Sleep Staging

FIGURE 2-1 Polysomnogram: CPAP montage; 30 second page.

Clinical: 29-year-old man.

Staging: Stage wake. There is a well-modulated alpha rhythm. The alpha rhythm is dramatically attenuated with eye opening. The alpha rhythm is most prominent posteriorly, but its scalp topography varies across individuals. In this patient, the alpha rhythm is well represented in the central derivations. (Copyright JNP Enterprises, 2017.)

FIGURE 2-2 Polysomnogram: CPAP montage; 30 second page.

Clinical: 29-year-old man.

Staging: Stage wake. There is a well-modulated alpha rhythm. The alpha rhythm increases with eye closure (star). The alpha rhythm is most prominent posteriorly, but its scalp topography varies across individuals. In this patient, the alpha rhythm is well represented in the central derivations. (Copyright JNP Enterprises, 2017.)

FIGURE 2-3 Polysomnogram: Standard montage; 30 second page.

Clinical: 35-year-old woman.

Staging: Stage wake. There is prominent motion artifact obscuring the EEG and EOG derivations. (Copyright JNP Enterprises, 2017.)

FIGURE 2-4 Polysomnogram: Standard montage; 30 second page.

Clinical: 31-year-old man.

Staging: Stage wake. There is partial obscuration of the background rhythms, but the well-modulated alpha rhythm can still be identified. (Copyright JNP Enterprises, 2017.)

FIGURE 2-5 Polysomnogram: Standard montage (prior recording/display montage); 30 second page.

Clinical: 17-year-old man.

Staging: Stage wake. There is a well-modulated 8-Hz alpha rhythm. The alpha rhythm is most prominent posteriorly, but its scalp topography varies across individuals. In this patient, the alpha rhythm is well represented in the central derivations.

FIGURE 2-6 Polysomnogram: CPAP montage; 30 second page.

Clinical: 33-year-old man.

Staging: Stage wake. There is a well-modulated alpha rhythm. The alpha rhythm begins to slow in the second half of the epoch. Furthermore, there is slowing of the eye movements. This suggests the transition into drowsiness toward light sleep. (Copyright JNP Enterprises, 2017.)

FIGURE 2-7 Polysomnogram: Standard montage; 30 second page.

Clinical: 25-year-old man.

Staging: Stage wake. There is a well-modulated alpha rhythm. There is slowing of the eye movements (star). This suggests the transition into drowsiness.

Technical: There is artifact in the pressure transducer channel (PRESS) secondary to the transducer becoming dislodged. (Copyright JNP Enterprises, 2017.)

FIGURE 2-8 Polysomnogram: Standard montage (prior recording/display montage); 30 second page.

Clinical: 39-year-old woman.

Staging: Stage wake. Although alpha activity is present during the majority of the epoch, intermittent prominent theta activity (*) is consistent with brief episodes of sleep (microsleep).

FIGURE 2-9 Polysomnogram: Standard montage; 30 second page.

Clinical: 44-year-old woman.

Staging: Stage N1. There are some slow eye movements, which diminish during the epoch. The alpha rhythm has attenuated. There is a vertex wave (star). (Copyright JNP Enterprises, 2017.)

FIGURE 2-10 Polysomnogram: CPAP montage (prior recording/display montage); 30 second page.

Clinical: 37-year-old man.

Staging: Stage N1 sleep with prominent theta activity. There are slow eye movements and a gradual reduction of EMG activity.

FIGURE 2-11 Polysomnogram: Standard montage; 30 second page.

Clinical: 28-year-old man.

Staging: Stage N1. The alpha rhythm is attenuated. There is an asymmetric (left greater than right) vertex wave (star). (Copyright JNP Enterprises, 2017.)

FIGURE 2-12 Polysomnogram: Standard montage (prior recording/display montage); 30 second page.

Clinical: 5-year-old girl.

Staging: Stage N1 sleep.

EEG: Rhythmic moderate- to high-amplitude 4- to 5-Hz activity, referred to as hypnagogic hypersynchrony (*), is a prominent feature of drowsy wakefulness and stage 1 sleep between the ages of 6 months and 6 years. It becomes less prominent during late childhood and adolescence. Near the end of the epoch, a K-complex (ˆ) indicates the transition to stage 2 sleep.

FIGURE 2-13 Polysomnogram: Standard montage (prior recording/display montage); 30 second page.

Clinical: 55-year-old man.

Staging: Stage N1 sleep. There are positive occipital sharp transients (POSTs) (*) and vertex waves (ˆ). These transients are seen in most persons during stage 1 sleep and occasionally during stage 2 sleep.

FIGURE 2-14 Polysomnogram: Standard montage (prior recording/display montage); 7.5 second page.

Clinical: 55-year-old man.

Staging: Stage N1 sleep with several POSTs and vertex waves (*).

FIGURE 2-15 Polysomnogram: Standard montage; 30 second page.

Clinical: 52-year-old man.

Staging: Stage N1 with an arousal (arrow). There is a respiratory event resulting in an arousal from stage N1 sleep toward the end of the epoch. There is associated motion artifact in the EEG derivations. (Copyright JNP Enterprises, 2017.)

FIGURE 2-16 Polysomnogram: Standard montage; 30 second page.

Clinical: 25-year-old man.

Staging: Stage N1. There is an arousal (star) with an associated increase in the alpha rhythm. The speed of the eye movements also increases.

Technical: There is artifact in the pressure transducer channel (PRESS) secondary to the transducer becoming dislodged. (Copyright JNP Enterprises, 2017.)

FIGURE 2-17 Polysomnogram: Standard montage; 30 second page.

Clinical: 52-year-old man.

Staging: Stage N1 with a transition to stage N2 toward the end of the epoch (star). There is a sleep spindle at this point. (Copyright JNP Enterprises, 2017.)