The cyclic alternating pattern demonstrates increased sleep instability and correlates with fatigue and sleepiness in adults with upper airway resistance syndrome.

OBJECTIVE: To clarify the relationship between sleep instability and subjective complaints in patients with upper airway resistance syndrome (UARS). METHODS: Thirty subjects (15 women) with UARS and 30 age- and sex-matched controls in a prospective, single-blind, case-control study. Blinded cyclic alternating pattern (CAP) electroencephalogram analysis and scales of fatigue and sleepiness were completed. ANALYSIS: Mann-Whitney U tests for independent, nonparametric variables between groups and chi2 tests for nonparametric variables with defined standard values. RESULTS: Patients with UARS had significantly more complaints of fatigue and sleepiness, compared with controls, demonstrated on their Fatigue Severity Scale (P < 0.001) and Epworth Sleepiness Scale (P < 0.001). By design, the mean apnea-hypopnea index was normal in both groups, whereas the respiratory disturbance index was greater in patients with UARS than in those without (14.5 +/- 3.0 vs 9 +/- 5.2, respectively [P < 0.001]). CAP analysis demonstrated abnormal non-rapid eye movement sleep with abnormally increased CAP rate, electroencephalogram arousals, A2 index, and A3 index. Decreased A1 index in controls was consistent with their more normal progression of sleep. CAP rate correlated with both the Epworth Sleepiness Scale (r = 0.38, P < 0.01) and the Fatigue Severity Scale (r = 0.51, P < 0.0001), and there was a positive trend between the Fatigue Severity Scale and phase A2 index (r = 0.29, P < 0.05). CONCLUSION: Compared with age- and sex-matched controls, patients with UARS have higher electroencephalogram arousal indexes and important non-rapid eye movement sleep disturbances that correlate with subjective symptoms of sleepiness and fatigue. These disturbances are identifiable with sensitive measures such as CAP analysis but not with traditional diagnostic scoring systems.

Non-REM sleep instability in patients with major depressive disorder: subjective improvement and improvement of non-REM sleep instability with treatment (Agomelatine).

OBJECTIVE: To assess the importance of non-rapid eye movement (NREM) sleep disturbance in major depressive disorder (MDD) patients using cyclic alternating pattern (CAP) analysis, and to determine the usefulness of CAP analysis in evaluating treatment effect. METHODS: Baseline sleep-staging data and CAP analysis of NREM sleep was compared in 15 MDD patients (Hamilton depression scale score>20) and normal controls. Longitudinal evaluation of sleep changes using similar analysis during a treatment trial was also performed. ANALYSIS: A single-blinded researcher scored and analyzed the sleep of MDD and age-matched normal controls at baseline and during a treatment trial using the international scoring system as well as CAP analysis. RESULTS: MDD patients had evidence of disturbed sleep with both analyses, but CAP analysis revealed more important changes in NREM sleep of MDD patients at baseline than did conventional sleep staging. There was a significant decrease in CAP rate, time, and cycle and disturbances of phase A subtype of CAP. NREM abnormalities, observed by CAP analysis, during the treatment trial paralleled subjective responses. Analysis of subtype A phase of CAP demonstrated better sleep improvement. CONCLUSION: CAP analysis demonstrated the presence of more important NREM sleep disturbances in MDD patients than did conventional sleep staging, suggesting the involvement of slow wave sleep (SWS) in the sleep impairment of MDD patients. Improvement of NREM sleep paralleled subjective mood improvement and preceded REM sleep improvement. CAP analysis allowed objective investigation of the effect of treatment on sleep disturbances.

Chronic snoring and sleep in children: a demonstration of sleep disruption.

OBJECTIVE: Chronic snoring that does not adhere to the criteria for a diagnosis of obstructive sleep apnea syndrome may be associated with learning and behavioral problems. We investigated the sleep structure of chronic snorers who had an apnea-hypopnea index of < 1 event per hour and analyzed the cyclic alternating pattern. METHODS: Fifteen successively seen chronic snorers (9.8 +/- 4 years) with an apnea-hypopnea index of <1 and 15 aged-matched control subjects (10.3 +/- 5 years) underwent an investigation of their sleep with the determination of non-apneic-hypopneic breathing abnormalities polysomnographic scoring using current criteria and analysis of the cyclic alternating pattern. RESULTS: Chronic snorers have evidence of flow limitations and tachypnea during sleep even if they do not present with apneas, hypopneas, and decrease in oxygen saturations. They also present with abnormal cyclic alternating pattern rates and changes in phase A of cyclic alternating pattern compared with control subjects. CONCLUSIONS: An apnea-hypopnea index value cannot be the sole determinant in evaluating sleep-disordered breathing in children. Children who have chronic snoring and do not respond to the criteria for obstructive sleep apnea syndrome can present with an abnormal sleep electroencephalogram as evidenced by a significant increase in cyclic alternating pattern rates, with a predominance of abnormalities in slow wave sleep.