alpha wave intrusion
Abnormal appearance of alpha waves (8-13 Hz) during non-REM sleep stages, often indicating poor sleep quality or arousal.
Full Definition
Alpha wave intrusion refers to the pathological presence of alpha frequency brain waves (8-13 Hz) during non-REM sleep stages where they should normally be absent. This phenomenon is commonly seen in fibromyalgia, chronic fatigue syndrome, and other conditions affecting sleep quality. The intrusion of these awake-state brain waves into sleep stages suggests incomplete sleep consolidation and may contribute to non-restorative sleep complaints. Sleep specialists use this finding on polysomnography to help diagnose sleep disorders and assess treatment effectiveness.
Usage
Usage note: Often hyphenated when used as an adjective modifier.
In Context
- "The polysomnogram revealed significant alpha wave intrusion during stage 2 sleep, consistent with the patient's complaints of unrefreshing sleep." — Sleep study report
- "Alpha wave intrusion was noted throughout the night, suggesting a possible fibromyalgia-related sleep disorder." — Clinical assessment