Neurology ·
Nocturnal REM-Onset Markers Show Poor Test–Retest Stability in Narcolepsy Type 1
In a study of 227 untreated children and adults with narcolepsy type 1, nocturnal sleep-onset REM periods showed poor agreement across two overnight sleep studies. The findings suggest that a single—or even repeated—absence of this marker should not be used to rule out the disorder.
- Nocturnal REM-onset markers varied between two sleep studies.
- nSOREMP test–retest agreement was poor (κ=0.26).
- Absence of nSOREMPs should not exclude narcolepsy type 1.
Researchers assessed nocturnal sleep-onset REM periods (nSOREMPs) and direct transitions from wakefulness or stage N1 sleep to REM (nDREM) in 227 untreated patients with narcolepsy type 1. Participants had two overnight polysomnograms; diagnosis was based on ICSD-3-TR criteria without using nSOREMPs. The mean age was 31.6 years, and 108 participants were male.
nSOREMPs were present on both recordings in 41.8% of patients, on one recording only in 35.7%, and on neither in 22.4%. Test–retest agreement was poor (κ=0.26; 95% CI 0.14–0.39). nDREM was present on both recordings in 15.9%, on one only in 37.4%, and on neither in 46.7%, also indicating limited stability.
Persistent markers were associated with younger age, shorter MSLT sleep latency and lower CSF hypocretin levels; nSOREMP persistence was also associated with more MSLT SOREMPs. The authors conclude that these nocturnal markers may reflect variable REM dysregulation rather than stable individual traits. In this diagnosed NT1 cohort, absence of nSOREMPs—even on two polysomnograms—should not exclude the diagnosis.
In practice
For clinicians evaluating suspected narcolepsy type 1, these findings caution against relying on nocturnal sleep-onset REM periods as a stable individual marker. Among 227 untreated patients already diagnosed using other criteria, nSOREMPs showed poor agreement across two overnight polysomnograms, and some patients lacked the finding on both. The study supports the authors’ conclusion that absence of nSOREMPs should not exclude NT1. It does not establish diagnostic accuracy in an undiagnosed population or validate a revised diagnostic approach.
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SLEEP: Poor Test–Retest Stability of Nocturnal REM Sleep Onset Markers in Narcolepsy Type 1 ↗This is an automated AI-condensed summary that has not yet been reviewed by an editor. Always consult the full item at the original source.