Well shielded from harmful influences are the "gray cells" in their solid bony envelope. Nevertheless, some pathogens manage to overcome the numerous protective barriers and penetrate to our tax center. The immune system reacts with an inflammatory reaction, often with fatal consequences. An inflammation of the brain tissue is a serious illness that often ends in death. Their name derives from "encephalon", the Greek term for brain. Often there is an inflammation of the meninges or the spinal cord - one then speaks of meningoencephalitis or encephalomyelitis.
Causes of encephalitis
Triggers are almost always pathogens, especially viruses. Particularly vulnerable are the elderly and children and people with a deficiency. But also in otherwise healthy it can come in the context of a general infection such as an influenza, measles or mumps infection (parainfektiöse encephalitis) or as a reaction of the immune system to a vaccine (postvakzinale encephalitis) concomitant brain inflammation.
Bacteria (eg meningococci, pneumococci) - and, even more rarely, parasites and fungi are also possible pathogens - usually as a result of blood poisoning or a poor immune system, eg. In AIDS patients. Particularly feared here are cytomegalovirus and herpesvirus as well as cryptococci and toxoplasmas.
Also via a tick bite viruses (early-summer meningo-encephalitis = TBE) and bacteria (Lyme disease) can be transmitted. Rarely, an inflammation in the brain instead of by pathogens by other processes such. As a result of multiple sclerosis or autoimmune diseases arise.
Symptoms of encephalitis
Whether tiny viruses, slightly larger bacteria or branching mushrooms have found access to the brain - the consequences are basically the same. The immune system sends its defenses to the place of action to render the invaders harmless, causing swelling of the brain tissue.
This in turn has fatal consequences: Due to the tight-fitting, solid skull bone, the tissue does not have many opportunities to spread. The intracranial pressure increases and there is severe headache, nausea and vomiting. Later, impaired consciousness, memory and orientation disorders, confusion or hallucinations are added.
Depending on where the pathogens have settled, functional failures may show up. These include numbness, paralysis, visual and speech disorders, as well as seizures. If the meninges are affected, neck stiffness is added. In addition, those affected usually have a high fever and feel seriously ill.
Important: Affected persons need medical treatment as soon as possible. An ambulance should be called or an emergency clinic should be visited!
Diagnosis of encephalitis
The symptoms are usually so typical that the doctor can quickly make the suspected diagnosis, initiate specific examinations and initiate treatment. In particular, a poisoning must be excluded, which can cause very similar symptoms. In addition to the physical examination blood is taken, in which one can find for signs of inflammation and after pathogens or defense cells.
Important is an examination of cerebral water (CSF), which can provide information about the type of inflammation. Imaging techniques such as magnetic resonance imaging or computed tomography can detect brain swelling and abscesses (removal of the pathogens) and rule out other causes of the symptoms, such as bleeding or a tumor. In some cases, it is also necessary to look for another source of illness in the body, from where the pathogens move out and enter the brain. In convulsions, the brain waves are measured by EEG.
Treatment of encephalitis
The treatment is started as soon as possible in the intensive care unit. Depending on the condition of the patient, inter alia circulation-stabilizing, pain-reducing and antipyretic measures, respiration, infusions and / or installation of a catheter are necessary. In addition, a specific therapy for combating pathogens is initiated, whereby the doctor selects the medicines according to the type of germs, immune status and pre-existing conditions.
In bacteria, antibiotics are administered, in fungi antifungals, in viruses so-called antivirals. However, not all viruses can fight with it, so in some cases only general measures to combat symptoms and prevent complications remain.
Course and prognosis in encephalitis
It is difficult to make general statements about the course of encephalitis, as it depends strongly on the type of pathogen and the general condition of the person affected and on how fast the therapy started. Estimates suggest that around 2% of those with TBE die, while the herpes virus encephalitis still accounts for about 20% despite specific therapy - previously it was over 80%!
Not infrequently it comes z. As by the scars to permanent damage such as seizures or paralysis. Particularly in this regard, it should be remembered that vaccines prevent a range of viral diseases that can cause brain inflammation, as well as some meningococci and pneumococci.