatal, perinatal, and infant periods through childhood and adolescence. These diseases are often dynamic throughout this period and the dynamic continues throughout life. There are four major categories: high-flow arteriovenous shunting lesions, arterial aneurysms, low-flow vascular lesions, and vascular occlusive disease. The high-flow lesions can be subdivided into a vein of Galen malformation, non-Galenic arteriovenous fistula, dural sinus malformations and fistula, and arteriovenous malformation. Low-flow vascular lesions include cerebral cavernous malformation, developmental venous anomaly, and capillary telangiectasia. The cerebrovascular occlusive disease can be divided between arterial occlusive disease and cerebral venous sinus thrombosis. The presentation of each of these entities can be very similar, especially in younger children; however, imaging and laboratory analysis can establish the diagnosis leading to the most appropriate therapy. A multidisciplinary team, dedicated to treating pediatric cerebrovascular disease, is important in delivering the best outcomes in these complex diseases. Given the relative rarity of pediatric presentation of cerebrovascular disease, many apply adult concepts to children. A better understanding of the diseases and their difference from adults makes a critical difference in selecting the correct approach.

Early obliteration of pediatric brain arteriovenous malformations after stereotactic radiosurgery: an international multicenter study

OBJECTIVE

Stereotactic radiosurgery (SRS) is a treatment option for pediatric brain arteriovenous malformations (AVMs), and early obliteration could encourage SRS utilization for a subset of particularly radiosensitive lesions. The objective of this study was to determine predictors of early obliteration after SRS for pediatric AVMs.

METHODS

The authors performed a retrospective review of the International Radiosurgery Research Foundation AVM database. Obliterated pediatric AVMs were sorted into early (obliteration ≤ 24 months after SRS) and late (obliteration > 24 months after SRS) responders. Predictors of early obliteration were identified, and the outcomes of each group were compared.

RESULTS

The overall study cohort was composed of 345 pediatric patients with obliterated AVMs. The early and late obliteration cohorts were made up of 95 (28%) and 250 (72%) patients, respectively. Independent predictors of early obliteration were female sex, a single SRS treatment, a higher margin dose, a higher isodose line, a deep AVM location, and a smaller AVM volume. The crude rate of post-SRS hemorrhage was 50% lower in the early (3.2%) than in the late (6.4%) obliteration cohorts, but this difference was not statistically significant (p = 0.248). The other outcomes of the early versus late obliteration cohorts were similar, with respect to symptomatic radiation-induced changes (RICs), cyst formation, and tumor formation.

CONCLUSIONS

Approximately one-quarter of pediatric AVMs that become obliterated after SRS will achieve this radiological endpoint within 24 months of initial SRS. The authors identified multiple factors associated with early obliteration, which may aid in prognostication and management. The overall risks of delayed hemorrhage, RICs, cyst formation, and tumor formation were not statistically different in patients with early versus late obliteration.

Fatal intracranial hemorrhage from brain AVM in a 7-week-old infant: case report and recent literature review

Brain arteriovenous malformations (AVMs) are vascular abnormalities that typically present with spontaneous hemorrhage, seizure, or as a mass lesion. Pediatric brain AVMs are rarely diagnosed but carry a higher rate of rupture. We report a 7-week-old infant with rapid fatal intracranial hemorrhage from an undiagnosed brain. AVM confirmed at autopsy. Literature review on pediatric patients who had acute death caused by previously undiagnosed brain AVM from 1992 to 2018 revealed that cerebellum is the most frequent location of such AVMs, followed by thalamus. All the children had extensive intracranial hemorrhage that led to their deterioration despite surgical intervention.

Evidence for endothelial-to-mesenchymal transition in human brain arteriovenous malformations

BACKGROUND

Brain arteriovenous malformations (AVMs) are rare, potentially devastating cerebrovascular lesions that can occur in both children and adults. AVMs are largely sporadic and the basic disease biology remains unclear, limiting advances in both detection and treatment. This study aimed to investigate human brain AVMs for endothelial-to-mesenchymal transition (EndMT), a process recently implicated in cerebral cavernous malformations (CCMs).

METHODS

We used 29 paraffin-embedded and 13 fresh/frozen human brain AVM samples to profile expression of panels of EndMT-associated proteins and RNAs. CCMs, a cerebrovascular disease also characterized by abnormal vasculature, were used as a primary comparison, given that EndMT specifically contributes to CCM disease biology. AVM-derived cell lines were isolated from three fresh, surgical AVM samples and characterized by protein expression.

