Neurology & Pain Management Coding Alert

Stumped by what code to use for inclusion body myositis (IBM)? ICD-9 2010 ends your search with a specific code.

There are three main types of inflammatory myopathies: polymyositis, dermatomyositis, and inclusion body myositis (IBM). Although the first two diseases are mentioned specifically in ICD-9 2009, the latter was absent. When coding for these diseases, here's how to hit a home run.

Although neurologists agree that IBM is the most common form of inflammatory myopathy in Americans older than 50, prior editions of ICD-9-CM have sorely missed out on providing a specific code for this disease. "In 2009, the alphabetic index did not include any referencing term under myositis and directed providers to 359.89 under inflammatory myopathy," according to Marvel J. Hammer, RN, CPC, CCS-P, PCS, ACS-PM, CHCO, with MJH Consulting in Denver.

When faced with a diagnosis of IBM, coders get stumped on what code to use.

Previously, applicable codes would have been:

• 359.89 -- Other myopathies

• 359.9 -- Myopathy, unspecified

• 729.1 -- Myalgia and myositis unspecified.

New way: For 2010, you will be able to benefit from specific code 359.71 (Inclusion body myositis). The new code is more specific to the documentation and therefore will be very helpful to the practice, says Gloria Galloway, MD, FAAN, professor of neurology and pediatrics in Nationwide Children's Hospital in Columbus, Ohio, who's had some prior experience with these diseases.

Do this: Add 359.71 to your list of the three main types of inflammatory myopathies. Codes for the other two types -- dermatomyositis (DM) and polymyositis (PM) are as follows:

• 710.3 -- Dermatomyositis

• 710.4 -- Polymyositis.

Change Other Myopathies' 4th Digit

Don't have enough info to code DM, IBM, or PM? You'll need to update your fourth digit as ICD-9 2010 breaks out inflammatory myopathies into its own "other" code.

When the neurologist makes a diagnosis of inflammatory myopathy but gives no more specificity, such as IBM, the ICD-9-CM 2009 Alphabetic Index points you to 359.89 (Other myopathies). A new code, however, changes this. ICD-9 2010 gives you 359.79 (Other inflammatory and immune myopathies, NEC).

"This new ICD-9 codes will allow for improved reporting of the patient's diagnosis," says Hammer. More specific diagnoses provide better communication to the payer, which helps support medical necessity for diagnostic tests and treatment. Increased specificity also provides more accurate data tracking and statistical research.

Don't assign 359.71, 710.3, or 710.4 when the inflammatory myopathy is related to or stemming from a preexisting medical condition. To code inflammatory myopathy that is a manifestation, use 359.6 (Symptomatic inflammatory myopathy in diseases classified elsewhere) and report it as an additional diagnosis.

Spotting certain diseases can clue you in that you should be reporting 359.6 as an additional diagnosis. Remember to code first the underlying disease. ICD-9 mentions thefollowing diseases with associated inflammatory myopathy:

• amyloidosis (277.30-277.39)

• disseminated lupus erythematosus (710.0)

• malignant neoplasm (140.0-208.9)

• polyarteritis nodosa (446.0)

• rheumatoid arthritis (714.0)

• sarcoidosis (135)

• scleroderma (710.1)

• Sjögren's disease (710.2).

Example: A patient diagnosed with disseminated lupus erythematosus sees a neurologist for complaints of weakness of both legs and difficulty in walking. The neurologist documents the diagnosis of inflammatory myopathy due to lupus, report:

• 710.0 (Systemic lupus erythematosus) as the principal ICD-9 code

• 359.6 as a secondary code.

Think signs and symptoms, when you see terms, such as "probable," "suspected," or "rule out." These indicate a definitive diagnosis has not been made. When the provider is unsure of the diagnosis, the ICD-9-CM guidelines direct you to report the codes for the signs and symptoms.

Example: An elderly male visits the neurologist with complaints of weakness of all his extremities. Since the patient's symptoms could be due to several different conditions, such as a myopathy, an electrolyte problem, or a simple case of muscle fatigue, the neurologist decides to order serum electrolyte and muscle enzyme tests and to perform neuromuscular electrodiagnostic tests, for instance, electromyography (EMG). Until a conclusive diagnosis is made, code the medical necessity for the diagnostic tests and visit as 728.87 (Muscle weakness [generalized]).