Diagnostic investigations. Part 1. Lumbar puncture

This article, the first in a three-part series on clinical investigations, discusses the technique and uses of lumbar puncture. This diagnostic procedure involves making a puncture into the subarachnoid space of the spinal cord, to remove an excess of fluid; to obtain fluid for examination and analysis, or to inject medication. The article includes an explanation of the relevant anatomy and the composition and role of cerebrospinal fluid, a detailed description of the procedure and the interpretation of results.