Vessel wall enhancement in herpes simplex virus central nervous system vasculitis

Viral Infection and Ischemic Stroke: Emerging Trends and Mechanistic Insights

Population studies have suggested that viral infections may be contributing to risk of ischemic stroke, although the mechanisms for this are unclear. In this review, we examine the epidemiological evidence supporting the involvement of viral diseases, including influenza, COVID-19, chronic herpesvirus infections, and hepatitis C in current trends of stroke incidence. To support these associations, we highlight the virus-host interactions that are critical in the context of stroke, including direct effects of acute and persistent viral infections on vascular function, inflammation, and thrombosis. Additionally, we evaluate the systemic changes that occur during viral infection that can predispose individuals to ischemic stroke, including alterations in blood pressure regulation, coagulation, and lipid metabolism. Our review emphasizes the need to further elucidate precise mechanisms involved in viral infections and stroke risk. Future research will inform the development of targeted interventions for stroke prevention in the context of viral diseases.

Herpesvirus latent infection promotes stroke via activating the OTUD1/NF-κB signaling pathway

OBJECTIVE

Our study aimed to reveal the molecular mechanisms underlying the regulation of cerebral infarction by herpes virus latency infection via the OTUD1/NF-κB signaling pathway using evidence-based medicine Meta-analysis and bioinformatics analysis.

METHODS

We conducted a Meta-analysis by searching Pubmed, Embase, and Web of Science databases to evaluate the correlation between herpes virus infection and increased risk of cerebral infarction. We obtained wild-type or mutant herpes virus latent infection-related brain tissue datasets from the GEO database and performed differential analysis to identify differentially expressed genes (DEGs) in the brain tissue after herpes virus latent infection. We further conducted WGCNA co-expression analysis on the cerebral infarction-related datasets from the GEO database to obtain key module genes and intersect them with the DEGs. We used ROC curve analysis to identify the key gene OTUD1 for predicting the occurrence of cerebral infarction and combined correlation and pathway enrichment analyses to identify the downstream pathways regulated by OTUD1.

RESULTS

Our meta-analysis revealed that herpes virus infection is associated with an increased risk of cerebral infarction. By integrating the differential analysis and WGCNA co-expression analysis of GEO chip data, we identified three key genes mediating cerebral infarction after herpes virus latent infection. ROC curve analysis identified the key gene OTUD1, and the correlation and pathway enrichment analyses showed that OTUD1 regulates the NF-κB signaling pathway to mediate cerebral infarction.

CONCLUSION

Herpes virus latent infection promotes cerebral infarction by activating the OTUD1/NF-κB signaling pathway.

Central Nervous System Vasculitis: Primary Angiitis of the Central Nervous System and Central Nervous System Manifestations of Systemic Vasculitis

Central nervous system vasculitis (CNSV) is a group of disorders leading to inflammatory vasculopathy within the brain, spinal cord, and leptomeninges. CNSV is divided into primary angiitis of the central nervous system (PACNS) and secondary CNSV based on the underlying etiology. PACNS is a rare inflammatory disorder with poorly understood pathophysiology and heterogeneous and highly variable clinical features. The diagnosis depends on a combination of clinical and laboratory variables, multimodal imaging, and histopathological examination as well as exclusion of mimics. Several systemic vasculitides, infectious etiologies and connective tissue disorders have been shown to cause secondary CNSV and require prompt recognition.

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.

Diagnosing and localizing the acute vestibular syndrome - Beyond the HINTS exam

When assessing the acutely dizzy patient, the HINTS 'Plus' (Head Impulse, Nystagmus, Test of Skew, 'Plus' a bedside assessment of auditory function) exam is a crucial component of the bedside exam. However, there are additional ocular motor findings that can help the clinician distinguish peripheral from central etiologies and enable accurate localization, especially when the patient has acute dizziness, vertigo and/or imbalance but without spontaneous nystagmus. We will review the literature on these findings which are 'beyond HINTS' and include saccades/ocular lateropulsion, smooth pursuit, and provocative maneuvers including head-shaking and positional testing (not part of the HINTS exam). Additionally, we will expound on the localizing value of nystagmus, ocular alignment and the ocular tilt reaction (parts of the HINTS exam). The paper has been organized neuroanatomically, based on brainstem and cerebellar structures that have been reported to cause the acute vestibular syndrome.

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.

Herpes simplex virus 2 vasculitis as cause of ischemic stroke in a young immunocompromised patient

Herpes simplex virus 2 (HSV-2) is a very rare cause of central nervous system (CNS) infections. We report a case of a young woman with a left middle cerebral artery (MCA) ischemic stroke. The patient had history of HIV-1 infection, with periods of therapeutic non-compliance. Initial computed tomography (CT) imaging studies showed stenosis of the M1 segment of the left MCA, and magnetic resonance imaging (MRI) confirmed infarction of the MCA territory. Serial transcranial Doppler ultrasound revealed progressive occlusion of the MCA and stenosis of the left anterior cerebral artery. Systemic investigation for other causes of stroke was normal. Lumbar puncture revealed a mildly inflammatory cerebrospinal fluid, and HSV-2 DNA was identified by PCR, with a positive viral load in favor of active replication. No other viral or microbiological infections were identified. MRI angiography confirmed a vasculitic process involving the left carotid artery, and a HSV-2 vasculitis diagnosis was assumed. The patient started acyclovir with improvement of clinical features and imaging abnormalities. In the HIV-infected patient, stroke is a multifactorial common cause of morbidity. The physician should take into account a broad differential diagnosis including rare causes and atypical presentations of common etiologies, including HSV-1 and HSV-2 CNS infection.

Cerebrovascular manifestations of herpes simplex virus infection of the central nervous system: a systematic review

BACKGROUND

Intracerebral hemorrhage and ischemic stroke are increasingly recognized complications of central nervous system (CNS) infection by herpes simplex virus (HSV).

AIM OF THE STUDY

To analyze clinical, imaging, and laboratory findings and outcomes of cerebrovascular manifestations of HSV infection.

METHODS

Systematic literature review from January 2000 to July 2018.

RESULTS

We identified 38 patients (median age 45 years, range 1-73) comprising 27 cases of intracerebral hemorrhage, 10 of ischemic stroke, and 1 with cerebral venous sinus thrombosis. Intracerebral hemorrhage was predominantly (89%) a complication of HSV encephalitis located in the temporal lobe. Hematoma was present on the first brain imaging in 32%, and hematoma evacuation was performed in 30% of these cases. Infarction was frequently multifocal, and at times preceded by hemorrhage (20%). Both a stroke-like presentation and presence of HSV encephalitis in a typical location were rare (25% and 10%, respectively). There was evidence of cerebral vasculitis in 63%, which was exclusively located in large-sized vessels. Overall mortality was 21% for hemorrhage and 0% for infarction. HSV-1 was a major cause of hemorrhagic complications, whereas HSV-2 was the most prevalent agent in the ischemic manifestations.

CONCLUSION

We found a distinct pathogenesis, cause, and outcome for HSV-related cerebral hemorrhage and infarction. Vessel disruption within a temporal lobe lesion caused by HSV-1 is the presumed mechanism for hemorrhage, which may potentially have a fatal outcome. Brain ischemia is mostly related to multifocal cerebral large vessel vasculitis associated with HSV-2, where the outcome is more favorable.

