High-Resolution Vessel Wall Magnetic Resonance Imaging in Varicella-Zoster Virus Vasculitis

Intracranial vessel wall magnetic resonance imaging features of infectious vasculitis

Vasculitis is a complication of several infectious diseases affecting the central nervous system, which may result in ischemic and/or hemorrhagic stroke, transient ischemic attack, and aneurysm formation. The infectious agent may directly infect the endothelium, causing vasculitis, or indirectly affect the vessel wall through an immunological mechanism. The clinical manifestations of these complications usually overlap with those of non-infectious vascular diseases, making diagnosis challenging. Intracranial vessel wall magnetic resonance imaging (VWI) enables the evaluation of the vessel wall and the diseases that affect it, providing diagnostic data beyond luminal changes and enabling the identification of inflammatory changes in cerebral vasculitis. This technique demonstrates concentric vessel wall thickening and gadolinium enhancement, associated or not with adjacent brain parenchymal enhancement, in patients with vasculitis of any origin. It permits the detection of early alterations, even before a stenosis occurs. In this article, we review the intracranial vessel wall imaging features of infectious vasculitis of bacterial, viral, and fungal etiologies.

High-resolution intracranial vessel wall imaging in cerebral viral infections evaluations

Purpose

Vascular complications can be seen in various viral CNS infections. Variable neuro-imaging findings have been described in the literature elucidating the parenchymal changes with vascular involvement. Vessel wall imaging (VWI) can help to detect these vascular involvements. We aimed to describe the role and usefulness of VWI in the evaluation of various viral CNS infections.

Methods

In this prospective study, we included 15 cases of various diagnosed viral CNS infections (varicella, HIV encephalopathy, HSV encephalitis, Japanese encephalitis, dengue, COVID-19). VWI and time-of-flight MR angiography (TOF MRA) were included in imaging protocol. All cases were evaluated for the presence of cerebral parenchymal changes, vascular enhancement, and vascular stenosis.

Results

We found infarctions in all 5 cases of varicella, 1 case of HIV encephalopathy, and 1 case of COVID-19 encephalopathy. All these cases also showed vascular enhancement and stenosis on VWI. The rest of the cases, including 1 case of HIV encephalopathy, 3 cases of herpes encephalitis, 2 cases of dengue, and 2 cases of Japanese encephalitis did not have any vascular complication, and also did not show vascular enhancement or stenosis.

Conclusion

VWI can be useful in the detection of vascular involvement in various viral infections of CNS which show a relatively higher cerebrovascular complication rate like varicella, HIV encephalopathy, and COVID-19. However, VWI may not be useful in the routine evaluation of other viral infections like herpes, dengue, and Japanese encephalitis, which have a very low rate of cerebrovascular complication rate.

Serial Radiological Findings in Meningovascular Neurosyphilis Presenting as Acute Ischemic Stroke: A Case Report

BACKGROUND

Meningovascular neurosyphilis, a form of early neurosyphilis, can cause infectious arteritis, which can be complicated by cerebral infarction. High-resolution vessel wall imaging (HR-VWI) is one of the techniques used to directly visualize the vessel wall. Herein, we present a rare case of meningovascular neurosyphilis, in which intracranial arterial vasculitis was evaluated using HR-VWI.

CASE PRESENTATION

A 22-year-old man with no medical history of any condition was brought to the emergency room with one day history of right upper and lower extremity weakness. Diffusion-weighted magnetic resonance (MR) imaging showed a high signal from the left putamen to the corona radiata, and MR angiography showed stenosis of the right internal carotid artery (ICA) and the bilateral middle cerebral arteries (MCAs). HR-VWI showed thickening, along with smooth, intense, and concentric enhancement of the right ICA and the bilateral MCAs. The patient was diagnosed with neurosyphilis based on the findings of the blood tests and cerebrospinal fluid examination. The patient's symptoms gradually improved after treatment with intravenous penicillin G and oral antiplatelet agents. HR-VWI, performed approximately 6 months after the treatment, revealed improvement in the contrast enhancement of the vessel wall and the vascular stenosis.

CONCLUSION

To the best of our knowledge, this is the first report of meningovascular neurosyphilis that evaluated the course of treatment using HR-VWI. Our report highlights the effectiveness of HR-VWI to determine the effects of treatment on meningovascular neurosyphilis.

Magnetic Resonance Vessel Wall Imaging in Central Nervous System Vasculitides: A Case Series

INTRODUCTION

We aim to report 3 cases of central nervous system (CNS) vasculitides, in which high-resolution magnetic resonance vessel wall imaging (HR-VWI) findings were instrumental in the diagnosis and management.

