Neurology & Pain Management Coding Alert

Trigeminal neuralgia involves a facial nerve disorder but also includes disorders of the fifth cranial nerve. Note that postherpetic trigeminal neuralgia differs from trigeminal neuralgia in that it is defined as "severe oral or nasal pain following a herpes zoster infection (shingles)." Postherpetic neuropathy refers to multiple areas of pain. Other causes of neurogenic pain can include chemotherapy, amputation (phantom limb pain), alcoholism, HIV infection or AIDS, spinal cord trauma, multiple sclerosis, and stroke.

Because even the slightest stimulation may cause extreme discomfort for neurogenic pain patients a condition that may manifest as hyperesthesia (extreme sensitivity to stimulation), hyperalgesia (increasing pain to normally painful stimuli) or allodynia (pain due to normally nonpainful stimuli) physicians generally treat them with drugs rather than with more traditional physical therapy methods.

Drug therapy may include antidepressants, such as amitriptyline (J1320), which is effective for postherpetic neurogenic pain but less effective with trigeminal neuralgia; antiepileptics, such as carbamazepine (J3490) and phenytoin (J1165); and antiarrhythmics, such as mexiletine (J3490).

Other common treatments for these conditions involve peripheral nerve blocks, epidural injections, or intrathecal (subarachnoid) injections containing anesthetic, antispasmodic, opioids or steroids. The physician will not usually use an epidural catheter for such blocks. More commonly, he or she will perform injections as described by 62310 (Injection, single [not via indwelling catheter], not including neurolytic substances, with or without contrast [for either localization or epidurography], of diagnostic or therapeutic substance[s] epidural or subarachnoid; cervical or thoracic) or 62311 ( lumbar, sacral [caudal]), depending on the injection site.

The physician may also perform an intercostal nerve block (64420*, Injection, anesthetic agent; intercostal nerve, single; and 64421*, intercostal nerves, multiple, regional block) and neurolysis (64620, Destruction by neurolytic agent, intercostal nerve) for patients with a diagnosis of herpes zoster with unspecified nervous system complication (053.10) and postherpetic neuralgia (053.12). If performed at the same time, you may also report fluoroscopic guidance using 76005 (Fluoroscopic guidance and localization of needle or catheter tip for spine or paraspinous diagnostic or therapeutic injection procedures [epidural, transforaminal epidural, subarachnoid, paravertebral facet joint, paravertebral facet joint nerve or sacroiliac joint], including neurolytic agent destruction), says Laurie A. Castillo, CPC, CPC-H, CCS-P, president and owner of Professional Coding & Compliance Consulting of Virginia.

Patients with trigeminal nerve disorders (350.1-350.9) and postherpetic neuralgia (053.12, 053.19) may benefit from therapeutic injections in the tendon sheath or ligament (20550). Depending on the carrier's guidelines, the physician may also be entitled to reimbursement for the anesthetic agent.

Most payers designate specific guidelines for nerve block/neurolysis codes. For example, Noridian Mutual (a Part B carrier for Alaska, Arizona, Colorado, Hawaii, Nevada, North Dakota, Oregon, South Dakota, Washington and Wyoming) has issued a local medical review policy (LMRP) stating, "If neurolysis is performed, i.e., the 646xx series, it follows and includes the nerve block, i.e., the 644xx series." In other words, the physician should administer intercostal nerve blocks prior to intercostal neurolysis. If the block fails to provide relief, there is no need to continue to neurolysis. To further support Noridian's claim that you should not report nerve block codes 64420 and 64421 in addition to intercostals nerve neurolysis (64620), the National Correct Coding Initiative (NCCI) bundles these procedures.

In addition, physicians providing more than one nerve block per date of service must provide documentation to justify the multiple injections. Noridian's LMRP warns, "More than one nerve block billed per day will require the submission of documentation with the claim. The claim will be denied when the necessary documentation is not submitted." If the physician performs more than one intercostal neurolysis, payers will usually apply a multiple-procedure payment reduction to the second and subsequent injections.

For intercostal nerve blocks and neurolysis, most LMRPs require that the medical record document the presence of radicular pain, the neuropathic diagnosis treated, a detailed pain history, and the failure of more conservative measures to treat the pain successfully.

Note: There are a number of treatment options for neurogenic pain, depending on the exact diagnosis, and the ICD-9 code(s) you choose may affect the procedures for which you may expect payment. For this reason, be sure to code to the highest level of specificity.