HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:
Guest Access | Sign In via User Name/Password

This Article Full Text Free Full Text (PDF) Free Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (20) Citing Articles via Google Scholar Google Scholar Articles by Heinzer, R. Articles by Montplaisir, J. Search for Related Content PubMed PubMed Citation Articles by Heinzer, R. Articles by Montplaisir, J.

Slow-Wave Activity in Sleep Apnea Patients Before and After Continuous Positive Airway Pressure Treatment^*

Contribution to Daytime Sleepiness

^* From the Department of Internal Medicine (Dr. Heinzer), Centre Hospitalier et Universitaire Vaudois, Lausanne, and Laboratoire de sommeil (Dr. Sforza), Division de Neuropsychiatrie, Hoitaux Universitaires de Genéve, Geneva, Switzerland; and Centre d’étude du sommeil (Ms. Gaudreau, and Drs. Décary, Petit, Morisson, and Montplaisir), Hôpital du Sacré-Cur de Montréal, and Department of Psychiatry, Université de Montréal, Montreal, Quebec, Canada.

Correspondence to: Jacques Montplaisir, MD, PhD, CRCPc, Centre d’étude du sommeil, Hôpital du Sacré-Coeur, 5400 Gouin Blvd West, Montréal (Québec) H4J 1C5, Canada; e-mail: j-montplaisir{at}crhsc.umontreal.ca

Study objectives: To estimate the course of slow-wave activity (SWA), its amount during the night, and its correlation with daytime sleepiness in sleep apnea syndrome (SAS) patients. This study also verified whether continuous positive airway pressure (CPAP) treatment also restores a normal pattern of SWA in severe SAS patients.

Participants: Ten patients with a diagnosis of severe SAS who showed a good clinical response to CPAP after approximately 9 months of treatment were included in this study. These patients were matched for sex and age with 10 control subjects.

Design: All subjects underwent 1 night of polysomnography (PSG), followed by the multiple sleep latency test (MSLT) the next day. For the SAS patients only, the same procedure was repeated after 9 ± 0.7 months of CPAP treatment. In addition to traditional scoring of sleep stages, apneas, hypopneas, and microarousals, the SWA, defined as the power in the 0.75- to 4.5-Hz frequency band, was evaluated.

Results: A positive correlation between SWA of the first cycle and the MSLT (r = 0.56; p = 0.045) was found before treatment. Moreover, SAS patients significantly increased their mean SWA after CPAP treatment in the first (p = 0.024) and second (p = 0.002) sleep cycles and restored a more physiologic decay of SWA across the night.

Conclusions: These results suggest that daytime sleepiness in SAS patients may be the result of a lack of SWA during the first part of the night, and show that CPAP restores a more physiologic pattern of SWA across the night.

Key Words: continuous positive airway pressure • quantitative EEG • sleep apnea syndrome • sleepiness • slow-wave activity

This article has been cited by other articles:

				R. D. Chervin, J. W. Burns, and D. L. Ruzicka Electroencephalographic Changes during Respiratory Cycles Predict Sleepiness in Sleep Apnea Am. J. Respir. Crit. Care Med., March 15, 2005; 171(6): 652 - 658. [Abstract] [Full Text] [PDF]