Migraine may be among your most rule-intensive diagnoses in the ED. Choosing the correct diagnosis code when you see a patient with a migraine attack in the ED is about as involved as it gets in terms of ICD-10 coding. Why? You’ve got to code all the way to the sixth character in order to accurately portray the migraine that the patient is suffering from. Along the way to that final diagnosis, you’ll have to answer questions about type of migraine and the presence or absence of several characteristics. With a few quick tips, however, you’ll be on your way to smooth ICD-10-CM coding for migraine attacks. Know Aura Definition First, you should know that all migraine diagnosis codes start with G43 (Migraine). From there, the exact codes diverge depending on many factors. The terms “with aura” and “without aura” appear often in ICD-10’s migraine descriptors, so you need to know what aura means in migraine-speak. “The term aura when being used with a migraine are specific nervous system symptoms that typically occur or begin approximately five to 20 minutes prior to the onset of the headache,” says Yvonne Dillon, CPC, CEDC, manager of coding documentation at ZOTEC Partners in Carmel, Indiana. These symptoms can include the following: When considering aura, “I look for notes indicating visual disturbances, like seeing patterns or lights or losing vision, tunnel vision, etc.,” explains Cathy Satkus, CPC, COBGC, of Harvard Family Physicians in Tulsa, Oklahoma. 4th Character: The Condition Question When you get to the fourth character, migraine coding starts to get interesting. There are more than a dozen fourth character options — ICD-10 had to move to alphabetic fourth characters because they ran out of numbers (e.g. G43.B (Ophthalmoplegic migraine)). Describing all of the fourth character migraine options would fill an entire issue of this publication, so here are some of the characteristics of the most common fourth character migraine choices: Hemiplegic migraine (G43.4--): This is a “migraine with weakness or paralysis on one side of the body; numbness on one side of your body,” says Satkus. According to Dillon, other symptoms of hemiplegic migraine can include: Migraine with cerebral infarction (G43.6--): “A migraine with cerebral infarction, or migrainous infarction, refers to when a cerebral infarction occurs during or at the time of a typical migraine. This may cause a stroke in the patient,” explains Dillon. To qualify as a migraine with cerebral infarction, “the infarction has to be confirmed by imaging,” says Satkus. Chronic migraine (G43.7--): “Chronic migraines are those that occur 15 or more days in a month within at least a three-month span without medication overuse,” Dillon says. Further, the patient must have experienced two or more of the following symptoms eight or more days per month for at least three months: 5th Character: The Intractable Question Once you’ve got your fourth character choice set, it’s time to move onto the fifth character, which will indicate whether the migraine was intractable. Definition: If a patient notes that their migraine won’t go away, it could be an intractable headache; it is a relentless, seemingly untreatable headache. You’ll note whether a headache was intractable with the fifth characters for not intractable (0) or intractable (1). When reviewing documentation, the following terms are considered to be equivalent to intractable: Symptoms: Intractable migraines are often accompanied by autonomic nervous system symptoms such as nausea, vomiting, and sensitivity to light and/or sound. Triggers can include caffeine withdrawal, stress, lack of sleep, smoking, missed meals, certain foods, loud noises, and bright lights. 6th Character: The Status Migrainosus Question Migraine codes can also require a sixth character that identifies the migraine as occurring with status migrainosus (1) or without status migrainosus (9). Status migrainosus refers to a migraine that has lasted more than 72 hours. Note: You’ll need to go to the sixth character for most, but not all, of your migraine diagnoses. Codes for some migraine variants — such as G43.A0 (Cyclical vomiting, in migraine, not intractable), G43.C1 (Periodic headache syndromes in child or adult, intractable), and G43.D1 (Abdominal migraine, intractable) — only require you to code to the fifth character. Much like the fifth character, the sixth character of a migraine diagnosis answers a single question: Does status migrainosus accompany the migraine? The symptoms of status migrainosus are similar to symptoms of a typical migraine. Along with pain in the head, common symptoms include: Because status migrainosus lasts for at least three days, prolonged vomiting and pain can lead to: