Enhanced Frontoparietal Synchronized Activation During the Wake-Sleep Transition in Patients with Primary Insomnia

• Published in: Sleep (New York, N.Y.) Vol. 35; no. 4; pp. 501 - 511
• Main Authors: Corsi-Cabrera, María, Figueredo-Rodríguez, Pedro, del Río-Portilla, Yolanda, Sánchez-Romero, Jorge, Galán, Lídice, Bosch-Bayard, Jorge
• Format: Journal Article
• Language: English
• Published: United States Associated Professional Sleep Societies, LLC 01.04.2012
• Subjects: Adult; Arousal - physiology; Case-Control Studies; Electroencephalography; Enhanced Pronto-Parietal Activation in Primary Insomniacs; Female; Frontal Lobe - physiopathology; Humans; Male; Parietal Lobe - physiopathology; Polysomnography; Sleep Initiation and Maintenance Disorders - physiopathology; Sleep Stages - physiology; Young Adult; VARETA; spectral EEG; EEG temporal coupling; EEG topography; EEG coherence; Primary insomnia
• ISSN: 0161-8105; 1550-9109; 1550-9109
• DOI: 10.5665/sleep.1734

Cognitive and brain hyperactivation have been associated with trouble falling asleep and sleep misperception in patients with primary insomnia (PI). Activation and synchronization/temporal coupling in frontal and frontoparietal regions involved in executive control and endogenous attention might be implicated in these symptoms. Standard polysomnography (PSG) and electroencephalogram (EEG) were recorded in 10 unmedicated young patients (age 19-34 yr) with PI with no other sleep/medical condition, and in 10 matched control subjects. Absolute power, temporal coupling, and topographic source distribution (variable resolution electromagnetic tomography or VARETA) were obtained for all time spent in waking, Stage 1 and Stage 2 of the wake-sleep transition period (WSTP), and the first 3 consecutive min of N3. Subjective sleep quality and continuity were evaluated. In comparison with control subjects, patients with PI exhibited significantly higher frontal beta power and current density, and beta and gamma frontoparietal temporal coupling during waking and Stage 1. These findings suggest that frontal deactivation and disengagement of brain regions involved in executive control, attention, and self-awareness are impaired in patients with PI. The persistence of this activated and coherent network during the wake-sleep transition period (WSTP) may contribute to a better understanding of underlying mechanisms involved in difficulty in falling asleep, in sleep misperception, and in the lighter, poorer, and nonrefreshing sleep experienced by some patients with PI.