Other CNS Infections Year 4 Paediatrics Notes OmpathStudy

Other CNS Infections Year 4 · Paediatrics Collection: 4TH YEAR ALL NOTES / PAEDS / PAEDS 4.3 / Munge / CNS -- Slide 1 Other CNS Infections Dr Rose Munge Slide 2 Outline Viral Meningoencephalitis Eosinophilic Meningitis Brain Abcess Slide 3 Viral Meningoencephalitis Viral meningoencephalitis is an acute inflammatory process involving the meninges and/or brain parenchymal tissue.\nThese infections are caused by a number of different pathogens, quite often, no pathogen can be identified from the CSF and brain tissue specimens.\nThe CSF is characterized by pleocytosis and the absence of microorganisms on Gram stain and routine bacterial culture.\nOutcomes are variable because cases of meningoencephalitis caused by some pathogens are self-limited whereas others cause significant long-term neurologic sequelae. Slide 4 Etiology Among the most common causes of viral meningoencephalitis are viruses of the family Picornaviridae, including the enteroviruses (poliovirus, coxsackievirus, enterovirus, and echovirus) and parechoviruses.\nMeningoencephalitis caused by these viruses is often self-limited but can be severe in neonates or chronic in immunocompromised hosts.\nHuman coxsackievirus A7 and enteroviruses D68 and 71 have been associated with neurologic symptoms, including acute flaccid paralysis. Slide 5 Parechoviruses are an important cause of meningoencephalitis in infants and rarely cause disease in older children.\nThe clinical manifestations are similar to those of the enteroviruses, but infants with parechovirus infection may exhibit abdominal signs or a sepsis-like syndrome.\nIn addition, parechovirus infection is associated with more severe MRI lesions of the cerebral cortex, and CSF pleocytosis may be minimal or absent Slide 6 Arbovirus refers to a broad range of viruses from multiple viral families that are transmitted by arthropod vectors, typically mosquitoes or ticks.\nMost of these viral infections are considered zoonotic, as their primary reservoir is in birds or small animals.\nHumans are often dead-end hosts because a sufficient viremia does not develop to enable transmission back to arthropod vectors.\nHumans are the primary reservoir for viruses such as Zika, chikungunya, and dengue.\nThe most common arboviruses that cause meningoencephalitis include West Nile virus (WNV), Japanese encephalitis virus, and La Crosse virus, with other arboviruses. Slide 7 WNV may also be transmitted by blood transfusion, organ transplantation, or vertically across the placenta.\nMost children with WNV are either asymptomatic or have a nonspecific viral-like illness.\nApproximately 1% of infected humans develop CNS disease; adults are more severely affected than children.\nSeveral members of the viral family Herpesviridae can cause meningoencephalitis.\nHerpes simplex virus (HSV) type 1 is an important cause of severe, sporadic encephalitis in children and adults, with progression to coma and death in 70% of cases without antiviral therapy.\nIn neonates, severe encephalitis with diffuse brain involvement can be caused by HSV type 2, transmitted vertically at delivery. Slide 8 A mild transient (and sometimes recurrent) form of meningoencephalitis with HSV type 2 may accompany genital herpes infection in sexually active adolescents and adults.\nVaricella-zoster virus may cause CNS infection in a close temporal relationship with clinical manifestations of chickenpox.\nThe most common manifestation of CNS involvement is cerebellar ataxia and the most severe is acute encephalitis.\nAfter primary infection, varicella-zoster virus becomes latent in spinal and cranial nerve roots and ganglia, and reactivation occurs as herpes zoster that can be accompanied by mild meningoencephalitis.\nEpstein-Barr virus is associated with various CNS syndromes. Slide 9 Cytomegalovirus infection of the CNS can occur with congenital infection or disseminated disease in immunocompromised hosts, but is a rare cause of meningoencephalitis in immunocompetent infants and children.\nHuman herpesvirus 6 is associated with encephalitis, but detection of the virus can also be reflective of latency in lymphocytes with reactivation due to inflammation. Mumps can cause meningoencephalitis and has a higher incidence in regions where the mumps vaccine is not distributed.\nMumps meningoencephalitis is typically mild, but deafness from damage of the 8th cranial nerve can occur. Slide 10 Meningoencephalitis is also associated with acute infection with measles, rubella, respiratory viruses (adenovirus, coronaviruses, influenza virus, parainfluenza virus, respiratory syncytial virus), rotavirus, lymphocytic choriomeningitis virus, or rabies.\n HIV is associated with acute meningoencephalitis and can cause chronic encephalopathy leading to neurocognitive decline.\n In exceptionally rare situations, meningoencephalitis may follow live virus vaccination against polio, measles, mumps, or rubella. Slide 11 Epidemiology Most cases of meningoencephalitis occur in the