A 37-year-old has multilevel lumbar degenerative disc disease and is coming in for an epidural injection. Localizing the skin over the area of L5-S1, the physician uses the transforaminal approach under fluoroscopy guidance for needle positioning. The spinal needle is inserted, and the patient experiences paresthesias in her left lower extremity. The anesthetic drug is injected into the epidural space.

What CPT® code(s) is/are reported?

A lumbar puncture is performed in the lower lumbar region to sample CSF because the spinal cord ends around L1 or L2, creating a safe zone for the needle insertion without the risk of direct spinal cord injury.

Explanation:

A lumbar puncture, also known as a spinal tap, is a medical procedure that involves inserting a needle into the lumbar region of the vertebral column to sample cerebrospinal fluid (CSF). This procedure is carried out in the lower lumbar area because the spinal cord does not extend through the lower lumbar region. Thus, inserting a needle in this area avoids the risk of damaging central nervous system (CNS) tissue.

The lumbar puncture is performed between two lumbar vertebrae, typically between L3 and L4, or L4 and L5, where there is a natural gap in the spinal column. Since the spinal cord ends at the upper lumbar vertebrae, specifically around L1 or L2, the lower lumbar region only contains nerve roots (cauda equina) suspended in CSF. This anatomy provides a “safe zone” for the procedure without the risk of directly injuring the spinal cord.

CSF surrounds and cushions the brain and spinal cord, and analyzing it can help diagnose a variety of neurological disorders, including meningitis, encephalitis, and other conditions that affect CNS functioning. Should there be a suspicion of such conditions, a lumbar puncture might be indicated to obtain a CSF sample for analysis.