RESULTS

We observed high collagen deposition, high PAI-1 expression, and expression of EndMT-associated transcription factors such as KLF4, SNAI1, and SNAI2 and mesenchymal-associated markers such as VIM, ACTA2, and S100A4. SMAD-dependent TGF-β signaling was not strongly activated in AVMs and this pathway may be only partially involved in mediating EndMT. Using serum-free culture conditions, we isolated myofibroblast-like cell populations from AVMs that expressed a unique range of proteins associated with mature cell types and with EndMT. Conditioned medium from these cells led to increased proliferation of HUVECs and SMCs.

CONCLUSIONS

Collectively, our results suggest a role for EndMT in AVM disease. This may lead to new avenues for disease models to further our understanding of disease mechanisms, and to the development of improved diagnostics and therapeutics.

Neuroimaging of Pediatric Intracerebral Hemorrhage

Hemorrhagic strokes account for half of all strokes seen in children, and the etiologies of these hemorrhagic strokes differ greatly from those seen in adult patients. This review gives an overview about incidence and etiologies as well as presentation of children with intracerebral hemorrhage and with differential diagnoses in the emergency department. Most importantly it describes how neuroimaging of children with intracerebral hemorrhage should be tailored to specific situations and clinical contexts and recommends specific imaging protocols for acute and repeat imaging. In this context it is important to keep in mind the high prevalence of underlying vascular lesions and adapt the imaging protocol accordingly, meaning that vascular imaging plays a key role regardless of modality. Magnetic resonance imaging (MRI), including advanced sequences, should be favored whenever possible at the acute phase.

Stereotactic radiosurgery for pediatric brain arteriovenous malformations: long-term outcomes

OBJECTIVE

Contrary to the better described obliteration- and hemorrhage-related data after stereotactic radiosurgery (SRS) of brain arteriovenous malformations (AVMs) in pediatric patients, estimates of the rarer complications, including cyst and tumor formation, are limited in the literature. The aim of the present study was to assess the long-term outcomes and risks of SRS for AVMs in pediatric patients (age < 18 years).

METHODS

The authors retrospectively analyzed the International Radiosurgery Research Foundation pediatric AVM database for the years 1987 to 2018. AVM obliteration, post-SRS hemorrhage, cyst formation, and tumor formation were assessed. Cumulative probabilities, adjusted for the competing risk of death, were calculated.

RESULTS

The study cohort comprised 539 pediatric AVM patients (mean follow-up 85.8 months). AVM obliteration was observed in 64.3% of patients, with cumulative probabilities of 63.6% (95% CI 58.8%-68.0%), 77.1% (95% CI 72.1%-81.3%), and 88.1% (95% CI 82.5%-92.0%) over 5, 10, and 15 years, respectively. Post-SRS hemorrhage was observed in 8.4% of patients, with cumulative probabilities of 4.9% (95% CI 3.1%-7.2%), 9.7% (95% CI 6.4%-13.7%), and 14.5% (95% CI 9.5%-20.5%) over 5, 10, and 15 years, respectively. Cyst formation was observed in 2.1% of patients, with cumulative probabilities of 5.5% (95% CI 2.3%-10.7%) and 6.9% (95% CI 3.1%-12.9%) over 10 and 15 years, respectively. Meningiomas were observed in 2 patients (0.4%) at 10 and 12 years after SRS, with a cumulative probability of 3.1% (95% CI 0.6%-9.7%) over 15 years.

CONCLUSIONS

AVM obliteration can be expected after SRS in the majority of the pediatric population, with a relatively low risk of hemorrhage during the latency period. Cyst and benign tumor formation after SRS can be observed in 7% and 3% of patients over 15 years, respectively. Longitudinal surveillance for delayed neoplasia is prudent despite its low incidence.

Characteristics and Long-Term Outcome of 127 Children With Cerebral Arteriovenous Malformations

BACKGROUND

Population-based long-term data on pediatric patients with cerebral arteriovenous malformations (AVMs) are limited.

OBJECTIVE

To clarify the characteristics and long-term outcome of pediatric patients with AVM.

METHODS

A retrospective analysis was performed on 805 consecutive brain AVM patients admitted to a single center between 1942 and 2014. The patients were defined as children if they were under 18 yr at admission. Children were compared to an adult cohort. Changing patterns of presentation were also analyzed by decades of admission.

