Part B Insider (Multispecialty) Coding Alert

Understanding Character No. 4 is essential to select the right diagnosis code.

When you’re coding for your patient’s migraine headaches, ICD-10 offers a challenge ICD-9 did not: more choices for more specific migraine diagnoses.

Benefit: More specific diagnoses could lead to more specific treatments, which might improve patient outcomes. There is a learning curve to mastering ICD-10 migraine coding, however.

In short, migraine ICD-10 coding goes long. Coding migraine patients correctly often involves coding to the sixth character. Before you get there, however, you must ID the correct fourth character of the ICD-10 code, as these numbers represent the most general migraine classifications.

Check out this primer on choosing the proper fourth digit for your migraine diagnoses, and you’ll end up with the most accurate ICD-10 code possible for each patient’s migraine — as well as a road map to which fifth/sixth character(s) you might need.

‘Prodrome’ Often Equates to Aura

The four-character code for the most common migraine presentation is G43.0- (Migraine without aura…). If a patient does have an aura with the migraine, you’d opt for G43.1- (Migraine with aura…), confirms Mary I. Falbo, MBA, CPC, CEO of Millennium Healthcare in Lansdale, Pa.

Aura definition: The term defines “specific nervous system symptoms that occur or begin approximately five to 20 minutes prior to the onset of the headache,” explains Yvonne Bouvier, CPC, CEDC, senior coding analyst for Bill Dunbar and Associates, LLC, in Indianapolis, Ind.

According to Bouvier, these symptoms can include, but are not limited to:

• Visual field blind spots
• Patient sees a “zigzag” pattern
• Blindness that affects half of the visual field, in one or both eyes
• Visual hallucinations
• Patient sees flashing lights
• Patient suffer a pins and needles sensation in his arm or leg
• Patient has difficulty speaking.

These early migraine symptoms are also called a “prodrome,” reports Falbo. So if you see “prodrome” in the notes for a patient suffering from a migraine, he might also have an accompanying aura.

‘Stroke-Like’ Symptoms Can Come With Hemiplegic Migraines

Another fourth-character subcategory of migraines in ICD-10 is hemiplegic migraines. When a patient has a hemiplegic migraine, you’ll choose a code from the G43.4- (Hemiplegic migraine…) code set.

Definition: “Hemiplegic migraine is a rare condition which has been linked to a genetic abnormality. Symptoms include temporary weakness down one side of the body, which usually lasts between five minutes and one day, but can last for several days,” explains Falbo.

Though all migraines are serious medical conditions, hemiplegic migraines are especially nasty.

Symptoms of a hemiplegic migraine “can range from worrisome to debilitating, and these headaches aren’t easy to treat,” says Falbo. You must identify patients with hemiplegic migraines early, because if they don’t get the care they need quickly, the end result could be disastrous.

“Migraines are unpredictable and unique to each person. You may have a hemiplegic migraine headache with extreme pain and minor paralysis one month,” Falbo says. “Then, the next attack might bring extreme paralysis without much headache pain at all.”

Falbo reports that other symptoms of hemiplegic migraine include:

• Persistent and severe, throbbing pain. This might only occur on one side of the patient’s head.
• A pins-and-needles feeling. The feeling might move from the patient’s hand and up his arm.
• Balance and coordination issues.
• Patient sees zigzag pattern, or suffers double vision/blind spots.
• Patient has slurred speech or difficulty with language. For example, he might mix words up in a sentence or have trouble remembering a word.
• Dizziness/vertigo.
• Nausea/vomiting.
• Extreme sensitivity to light, sound, and/or smell.
• Extreme confusion.
• Decreased consciousness/coma.

Look to G43.6- When CI Accompanies Migraine

Sometimes, the migraine isn’t the only problem the patient is suffering from when you treat him. One of the complicating factors for patients suffering from persistent migraine with aura can be cerebral infarction (CI), which you’d code with G43.6- (Persistent migraine aura with cerebral infarction…). This condition is often marked in the notes as a “migrainous infarction,” Bouvier relays.

When a patient has a migrainous infarction, it’s a very serious situation. The provider will have to treat the infarction and the migraine, as the combination of conditions could lead to stroke for the patient, Bouvier explains.

However serious migrainous infarctions might be, they are “rare and occur more commonly in patients who have migraine with aura, as opposed to those without aura,” explains Bouvier.

Also: Don’t forget to report the CI as well as the migraine when coding migraines with cerebral infarction. According to notes under G43.6-, you need to select from the I63.- (Cerebral infarction…) family when you code for this type of migraine.

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