Viral central nervous system infections in children

[Sommer]

Central nervous system infections are extremely serious. Meningitis affects the membranes surrounding the brain and spinal cord. Encephalitis affects the brain itself.

Central nervous system infections caused by viruses can cause meningitis and encephalitis.
Symptoms usually start with fever and can progress to irritability, refusal to eat, headache, neck pain, and sometimes seizures.
The diagnosis of viral central nervous system infections is based on a spinal tap.
Many infections are mild, but others are severe and can cause death.
Antiviral drugs are usually not effective for most viruses that cause central nervous system infections, so children need to receive supportive measures (such as fluids and drugs to control fever and pain).

Viruses that infect the central nervous system (brain and spinal cord) include herpesviruses (see also herpes simplex virus infections), arboviruses, coxsackieviruses, echoviruses, and enteroviruses.
Some of these infections affect primarily the meninges (the tissues covering the brain and spinal cord) and are called meningitis. Viral meningitis is sometimes called aseptic meningitis. Meningitis can also be caused by bacteria (see Acute Bacterial Meningitis).
Other viral infections affect primarily the brain and are called encephalitis. Infections that affect both the meninges and brain are called meningoencephalitis. Meningitis is far more common among children than is encephalitis.
Viruses affect the central nervous system in two ways:

They can directly infect and destroy cells in the central nervous system and cause local swelling during the acute illness.
Certain viral infections elsewhere in the body can cause the immune system to attack and damage cells around the nerves.

This later damage (postinfectious encephalomyelitis or acute disseminated encephalomyelitis) typically causes symptoms a few weeks after recovery from the acute illness.
Children acquire infections of the central nervous system through various routes. Newborns can develop herpesvirus infections through contact with infected secretions in the birth canal (see Herpes Simplex Virus (HSV) Infection in Newborns). Other viral infections are acquired by breathing air contaminated with virus-containing droplets exhaled by an infected person. Arbovirus infections are acquired from bites by infected insects.
The symptoms and treatment of viral meningitis and encephalitis in older children and adolescents are similar to those in adults. The inability of infants to communicate directly makes it difficult to understand their symptoms. Usually, however, infants with central nervous system infections have some of the symptoms described below.