CASE REPORT

Case 1: A 41-year-old obese, smoker female with arterial hypertension presented with recurrent transient ischemic attacks. Computed topography angiography demonstrated bilateral middle cerebral artery (MCA) stenosis. HR-VWI revealed uniform enhancement and thickening of the arterial wall, suggestive of MCA vasculitis. The patient reported chronic calf rash that was biopsied and revealed unspecified connective tissue disease. With immunomodulation, patient remained asymptomatic and 6-month surveillance HR-VWI showed improved MCA stenoses.Case 2: A 56-year-old male with herpes simplex virus 1 encephalitis was treated with antiviral therapy and improved clinically. Two months later, the brain magnetic resonance imaging revealed new temporo-parietal edema and distal MCA hyperintense vessels. HR-VWI showed MCA concentric smooth contrast enhancement, that was attributed to postinfectious vasculitis and had resolved on follow-up HR-VWI.Case 3: A 41-year-old male presented with 1-week of headache and encephalopathy. Brain magnetic resonance imaging revealed punctate multifocal acute ischemic infarcts and no contrast-enhancement. HR-VWI showed multifocal diffuse enhancement of distal cerebral vasculature. Patient subsequently developed branch retinal artery occlusion and hearing loss and was diagnosed with Susac syndrome. No recurrent symptoms were noted after immunotherapy initiation.

CONCLUSIONS

In these 3 cases, HR-VWI identified distinctive vascular inflammatory changes, which were crucial to guide the etiological workup, positive diagnosis, surveillance neuroimaging, and targeted treatment. HR-VWI is an important diagnostic tool in CNS vasculitides, by providing nuanced information about arterial wall integrity and pathology.

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

OBJECTIVE

Post-varicella arterial ischemic stroke (AIS) is considered an uncommon cause of pediatric stroke that is considered a self-limiting, monophasic disease. However, in a subset of patients, disease recurs; the prevalence of vasculopathy or AIS recurrence, severity of clinical outcomes, and standardized therapies have not been well characterized. Herein, we determined the clinical-neuroradiological features, long-term evolution, and relationship between acute phase treatment and vasculopathy recurrence in a pediatric population with post-varicella AIS.

METHODS

Clinical, laboratory, and neuroradiological features of 22 children with post-varicella AIS between 2010 and 2019 (16 males, mean age at stroke 4 years, range 1.7-10) were reviewed. Statistical analyses were performed using χ² and Fisher exact tests.

RESULTS

Of the 22 cases, mean time from varicella to stroke was 4.5 months with 3 cases presenting more than 12 months after rash; 21 (95%) were not vaccinated for varicella; 3 (13.6%) had posterior circulation involvement; and 5 (22.7%) had AIS or vasculopathy recurrence, of which 4 recurred 6.1 months to 2.8 years after initial clinical onset. Recurrence was associated with lack of antiviral treatment during the first episode (p = 0.02).

CONCLUSIONS

Post-varicella AIS can occur months after rash making diagnosis challenging. Because recurrent vasculopathy was seen predominantly in cases not treated with antiviral therapy during initial presentation, it is important to rapidly diagnose post-varicella AIS through clinical criteria and/or virological testing then treat with antivirals to prevent recurrence.

High-Resolution Magnetic Resonance Vessel Wall Imaging for the Evaluation of Intracranial Vascular Pathology

Intracranial vessel wall imaging (IVWI) is an advanced MR imaging technique that allows for direct visualization of the walls of intracranial blood vessels and detection of subtle pathologic vessel wall changes before they become apparent on conventional luminal imaging. When performed correctly, IVWI can increase diagnostic confidence, aid in the differentiation of intracranial vasculopathies, and assist in patient risk stratification and prognostication. This review covers the essential technical underpinnings of IVWI and presents emerging clinical research highlighting its utility for the evaluation of multiple intracranial vascular pathologies.

High resolution vessel wall MRI and vasculopathy related to herpes zoster ophthalmicus

Varicella zoster virus is a common viral infection with over 50% of patients over the age of 80 years infected with the virus. Following reactivation, some patients succumb to complications of VZV reactivation with neurologic and optic pathway pathology such as VZV vasculopathy resulting in transient ischemic attacks, strokes, aneurysms, as well as optic neuritis. We show that high resolution vessel wall magnetic resonance imaging can aid in the diagnosis of this condition with circumferential wall thickening and enhancement of the infected vessels. Prompt diagnosis is critical as this is a treatable condition that could result in substantial morbidity or mortality if not recognized early.