64400 - Trigeminal nerve or 5th Cranial nerve - 3 main divisions - V1 or Ophthalmic nerve, V2 or Maxillary nerve and V3 or Mandibular nerve. There are many branches off these three divisions that would also be reported with 64400, such as Supraorbital nerve, Infraorbital nerve, and Auriculotemporal. This is a good site on the anatomy of the Trigeminal nerve:
http://emedicine.medscape.com/article/1873373-overview#a2 Majority of Trigeminal nerve branches involve sensory function. Injections of local anesthetics commonly done for Trigeminal neuralgia
Dec 2008 CPT Assistant Q&A addressed the coding for 64400
Question: If a provider injected two separate unilateral branches or divisions of the trigeminal nerve (eg, injected the right supraorbital branch [V1] and also injected the right infraorbital branch [V2]), would these injections be reported as two units of code 64400 or just one unit, as the code description states "any division or branch"?
Answer: Code 64400 should be reported once for the injection into the right supraorbital nerve. Code 64400 with modifier 59, Distinct procedural service, appended should be reported for the right infraorbital branch injection. The descriptor of code 64400 represents a single injection into a single nerve in the anatomy and sensory distribution of the peripheral trigeminal nerve. Injection of each specific nerves has effects on different anatomy sensation in different areas.
An understanding of the neural distribution is key, since the right supraorbital nerve is above the orbit of the eye (about at the level of the eyebrow on the forehead), whereas the infraorbital nerve is below the orbit (lateral to the nose, middle of the face, and midline with the pupil of the eye).
To illustrate, the trigeminal nerve is the main cutaneous sensory nerve of the face and head, with three main branches (V1, ophthalmic; V2, maxillary; and V3, mandibular), each with its own nerve divisions. The right frontal nerve is a continuation of the ophthalmic nerve. The right supraorbital nerve leaves the orbit through the supraorbital foramen, providing filaments to the upper eyelid and the frontal muscles. The right infraorbital nerve is in the maxillary branch of the trigeminal nerve. The maxillary nerve becomes the infraorbital nerve, which emerges onto the face through the intraorbital foramen, thus providing cutaneous innervation to the middle of the face, lower eyelid, side of the nose, and upper lip.
64402 - Facial nerve or 7th Cranial nerve - primarily motor nerve function, controlling the muscles of the face, with individual branches such as Temporal, Zygomatic and Buccal
http://nf2is.org/facial_nerve.php Often injected with local anesthetic for anesthesia for facial laceration repair or in some cases ocular surgery; not a commonly performed in comparison to the trigeminal nerve blocks.
IF a botulinum toxin, i.e. Botox, Dysport, Myobloc, or Xeomin, is injected rather than a local anesthetic, then review the chemodenveration codes such as 64415.
Using google searches for the anatomy often helps clarify where the procedure report indicates the injection was performed.