Infection and Stroke: an Update on Recent Progress

The role of infection in cerebrovascular disease is complex and remains incompletely understood. Over the last 5 years, investigators have made notable inroads in untangling this thorny topic. In this review, we examine these recent developments, concentrating on four aspects of the relationship between infection and stroke. We first discuss specific infectious agents as direct causes of stroke, focusing on recent work implicating herpesviruses and HIV in cerebral vasculopathy. We then discuss systemic infection of any type as a stroke trigger, focusing on the relationship of infection to timing of acute stroke, both in children and adults, as well as the role of vaccination in stroke prevention. We examine the evidence for chronic infection or "infectious burden" as a stroke risk factor. Finally, we discuss recent work on infection as a risk factor for increased morbidity after stroke, possible mechanisms mediating this effect, and the evidence for prophylactic antibiotics.

Herpes Simplex Virus Type 2 Encephalitis as a Cause of Ischemic Stroke: Case Report and Systematic Review of the Literature

BACKGROUND AND AIM

Our objective is to describe a patient who developed an ischemic stroke as a complication of herpes simplex virus type 2 (HSV-2) encephalitis and to review the literature.

PATIENTS AND METHODS

A 45-year-old immune-competent Caucasian man presented with a 24-hour history of confusion and fever, and following clinical and laboratory examination was diagnosed with HSV-2 encephalitis. However, the brain magnetic resonance imaging also showed an acute ischemic infarct in the left frontal lobe corresponding to vascular territories of middle cerebral artery branches. Further screening failed to identify any other cause of the stroke. A systematic literature search was conducted in February 2015 using the PubMed database.

RESULTS

Six more cases of herpes simplex virus (HSV) central nervous system (CNS) infection that developed a definite ischemic stroke as a complication of the infection were identified.

CONCLUSIONS

Ischemic stroke, although infrequent, can complicate the evolution of herpes simplex meningitis or encephalitis. Clinicians should include HSV CNS infection as a possible cause of ischemic stroke, especially in young patients with ischemic stroke of unknown etiology.

Multiple strokes associated with herpes simplex virus type-2 infection: case report

Herpes simplex virus (HSV) type-2 is known to cause meningitis and usually runs a benign course. Association of such infection with vasculitis of the central nervous system is not well known. Presented here is a case initially diagnosed as aseptic meningitis that subsequently evolved as stroke and exhibited angiographic evidence of widespread vasculitis of the intracranial vessels in association with a positive polymerase chain reaction (PCR) for HSV-2 in the cerebrospinal fluid (CSF).

Advances in primary angiitis of the central nervous system

Primary angiitis of the central nervous system (PACNS) is a rare idiopathic inflammatory syndrome targeting the vessels of the brain and spinal cord. Clinical presentation is variable, insidious, and non-specific; headache and encephalopathy are the most common symptoms. Multiple strokes affecting numerous vascular territories may be seen, and both focal and diffuse neurologic dysfunction may be present. Cerebrospinal fluid (CSF) analysis is crucial; a normal CSF along with normal brain parenchymal imaging carries a high negative predictive value in excluding PACNS. The role of imaging continues to evolve, and most patients have abnormal vascular imaging; however, the specificity of imaging for PACNS has historically been poor. Cerebral and meningeal biopsy is a valuable tool in confirming the diagnosis and excluding mimics. PACNS generally responds to immunosuppressive therapy. Failure to respond should prompt evaluation for an alternative diagnosis. Given the rarity of this disorder, exclusion of mimics such as the reversible cerebral vasoconstriction syndromes (RCVS) and infectious processes is essential.

Lumbar puncture requirement in acute hemiparesis: diagnosis of tuberculous meningitis after hemiparesis in a child

BACKGROUND

Infections are an important acquired cause of cerebral arteriopathy. Tuberculous (TB) meningitis leading to infectious cerebral vasculopathy is a rare cause of acute hemiparesis.

