Prophylaxis
As with all pathogens, hygiene precautions are generally considered the most effective prophylaxis against infections. Washing hands and disinfection after using public toilets or similar can kill most of the bacteria and viruses ingested. Likewise, various diseases transmitted during sexual intercourse, such as infections with HIV or Treponema pallidum, can be prevented by contraception with condoms.
Other contraceptives do not protect against sexually transmitted diseases. Infection with herpes simplex I viruses is almost unavoidable, as the rate of infection in the population is extremely high. However, an outbreak of the diseases caused by the virus can be prevented by keeping the body healthy.
Vaccination against encephalitis causative agents is only possible to a limited extent. For example a standard ̈Dreifach ̈ vaccination of all children against rubella, measles and mumps is carried out. In some cases, vaccination against poliovirus is also carried out as part of this.
Three of these four viruses can cause severe infections of the CNS with permanent secondary damage, which is why all children should be vaccinated. Vaccination against the rabies virus can also be carried out. This is especially recommended for people who work a lot with wild animals, such as foresters. An infection with chickenpox should be overcome in childhood. This disease, caused by the varicella zoster virus, can cause severe permanent damage in adults.
Special forms of encephalitis
In meningoencephalitis, not only the brain (encephalitis) but also the meninges are affected by the inflammation. The meninges are structures of connective tissue that attach themselves to the brain and serve to protect the brain. Meningoencephalitis is mainly caused by viruses and less frequently by bacteria.
One of the most common forms in our latitudes is early summer meningoencephalitis (TBE). Typically, meningoencephalitis precedes another disease, e.g. an infection with measles, rubella or mumps. Children, the elderly and immunodeficient persons in particular are at increased risk of developing meningoencephalitis.
The symptoms of meningoencephalitis include severe headaches, nausea, stiff neck, loss of consciousness and various neurological deficits such as paralysis or speech disorders. The prognosis of a combined inflammation of the brain and spinal cord depends largely on the pathogen, but in all cases a rapid diagnosis and immediate start of therapy have a major influence on the course of the disease. The earlier treatment is started, the lower the risk of the patient suffering consequential damage.
Brainstem encephalitis or Bickerstaff encephalitis is a rare disease of the central nervous system in which antibodies are produced against the brain stem. The brainstem is a part of the brain that lies below the diencephalon and regulates important functions such as breathing and heart rate. The cause of brainstem encephalitis is not yet known, but it is suspected that the disease is caused by an infection with bacteria or viruses.
Typical symptoms are dizziness, speech disorders and coordination difficulties. With the right treatment, brainstem encephalitis can be treated well and heals completely. When the central nervous system is infected with viruses or bacteria, the body tries to eliminate the pathogens through an acute inflammatory reaction.
Lymphatic encephalitis is characterized by a lymphocyte-dominated inflammatory reaction. Lymphocytes are part of the immune system and include certain cell types that lead to a specific defense reaction. Certain pathogens cause necrotising encephalitis, in which the tissue in the brain dies by a certain form of cell death – necrosis.
Herpes simplex viruses, for example, lead to hemorrhagic necrosis of certain areas of the brain: this means that nerve cells die by necrosis and at the same time there is heavy bleeding into the affected area (“hemorrhagic”). The severe course of the disease means that the inflammation of the brain is often fatal or the survivors suffer permanent neurological damage.Encephalitis lethargica is also known as European sleeping sickness and is an inflammation of the brain that leads to sudden sleep attacks. The disease was first described at the beginning of the 20th century and occurred more frequently in Europe at that time.
Nowadays, the disease is rare and some diseases occur only sporadically. The exact causative agent of European sleeping sickness is not known yet, but it is probably a virus. The main characteristic of Encephalitis lethargica is the uncontrolled sleep attacks from which the affected persons cannot be awakened at all or only with great difficulty.
In addition, the patients show neurological disorders similar to Parkinson’s disease. After the strokes, the patients suffer from severe headaches, nausea and high fever. Neurological disorders can still occur years after the disease has healed.
Encephalitis disseminata is better known as multiple sclerosis (MS). It is a chronic autoimmune disease with a relapsing or progressive course. The trigger of the disease is not yet known, but it is suspected that a genetic predisposition and various environmental components contribute to the onset of the disease.
In multiple sclerosis, the body erroneously produces antibodies against the envelope layer of nerve fibers. This destroys these structures and leads to inflammation in the brain and spinal cord. Multiple sclerosis is diagnosed by means of magnetic resonance imaging (MRI) and lumbar puncture, during which spinal fluid is taken and examined for destroyed nerve components.
MRI reveals lesions and scars in the brain caused by the inflammation. The symptoms are very varied, which is why the disease is also known as the “disease with a thousand faces”. The symptoms range from visual disturbances, paralysis and sensory disturbances to coordination disorders.
So far, Encephalitis disseminata is not curable, but there are very good treatment options that enable those affected to lead an almost symptom-free life. Vascular means “affecting the blood vessels“. In vascular encephalitis, the inflammation damages the blood vessels in the brain.
This results in circulatory disorders and an undersupply of oxygen to the nerve cells. The consequences are severe neurological symptoms such as speech disorders, dizziness, nausea or blindness.