ABSTRACT
Group of viral, bacterial, and protozoan infections that gain access to the fetal bloodstream transplacentally, results in severe fetal anomalies or even fetal loss. Other differentials include congenital Zika virus, which is an intensely neurotropic virus and presents with microcephaly, ventriculomegaly, calcifications at gray—white matter junction, premature closure of anterior fontanelle, callosal dysgenesis, and neuronal migration abnormalities. Infection of the meningeal coverings of the brain can be pyogenic (bacterial), acute lymphocytic (viral), or chronic. Imaging features of acute pyogenic meningitis are very non-specific and can be seen under a variety of conditions. Clinical correlation plays an important role. Temporal abscess occurs via erosion of tegmen tympani, and cerebellar abscess occurs via Trautmann’s triangle. Hemorrhagic necrotizing encephalitis is caused most commonly by Herpes simplex virus-1 (HSV1) through reactivation of latent virus from trigeminal nerve ganglia, usually under immunosuppressive conditions. In children, HSV2 is the more common causative organism, involving the parietal cortex but sparing the limbic system and the temporal lobes.
