^

Health

A
A
A

Encephalitis: causes and classification

 
, medical expert
Last reviewed: 21.11.2021
 
Fact-checked
х

All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.

We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.

If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.

Encephalitis is an inflammation of the brain substance. Currently, encephalitis is not only called infectious, but also infectious-allergic, allergic and toxic damage to the brain.

The classification of encephalitis reflects the etiological factors associated with them clinical manifestations and features of the course.

By the time of occurrence

  • Primary - independent diseases caused mainly by neurotropic viruses:
    • viral:
      • viral (polysone): herpetic, enterovirus, influenza, cytomegalovirus, rabies, etc .;
      • arbovirus (transmissible): tick-borne, mosquito (Japanese), Australian Murray Valley, American St. Louis;
      • caused by an unknown virus: epidemic (Economone);
  • microbial and rickettsial:
    • with syphilis;
    • borreliose;
    • typhus and others.
  • Secondary - diseases that occur against the background of the underlying disease:
    • postexemembrane:
      • measles;
      • rubella;
      • wind turbines;
    • post-vaccination:
      • after DTP;
      • after measles, rubella, mumps vaccination;
    • bacterial and parasitic:
      • staphylococcal;
      • streptococcal;
      • tubercular;
      • toxoplasmic;
      • chlamydial;
      • malarial and others;
    • demyelinating:
      • acute encephalomyelitis;
      • multiple sclerosis.

By the rate of development and flow:

  • super-fast;
  • sharp;
  • subacute;
  • chronic;
  • recurrent.

By localization:

  • cortical;
  • subcortical;
  • stem;
  • defeat of the cerebellum.

By prevalence:

  • leukoencephalitis (white matter damage);
  • polyoencephalitis (damage to gray matter);
  • panencephalitis.

By morphology:

  • necrotic;
  • hemorrhagic.

By gravity:

  • of moderate severity;
  • heavy;
  • extremely heavy.

Complications:

  • edema-swelling of the brain;
  • dislocation;
  • cerebral coma;
  • epileptic syndrome;
  • cystosis.

Outcomes:

  • recovery;
  • vegetative state;
  • gross focal symptoms.

Encephalitis caused by neurotropic viruses is characterized by epidemics, contagiousness, seasonality and climatic and geographic features of distribution. Depending on the primary localization of encephalitis are divided into stem, cerebellar, mesencephalic, diencephalic. Often, along with the substance of the brain, some parts of the spinal cord also suffer; in such cases they speak of encephalomyelitis. Encephalitis can be diffuse and focal, the nature of the exudate - purulent and serous.

Primary polyseason encephalitis

This group includes encephalitis of various etiologies, including those caused by enteroviruses Coxsackie (A9, B3, B6), ECHO (2, 11, 24) and many unknown viruses.

Clinical picture

In the clinical picture of enteroviral encephalitis several syndromes are distinguished: stem, cerebellar, hemispheric. Focal neurological symptoms develop against a background of moderately expressed common infectious and cerebral symptoms on the 2-5th day of the disease. The etiologic factor is identified in virological and serological studies. In the cerebrospinal fluid, lymphocytosis is usually detected.

The course is favorable, with complete regression of neurologic symptoms. Rarely are slight lesions of III, VI, VII pairs of cranial nerves, hemi and monoparesis, aphasic disorders. The most favorable cerebellar form, the recovery with it is always complete.

trusted-source[1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12]

Where does it hurt?

What do need to examine?

Translation Disclaimer: For the convenience of users of the iLive portal this article has been translated into the current language, but has not yet been verified by a native speaker who has the necessary qualifications for this. In this regard, we warn you that the translation of this article may be incorrect, may contain lexical, syntactic and grammatical errors.

You are reporting a typo in the following text:
Simply click the "Send typo report" button to complete the report. You can also include a comment.