Intermediate
Technical
IVT
K-complexes
Pronunciation: KAY kom-plek-siz
Large amplitude, biphasic EEG transients characteristic of stage 2 non-REM sleep.
Full Definition
K-complexes are high-amplitude, biphasic EEG waveforms consisting of an initial negative sharp wave followed by a positive slow wave, typically occurring during stage 2 non-REM sleep. These transients can be spontaneous or evoked by sensory stimuli and represent a partial arousal response that helps maintain sleep continuity. K-complexes are generated by thalamocortical circuits and are considered essential markers of sleep staging, distinguishing stage 2 from lighter stages of sleep.
Usage
Usage note: Hyphenated compound; named by Loomis, Harvey, and Hobart in 1937.
In Context
- "Well-formed K-complexes confirmed the transition to stage 2 sleep." — Polysomnography sleep staging
- "The sleep study showed decreased K-complexes, consistent with sleep fragmentation." — Sleep disorder evaluation
Don't confuse with
sleep spindles
vertex waves