Polysomnography of onset of sleepwalking in an 8-year-old child. On the right side of figure are the movement artifacts associated with the arousal and beginning of the parasomnias. The preceding recording segment (left side of figure) shows the abnormal breathing that occurred during SWS. The abnormal breathing can be seen on the nasal cannula/pressure transducer recording (Cannula). There is a flow limitation and very negative peak end inspiratory esophageal pressure (Pes) that resolve with the beginning of the arousal with a reversal of the abnormal respiratory effort (PES signal) and start of the sleepwalking. The patient snores continuously (microphone [MIC] channel) and is a mouth breather with a very good signal obtained from the mouth thermistor (Airflow channel). The child is in stage 3 NREM sleep just before the onset of the event. The drop in the pulse oximeter channel (Spo2) on the right of the figure is related to movement artifacts.
Onset of sleep terror in a 3-year-old boy. The child is in stage 4 NREM sleep with high amplitude slow waves. On the right of the figure, movement artifacts begin. The chin electromyelogram changes abruptly. Before the start of the event, the child presents flow limitation seen on the nasal cannula, with a “flattening” at the top of the “Cannula” signal. Esophageal pressure signal (Pes), indicative of respiratory effort, is abnormally negative at end inspiration, reaching here 20 cm H2O. With the beginning of the confusional arousal, there is a “Pes reversal” with drop in the negativity of the esophageal pressure and a change in the frequency of the high amplitude slow waves on the EEG (C3/A2, C4/A1). Both Figs 1 and 2 indicate presence of abnormal breathing preceding the confusional arousal. They also show that in children, abnormal breathing is often not indicated by an “apnea” but much more commonly by a more discrete polysomnographic pattern. Both children (Figs 1 and 2) were treated with tonsillectomy.
Discrete flow limitation on nasal cannula/pressure transducer signal, with “flattening” of the breath signal curve for at least 4 successive breaths. Repetitive abnormally negative peak end inspiratory pressures, ending at same negative inspiratory pressure without a crescendo pattern.
Termination of abnormal increase in respiratory effort with abrupt switch to a less negative peak end inspiratory pressure.
Respiratory event related arousals (RERAs)
As defined by the American Academy of Sleep Medicine14
Increase in respiratory rate, above that seen during quiet unobstructed breathing, by minimum of 3 breaths/minute in NREM sleep or 4 breaths/minute in REM sleep, for 30 seconds or more. No changes in oxygen saturation, Pes, or EEG were required.
Arousals and other EEG changes
Arousals defined according to the American Sleep Disorders Association Atlas.15 In addition, a breathing event may be associated with an abrupt burst of high-amplitude slow waves in the slow θ or fast δ range (2.5–4.5 Hz), not lasting more than 5 seconds. These high-amplitude slow waves are similar to the EEG burst described in part of the phase 1 of Cyclical Alternating Pattern16 or by Black et al17 in patients with upper airway resistance syndrome.
Same as in Rechtschaffen and Kales international manual18