RESULTS

The patients comprised 127 children with a mean age of 12 yr. The mean follow-up time was 21 yr (range 0-62). Children presented more often with intracerebral hemorrhage (ICH) but less often with epilepsy than adults. Basal ganglia, cerebellar, and posterior paracallosal AVMs were more common in pediatric than in adult patients. Frontal and temporal AVMs, in contrast, were more common in adult than in pediatric patients. As the number of incidentally and epilepsy-diagnosed AVMs increased, ICH rates dropped in both cohorts. In total, 22 (82%) pediatric and 108 (39%) adult deaths were assessed as AVM related. After multivariate analysis, small AVM size and surgical treatment correlated with a favorable long-term outcome.

CONCLUSION

Hemorrhagic presentation was more common in children than in adults. This was also reflected as lower prevalence of epileptic presentation in the pediatric cohort. Lobar and cortical AVM locations were less frequent, whereas deep and cerebellar AVMs were more common in children. Hemorrhagic presentation correlated negatively with incidentally and epilepsy-diagnosed AVMs. In children, AVM was a major cause of death, but in adults, other factors contributed more commonly to mortality.

Childhood haemorrhagic stroke: a 7-year single-centre experience

BACKGROUND

In recent years, there has been increasing research interest in improving diagnostic and management protocols in childhood arterial ischaemic stroke (AIS). However, childhood stroke comprises, in approximately equal parts, both arterial ischaemic and haemorrhagic stroke (HS).

OBJECTIVE

The aim of this study was to focus on the aetiology, clinical presentation, treatment and short-term outcome of children with spontaneous intracranial bleeding in a university hospital and elucidate differences to childhood AIS.

DESIGN

We performed a retrospective analysis of electronic medical records of children (28 days-18 years) diagnosed with HS between 2010 and 2016.

RESULTS

We included 25 children (male child, n=11) with a median age of 8 years 1 month. The most common clinical presentations were vomiting (48%), headache (40%) and altered level of consciousness (32%). In more than half of the patients, HS was caused by vascular malformations. Other risk factors were brain tumour, coagulopathy and miscellaneous severe underlying diseases. Aetiology remained unclear in one child. Therapy was neurosurgical in most children (68%). Two patients died, 5 patients needed further (rehabilitation) treatment and 18 children could be discharged home.

CONCLUSIONS

HS differs from AIS in aetiology (vascular malformations as number one risk factor), number of risk factors ('mono-risk' disease), clinical presentation (vomiting, headache and altered level of consciousness) and (emergency) therapy.

Stereotactic Radiosurgery for Unruptured Versus Ruptured Pediatric Brain Arteriovenous Malformations

Background and Purpose—

The effects of prior hemorrhage on stereotactic radiosurgery (SRS) outcomes for pediatric arteriovenous malformations (AVMs) are not well defined. The aim of this multicenter, retrospective cohort study is to compare the SRS outcomes for unruptured versus ruptured pediatric AVMs.

Methods—

The International Radiosurgery Research Foundation pediatric AVM database from 1987 to 2018 was reviewed retrospectively. Favorable outcome was defined as AVM obliteration, no post-SRS hemorrhage, and no permanently symptomatic radiation-induced changes. Associations between prior hemorrhage and outcomes were adjusted for baseline differences, inverse probability weights, and competing risks.

Results—

The study cohort comprised 153 unruptured and 386 ruptured AVMs. Favorable outcome was achieved in 48.4% and 60.4% of unruptured and ruptured AVMs, respectively (adjusted odds ratio, 1.353; P =0.190). Cumulative AVM obliteration probabilities were 51.2%, 59.4%, 64.2%, and 70.0% for unruptured and 61.0%, 69.3%, 74.0%, and 79.3% for ruptured AVMs at 4, 6, 8, and 10 years, respectively (subhazard ratio, 1.311; P =0.020). Cumulative post-SRS hemorrhage probabilities were 4.5%, 5.6%, 5.6%, and 9.8% for unruptured and 4.7%, 6.1%, 6.1%, and 10.6% for ruptured AVMs at 4, 6, 8, and 10 years, respectively (subhazard ratio, 1.086; P =0.825). Probabilities of AVM obliteration (adjusted subhazard ratio, 0.968; P =0.850) and post-SRS hemorrhage (adjusted subhazard ratio, 1.663; P =0.251) were comparable between the 2 cohorts after inverse probability weight adjustments. Symptomatic (15.8% versus 8.1%; adjusted odds ratio, 0.400; P =0.008) and permanent (9.2% versus 5.0%; adjusted odds ratio, 0.441; P =0.045) radiation-induced change were more common in unruptured AVMs.

