A case of intracranial saccular aneurysm after primary varicella zoster virus infection

Pediatric Intracranial Aneurysms: Considerations and Recommendations for Follow-Up Imaging

BACKGROUND

Pediatric intracranial aneurysms (IAs) are rare. Compared with adult IAs, they are more commonly giant, fusiform, or dissecting. Treatment often proves more complex, and recurrence rate and de novo aneurysmogenesis incidence are higher. A consensus regarding the most appropriate algorithm for following pediatric IAs is lacking.

METHODS

We sought to generate recommendations based on the reported experience in the literature with pediatric IAs through a thorough review of the PubMed database, discussion with experienced neurointerventionalists, and our own experience.

RESULTS

Digital subtraction angiography (DSA) was utilized immediately post-operatively for microsurgically-clipped and endovascularly-treated IAs, at 6-12 months postoperatively for endovascularly-treated IAs, and in cases of aneurysmal recurrence or de novo aneurysmogenesis discovered by non-invasive imaging modalities. Computed tomographic angiography was the preferred imaging modality for long-term follow-up of microsurgically clipped IAs. Magnetic resonance angiography (MRA) was the preferred modality for following IAs that were untreated, endovascularly-treated, or microsurgically-treated in a manner other than clipping.

CONCLUSIONS

We propose incidental untreated IAs to be followed by magnetic resonance angiography without contrast enhancement. Follow-up modality and interval for treated pediatric IAs is determined by initial aneurysmal complexity, treatment modality, and degree of posttreatment obliteration. Recurrence or de novo aneurysmogenesis requiring treatment should be followed by digital subtraction angiography and appropriate retreatment. Computed tomography angiography is preferred for clipped IAs, whereas contrast-enhanced magnetic resonance angiography is preferred for lesions treated endovascularly with coil embolization and lesions treated microsurgically in a manner other than clipping.

Varicella Zoster Virus: A Common Cause of Stroke in Children and Adults

BACKGROUND

Varicella zoster virus (VZV) is a neurotropic, exclusively human herpesvirus. Primary infection causes varicella (chickenpox), after which the virus becomes latent in ganglionic neurons along the entire neuraxis. As cell-mediated immunity to VZV declines with advancing age and immunosuppression, VZV reactivates to produce zoster (shingles). One of the most serious complications of zoster is VZV vasculopathy.

METHODS

We reviewed recent studies of stroke associated with varicella and zoster, how VZV vasculopathy is verified virologically, vaccination to prevent varicella and immunization to prevent zoster, and VZV in giant cell arteritis (GCA).

FINDINGS

We report recent epidemiological studies revealing an increased risk of stroke after zoster; the clinical, laboratory, and imaging features of VZV vasculopathy; that VZV vasculopathy is confirmed by the presence of either VZV DNA or anti-VZV IgG antibody in cerebrospinal fluid; special features of VZV vasculopathy in children; vaccination to prevent varicella and immunization to prevent zoster; and the latest evidence linking VZV to GCA.

CONCLUSION

In children and adults, VZV is a common cause of stroke.

Developments in Varicella Zoster Virus Vasculopathy

Varicella zoster virus (VZV) is a highly neurotropic human herpesvirus. Primary infection usually causes varicella (chicken pox), after which virus becomes latent in ganglionic neurons along the entire neuraxis. VZV reactivation results in zoster (shingles) which is frequently complicated by chronic pain (postherpetic neuralgia). VZV reactivation also causes meningoencephalitis, myelitis, ocular disorders, and vasculopathy, all of which can occur in the absence of rash. This review focuses on the association of VZV and stroke, and on the widening spectrum of disorders produced by VZV vasculopathy in immunocompetent and immunocompromised individuals, including recipients of varicella vaccine. Aside from ischemic stroke, VZV infection of cerebral arteries may lead to development of intracerebral aneurysms, with or without hemorrhage. Moreover, recent clinical-virological case reports and retrospective pathological-virological analyses of temporal arteries positive or negative for giant cell arteritis (GCA) indicate that extracranial VZV vasculopathy triggers the immunopathology of GCA. While many patients with GCA improve after corticosteroid treatment, prolonged corticosteroid use may potentiate VZV infection, leading to fatal vasculopathy in the brain and other organs.

[Cerebral infarction and intracranial aneurysm related to the reactivation of varicella zoster virus in a Japanese acquired immunodeficiency syndrome (AIDS) patient]

A 35-years-old right-handed man admitted to our hospital with a worsening of dysarthria, left facial palsy and left hemiparesis for 2 days. Acquired immunodeficiency syndrome (AIDS) was diagnosed when he was 28 years old. At that time, he also was treated for syphilis. After highly active antiretroviral treatment (HAART) was introduced at the age of 35 years old, serum level of human immunodeficiency virus (HIV) was not detected, but the number of CD4+ T cells was still less than 200/μl. He had no risk factors of atherosclerosis including hypertension, diabetes and hyperlipidemia. He had neither coagulation abnormality nor autoimmune disease. Magnetic resonance imaging (MRI) showed acute ischemic infarction spreading from the right corona radiate to the right internal capsule without contrast enhancement. Stenosis and occlusion of intracranial arteries were not detected by MR angiography. Although argatroban and edaravone were administered, his neurological deficits were worsened to be difficult to walk independently. Cerebrospinal fluid (CSF) examination showed a mild mononuclear pleocytosis (16/μl).　Oligoclonal band was positive. The titer of anti-varicella zoster virus (VZV) IgG antibodies was increased, that indicated VZV reactivation in the central nervous system (CNS), although VZV DNA PCR was not detected. Therefore, acyclovir (750 mg/day for 2 weeks) and valaciclovir (3,000 mg/day for 1 month) were administered in addition to stroke therapy. He recovered to be able to walk independently 2 month after the admission.Angiography uncovered a saccular aneurysm of 3 mm at the end of branch artery of right anterior cerebral artery, Heubner artery, 28 days after the admission. We speculated that VZV vasculopathy caused by VZV reactivation in CNS was involved in the pathomechanism of cerebral infarction rather than HIV vasculopathy in the case.

[Current management of post-varicella stroke in children: a literature review]

Among infectious factors, varicella-zoster virus (VZV) is a leading cause of central nervous system vasculopathy and stroke in childhood. Not only have viral markers been detected in the cerebrospinal fluid of affected patients, but also direct evidence of viral particles in the wall of cerebral arteries has been demonstrated in rare pathological specimens. This certainly reflects a localized infectious process likely associated with variable indirect inflammatory responses. Yet the usefulness in this setting of a lumbar puncture as well as of subsequent targeted antiviral and/or anti-inflammatory therapies is uncertain. Indeed, in the majority of cases, the so-called post-varicella angiopathy has a monophasic evolution with spontaneous resolution or stabilization, explaining diverging diagnostic and treatment approaches. In this paper, we have addressed this problematic area by reviewing 26 published cases from the year 2000 and three unpublished cases. Post-varicella stroke is typically associated with angiopathy most often involving the initial portion of the middle cerebral artery, causing a basal ganglia stroke. It tends to occur in young immunocompetent children. Thrombophilia work-up is in general negative. Lumbar puncture was performed in 17 out of 29 cases. Viral markers were examined in 14 cases, but were positive in only eight cases. Antiviral therapy was administrated in 11 children. In this small retrospective study, the treated children's vasculopathy did not progress more favorably nor was there a better outcome compared with untreated subjects.