CASE REPORT

A 14-year-old male patient was examined after acute hemiparesis developing within 1 day. Neurological examination revealed total hemiplegia on the left side. Brain MRI findings showed bilateral focal T2-weighted signal hyperintensity in the subcortical and deep white matter regions. There were also areas of restricted diffusion in the right basal ganglia. Although the father had a history of pulmonary TB, the patient had not been given TB prophylaxis because of PPD negativity. At lumbar puncture, opening cerebrospinal fluid (CSF) pressure was 50 cm/H20, CSF protein 66.9 mg/dL, and glucose 54 mg/dL (concurrent blood glucose 93 mg/dL); 170 polymorphonuclear leukocytes per cubic millimeter were present in CSF. Following tests for TB, treatment was started immediately with four anti-TB drugs. TB PCR of CSF and acid-fast bacteria (AFB) staining in gastric aspirate were positive. At clinical follow-up, the patient was able to walk with support at the end of the first month.

CONCLUSION

Various infectious agents have been reported as causes of cerebral vasculopathy. TB, which affects a significant number of patients worldwide, should be kept in mind in terms of cerebral vascular complications. Lumbar puncture is essential in order to diagnose TB meningitis.

Skew deviation: clinical updates for ophthalmologists

PURPOSE OF REVIEW

This article discusses the current approach in diagnosing skew deviation, as well as recent findings in the lesion localization.

RECENT FINDINGS

Skew deviation can be defined as vertical misalignment of the eyes that does not map to any of cyclovertical muscles, in association with neurologic symptoms and signs and with posterior fossa lesion. It can be differentiated from trochlear nerve palsy by the direction of ocular torsion and the change in the degree of vertical deviation with upright and supine head position. It is commonly caused by ischemia of the posterior paramedian pons, medial thalamus, or cerebellum. Other less common mechanism being demyelinating lesion, mass effect, infection, hemorrhage, or intracranial hypertension. When the vestibular nuclei are involved, skew deviation may occur with acute vestibular syndrome. Ground-in or Fresnel prism may alleviate diplopia in relatively small vertical deviation; however, patient with larger deviation or with the presence of ocular torsion may benefit from surgery of the cyclovertical muscles.

SUMMARY

Skew deviation can be appropriately diagnosed from the nature of the ocular torsion and the vertical deviation, along with the presence of lesion involving posterior paramedian pons and/or medial thalamus.

Hemorrhagic and ischemic stroke secondary to herpes simplex virus type 2 meningitis and vasculopathy

Herpes simplex virus type 2 (HSV-2) meningitis dogmatically is benign and self-limited in the immune competent patient. However, we describe how left untreated HSV-2 meningitis can be complicated by vasculitis and both ischemic and hemorrhagic stroke. We report a 57-year-old woman with lymphocytic meningitis complicated by ischemic stroke and intracerebral hemorrhage in the setting of vasculopathy and HSV-2 DNA detected in CSF successfully treated with acyclovir and corticosteroids. Subsequent angiographic magnetic resonance imaging revealed improvement in the vasculopathy after treatment. This case demonstrates that HSV-2 meningitis may take a less benign course and further provides the first evidence of angiographic improvement in addition to clinical improvement after definitive treatment.

Primary herpes virus infection and ischemic stroke in childhood: a new association?

We describe, to our knowledge, the first case of arterial ischemic stroke after primary herpes simplex virus type 1 (HSV1) infection in a previously healthy child, without signs of encephalitis. A 10-year-old previously healthy girl was admitted to our hospital with acute left-sided hemiparesis which involved the lower half of her face. Submandibular lymphadenitis and oral vesicular lesions were present. MRI confirmed the suspicion of an acute ischemic stroke. Immunoglobulin M antibodies to HSV1 were detected. Cerebrospinal fluid polymerase chain reaction for herpes virus was negative. She was treated with aspirin (3mg/kg) and intravenous acyclovir (10mg/kg every 8 hours) for 21 days. Immunoglobulin G antibodies to HSV1 appeared 16 days after admission. Twelve months after her hospitalization the patient's examination was normal. Stroke should be considered a possible complication of HSV1 primary infection. Guidelines for the management of acute stroke in children are needed.