Definition:

lumbar puncturelisten (LUM-bar PUNK-cher)

A procedure in which a thin needle called a spinal needle is put into the lower part of the spinal column to collect cerebrospinal fluid or to give drugs. Also called spinal tap.

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Lumbar puncture; drawing shows a patient lying in a curled position on a table and a spinal needle (a long, thin needle) being inserted into the lower back. Inset shows a close-up of the spinal needle inserted into the cerebrospinal fluid (CSF) in the lower part of the spinal column.