Internal Medicine Coding Alert

Question: I overheard a coworker discussing facial nerve monitoring testing for patients with Bell's palsy. I am new to internal medicine coding and have never heard of the condition or the test. What is this condition and how should I report it?


Louisiana Subscriber

Answer: Bell's palsy (351.0) is a temporary facial paralysis--a result of damage to one of the two facial nerves. Bell's palsy usually affects only one of the facial nerves and one side of the face.

A viral infection, such as viral meningitis or herpes simplex can cause Bell's palsy when the facial nerve swells and becomes inflamed as a reaction to the infection.

Each facial nerve controls all muscles on one side of your face, except for muscles involved in chewing. The cause of Bell's palsy is still unclear, and its development isn't well understood.

But many scientists believe that a viral infection--perhaps most commonly by the herpes simplex virus, the same virus that causes cold sores--can cause the facial nerve to become swollen and injured.     

Impairment of electrical impulses directed to your facial muscles by the damaged nerve results in the weakness or paralysis of these muscles.

As for the facial nerve monitoring, internists might perform this test primarily to diagnose Bell's palsy and other facial paralysis disorders. When your internist performs this procedure, report 92516 (Facial nerve function studies [e.g., electroneuronography]). 

But this is not a test that an internist performs very often; he'll most likely refer the patient to a neurologist or neurosurgeon for facial nerve monitoring. If the internist sees a patient and refers her to the neurologist for testing, report the appropriate level evaluation and management (E/M) for the encounter.