P Collard, M Dury, P Delguste, G Aubert and DO Rodenstein
Unit of Pneumology, Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Brussels, Belgium.

Sleep fragmentation (an increase in the number of short EEG arousals) is considered a major determinant of excessive daytime sleepiness but is seldom quantified in sleep studies, and reference values are scarce at best. We present data on the movement arousal index (MAI) in five groups of subjects: normals, simple snorers, patients with the sleep apnea-hypopnea syndrome (SAHS), and patients with sleep-related oxygen desaturations due to chronic obstructive pulmonary disease or neuromusculoskeletal disorders. In normal subjects, the MAI was 13 +/- 7 (mean +/- SD). MAI was distinctly increased in most patients with SAHS and was strongly correlated with the apnea-hypopnea index and loss of both slow wave and REM sleep. It was corrected to normal by nasal continuous positive airway pressure (CPAP). There was some overlap of MAI between SAHS patients and snorers, suggesting that a minority of nonapneic snorers may suffer from daytime sleepiness due to upper airway dysfunction. Sleep fragmentation is not a feature of sleep- related hypoventilation due to COPD or neuromusculoskeletal disorders, and an increase of the number of movement arousals (MA) is very suggestive of upper airway dysfunction and of potential success of CPAP. Quantification of sleep fragmentation is feasible and clinically useful; it should be included in the assessment of sleep-related breathing disorders.

This article has been cited by other articles:

				Y. F. Guo, E. Sforza, and J. P. Janssens Respiratory Patterns During Sleep in Obesity-Hypoventilation Patients Treated With Nocturnal Pressure Support: A Preliminary Report Chest, April 1, 2007; 131(4): 1090 - 1099. [Abstract] [Full Text] [PDF]

				F. Fanfulla, M. Delmastro, A. Berardinelli, N. D. Lupo, and S. Nava Effects of Different Ventilator Settings on Sleep and Inspiratory Effort in Patients with Neuromuscular Disease Am. J. Respir. Crit. Care Med., September 1, 2005; 172(5): 619 - 624. [Abstract] [Full Text] [PDF]

				G M Nixon and R T Brouillette Sleep {middle dot} 8: Paediatric obstructive sleep apnoea Thorax, June 1, 2005; 60(6): 511 - 516. [Abstract] [Full Text] [PDF]

				W.T. McNicholas, P.M.A. Calverley, A. Lee, and J.C. Edwards Long-acting inhaled anticholinergic therapy improves sleeping oxygen saturation in COPD Eur. Respir. J., June 1, 2004; 23(6): 825 - 831. [Abstract] [Full Text] [PDF]

				G. Liistro, Ph. Rombaux, C. Belge, M. Dury, G. Aubert, and D.O. Rodenstein High Mallampati score and nasal obstruction are associated risk factors for obstructive sleep apnoea Eur. Respir. J., February 1, 2003; 21(2): 248 - 252. [Abstract] [Full Text] [PDF]

				V. Jounieaux, V. F. Parreira, G. Aubert, M. Dury, P. Delguste, and D. O. Rodenstein Effects of Hypocapnic Hyperventilation on the Response to Hypoxia in Normal Subjects Receiving Intermittent Positive-Pressure Ventilation* Chest, April 1, 2002; 121(4): 1141 - 1148. [Abstract] [Full Text] [PDF]

				F. Brijker, Y. F. Heijdra, F. J. J. van den Elshout, and H. Th. M. Folgering Discontinuation of Furosemide Decreases PaCO2 in Patients With COPD Chest, February 1, 2002; 121(2): 377 - 382. [Abstract] [Full Text] [PDF]

				A. I. PACK, J. E. BLACK, J. R. L. SCHWARTZ, and J. K. MATHESON Modafinil as Adjunct Therapy for Daytime Sleepiness in Obstructive Sleep Apnea Am. J. Respir. Crit. Care Med., November 1, 2001; 164(9): 1675 - 1681. [Abstract] [Full Text] [PDF]

				N. MCARDLE and N. J. DOUGLAS Effect of Continuous Positive Airway Pressure on Sleep Architecture in the Sleep Apnea-Hypopnea Syndrome . A Randomized Controlled Trial Am. J. Respir. Crit. Care Med., October 15, 2001; 164(8): 1459 - 1463. [Abstract] [Full Text] [PDF]

				F. Barbe, L. R. Mayoralas, J. Duran, J. F. Masa, A. Maimo, J. M. Montserrat, C. Monasterio, M. Bosch, A. Ladaria, M. Rubio, et al. Treatment with Continuous Positive Airway Pressure Is Not Effective in Patients with Sleep Apnea but No Daytime Sleepiness: A Randomized, Controlled Trial Ann Intern Med, June 5, 2001; 134(11): 1015 - 1023. [Abstract] [Full Text] [PDF]

				F. Brijker, F. J. J. van den Elshout, Y. F. Heijdra, and H. Th. M. Folgering Underestimation of Nocturnal Hypoxemia Due to Monitoring Conditions in Patients With COPD Chest, June 1, 2001; 119(6): 1820 - 1826. [Abstract] [Full Text] [PDF]

				M.V. Smurra, M. Dury, G. Aubert, D.O. Rodenstein, and G. Liistro Sleep fragmentation: comparison of two definitions of short arousals during sleep in OSAS patients Eur. Respir. J., April 1, 2001; 17(4): 723 - 727. [Abstract] [Full Text] [PDF]

				W. H. TSAI, W. WARD FLEMONS, W. A. WHITELAW, and J. E. REMMERS A Comparison of Apnea-Hypopnea Indices Derived from Different Definitions of Hypopnea Am. J. Respir. Crit. Care Med., January 1, 1999; 159(1): 43 - 48. [Abstract] [Full Text]

				L. S. BENNETT, B. A. LANGFORD, J. R. STRADLING, and R. J. O. DAVIES Sleep Fragmentation Indices as Predictors of Daytime Sleepiness and nCPAP Response in Obstructive Sleep Apnea Am. J. Respir. Crit. Care Med., September 1, 1998; 158(3): 778 - 786. [Abstract] [Full Text] [PDF]