ICD-10 Diagnosis Code for Periodic Limb Movement Disorder
The ICD-10 diagnosis code for Periodic Limb Movement Disorder (PLMD) is G47.61.
Understanding PLMD vs. Related Conditions
PLMD is a distinct sleep disorder that must be differentiated from related conditions:
- PLMD requires polysomnographic confirmation showing a PLMS Index exceeding 15 per hour in adults (raised from the previous threshold of 5), along with clinical sleep disturbance or daytime fatigue that is not better explained by another disorder 1
- PLMD is a diagnosis of exclusion - it arises in individuals without Restless Legs Syndrome (RLS) and requires ruling out other sleep disorders, medical/neurological disorders, mental disorders, medication use, or substance use disorders 1, 2
- Periodic limb movements themselves are nonspecific and can occur with RLS, other sleep disorders, medications, and in normal individuals 1, 3
Key Diagnostic Distinctions
PLMD vs. RLS
- Up to 90% of individuals with RLS have periodic limb movements, but PLMs are neither necessary nor sufficient to diagnose RLS 1
- RLS is diagnosed clinically by history alone without requiring polysomnography in most cases 4
- RLS features an uncomfortable urge to move the legs with dysesthesias, worsening at rest and in the evening, relieved by movement 4, 1
PLMD vs. Nocturnal Leg Cramps
- Nocturnal leg cramps are painful, involuntary muscle contractions (typically in calf muscles) with no urge to move the legs 1
- Relief comes from stretching the affected muscle, not general movement 1
Clinical Characteristics of PLMD
The movements in PLMD are:
- Rhythmic, stereotyped extensions of the big toe and dorsiflexions of the ankle, occasionally with knee and hip flexions 1
- Each movement lasts approximately 2 to 4 seconds with a frequency of about 1 every 20-40 seconds 1
- May cause brief awakenings or arousals that the patient may not be aware of 1
When to Consider Polysomnography
Consider polysomnography only if PLMD is suspected based on sleep disturbance not explained by other causes 1. The diagnosis cannot be made without objective sleep study confirmation showing the characteristic movements and elevated PLMS Index 1, 3.