Cyclic Alternating Pattern Rate Research Articles

Alterations in cyclic alternating pattern associated with phase advanced sleep are differentially modulated by gaboxadol and zolpidem.

to evaluate cyclic alternating pattern (CAP) in a phase advance model of transient insomnia and the effects of gaboxadol and zolpidem. a randomized, double-blind, cross-over study in which habitual sleep time was advanced by 4 h. 6 sleep research laboratories in US PARTICIPANTS: 55 healthy subjects (18-57 y) Gaboxadol 15 mg (GBX), zolpidem 10 mg (ZOL), and placebo (PBO). routine polysomnographic (PSG) measures, CAP, spectral power density, and self-reported sleep measures The phase advance model of transient insomnia produced significant changes in CAP parameters. Both GBX and ZOL significantly and differentially modified CAP parameters in the direction of more stable sleep. GBX brought the CAP rate in stage 1 sleep and slow wave sleep (SWS) closer to baseline levels but did not significantly change the CAP rate in stage 2. ZOL reduced the CAP rate in stage 2 to near baseline levels, whereas the CAP rate in stage 1 and SWS was reduced substantially below baseline levels. The CAP parameter A1 index (associated with SWS and sleep continuity) showed the highest correlation with self-reported sleep quality, higher than any traditional PSG, spectral, or other self-reported measures. disruptions in CAP produced by phase advanced sleep were significantly and differentially modulated by gaboxadol and zolpidem. The relative independence of CAP parameters from other electrophysiological measures of sleep, their high sensitivity to sleep disruption, and their strong association with subjective sleep quality suggest that CAP variables may serve as valuable endpoints in future insomnia research.

Cyclic alternating pattern in normal children aged 12 to 24 months

The aim of this study is to complement existing data on the expression and characteristics of cyclic alternating pattern (CAP) in children, specifically in the 12 to 24 month age bracket. Descriptive study. a university pediatric sleep laboratory. Twelve normal and healthy subjects (6 girls and 6 boys, mean age 18.9 ± 4.72 months; range 12-24 months underwent a standard polysomnography night recording in our pediatric sleep laboratory. Sleep stages and CAP were analyzed according to standard international rules. CAP rate found in children of 12 to 24 months of age was (25.78 ± 10.18%) and it is characterized by a linear increase of 2% per month, from 12% at 12 months reaching 35% at 24 months. With coefficient of determination R² of 0.91. The duration of A phases was 6.93 ± 1.06 seconds, and B phases was found to last 21.44 ± 2.31 seconds. The number of CAP cycles was 173.25 ± 7 3.85 with an average index per hour of 33.55 ± .61. The number of CAP sequences reached 25.25 ± 9.55 per recording. CAP rate for the different type of A phases are (21.83 ± 9.68%), for A1, (2.43 ± 2.30%) for A3 and (1.67 ± 1.11%) for A2. Our study provides normative data on CAP in a group of young children (12 to 24 months). The most salient result of this study is the strong correlation of CAP rate of 2% per month in this age group.

Sleep cyclic alternating pattern analysis in healthy children during the first year of life: A daytime polysomnographic study

We evaluated the cyclic alternating pattern (CAP) during the first year of life in order to obtain information on the maturation of arousal mechanisms during NREM sleep and to provide normative data for CAP parameters in this age range (5–16 months). Eleven healthy children (mean age 7.9 ± 3.3 months, seven boys) were studied while they slept in the morning. They underwent a 3-h video-EEG-polysomnographic recording at the Pediatric Sleep Unit of Sant’Andrea Hospital in Rome, Italy. Sleep was scored visually for sleep architecture and CAP analysis using standard criteria. Our results were complemented by CAP data from a previous sample of healthy infants (2–4 months), studied when they slept during the morning, in order to correlate CAP parameters with age. The total sample comprised 24 children. The sleep period was approximately 2 h, with a first REM latency of about 30 min, and a clear distinction between stages N1, N2, and N3. The arousal index was 12 ± 2.1 events/hour of sleep. The total CAP rate was 23.7 ± 7.6%, and it increased progressively with the deepness of sleep; the highest values were observed during stage N3 and the lowest values during stage N1. A1 phases were the most numerous (78.2%), followed by A2 (14%) and A3 (7.7%) phases. The A1 index was higher than the A2 and A3 indices, whereas the mean duration of B was higher than that of A. The correlation showed that the CAP rate, A1, A2, A3 indices, A2, A3 percentages, and the average duration of B increased with age, whereas the A1 percentage decreased. We provide the first data on CAP analysis in children aged 5–16 months, studied when they slept during the morning. Our results confirm the trend toward an increase in CAP rate during the first year of life. In addition, we observed a progressive increase in CAP rate with deepness of sleep, and with age, reflecting maturation of slow-wave activity. The decreased percentage of A1 subtypes may reflect the maturation of arousability.

The effects of experimental sleep fragmentation on cognitive processing

Objective The primary objective of this study was to characterize the association between cyclic alternating pattern (CAP) and neurocognitive performance in a group of normal subjects before and after two nights of experimentally-induced sleep fragmentation. Subjects and methods Fifteen healthy subjects underwent one night of uninterrupted and two sequential nights of experimental sleep fragmentation achieved by auditory and mechanical stimuli. Eight subjects were re-examined using a similar paradigm with three nights of uninterrupted sleep. Sleep was polygraphically recorded and CAP analysis was performed for all recordings. A battery of neurocognitive tests was performed for spatial attention, inhibition of return, mental rotation, and Stroop color word test in the afternoon following the first and third night of sleep under fragmented and non-fragmented conditions. Results With sleep fragmentation, the percentage of slow-wave sleep was dramatically reduced and there was a twofold increase in total CAP rate across all NREM sleep stages. Moreover, the number of all CAP A subtypes/hour of sleep (index) was significantly increased. Total CAP rate during the non-fragmented night correlated with reaction times. Similarly, the percentages of A1 and A3 subtypes were negatively and positively correlated with reaction times, respectively. Of the neurocognitive test battery, however, only values obtained from some subtests of the mental rotation test showed a significant improvement after sleep fragmentation. Conclusions The results of this study suggest that CAP A1 subtypes are associated with higher cognitive functioning, whereas CAP A3 subtypes are associated with lower cognitive functioning in young healthy subjects. The lack of cognitive functioning impairment after sleep fragmentation may be due to persistence and even enhancement of transient slow-wave activity contained in CAP A1 subtypes which also caused a significant enhancement of the EEG power spectrum in the lower frequencies.

