Lumbar Puncture

Spinal Tap

What Affects the Test

Reasons you may not be able to have the biopsy or why the results may not be helpful include:

• Not being able to lie still during the procedure.
• Having conditions such as obesity, dehydration, spinal disease, severe arthritis, or recent spinal surgery. These conditions may make it hard to do a lumbar puncture with the person lying down. The procedure may need to be done with the person sitting up and bent forward. In some cases, the procedure may need to be done with a special X-ray method called fluoroscopy. This is used to guide the placement of the spinal needle.
• Bleeding into the cerebrospinal fluid (CSF). The needle puncture can cause bleeding into the CSF. Several samples of the fluid can show the difference between bleeding from the puncture and bleeding caused by a brain hemorrhage.
• Not being able to collect a sample of the fluid. This is called a "dry tap."

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Author:	Jan Nissl, RN, BS	Last Updated: December 4, 2006
Medical Review:	Patrice Burgess, MD - Family Medicine Joseph O'Donnell, MD - Hematology/Oncology
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