Neurosurgery Coding Alert

When it comes to diagnosis coding, it doesn’t get much more involved—and potentially confusing—that choosing a migraine code.

The reason: 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.

Don’t be confused, though; we’ve got all the info you need to go all the way to the final character for every migraine diagnosis you choose.

Know Aura Definition to Demystify Coding

First, 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 occur or begin approximately five to 20 minutes prior to the onset of the headache,” says Yvonne Bouvier, CPC, CEDC, manager of coding documentation at ZOTEC Partners in Carmel, Indiana. These symptoms can include the following:

• Blind spots within the patient’s visual field
• Seeing a “zigzag” pattern
• Blindness affecting half of the patient’s visual field in either both or one eye
• Visual hallucinations
• Seeing flashing lights
• Pins and needles sensation in arm or leg
• Difficulty speaking

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 Describes Specific Condition

When you get to the 4th character, migraine coding starts to get interesting. There are more than a dozen 4th character options — ICD-10 had to move to alphabetic 4th characters because they ran out of numbers (e.g. G43.B [Ophthalmoplegic migraine]).

Describing all of the 4th character migraine options would fill an entire issue of the newsletter, 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 Bouvier, other symptoms of hemiplegic migraine can include:

• Confusion
• Speech problems
• Severe, throbbing pain, often on one side of your head
• A pins-and-needles feeling, often moving from your hand up your arm
• Weakness or paralysis on one side of your body
• Loss of balance and coordination
• Visual aura, such as seeing zigzag lines, , or blind spots
• Language difficulties, such as mixing words or trouble remembering a word
• Slurred speech
• Dizziness or vertigo
• Nausea and vomiting
• Extreme sensitivity to light, sound, and smell
• Confusion
• Decreased consciousness or coma

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 Bouvier.

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,” Bouvier 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:

• Moderate to severe headaches
• Each headache lasts four hours or more
• Headaches occurring on one side of your head only
• Headaches that are pulsating pain
• Headaches that are aggravated by routine physical activity
• Headaches causing vomiting/nausea or both
• Headaches coupled with sensitivity to light and sound

Indicate Intractability With 5th Character

Once you’ve got your 4th character choice set, it’s time to move onto the 5th 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 5th characters for not intractable (0) or intractable (1). When reviewing documentation, the following terms are considered to be equivalent to intractable:

• Pharmacoresistant
• Pharmacologically resistant
• Treatment resistant
• Refractory
• Medically refractory
• Poorly controlled

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.

Use 6th Character to I.D. Status Migrainosus

Migraine codes can also require a 6th 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 6th 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 5th character.

Much like the 5th character, the 6th 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:

• Sensation of sparkling lights or other vision changes (aura)
• Nausea and vomiting
• Difficulty thinking properly

Because status migrainosus lasts for at least three days, prolonged vomiting and pain can lead to:

• Dehydration
• Fatigue due to sleep loss.