Encephalitis – brain at risk

Well shielded from harmful influences, the “grey cells” lie in their solid bone shell. Nevertheless, some pathogens overcome the protective barriers and penetrate our control centre. The immune system reacts with an inflammatory reaction, often with fatal consequences. Inflammation of the brain tissue is a severe disease that usually ends fatally. Their name derives from “encephalon”, the Greek term for brain. There is often simultaneous inflammation of the meninges or spinal cord – one then speaks of meningoencephalitis or encephalomyelitis.

Causes of encephalitis

The triggers are almost always pathogens, especially viruses. Older adults, children, and people with a weakened immune system are particularly at risk. But even in otherwise healthy people, accompanying inflammation of the brain can occur as part of a general infection such as influenza, measles or mumps infection ( parainfectious encephalitis ) or as a reaction of the immune system to a vaccination ( postvaccinal encephalitis ).

Bacteria (e.g. meningococci, pneumococci ) – and, even more rarely, parasites and fungi are also possible pathogens – mainly due to blood poisoning or a poor immune system, e.g. B., in AIDS patients. The cytomegalovirus and herpes virus, as well as cryptococci and toxoplasma, are particularly feared here.

Viruses (tick-borne encephalitis = TBE) and bacteria ( Lyme disease ) can also be transmitted via a tick bite. Rarely, inflammation in the brain can be caused by other processes instead of pathogens, e.g. B. in the context of multiple sclerosis or autoimmune diseases.

 

Symptoms of encephalitis

It doesn’t matter whether tiny viruses, slightly larger bacteria or branching fungi have found access to the brain – the consequences are the same. The immune system sends defences to the scene to render the invaders harmless, which causes brain tissue to swell.

This, in turn, quickly has fatal consequences: due to the close-fitting, solid skull bones, the tissue does not have many opportunities to spread. The intracranial pressure increases, and severe headaches, nausea and vomiting occur. Disorders of consciousness, memory and orientation disorders, confusion or hallucinations arise later.

Depending on where the pathogens have settled, functional failures can occur. These include numbness, paralysis, visual and speech disorders, but also seizures. If the meninges are also affected, a stiff neck occurs. In addition, those affected usually have a high fever and feel seriously ill.

Important:  those affected must seek medical treatment as soon as possible. An ambulance should be called or an emergency room visited!

Diagnosis of encephalitis

The symptoms are usually so typical that the doctor can quickly make a suspected diagnosis, arrange for specific examinations and initiate treatment. In particular, poisoning, which can cause similar symptoms, must be ruled out. In addition to the physical examination, blood is taken, in which one can find signs of inflammation and pathogens or immune cells.

Examining the cerebrospinal fluid (liquor puncture) is essential, as it can provide information about the type of inflammation. Imaging procedures such as magnetic resonance imaging or computer tomography can detect brain swelling and abscesses (colonization of the pathogen) and rule out other causes of the symptoms, such as bleeding or a tumour. Sometimes, you have to look for another focus of the disease in the body from where the pathogens can move out and get into the brain. In the case of cramps, the brain waves are measured using EEG.

 

treatment of encephalitis

Treatment begins as soon as possible in the intensive care unit. Depending on the patient’s condition, measures to stabilize the circulation and reduce pain and fever, ventilation, infusions, and the installation of a catheter may be necessary. In addition, a specific therapy to combat pathogens is initiated, whereby the doctor selects the medication, among other things, according to the type of germs, immune system and previous illnesses.

Antibiotics are administered to bacteria, antimycotics to fungi, and antiviral drugs to viruses. However, not all viruses can be combated with it, and 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 since this depends heavily on the type of pathogen, the general condition of the person affected, and how quickly the therapy was started. Estimates assume that about 2% of those affected die from TBE, and about 20% die from encephalitis caused by the herpes virus despite specific therapy – it used to be over 80%!

It is not uncommon for B. scars to cause permanent damage, such as seizures or paralysis. From this point of view, it is essential to remember that vaccinations can be used to prevent several viral diseases that can cause encephalitis, as well as some meningococci and pneumococci.