What causes viral encephalitis?

Viral meningitis is a relatively common form of meningitis. The characteristic of this type of meningitis is that it develops very quickly, causing great pain to patients. If it is not treated well, it may lead to some sequelae and even have a greater impact on the patient's future life. There are many causes of viral encephalitis, the most common of which is enterovirus infection, as well as mumps virus and lymphocytic choriomeningitis virus.

What causes viral encephalitis?

With the development of virological research, especially tissue cell culture, blood and cerebrospinal fluid infection etiology detection technology, it has been made clear that most of the diseases are enterovirus infections, followed by mumps virus and lymphocytic choriomeningitis virus, and a few are herpes viruses including herpes simplex virus and varicella-zoster virus. In addition, viruses such as infectious mononucleosis virus and cytomegalovirus can occasionally cause this disease. Enterovirus is a smallest non-enveloped RNA virus that can survive in sewage for a long period of time. Humans are the natural host of enterovirus. Once enterovirus enters the human body, it can enter the cell cytoplasm and damage and kill the cell. Enteroviruses are generally divided into three types, namely poliovirus, coxsackievirus and echovirus. In addition, there are enteroviruses that have not yet been classified. Each of these enteroviruses has many subtypes. For example, Coxsackievirus has type A and type B, but both types can cause viral meningitis, and occasionally encephalitis and acute cerebellar ataxia. Echovirus can be isolated from normal feces through cell culture and is generally not pathogenic. There are more than 30 serotypes of echovirus.

Pathogenesis of viral meningeal diseases

The virus enters the lymphatic system through the intestines (such as enterovirus) or respiratory tract (such as adenovirus and rash disease) to multiply, and then infects certain extracranial organs through the bloodstream (arboviruses enter the bloodstream directly). At this time, the patient may have systemic symptoms such as fever. In the later stage of viremia, it enters the central nervous system and enters the cerebrospinal fluid through the choroid plexus, causing central nervous system symptoms. If the host develops a strong immune response to viral antigens, it will further lead to demyelination and damage to vascular and perivascular brain tissue. The virus can also cause myocarditis, pharyngitis, intercostal muscle pain and skin damage in the human body. Pathological changes are mostly diffusely distributed, but may also be prominent in certain cerebral lobes and tend to be relatively localized.