sleep spindle
Characteristic EEG waveforms of 12-14 Hz frequency appearing in bursts during NREM sleep, generated by the thalamus.
Full Definition
Sleep spindles are distinctive electroencephalographic (EEG) waveforms that appear as brief bursts of rhythmic activity at 12-14 Hz frequency during non-REM sleep stages. These spindle-shaped waveforms are generated by the thalamic reticular nucleus and represent one of the hallmark features of stage 2 NREM sleep. Sleep spindles typically last 0.5-2 seconds and occur every 3-10 seconds during stable sleep. They are considered markers of sleep stability and are thought to play a role in sleep maintenance by gating sensory information from reaching the cortex. The density and characteristics of sleep spindles can vary with age, medication use, and certain neurological conditions.
In Context
- "Sleep spindle density was reduced in patients with insomnia compared to healthy controls." — Research publication
- "The technologist noted well-formed sleep spindles throughout stage 2 NREM sleep." — Polysomnography report