Conclusions—

The overall outcomes after SRS for unruptured versus ruptured pediatric AVMs are comparable. However, symptomatic and permanent radiation-induced change occur more frequently in pediatric patients with unruptured AVMs.

Neurovascular Lesions in Pediatric Epilepsy

INTRODUCTION

Neurovascular lesions are rare and understudied in the pediatric population. Their initial presentation can range from seizures to focal neurologic deficits, as well as headaches. The goal of this study was to examine the clinical presentation and natural history of neurovascular lesions in children with epilepsy.

METHODS

We reviewed all pediatric epilepsy patients with neurovascular lesions diagnosed between 2006 and 2018 at the University of Alberta and the Stollery Children's Hospital, Edmonton, Canada. Initial clinical presentation and brain imaging, as well as long-term epilepsy and postsurgical outcome, were assessed.

RESULTS

Of the 14 patients, 10 patients had an initial presentation of focal seizures with impaired awareness, whereas 2 patients presented with headache, 1 presented with visual field defects as well as chronic headaches, and 1 with decreased level of consciousness. Seven patients had cavernous angiomas, 6 had arteriovenous malformation, and 1 patient had an arteriovenous fistula. Notably, all patients with cavernous angiomas and 4 of 6 patients with arteriovenous malformations presented with seizures. Among 9 of the 14 who underwent neurovascular corrective surgery, all 9 patients required long-term antiepileptic treatment of at least 1 antiepileptic drug for seizure control after the operation.

CONCLUSION

In this novel case series, we describe focal seizures as the initial presentation of pediatric neurovascular lesions. This clinical presentation appears to be independent of the type of neurovascular lesion. Furthermore, unlike our pediatric surgical patients with epilepsy due to other causes, seizure freedom following neurovascular surgery is limited, and patients require long-term antiepileptic treatment.

Language and cognitive outcomes after childhood stroke: Theoretical implications for hemispheric specialization

The purpose of this study was to investigate language and cognitive outcomes following severe childhood stroke, and the role of age at stroke according to lesion lateralization. We retrospectively included children consecutively admitted to a physical medicine and rehabilitation department between 1992 and 2015 following childhood stroke (age at stroke 1 month to15 years). Data collection included demographic and clinical information, results of cognitive assessments on the Wechsler Intelligence scales, detailed language assessments by speech and language therapists, and long-term academic outcome. Overall, 184 children (52% boys; mean age at assessment = 8.5 years, range .7-15.4 years) were hospitalized following ischemic (n = 79) or hemorrhagic (n = 105) stroke. After a median time since stroke of 4 months (n = 135), mean Full-Scale, Verbal, and Performance Intellectual Quotient (FSIQ, VIQ and PIQ) were 85 (SD = 19), 93 (SD = 22), and 85 (SD = 20), respectively. In language tests (n = 130) assessing lexical and syntactic expression and comprehension, 26%-53% of the children exhibited impairments (scores <2SD). After a median follow-up of 40 months, only 27% of the children were following a normal curriculum without adaptations or delay, and 27% were attending special education programs. School situation was strongly associated with language and FSIQ scores. Language and verbal IQ scores were significantly lower (p < .01) among patients with lesions in the left hemisphere as opposed to the right. After a left hemisphere lesion, language skills were not associated with age at stroke, but for right hemisphere lesions, language was more impaired among children who were younger at stroke onset. PIQ tended to correlate positively with age at stroke in left hemisphere lesions (poorer PIQ in early lesions) and negatively for right hemisphere lesions (poorer PIQ in late lesions). These findings, discussed in the light of the brain vulnerability and plasticity hypotheses, are in favor of a developmental view of hemispheric specialization.

Spontaneous intracranial haemorrhage in children-intensive care needs and predictors of in-hospital mortality: a 10-year single-centre experience

PURPOSE

Spontaneous intracranial haemorrhage (SICH) in children, although uncommon, is associated with significant mortality and morbidity. Paediatric data is however limited.

MATERIAL AND METHODS

Case records of 105 children with SICH, > 1 month to 12 years, admitted to a tertiary level PICU of a teaching and referral hospital between January 2009 and May 2018 were analysed retrospectively. In-hospital mortality was the primary outcome. Variables between survivors and non-survivors were compared to  determine predictors of mortality.

