Why it's done

A lumbar puncture may be done to:

• Collect cerebrospinal fluid for laboratory analysis
• Measure the pressure of your cerebrospinal fluid
• Inject spinal anesthetics, chemotherapy drugs or other medications
• Inject dye (myelography) or radioactive substances (cisternography) into cerebrospinal fluid to make diagnostic images of the fluid's flow

Information gathered from a lumbar puncture can help diagnose:

• Serious bacterial, fungal and viral infections, including meningitis, encephalitis and syphilis
• Bleeding around the brain (subarachnoid hemorrhage)
• Certain cancers involving the brain or spinal cord
• Certain inflammatory conditions of the nervous system, such as multiple sclerosis and Guillain-Barre syndrome