Neurology & Pain Management Coding Alert

Educating yourself about anatomy can help you pinpoint codes.

Trigeminal and occipital nerve blocks for headache treatment are both common procedures for pain management specialists or neurologists. But do you understand the difference? Read on for the lowdown that will help you better understand your provider's service.

Starting point: Whether you're reporting unilateral or bilateral blocks, you have one code choice for each type:

• 64405 – Injection, anesthetic agent; greater occipital nerve
• 64400 – Injection, anesthetic agent; trigeminal nerve, any division or branch.

Think 'Scalp' for Occipital Injection

The greater occipital nerve originates from the C2 spinal nerve and provides sensory innervation to the posterior area of the scalp extending to the top of the head. Physicians typically inject the greater occipital nerve (GON) just above the base of the skull to treat occipital or cervicogenic headaches or neck pain (723.1, Cervicalgia).

Providers often report 64405 for greater occipital nerve blocks in patients diagnosed with occipital neuralgia. This is a painful condition that produces an aching, burning, or throbbing type of pain, tingling, and sometimes numbness on the back of the head -- in the distribution of the greater occipital nerve. It is a persistent neuropathic type pain often caused by an injury or irritation to the occipital nerve.

Use: A nerve block can be either diagnostic, therapeutic, or both. Physicians also might administer an occipital nerve block to treat certain types of headache including cluster headache.

Diagnosis choices: If your physician documents "occipital neuralgia," the ICD-9 alphabetic index directs you to the musculoskeletal system chapter rather than the nervous system chapter, and you would report 723.8 (Other syndromes affecting cervical region). Now, with ICD-10, you'll submit a more specific code with M54.81 (Occipital neuralgia).

If your neurologist provides you "occipital headache" as the diagnosis, there isn't a specific listing for occipital under "headache" in the ICD-9 alphabetic index, so you would use the diagnosis code 784.0 (Headache) from the "Symptoms, Signs, and Ill-Defined Conditions" chapter. This diagnosis will shift to either G44.1 (Vascular headache, not elsewhere classified) or R51 (Headache) in ICD-10.

Diagnosis 723.1 for cervicalgia will change to M54.2 under ICD-10.

Think 'Face' for Trigeminal Injection

In contrast, the trigeminal nerve -- also known as cranial nerve V or the fifth cranial nerve -- provides sensory innervation to most of the face. The "trigeminal" name is derived from the fact that the cranial nerve has three major divisions or branches. The ophthalmic nerve, or V1 division, primarily provides sensory innervation to the forehead and eye area. The maxillary nerve, or V2 division, provides sensory innervation to the upper jaw area from below the eye to the upper lip. The mandibular nerve, or V3 division, provides both sensory and motor innervation to the lower jaw area of the face.

Use: Trigeminal injections can be performed at any of the three divisions or branches of the divisions and can be used for cluster (339.0x), tension (307.81), or migraine headaches (346.xx) or atypical facial pain (350.2). Other diagnoses treated with trigeminal injections can include postherpetic neuralgia due to herpes zoster (shingles) (053.12, Postherpetic trigeminal neuralgia) or trigeminal neuralgia/tic douloureux (350.1).

Future coding: Common diagnoses associated with trigeminal nerve injections have a wide range of associated codes in ICD-10. Some will have simple,
one-to-one translations:

• 307.81 will change to G44.209 (Tension-type headache, unspecified, not intractable)
• 053.12 will become B02.22 (Postherpetic trigeminal neuralgia)
• 350.1 will shift to G50.0 (Trigeminal neuralgia).

Your migraine codes will also make an easy switch with ICD-10, thanks in part to recent headache/migraine ICD-9 updates descriptors that included "migraine with aura" and a fifth digit for added specificity. Your crosswalks for some of these codes will include:

• G43.101 – Migraine with aura, not intractable, with status migrainosus
• G43.109 – Migraine with aura, not intractable, without status migrainosus
• G43.111 – Migraine with aura, intractable, with status migrainosus
• G43.119 – Migraine with aura, intractable, without status migrainosus.

Watch the terminology: Providers may use different terms than "trigeminal" when noting the branch being injected, which could confuse coders; using an anatomy book can help you decipher the documentation. Use 64400 for injections to any of the three divisions or more distal branches including the supraorbital, the infraorbital, and the auriculotemporal nerve.