Inside and around the brain and spine there is a space filled with cerebrospinal fluid. To obtain and examine this fluid, a puncture with a needle is done in the lower back.
Usually, this puncture is done in a sitting position but occasionally in a supine position. In a sitting position, the patient is asked to sit on the edge of the bed, bending forward around a pillow with both feet on a chair.
First we mark the exact spot of the puncture on the skin. Then we disinfect the skin (this might feel a bit cold) and a sterile tissue is placed on the bed. Usually some local anaesthesia is infiltrated first, which might cause some local pressure. The actual lumbar puncture follows soon after and is usually a smooth procedure. The cerebrospinal fluid is obtained drip by drip so the collection might take some minutes. Meanwhile it’s important to remain still in the bending position. The cerebrospinal fluid is clear and looks like water. It is replaced by your body soon after the puncture.
After the puncture you should stay in the bed during at least 2 hours. You should also drink a lot and remain calm during the rest of the day.
To do this puncture, people are usually admitted and stay one night in the hospital.
Rarely a patient might have headache after the puncture. This is supposed to be caused by leakage of cerebrospinal fluid and is easily dealt with by a blood patch.