Zika virus infection disrupts neurovascular development and results in postnatal microcephaly with brain damage.

Zika virus (ZIKV) infection of pregnant women can result in fetal brain abnormalities. It has been established that ZIKV disrupts neural progenitor cells (NPCs) and leads to embryonic microcephaly. However, the fate of other cell types in the developing brain and their contributions to ZIKV-associated brain abnormalities remain largely unknown. Using intracerebral inoculation of embryonic mouse brains, we found that ZIKV infection leads to postnatal growth restriction including microcephaly. In addition to cell cycle arrest and apoptosis of NPCs, ZIKV infection causes massive neuronal death and axonal rarefaction, which phenocopy fetal brain abnormalities in humans. Importantly, ZIKV infection leads to abnormal vascular density and diameter in the developing brain, resulting in a leaky blood-brain barrier (BBB). Massive neuronal death and BBB leakage indicate brain damage, which is further supported by extensive microglial activation and astrogliosis in virally infected brains. Global gene analyses reveal dysregulation of genes associated with immune responses in virus-infected brains. Thus, our data suggest that ZIKV triggers a strong immune response and disrupts neurovascular development, resulting in postnatal microcephaly with extensive brain damage.

A dural arteriovenous fistula in cavernous sinus developed from viral meningitis.

Although hormonal influences, inflammation, trauma, sinus thrombosis, venous hypertension, and congenital origin have been proposed as sources of dural arteriovenous fistulas (DAVFs) in cavernous and sigmoid sinuses, the etiology of these lesions remains controversial. We present a case with a cavernous sinus DAVF developed from viral meningitis which has not been previously described. A 24-year-old male was admitted to our institute because of periorbital pain, decreased vision, pulsatile tinnitus, chemosis, and exophthalmos on the right side after he had suffered viral meningitis four months before. Cerebral angiography demonstrated a cavernous sinus DAVF, which was successfully obliterated with several platinum coils using a transvenous approach. The viral meningitis most likely caused the inflammation, that may be responsible for the occurrence of the cavernous sinus DAVF. Prompt treatment for inflammation may help to prevent the development of DAVFs.