Spinal tap procedure is a diagnostic technique that involves withdrawal of the cerebrospinal fluid from the body to determine disease conditions of the central nervous system. In order to withdraw the cerebrospinal fluid, a needle is inserted into the lumbar portion. This is why, it is also known as lumbar puncture. There are also many other terms for spinal tap. Some of them are spinal puncture, rachicentesis and thecal puncture.
In human body, the central nervous system consists of brain and spinal cord. Cerebrospinal fluid is a liquid that circulates in the central nervous system. It acts as a buoyant support for the brain and spinal cord. It protects them from trauma and shock. The cerebrospinal fluid is composed of protein, glucose and mononuclear cells. It is normally clear in appearance. The study of cerebrospinal fluid reveals a lot about the condition of the central nervous system.
Spinal tap assists in the finding of stroke, spinal cord tumors, tuberculosis, Guillain-Barre syndrome, multiple sclerosis and infections like meningitis. It can also be done for therapeutic purposes. Some examples of spinal tap being used for treatment are administration of antibiotics, anesthetic agents, cancer medicines, etc. It is also used for withdrawing excess of cerebrospinal fluid to decrease the fluid pressure in the body of the patients suffering from benign intracranial hypertension.
Because of the various benefits of spinal tap procedure, it is quite popular among the medical practitioners. For the performance of spinal tap, you would most likely be asked by your doctor to lay your body in a lateral position. It can be either on the left or right. Your body should be bent in full flexion. It means that you would have to bend your neck and knees as much as you can.
Actually, you are supposed to bring your body in a position that resembles a fetus inside the mother's womb. Such a position curves the back and broadens the spaces between the vertebrae. This permits proper placement of the needle used in the spinal tap. Many doctors, while conducting spinal tap procedure for diagnosis, prefer their patient to sit on a stool with their head and shoulders bent forward. Therefore, it is a possibility that you may undergo spinal tap in a sitting posture as well.
The region around the lower back is prepared for the procedure with aseptic techniques. This is necessary to minimize the risk of infection. When the appropriate location is touched, the doctor infiltrates required amount of local anesthetic under the skin. It is done to numb the back so that the pain felt is minimum during spinal tap. It is then injected along the path that has been intended for the spinal tap process.
A spinal needle is inserted between the lumbar vertebrae L3/L4 or L4/L5 to withdraw a few drops of cerebrospinal fluid. A manometer can be used to measure the opening pressure of the cerebrospinal fluid during the collection. After the spinal tap procedure has been done, you should lie on your back or stomach continuously for 2-3 hours. This reduces the chances of getting a headache.
The cerebrospinal fluid is examined in detail to determine abnormalities of the brain and the spinal cord. Its appearance indicates a lot about the state of your central nervous system. For example, red or bloody fluid indicates bleeding in some part of the brain or spinal cord. It may also indicate some sort of obstruction in the spinal cord. If the cerebrospinal fluid is cloudy, you may be suffering from infection. In case the cerebrospinal fluid is white, yellow or orange in color, you may have levels of protein higher than the optimum limit.
While spinal tap procedure is being conducted, you are supposed to be perfectly still. Otherwise, the spinal-cord nerve may get damaged. There can be some side effects from spinal tap procedure. They range from infections to headache. Infections generally get introduced in your body by unsterilized needles and other instruments.
You might be allergic to the ingredients of local anesthetic. The allergic reaction produced by your body may cause a lot of discomfort. The serious side effects of spinal tap include damage to the spinal cord or spinal nerve roots. This generally result in weakness, loss of sensation, or even paralysis. The risks are higher in case of patients suffering from epidural infection, dermatological infection, severe psychosis or neurosis.
Once the spinal tap is completed, you should lie either on your stomach or back, continuously for 2-3 hours. This reduces the chances of headache to a great extent. You should drink plenty of water to rehydrate your body. This helps in replenishment of the lost cerebrospinal fluid. Ask your doctor about the spinal tap recovery time. You should try to be least physically active during this time period. You should follow all the instructions given by your doctor for a comfortable recovery from the spinal tap procedure.