Expanding the clinical and neuroimaging features of post-varicella arteriopathy of childhood

Stroke risk after varicella-zoster virus infection: a systematic review and meta-analysis

Varicella-zoster virus (VZV) infection may cause vascular inflammatory changes leading to an increased risk of stroke. Previous studies have focused on the risk of stroke and less on changes in stroke risk and prognosis. We aimed to explore the changing patterns of stroke risk and stroke prognosis after VZV infection. This study is a systematic review and meta-analysis. We searched PubMed, Embase, and the Cochrane Library for studies on stroke after VZV infection between January 1, 2000, and October 5, 2022. Relative risks were combined for the same study subgroups using a fixed-effects model and pooled across studies using a random-effects model. 27 studies met the requirements, including 17 herpes zoster (HZ) studies and ten chickenpox studies. There was an increased risk of stroke after HZ, and this risk decreased over time: relative risk 1.80 (95% CI 1.42-2.29) within 14 days, 1.61 (95% CI 1.43-1.81) within 30 days, 1.45 (95% CI 1.33-1.58) within 90 days, 1.32 (95% CI 1.25-1.39) within 180 days, 1.27 (95% CI 1.15-1.40) at one year and 1.19 (95% CI 0.90-1.59) after one year, with the same trend in the stroke subtype. The risk of stroke after herpes zoster ophthalmicus was higher, with a maximum relative risk of 2.26 (95% CI 1.35-3.78). The risk of stroke after HZ was higher in patients aged around 40 years: relative risk 2.53 (95% CI 1.59-4.02), and similar in men and women. Also, after pooling studies of post-chickenpox stroke, we found that the middle cerebral artery and its branches were most frequently involved (78.2%), with a better prognosis in most patients (83.1%) and less frequent vascular persistence progression (8.9%). In conclusion, the risk of stroke increases after VZV infection, decreasing over time. Post-infection vascular inflammatory changes often occur in the middle cerebral artery and its branches, with a better prognosis in most patients and less frequent persistent progression.

Imaging of Suspected Stroke in Children, From the AJR Special Series on Emergency Radiology

Pediatric stroke encompasses different causes, clinical presentations, and associated conditions across ages. Although it is relatively uncommon, pediatric stroke presents with poor short- and long-term outcomes in many cases. Because of a wide range of overlapping presenting symptoms between pediatric stroke and other more common conditions, such as migraine and seizures, stroke diagnosis can be challenging or delayed in children. When combined with a comprehensive medical history and physical examination, neuroimaging plays a crucial role in diagnosing stroke and differentiating stroke mimics. This review highlights the current neuroimaging workup for diagnosing pediatric stroke in the emergency department, describes advantages and disadvantages of different imaging modalities, highlights disorders that predispose children to infarct or hemorrhage, and presents an overview of stroke mimics. Key differences in the initial approach to suspected stroke between children and adults are also discussed.

Pediatric Stroke-Are We Asking the Right Questions? The 2022 Sidney Carter Award Lecture

Over the past few decades, robust clinical and research collaborations among pediatric stroke researchers have informed and improved the care of children with stroke. Risk factors and presentation of childhood stroke have been described, and the acute and chronic burden of childhood stroke has been better delineated. Nevertheless, high-quality data for the treatment of children with stroke is dwarfed by that available for adult stroke, and it is therefore tempting to extend research questions and treatment trials from adults to children. A trial designed to answer a question about stroke in adults may yield useful information about stroke in childhood, but a trial that incorporates the unique neurodevelopmental and etiologic aspects of childhood stroke is more likely to truly advance care. Research questions and study design in childhood stroke must capture the complexity of stroke mechanisms and medical comorbidities in children who suffer stroke, the impact on the developing nervous system, and the role of normal and aberrant neurodevelopment in recovery.

Capsular Warning Syndrome Leading to Acute Ischemic Stroke in a Pediatric Patient Secondary to Varicella Zoster Virus

We report the case of a 3-year-old boy who presented with recurrent stereotyped transient episodes of left sided weakness consistent with capsular warning syndrome (CWS) which eventually progressed to acute ischemic stroke (AIS). He received thrombolytic therapy with tissue plasminogen activator. Workup was notable for positive CSF varicella (VZV) PCR, and positive CSF and serum VZV IgG and negative IgM. On further history, he was unvaccinated and had a rash consistent with VZV 5 months prior to presentation. This case highlights the importance of recognizing CWS given the increased risk of progression to AIS. In addition, it emphasizes the importance of considering VZV vasculopathy in pediatric AIS and inquiring about infectious history and immunization status despite high rates of vaccination in the United States.

Retinal vasculopathy following varicella zoster virus infection

PURPOSE OF REVIEW

Varicella zoster virus (VZV) ocular infection can manifest purely as a vasculopathy that leads to retinal arteriole occlusion, without any retinitis or vasculitis. This review summarizes our current knowledge of such VZV ocular infection phenotype, incorporating initial descriptions from 1988. We describe the pathogenesis and VZV's manifestations in the retina using fundus photography, fundus fluorescein angiography, optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). Laboratory investigations, diagnostic procedures, prognoses, and treatment options are also being reviewed.

RECENT FINDINGS

Ten case reports where VZV retinal vasculopathy was the primary feature observed after varicella or zoster rash are described. The retinal arteriole, cilioretinal artery, branches of retinal artery, central retinal artery and ophthalmic artery were found to be areas of more rarely affected, neither in the form of vasculitis nor retinitis. Diagnosis is typically made from positive polymerase chain reaction (PCR) for VZV from extracted intraocular fluid or positive serum or cerebrospinal fluid (CSF) anti-VZV immunoglobulin G antibody in the context of compatible ocular findings. In addition, retinal vasculopathy occurring in the setting of confirmed varicella or zoster rashes could be considered potentially pathognomonic. Pathological concepts, including direct VZV infection of affected tissue, persistent inflammation, and/or virus-induced hypercoagulability are also discussed.

SUMMARY

VZV may produce a wide spectrum of ocular manifestations with isolated VZV retinal vasculopathy being a rarer presentation. A prompt diagnosis followed by an early treatment of systemic acyclovir with or without corticosteroids is the mainstay of treatment.

Neuroimaging in Pediatric Stroke

Pediatric stroke is unfortunately not a rare condition. It is associated with severe disability and mortality because of the complexity of potential clinical manifestations, and the resulting delay in seeking care and in diagnosis. Neuroimaging plays an important role in the multidisciplinary response for pediatric stroke patients. The rapid development of adult endovascular thrombectomy has created a new momentum in health professionals caring for pediatric stroke patients. Neuroimaging is critical to make decisions of identifying appropriate candidates for thrombectomy. This review article will review current neuroimaging techniques, imaging work-up strategies and special considerations in pediatric stroke. For resources limited areas, recommendation of substitute imaging approaches will be provided. Finally, promising new techniques and hypothesis-driven research protocols will be discussed.