Definition
Lumbar puncture is a procedure for the removal of cerebrospinal fluid (liquor). The derivation of the word lumbar puncture already reveals a lot about how this procedure is performed. The word part “lumbar” is derived from the Latin word lumbus, which means loin.
This means that a puncture is performed in the area of the lumbar or lumbar spine. Puncture is understood to be the insertion of a special needle into a cavity of vessels or organs. In the case of a lumbar puncture, a needle is inserted into the lumbar spine to extract cerebrospinal fluid, which flows around the spinal cord.
Indication Purpose
Lumbar puncture is used to remove liquor. This is then further examined in the laboratory to draw conclusions about possible neurological diseases. It is determined which proportions of cells are present in which concentration, because deviations from the normal concentration can allow conclusions to be drawn about the cause of the illness.
For example, bacteria can be detected in the cerebrospinal fluid, which can cause inflammation of the nerves and brain. Inflammation also results in more white blood cells (leukocytes), which can be detected in the cerebrospinal fluid by laboratory analysis. Furthermore, the sugar level (glucose) in the cerebrospinal fluid and nerve fluid can be determined.
This value is, for example, lower in inflammations than in healthy patients. Consequently, a diagnostic indication for lumbar puncture is the detection of inflammatory diseases of the central nervous system, such as meningitis, encephalitis or multiple sclerosis (MS). In addition to physical examinations and imaging procedures for the diagnosis and monitoring of multiple sclerosis (MS), an important component is lumbar puncture and the associated examination of cerebrospinal fluid.
In patients suffering from MS, the components of the cerebrospinal fluid change in comparison to patients not suffering from MS, so that certain antibodies (part of the body’s immune system) and proteins are found in the cerebrospinal fluid. The diagnosis “MS” is made together with the patient’s medical history and physical examination to determine the presence of certain antibodies in specific concentrations in the cerebrospinal fluid. The indications for a lumbar puncture in children are similar to those for adults.
However, the performance of a lumbar puncture varies depending on the age of the child. For children, CSF puncture can also be performed lying down or sitting down. A special feature, however, is that the puncture for obtaining cerebrospinal fluid can be performed not only in the lumbar region, i.e. lumbar, but also directly between the first cervical vertebra and the skull (suboccipital puncture), while the chin points to the chest.
This examination is also performed on children under sedative and anaesthetic medication. It is very important that the lumbar puncture is performed in the presence of the parents, so that the children are calmer and less afraid. In addition, bleeding can also be detected by lumbar puncture, because blood or free hemoglobin (a component of red blood cells) is found in the puncture site.
Normally, blood and cerebrospinal fluid components should be strictly separated by the blood-cerebrospinal fluid barrier, and any deviation or disturbance of this barrier can also be detected by a lumbar puncture. Lumbar puncture is also used if a tumor disease is suspected, because tumor cells can be found in the cerebrospinal fluid. A further indication for lumbar puncture is the suspicion of an increase in pressure in the brain.
Similar to blood pressure, cerebrospinal fluid is also subject to a limit that is healthy for humans. Deviations from the healthy norm can be determined by measuring the cerebrospinal fluid pressure. In summary, it can be concluded that CSF puncture has a diagnostic value.
However, cerebrospinal fluid puncture is also important in everyday therapy, especially when drugs have to act in the central nervous system and cannot reach their site of action because of the blood-brain barrier. In this case, drugs (chemotherapeutics, antibiotics, painkillers for epidural anesthesia) can be injected into the cerebrospinal fluid via lumbar puncture and thus reach their site of action. In conclusion, it can be said that lumbar puncture can be used to detect and treat diseases.Before the lumbar puncture, a blood sample is taken to check for blood clotting.
It is also checked whether there is an increased intracranial pressure. If there is impaired blood coagulation and increased intracranial pressure, the lumbar puncture should be avoided. The collection of cerebral fluid is performed in the area of the lumbar spine, more precisely between the third and fifth lumbar vertebrae, because the spinal cord can no longer be injured at this point and a lot of cerebrospinal fluid is found there.
The procedure is performed in a sitting position while the patient bends the upper body forward or in a lying position with a slightly curved back. In this position, the space between the vertebrae is the greatest and the blood vessels are compressed, which reduces the risk of bleeding. Lumbar puncture is a procedure that can be painful under certain circumstances, which is why the affected area can be given a local anaesthetic as an option.
However, as this occurs very rarely, local anesthesia is often not used. Alternatively, the patient can also take a sedative drug which loosens the muscles and has a general calming and anxiety-relieving effect. In any case, a thorough disinfection of the skin area and the sterile execution of the brain water extraction are important.
When the local anesthetic is effective, a hollow needle is used to puncture the skin, the spinal column’s supporting apparatus of ligaments and the meninges lining the space around the spinal cord. Once these structures are overcome, the closure that blocks the needle from the inside is retracted to allow the cerebral fluid to drip out. Usually several samples of one to two milliliters are taken.
It is not necessary to suture the tiny wound afterwards, as it closes by itself. However, a sterile dressing should be applied and the wound should be checked at regular intervals, and the dressing should remain sterile to prevent infection. Lumbar puncture is usually a relatively short procedure of about 30 minutes, with preparation and follow-up, which can also be performed on the bed in the patient’s room. A thorough working method is required to prevent the spread of germs and other complications. If cerebrospinal fluid is not drained immediately, the procedure will be prolonged somewhat.
