Reading the Leg EMG Channel on a Polysomnogram
Placeholder: the tibialis anterior EMG trace is the primary channel for scoring limb movements.
- Tibialis ant.: Primary channel (Placeholder short caption)
- 0.5–10 s: Min duration (Placeholder short caption)
- ≥8µV rise: Amplitude rule (Placeholder short caption)
- 30 s: Recording epoch (Placeholder short caption)
Placeholder section heading about EMG baseline reading
Placeholder short paragraph describing baseline EMG amplitude and scoring rules.
The Rhythmic Periodic Limb Movement Pattern of PLMD
Placeholder: PLMD jerks recur at regular intervals strictly during sleep.
- 20–40 s: Inter-movement interval (Placeholder short caption)
- ≥4: Movements per series (Placeholder short caption)
- Sleep only: Occurs during (Placeholder short caption)
- NREM 1–2: Typical stage (Placeholder short caption)
Placeholder section heading about periodic clustering
Placeholder short paragraph describing how rhythmic clusters are visually identified.
Calculating the Limb Movement Index for PLMD Severity
Placeholder: index divides total scored movements by total sleep hours.
- <5/hr: Normal threshold (Placeholder short caption)
- 5–14/hr: Borderline (Placeholder short caption)
- ≥15/hr: Diagnostic cutoff (Placeholder short caption)
- n / TST(hr): Formula (Placeholder short caption)
Placeholder section heading about index calculation
Placeholder short paragraph describing the movements-per-hour formula.
RLS Waking Urge-to-Move Symptoms vs. Sleep-Only PLMD Jerks
Placeholder: RLS is a subjective waking urge, not a PSG-scored event.
- Pre-sleep/rest: Timing (Placeholder short caption)
- Movement: Relief by (Placeholder short caption)
- Evening/night: Worsens (Placeholder short caption)
- None required: PSG signature (Placeholder short caption)
Placeholder section heading about RLS symptom criteria
Placeholder short paragraph describing the four core RLS diagnostic criteria.
Overlap Syndrome — When RLS and PLMD Coexist
Placeholder: most RLS patients also show elevated PLMD index on PSG.
- ~80%: RLS with PLMD (Placeholder short caption)
- Possible: PLMD alone (Placeholder short caption)
- Symptom+PSG: Diagnostic key (Placeholder short caption)
- Overlap dx: Combined label (Placeholder short caption)
Placeholder section heading about combined diagnosis logic
Placeholder short paragraph describing how classification combines both metrics.
Placeholder highlight: combine limb movement index with waking urge history for final call.