hypnagram
Pronunciation: HIP-no-gram
A graphical representation of sleep stages plotted against time during a polysomnography study, showing sleep architecture patterns.
Full Definition
A hypnagram is a visual display that plots sleep stages (wake, N1, N2, N3, and REM) against time throughout a polysomnography recording. This graph provides a comprehensive overview of sleep architecture, showing sleep stage transitions, sleep fragmentation, and the timing of different sleep phases. The hypnagram reveals important patterns such as REM latency, slow-wave sleep distribution, and wake frequency. Abnormal hypnagram patterns can indicate various sleep disorders, including sleep apnea, periodic limb movement disorder, or circadian rhythm disturbances.
Usage
Usage note: Use 'hypnagram' rather than 'hypnogram' which refers to the entire sleep recording.
In Context
- "The hypnagram revealed frequent awakenings and reduced REM sleep throughout the night." — Sleep study interpretation
- "Analysis of the hypnagram showed normal sleep stage progression with appropriate slow-wave sleep in the first half of the night." — Polysomnography report