A lumbar puncture (also known as a spinal tap) is a procedure used to take a sample of cerebrospinal fluid (CSF) from the spinal canal so that it can be tested. Cerebrospinal fluid (CSF) is the fluid that surrounds your brain and spinal cord. It helps to support and protect the brain and spinal cord from trauma.
The CSF is tested because it is in close contact with the brain. Analysing it helps doctors find out how the brain may be affected by conditions such as acute lymphoblastic leukaemia or non-Hodgkins lymphoma.
The spinal canal is the passageway through the back bones (vertebrae) which contains the spinal cord.
A hollow needle is inserted into the lower part of the spinal canal to draw out the CSF. Usually only a few millilitres are taken. The procedure is carried out under a local anaesthetic
The procedure is very safe and takes place routinely without complications.
A lumbar puncture is carried out to determine if leukaemia or lymphoma has infiltrated the spinal fluid or brain. A lumbar puncture can also be used to give chemotherapy drugs. This is mainly for patients with acute lymphoblastic leukaemia and some patients with non Hodgkins lymphoma.