Loss of sleep spindle frequency deceleration in Obstructive Sleep Apnea

Author(s)

Carvalho, Diego Z. ^[1] ; Gerhardt, Guenther J. L. ^[2] ; Dellagustin, Guilherme ^[1] ; de Santa-Helena, Emerson L. ^[3] ; Lemke, Ney ^[4] ; Segal, Alan Z. ^[5] ; Schoenwald, Suzana V. ^[1]

Affiliation

^[1] Univ Fed Rio Grande do Sul, Sleep Lab, Div Pulm Med, Hosp Clin Porto Alegre, BR-90035003 Porto Alegre, RS - Brazil

^[2] Univ Caxias do Sul, Dept Chem & Phys, Caxias Do Sul - Brazil

^[3] Univ Fed Sergipe, Dept Phys, Aracaju - Brazil

^[4] Univ Estadual Paulista, Dept Phys & Biophys, Inst Biosci, Rio De Janeiro - Brazil

^[5] Weill Cornell Med Coll, Dept Neurol & Neurosci, New York, NY - USA

• Document type: Journal article
• Source: CLINICAL NEUROPHYSIOLOGY; v. 125, n. 2, p. 306-312, FEB 2014.
• Web of Science Citations: 14

Abstract

Objective: Sleep spindles have been suggested as surrogates of thalamo-cortical activity. Internal frequency modulation within a spindle's time frame has been demonstrated in healthy subjects, showing that spindles tend to decelerate their frequency before termination. We investigated internal frequency modulation of slow and fast spindles according to Obstructive Sleep Apnea (OSA) severity and brain topography. Methods: Seven non-OSA subjects and 21 patients with OSA contributed with 30 min of Non-REM sleep stage 2, subjected to a Matching pursuit procedure with Gabor chirplet functions for automatic detection of sleep spindles and quantification of sleep spindle internal frequency modulation (chirp rate). Results: Moderate OSA patients showed an inferior percentage of slow spindles with deceleration when compared to Mild and Non-OSA groups in frontal and parietal regions. In parietal regions, the percentage of slow spindles with deceleration was negatively correlated with global apnea-hypopnea index (r(s) = -0.519, p = 0.005). Discussion: Loss of physiological sleep spindle deceleration may either represent a disruption of thalamocortical loops generating spindle oscillations or some compensatory mechanism, an interesting venue for future research in the context of cognitive dysfunction in OSA. Significance: Quantification of internal frequency modulation (chirp rate) is proposed as a promising approach to advance description of sleep spindle dynamics in brain pathology. (C) 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved. (AU)

• FAPESP's process: 09/10382-2 - Machine learning for molecular systems biology
• Grantee: Ney Lemke
• Support Opportunities: Regular Research Grants