Definition
Viral encephalitis is an inflammation of the brain caused by viruses. There are various pathogens, such as the Herpes Simplex Virus or TBE. Often the symptoms begin abruptly, symptoms such as confusion, restlessness, paralysis can occur. Encephalitis is a life-threatening disease and requires rapid therapy.
Acute viral encephalitis
Viruses can enter the central nervous system (CNS, brain and spinal cord) in two ways:
- Either along nerves and nerve roots, e.g. the olfactory bulb, optic nerve, etc.
- Or via the bloodstream (hematogenic), which is far more common. Here, the viruses cross the blood – liquor – barrier or blood-brain barrier. This “barrier” is an (electron) microscopic filter between the blood vessels and the cerebrospinal fluid (nerve water) spaces of the brain, which ensures that no blood components enter the nerve water that flows around the brain. Sometimes this filter is not particularly tight, so that pathogens can cross the barrier more easily, or the pathogens themselves cause inflammatory processes in the vessels, which make the barrier leak. However, this depends on many factors, some of which are still unknown, such as the aggressiveness (virulence) of the pathogen and the current state of the human immune system and receptivity.
Symptoms of acute viral encephalitis
With a few exceptions listed below, the symptoms of viral encephalitis are similar for most pathogens. Often the symptoms begin abruptly. The temperature is elevated, neck stiffness, as it occurs in meningitis, is usually absent.
Many patients are clouded in their consciousness (i.e. not in a clear state of consciousness) and often exhibit other psychological symptoms such as:. Psychosis occurs in half of the cases. Depending on where in the brain the inflammatory process is predominant, different symptoms occur (neurological focal symptoms). These range from: Typically, viral encephalitis is preceded by a general viral disease such as rubella, measles, mumps, chickenpox, rubella.
- Confusion
- Unrest
- Aggressiveness
- Lack of drive
- Arm Paralysis
- Leg Paralysis
- Eye Paralysis
- Speech disorder
- Balance disorders
- Muscle rigidity
- Epileptic seizure
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