G43.411

HCC Category Mapping

What This Code Means

This is a severe type of migraine headache where one side of the body becomes temporarily paralyzed or weakened, and the migraine is not responding to treatment and has lasted for an extended period (status migrainosus means the migraine persists for more than 72 hours). The paralysis-like symptoms are part of the migraine itself and resolve when the headache ends.

Coding Tips

• •Verify that the provider documentation explicitly states both 'hemiplegic migraine' and 'intractable' (drug-resistant) status, as well as confirmation of status migrainosus (migraine lasting >72 hours) before assigning this specific code
• •Do not confuse hemiplegic migraine with actual stroke or TIA; hemiplegic migraine is a migraine variant with temporary neurological symptoms that resolve with the headache, whereas stroke causes permanent damage

Clinical Significance

Hemiplegic migraine is a rare and serious migraine subtype characterized by temporary motor weakness or paralysis on one side of the body, mimicking stroke presentation. Accurate coding is critical because hemiplegic migraine requires distinct management protocols and may indicate increased cerebrovascular risk. This code maps to RxHCC 166 (Severe Head Injury) in the prescription drug risk adjustment model, impacting pharmacy cost predictions.

Documentation Requirements

• ✓Documented unilateral motor weakness or hemiplegia during migraine episode
• ✓Neurological examination findings differentiating from stroke (reversibility, associated aura symptoms)
• ✓Characterization as intractable or not intractable (refractory to standard treatment vs. responsive)
• ✓Status migrainosus documentation: migraine lasting >72 hours with notation of duration
• ✓Family history of hemiplegic migraine if applicable (familial vs. sporadic subtype)
• ✓Neuroimaging results (CT/MRI) to exclude cerebrovascular accident
• ✓Current treatment plan and medication regimen

Commonly Confused Codes