Lumbar puncture

Definition

A lumbar puncture, or spinal tap, is a medical procedure where a needle is inserted into the lower back to collect cerebrospinal fluid (CSF) for diagnostic testing. It is often used to diagnose infections of the central nervous system.

5 Must Know Facts For Your Next Test

1. Lumbar punctures are crucial for diagnosing meningitis, which can be caused by bacteria such as Neisseria meningitidis and Streptococcus pneumoniae.
2. The procedure involves inserting a needle between the third and fourth lumbar vertebrae to avoid damaging the spinal cord.
3. Cerebrospinal fluid collected during a lumbar puncture can be analyzed for the presence of pathogens, white blood cell count, glucose levels, and protein concentrations.
4. A key risk associated with lumbar punctures is post-lumbar puncture headache, which occurs in up to 30% of patients.
5. Sterile technique is essential during a lumbar puncture to prevent introducing new infections into the central nervous system.

Review Questions

• What are two primary bacterial causes of meningitis that can be diagnosed through a lumbar puncture?
• Why is cerebrospinal fluid collected from between the third and fourth lumbar vertebrae?
• What are some key components analyzed in cerebrospinal fluid obtained from a lumbar puncture?

Related terms

Cerebrospinal Fluid (CSF):

A clear fluid found in the brain and spinal cord that provides cushioning and maintains nutrient balance.

Meningitis:

An inflammation of the protective membranes covering the brain and spinal cord, often due to infection.

Neisseria meningitidis:

A bacterium that causes bacterial meningitis and other serious infections like septicemia.