Scoring of Sleep & Associated Events (AASM Guidelines)

Delta Wave Frequency

0-3.99 Hz

Slow Wave Activity Frequency

0.5-2.0 Hz and peak-to-peak amplitude of >75 µV (Frontal Regions)

Scoring Stage R sleep in epochs with ALL of the following phenomena (definite stage R):

1. LAMF EEG activity without K complexes or sleep spindles 2. Low chin EMG tone for the majority of the epoch and concurrent with REMs 3. REMs at any position within the epoch

Notes for Scoring N1:

1. Vertex sharp waves may be present but are not required for scoring stage N1. 2. The EOG will often show slow eye movements in stage N1, but these are not required for scoring. 3. During stage N1, the chin EMG amplitude is variable, but often lower than in stage W. 4. As slow eye movements often commence before attenuation of alpha rhythm, sleep latency may be slightly shorter for some individuals who do not generate alpha rhythm compared to those who do.

Theta Wave Frequency

4-7.99 Hz

Scoring Stage Wake (Rule 2):

50% or more of the epoch contains either: a. Alpha rhythm (posterior dominant rhythm) over the occipital region b. Other findings consistent with stage W: i. Eye blinks (0.5 to 2 Hz) ii Rapid eye movements associated with normal or high chin muscle tone iii. Reading eye movements

Alpha Wave Frequency

8-13 Hz

Beta Wave Frequency

>13 Hz

Scoring Stage N2, Rule 2 (Continue Scoring):

Begin scoring stage N2 if EITHER OR BOTH of the following occur during the first half of that epoch or the last half of the previous epoch: a. One or more K complexes unassociated with arousals b. One or more sleep spindles

Scoring N2, Rule 2:

In individuals who generate alpha rhythm, score stage N1 if the alpha rhythm is attenuated and replaced by LAMF activity for more than 50% of the epoch.

Major Body Movements

Movement and muscle artifact obscuring the EEG for more than half an epoch to the extent that the sleep stage cannot be determined.

Scoring Stage N2, Rule 3 (continue scoring):

Score a given epoch as stage N2 if the majority of the epoch meets criteria for stage N2. If the waveforms in rules 1 & 2 are followed by an arousal in the same or subsequent epoch, the segment of the recording preceding the arousal is considered N2.

Scoring Stage W Criteria (Rule 1):

a. Alpha Rhythm (Posterior Dominant Rhythm with eyes closed) b. Eye Blinks at a 0.5-2 Hz Frequency c. Reading Eye Movements d. Rapid Eye Movements e. Slow Eye Movements

Scoring Stage N1 (Pts without Alpha Rhythm), Rule 3:

a. EEG activity activity 4-7 Hz with slowing background frequencies by ≥1 Hz from those of stage W b. Vertex sharp waves c. SEMs

Sawtooth Wave Frequency

a. EEG pattern consisting of trains of sharply contoured, often serrated (2-6 Hz) waves b. Maximal amplitude over central head regions

Recommended PSG/EEG Derivations:

a. F4-M1 b. C4-M1 c. 02-M1 Backup electrodes should be placed at F3, C3, O1 and M2.

Scoring Stage N2 Criteria, Rule 1:

a. LAMF background activity b. K-Complexes c. Sleep spindles

Scoring preceding and contiguous sleep of definite Stage R sleep, in the absence of REMs, if all the following are present:

a. LAMF without K complexes or sleep spindles b. Low chin EMG tone c. There is no intervening arousal d. Slow Eye Movements following an arousal or stage W are absent

Scoring Stage R In accordance to these definitions:

a. Rapid Eye Movements b. Lowest EMG chin activity c. Sawtooth Waves d. Transient Muscle Activity (Short irregular bursts of EMG activity usually with duration <0.25 seconds superimposed on low EMG tone).

Scoring Stage N1, Rule 1 Criteria:

a. SEMs b. LAMF Activity at 4-7 Hz c. Vertex sharp waves (V waves- duration of <0.5 seconds) d. Sleep Onset- first epoch typically scored other than stage W

Scoring Epochs with Major Body Movements:

a. Score in accordance to to the Major Body Movement definition b. If alpha rhythm is present for part of the epoch (even <15 seconds duration), score as stage W c. If no alpha rhythm is discernible, but an epoch scoreable as stage W either precedes or follows the epoch with a Major Body Movement, score as stage W d. Otherwise, score the epoch as the same stage as the epoch that follows it

Score epochs using the following parameters:

a. Score sleep stages in 30-second periods, sequential epochs commencing at the start of the study. b. Assign a stage to each epoch. c. If two or more stages coexist during a single epoch, assign the stage comprising the greatest portion of the epoch. d. When three or more segments of an epoch meet criteria for different stages: i. Score the epoch as sleep if the majority meets criteria for stage N1, N2, N3, or R. ii. Assign the sleep stage that occurs for the majority of sleep within the epoch.

K-Complex Frequency

a. Sharp, negative waves followed by slower positive components lasting ≥0.5 seconds b. Maximum amplitude when recorded using frontal derivations

Scoring Stage N3 Criteria:

a. Slow Wave Activity b. Score Stage N3 when ≥20% of an epoch consists of SWA, irrespective of age

Sleep Spindles

a. Train of distinct sinusoidal waves with frequency 11-16 Hz with a duration of ≥0.5 seconds b. Maximal amplitude in the central derivations