Viral Encephalitis

Viral Encephalitis
Body Parts: Head
Medical Subjects: Children's Health Nervous System Brain

What Is Viral Encephalitis?

Viral encephalitis refers to brain inflammation caused by virus, which is manifested as neurological dysfunction. Such as mental state, behavioral or personality changes, motor or sensory dysfunction, speech or motor disorders, and seizures.

Is the incidence, disability and death rate of viral encephalitis high?

International data show that the hospitalization rate related to pediatric encephalitis is 3~13 times per 100,000 children every year. However, some children's encephalitis is not caused by viruses.

The overall death risk of childhood encephalitis is 0~7%. However, the mortality rate of some specific pathogens, such as herpes simplex encephalitis, is higher. Without treatment, the mortality rate of patients with herpes simplex encephalitis can be close to 70%, and most survivors have severe neurological dysfunction, and obvious neuropsychiatric and neurobehavioral problems appear. Even if patients are properly diagnosed and treated, their mortality rate may still be as high as 20%-30%.

Is viral encephalitis contagious? In what ways is viral encephalitis mainly transmitted?

Viral encephalitis itself is not contagious. But the virus that causes viral encephalitis is contagious. Different viruses are transmitted in different ways. This can be roughly divided into:

Direct contact propagation

Non-polio enteroviruses, paraenteroviruses are the most common. It is transmitted by direct or indirect oral contact with viruses excreted in the feces. Such transmission is mostly caused by poor sanitation conditions and may involve multiple routes of contaminated water, food and pollutants. A few of these serotypes can be transmitted by respiratory route, such as coxsackievirus A21 and enterovirus D68.

Herpes simplex virus is also a relatively common pathogen. The modes of infection include intrauterine infection, HSV infection in the reproductive tract of pregnant women during childbirth, and close contact between newborns and caregivers who carrying virus.

Insect bite transmission

Arbovirus, such as Japanese encephalitis virus (JEV), dengue virus, is relatively common in mosquito-infested areas and is transmitted by mosquito bites.

Respiratory transmission

Such as influenza virus, respiratory syncytial virus(RSV), human metapneumovirus, adenovirus, and parainfluenza virus, are transmitted through the respiratory tract.


What Is The Cause Of Viral Encephalitis?

Viruses that can cause viral encephalitis include Japanese encephalitis virus, herpes simplex virus, influenza virus, adenovirus, enterovirus and cytomegalovirus.

In which groups are viral encephalitis prone to disease?

Children are relatively common. It may be because children's immunity is relatively low.


What Are The Symptoms Of Viral Encephalitis?

  • Fever.
  • Epilepsy: manifested as body convulsions, twisting of one limb, facial convulsions, etc.
  • Other nervous system positioning signs: limb strength decline, cranial nerve dysfunction, etc.
  • Low level of consciousness: easy to fall asleep, confused about time, location and so on.

What serious consequences can viral encephalitis cause?

Severe cases can lead to death, respiratory failure, etc. After cure, some patients will have sequelae, such as mental decline, limb hemiplegia, limb activity difficulties or abnormal movements.


What Tests Do Viral Encephalitis Need?

Generally, cranial MRI, lumbar puncture, and laboratory tests are performed as quickly as possible. Cranial MRI is best performed as quickly as possible, and lumbar puncture is performed thereafter. Cerebrospinal fluid was extracted by lumbar puncture for relevant examination, and certain characteristic manifestations of cerebrospinal fluid can suggest viral encephalitis. Pathogens can also be better identified in cerebrospinal fluid by etiological testing.

What conditions do patients with viral encephalitis need to seek medical treatment in time?

Encephalitis often has fever, headache, nausea and vomiting and is accompanied by one of the following symptoms:

  • Sleepiness.
  • Character change.
  • Abnormal behavior.
  • Seizures.

Is viral encephalitis meningitis? How is viral encephalitis and meningitis distinguished?

  • Encephalitis refers to inflammation of the brain parenchyma. Meningitis is inflammation of the meninges.
  • The most dangerous type of meningitis is bacterial meningitis, but most of the viruses that cause viral encephalitis can also cause meningitis.
  • The main feature of meningitis is the clinical symptoms and signs of meningeal irritation. The symptoms suggesting meningitis include neck stiffness, photophobia, and fontanelle bulge in children. The pain of meningitis often points to the back of the orbit or the forehead. The headache of encephalitis is not clear and can be diffuse.
  • It should also be noted that many children will suffer from viral encephalitis + viral meningitis at the same time, which we collectively call viral meningoencephalitis.

How To Prevent Viral Encephalitis?

  • Both adults and children should wash their hands actively.
  • Appropriate identification and treatment of genital herpes simplex virus infection during pregnancy to prevent neonatal herpes simplex infection.
  • Vaccination. such as measles, mumps, rubella, chickenpox, Japanese encephalitis, influenza.
  • Prevent pests. For example, use mosquito nets and DEET. Drain the standing water. Avoid being bitten by insects when passing through forests, grasses, etc.

How To Treat Viral Encephalitis?

Can viral encephalitis heal on its own?

Although there is a self-healing phenomenon of viral encephalitis. However, many viral encephalitis have a high mortality rate without treatment and a high incidence of sequelae. Treatment can reduce the mortality and the incidence of sequelae.

How effective is the treatment of viral encephalitis?

Different pathogens have different therapeutic effects, and the results of different ages and different severity are also very different. At the same time, the speed of recovery under different conditions is also different, and it cannot be generalized.

Will viral encephalitis recur? What are the characteristics of relapse?

Some viral encephalitis will not recur, such as Japanese encephalitis, which can produce lifelong immunity after infection. However, many viruses cannot. Even if immunity occurs, different serotypes may repeat.

In addition, it has been found that some viral encephalitis can induce autoimmune encephalitis. This point is most certain in herpes simplex encephalitis, which begins to appear 4~6 weeks (median time) after the initial virus infection. That is, it can appear at the same time as herpes simplex encephalitis, and it can also appear in the rehabilitation process of herpes simplex encephalitis.

In terms of symptoms, there is no difference between the recurrence of viral encephalitis and the secondary autoimmune encephalitis. However, it is necessary to distinguish the recurrence of viral encephalitis from secondary autoimmune encephalitis, because their treatment is quite different.

Can viral encephalitis affect children's intelligence development?

Mild infections often do not, but moderate and severe infections often do it.

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