Synonyms
Cerebrospinal fluid Medical: Cerebrospinal fluid
Definition
The cerebrospinal fluid (liquor cerebrospinalis), also known as cerebrospinal fluid, is an endogenous fluid that is largely formed in the chambers (ventricles) of the brain by specialized vascular plexuses, the so-called plexus choroidei. It is formed by filtering the blood. The human body has about 100-150 ml of cerebrospinal fluid (liquor).
However, since the specialized cells of the plexus choroid egg produce about 500 ml of cerebrospinal fluid per day, the entire fluid volume must be exchanged between 3 and 4 times a day. This is done by reabsorption of the cerebrospinal fluid into the venous vascular system via protuberances of the spider web skin (arachnoidea). The protuberances are known as Pacchioni granulations or arachnoid villi.
If this resumption did not exist, the intracranial pressure would steadily increase and lead to hydrocephalus. The normal cerebrospinal fluid pressure is between 70 and 220 mmH2O, but can fluctuate throughout the day as well as during pressurized breathing or when changing position. Since the cerebrospinal fluid is connected to the tissue fluid of the brain, its composition is similar.
By flushing around the brain and the spinal cord, the cerebrospinal fluid protects the central nervous system from external influences such as vibration. It is also said to have a nutritional function for nerve cells. However, more precise details are not yet known.
The cerebrospinal fluid/spinal fluid is located in two anatomically distinct spaces that are, however, connected to each other: the outer and inner cerebrospinal fluid space. The system consists of 4 ventricles connected in series: 2 symmetrical lateral ventricles in the cerebrum (telencephalon), a 3rd ventricle in the diencephalon and a 4th ventricle in the rhomboid brain (rhombencephalon). The ventricles are connected to each other.
Between the two lateral ventricles and the 3rd ventricle there is a connection in the form of one foramen interventricularis each. The aqueduct leads from the 3rd to the 4th ventricle. The latter passes into the central channel of the spinal cord.
Outer and inner CSF space are also connected via a total of three openings: two lateral apertures and one median aperture, which lead from the ventricle system into the subarachnoid space. Examination of the cerebrospinal fluid obtained during the puncture allows conclusions to be drawn about the pathogen causing the disease. The pathogen of the disease can be of bacterial or viral origin.
Sometimes the pathogens are also fungi, and in the case of a brain tumor, tumor cells can also be detected in the cerebrospinal fluid. The composition of the electrolytes, the sugar (glucose) and proteins allows to determine which therapy is most appropriate. This system can be well illustrated using the example of meningitis.
For example, in a bacterially caused meningitis, the protein is greatly increased, while the sugar is very low and the lactate is also greatly increased. In viral meningitis, on the other hand, the proteins are only slightly elevated, while sugar and lactate remain inconspicuous. A special case is meningitis, which is caused by the tuberculosis pathogen.
Here too, the protein is greatly increased, but the lactate is only slightly increased, while the sugar is decreased.
- The outer cerebrospinal fluid space is located between the two parts of the soft meninges, between pia mater and spider web skin (arachnoidea). This gap, in which the cerebrospinal fluid flows, is also called the subarachnoid space and is found around both the brain and the spinal cord.
- The inner cerebrospinal fluid space consists of a system of cavities in the brain, the so-called ventricle system.
These ventricles also contain the plexuses in which the cerebrospinal fluid is produced. They therefore have a transport and production function.
Of course, not only these parameters are investigated in the spinal fluid. The so-called cerebrospinal fluid is usually still examined by microbiologists.
During the examination, the pathogens are incubated from the cerebrospinal fluid so that after a few days it is clear which specific pathogen is involved. These can be bacteria such as meningococcus or pneumococcus. These can then be treated with antibiotics.
It is important to choose the right antibiotic, this is determined by a so-called antibiotic test.For this antibiogram, culture media are inoculated with the bacteria and various antibiotics and incubated for a few days. If the bacterium can grow despite the antibiotic, this is called resistance. If the bacterium cannot grow in places where there is also an antibiotic, this antibiotic can be used to treat this bacterium.
The antibodies IgM and IgG initially play an important role in the diagnosis of viral pathogens. These antibodies are produced by the body and allow conclusions to be drawn as to whether it is an old or a new viral infection. The viral proteins, which are, so to speak, the business card of the viruses, can be examined in a Western blot or by an immunofluorescence test. If the virus itself is to be broken down, genome sequencing can be performed.