RESULTS

The median (IQR) age of subjects was 6 (2.25, 70) months. Common clinical features were altered sensorium (n = 87, 82.9%), seizures (n = 73, 69.5%), pallor (n = 66, 62.9%) and bulging anterior fontanelle (n = 52, 49.5%). Median (IQR) Glasgow Coma Scale (GCS) at admission was 10 (6, 13) with herniation noted in 27 (25.7%) children. Vitamin K deficiency bleeding (VKDB) and arteriovenous malformation (AVM) were the most common etiology for bleeding among infants and older children respectively. The most common site of bleeding was intracerebral (n = 47, 44.8%) followed by subdural (n = 26; 24.8%). Sixteen (15.2%) children died during hospital stay. On univariate analysis, GCS < 8, Pediatric Risk of Mortality score (PRISM III) > 20, need for intubation, thiopentone coma for refractory intracranial pressure (ICP) and progression to shock and acute kidney injury (AKI) predicted mortality. Seizures were favourably associated with survival. Age, site of bleeding, etiology or type of management for raised ICP (conservative versus decompressive craniectomy) did not affect the outcome. On multivariable analysis, progression to AKI (OR 5.86; 95% CI, 1.53-22.4; p 0.01) predicted poor outcome. Seizures, however, were associated with better odds for survival (OR 0.12; 95% CI, 0.03-0.47; p 0.002).

CONCLUSIONS

VKDB and AVM were the common etiologies among infants and older children respectively. Age, site, etiology of bleeding and type of management did not affect outcome. Severe decompensation at presentation, thiopentone for refractory ICP and progression to multiorgan dysfunction determined mortality.

RNA Sequencing Reveals the Activation of Wnt Signaling in Low Flow Rate Brain Arteriovenous Malformations

Background

The blood flow rate of brain arteriovenous malformations (bAVMs) is an important clinical characteristic closely associated with the hemorrhage risk and radiosurgery obliteration rate of bAVMs. However, the underlying molecular properties remain unclear. To identify potential key molecules, signaling pathways, and vascular cell types involved, we compared gene expression profiles between bAVMs with high flow rates and low flow rates (LFR) and validated the functions of selected key molecules in vitro.

Methods and Results

We performed RNA‐sequencing analysis on 51 samples, including 14 high flow rate bAVMs and 37 LFR bAVMs. Functional pathway analysis was performed to identify potential signals influencing the flow rate phenotype of bAVMs. Candidate genes were investigated in bAVM specimens by immunohistochemical staining. Migration, tube formation, and proliferation assays were used to test the effects of candidate genes on the phenotypic properties of cultured human umbilical vein endothelial cells and human brain vascular smooth muscle cells. We identified 250 upregulated and 118 downregulated genes in LFR bAVMs compared with high flow rate bAVMs. Wnt signaling was activated in the LFR group via upregulation of FZD10 and MYOC. Immunohistochemical staining showed that vascular endothelial and smooth muscle cells of LFR bAVMs exhibited increased FZD10 and MYOC expression. Experimentally elevating these genes promoted human umbilical vein endothelial cells and migration and tube formation by activating canonical Wnt signaling in vitro.

Conclusions

Our results suggest that canonical Wnt signaling mediated by FZD10 and MYOC is activated in vascular endothelial and smooth muscle cells in LFR bAVMs.

Cerebrovascular Accident in a Pediatric Patient Presenting With Influenza

BACKGROUND

Acute ischemic stroke (AIS) in pediatric populations accounts for more than half of pediatric strokes and is associated with significant morbidity and mortality. Pediatric AIS can present with nonspecific symptoms or symptoms that mimic alternate pathology.

CASE REPORT

A 4-month-old female presented to the emergency department for fever, decreased oral intake, and "limp" appearance after antibiotic administration. She was febrile, tachypneic, and hypoxic. Her skin was mottled with 3-s capillary refill, her anterior fontanelle was tense, and she had mute Babinski reflex bilaterally but was moving all extremities. The patient was hyponatremic, thrombocytopenic, and tested positive for influenza A. A computed tomography scan of the brain revealed an acute infarction involving the right frontal, parietal, temporal, and occipital lobes in addition to hyperdensities concerning for thrombosed cortical veins. The patient was transferred for specialty evaluation and was discharged 2 weeks later on levetiracetam. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Pediatric AIS can present with nonspecific symptoms that mimic alternate pathology. A high level of suspicion is needed so as not to miss the diagnosis of pediatric AIS in the emergency department. A thorough neurologic assessment is warranted, and subtle abnormalities should be investigated further.