A
Apnea:
An interruption of airflow lasting at least 10 seconds in adults or the equivalent of 2 breaths in children.
Alpha rhythm:
An EEG pattern consisting of trains of sinusoidal 8-13 Hz activity recorded over the occipital region with eye closure and attenuating with eye opening.
Asystole:
An interruption of cardiac rhythm lasting more than 3 seconds.
Atrial fibrillation:
An irregularly irregular ventricular rhythm associated with replacement of consistent P waves by rapid electrical oscillations.
B
Beta rhythm:
An EEG rhythm consisting of 13-30 Hz activity.
Bradycardia:
A sustained heart rate less than 40 beats per minute.
Bruxism:
Grinding or clenching of the teeth during sleep that is often associated arousal.
C
Cheyne-Stokes breathing:
A breathing rhythm with a specified crescendo and decrescendo change in breathing amplitude.
Consensus:
A specified agreement of appropriateness amongst a minimum of 7 individuals using RAND/UCLA methods.
D
Delta rhythm:
An EEG rhythm consisting of 1-4 Hz activity.
Dominant posterior rhythm:
An EEG pattern with frequency appropriate to age which is observed over the occipital regions during relaxed wakefulness with eyes closed and attenuates with eye opening or attention.
Dypnagogic hypersynchrony:
An EEG pattern consisting of paroxysmal runs or bursts of diffuse high amplitude sinusoidal 75 to 350 u V 3-4.5 Hz waves which begin abruptly, are usually widely distributed but often maximal over the central, frontal, or frontocentral scalp regions.
E
Excessive fragmentary myoclonus:
Limb EMG activity of a specified frequency and duration often unassociated with visible movement; not a defined disorder.
Eye blinks:
EOG events consisting of conjugate vertical eye movements at a frequency of 0.5-2 Hz present in wakefulness with the eyes open or closed.
F
G
Guideline:
A recommendation based on level 2 evidence or a consensus of level 3 evidence.
H
Hypanagogic foot tremor:
Trains of EMG activity of the lower limb with a specified frequency,; not a defined disorder.
Hypopnea:
A specified reduction in airflow lasting at least 10 seconds in adults or the equivalent of 2 breaths in children.
I
J
K
K complex:
An EEG event consisting of a well delineated negative sharp wave immediately followed by a positive component standing out from the background EEG with total duration >0.5 seconds, usually maximal in amplitude over the frontal regions.
Low amplitude, mixed frequency activity:
An EEG pattern consisting of low amplitude, predominantly 4-7 Hz activity.
Low chin EMG tone: Baseline EMG activity in the chin derivation no higher than in any other sleep stage and usually at the lowest level of the entire recording.
L
