G47.419

HCC Category Mapping

What This Code Means

A sleep disorder characterized by excessive daytime sleepiness and sudden sleep attacks without episodes of muscle weakness or paralysis.

Coding Tips

• •This code is used when cataplexy is explicitly absent or not documented
• •Narcolepsy type 2 does not include cataplexy; verify documentation confirms absence of muscle weakness episodes

Clinical Significance

Narcolepsy without cataplexy (Type 2 narcolepsy) is characterized by excessive daytime sleepiness with abnormal sleep architecture but without the muscle tone loss seen in cataplexy. While less severe than Type 1, it still significantly impacts daily functioning, employment, and driving safety. The absence of cataplexy means normal or borderline hypocretin levels, and the condition may evolve into Type 1 over time.

Documentation Requirements

• ✓Diagnosis of narcolepsy with documented excessive daytime sleepiness
• ✓Documentation of absent cataplexy (distinguishes Type 2 from Type 1)
• ✓MSLT results showing mean sleep latency <=8 minutes with >=2 sleep-onset REM periods
• ✓Normal cerebrospinal fluid hypocretin-1 levels (if tested) — helps confirm Type 2
• ✓Impact on daily functioning documented
• ✓Current treatment plan (typically stimulants/wake-promoting agents without cataplexy-specific drugs)
• ✓Exclusion of other hypersomnia causes (sleep apnea, insufficient sleep, medications)

Commonly Confused Codes