CAP characteristics differ in patients with arousal parasomnias and frontal and temporal epilepsies

Arousal parasomnias (AP) and frontal and temporal epilepsies consist of pathologic arousals originating in abnormal thalamocortical circuits, reflecting increased sleep instability and arousal oscillations--the cyclic alternating pattern (CAP). In this study, the authors aim to investigate the CAP characteristics in 27 patients with AP, 22 patients with frontal and temporal epilepsies, and age- and gender-matched 20 healthy subjects. The mean CAP sequence and cycle was significantly higher in patients than in control subjects (P < 0.003). The total CAP duration was always higher in the patients with AP than in those with frontal and temporal epilepsies, reaching statistically significant level at the first (P = 0.044), second (P = 0.024), third (P = 0.010), and sixth (P < 0.001) sleep cycles. The duration of A1 in descending branch (P = 0.062) and trough phase of sleep cycles (P = 0.038) was longer in the patients with AP. The duration of A2 subtype of CAP in ascending branch (P = 0.039) and the number (P = 0.036) and duration (P = 0.050) of A3 subtype of CAP in descending branch of sleep cycles were higher in the patients with frontal and temporal epilepsies. This difference in CAP parameters might suggest that AP are associated with milder activation in specific brain areas, showing a similar evolution with physiologic homeostatic decrease in sleep synchronization. Frontal and temporal epilepsies, however, is associated with a moderate-to-powerful activation in wider brain networks.