Neurosurgery Coding Alert

You will come across three distinct sets of occipital nerves in the body, so you’ll need to know that which one in specific your physician is treating. You report distinct codes for procedures on each nerve.

Coding connection: To get to the right code, you should know the origin of the nerves, the structures these nerves supply and their distribution, and also what are the common complaints due to involvement of these nerves in any pathology.

The TON is neither anatomically nor functionally synonymous with the GON. Look carefully in the procedure notes what necessitated the physician to perform the block and where the needle was inserted for the procedure. Your physician may perform the block on either of the occipital nerves to either diagnose or treat the patient’s headache. Your physician will record the medical history and do a clinical examination to narrow down the choice to block a particular occipital nerve.

Find Needle Insertion Site: Read in the procedure note to identify where your physician inserted the needle. This is going to be your prime clue to choosing the right code.

Examples: If you read in the procedure note that your physician inserted the needle near the midline at the back of the head, you will be reporting an injection for the GON. Similarly, an injection behind the ear is your hint for an LON procedure. If you read that the injection was given in the medial branch of C3, you report the procedure for TON.

Note: Only the injection of the TON requires image-guidance, which may also help you differentiate when a C2-3 paraverterbal facet joint nerve is performed.

Review Trigeminal Basics

Knowing the anatomy will make your code selection very easy. Trigeminal nerve, the largest cranial nerve, is a mixed nerve with a predominant sensory component. It mainly supplies the face through the three branches, i.e. ophthalmic nerve (V1), maxillary nerve (V2), and mandibular nerve (V3). The V1 division primarily provides sensory innervation to the forehead and eye area. The V2 division provides sensory innervation to the cheek area from below the eye to the upper lip. The V3 division provides both sensory and motor innervation to the lower jaw area of the face.

The three nerves converge on the trigeminal ganglion that contains cell bodies of the incoming sensory fibers. Trigeminal ganglion is also called the semilunar ganglion or the gasserian ganglion. From the trigeminal ganglion, the central fibers emerge as a tract and go down through the pons to the medulla to then finally cross the midline in the upper spine and ascend to the brain where the sensations are perceived.