Reduced NREM sleep instability in benign childhood epilepsy with centro-temporal spikes

To analyze sleep architecture and NREM sleep instability by means of the cyclic alternating pattern (CAP) in children with benign epilepsy with rolandic spikes (BERS). Ten children with BERS, drug free at the time of the study and 10 age-matched normal controls were included in this study. Sleep was visually scored for sleep architecture and CAP using standard criteria. Sleep architecture in BERS showed only few significant differences vs. controls with a reduction of total sleep time, sleep efficiency, and REM sleep percentage. CAP analysis revealed several significant differences: reduced total CAP rate, mainly in sleep stage 2, and reduced EEG slow oscillations and arousals during stages N1 and N2. Sleep architecture is not importantly affected in BERS but CAP analysis reveals a decrease of NREM instability, mainly in sleep stage 2. Since there is a spindle-related spike activation in BERS, we speculate that the decrease of CAP and of EEG slow oscillations and arousals might be linked with the inhibitory action of spindling activity and spikes on arousals. CAP analysis discloses sleep structure abnormalities in children with BERS not shown by the classical sleep scoring. Spike activity and CAP A1 subtypes seem to be mutually exclusive probably because centro-temporal spikes disturb the physiological synchronization mechanisms needed for the generation of slow-wave components of CAP.

Cyclic alternating pattern and sleep quality in healthy subjects—Is there a first-night effect on different approaches of sleep quality?

Objective Cyclic alternating pattern (CAP) is defined as periodic EEG activity during NREM sleep that reflects unstable sleep and represents a marker of instability of the sleep process. The aim of the present investigation was to analyze sleep quality of 28 healthy subjects (mean age 53.3 ± 21.3 years) over two consecutive nights and determine potential differences between them (“first-night effect”). Methods Evaluations comprised objective and subjective sleep variables as well as macrostructural and microstructural variables of sleep. Results Macrostructural analysis showed significant differences between the first and the second sleep laboratory night in REM latency (122.39 ± 60.46 min vs. 95.43 ± 36.60 min; T = 3.431; p = 0.002) and the amount of sleep stage 1 (42.60 ± 21.80 min vs. 39.70 ± 18.95 min; T = 2.223; p = 0.035). Microstructural analysis revealed a significant decrease in the CAP rate (1st night: 33.29%; 2nd night: 26.34%; T = 3.288; p = 0.003) and in the amount of subtype A2 (74.79 ± 43.47 vs. 58.50 ± 23.22; T = 2.185; p = 0.038). Subjective variables also demonstrated a significant increase of drive ( T = 2.564; p = 0.016). Conclusion Healthy subjects show hardly any macrostructural differences between the first and the second night in the sleep laboratory. On the microstructural level differences in CAP variables were found. Significance Microstructural analysis can be seen as a further approach to the classification of sleep and CAP turned out to be sensitive to environmental influences on sleep.

Slow EEG Amplitude Oscillations During NREM Sleep and Reading Disabilities in Children With Dyslexia

Study Objectives: To analyze non-rapid eye movement (NREM) sleep microstructure of children with dyslexia, by means of cyclic alternating pattern (CAP) analysis and to correlate CAP parameters with neuropsychological measures. Design: Cross-sectional study using polysomnographic recordings and neuropsychological assessments. Setting: Sleep laboratory in academic center. Participants: Sixteen subjects with developmental dyslexia (mean age 10.8 years) and 11 normally reading children (mean age 10.1 years) underwent overnight polysomnographic recording. Intervention: N/A. Measurements and Results: Sleep architecture parameters only showed some statistically significant differences: number of sleep stage shifts per hour of sleep, percentage of N3, and number of R periods were significantly lower in dyslexic children versus controls. CAP analysis revealed a higher total CAP rate and A1 index in stage N3. A2% and A2 index in stage N2 and N3 were lower in dyslexic children while no differences were found for A3 CAP subtypes. The correlation analysis between CAP parameters and cognitive-behavioral measures showed a significant positive correlation between A1 index in N3 with Verbal IQ, full-scale IQ, and Memory and Learning Transfer reading test; while CAP rate in N3 was positively correlated with verbal IQ. Conclusions: To overcome reading difficulties, dyslexic subjects overactivate thalamocortical and hippocampal circuitry to transfer information between cortical posterior and anterior areas. The overactivation of the ancillary frontal areas could account for the CAP rate modifications and mainly for the increase of CAP rate and of A1 index in N3 that seem to be correlated with IQ and reading abilities.

Sleep Polygraphic Study of Children and Adolescents With Narcolepsy/Cataplexy

The alterations of the Cyclic Alternating Pattern (CAP) recently found in narcoleptic adult patients suggest the presence of an impaired modulation of the fluctuations of the arousal level during their non-rapid eye movement (NREM) sleep, possibly because of the persistence of neurophysiological mechanisms typical of rapid eye movement (REM) sleep. The same mechanism might play a role in the occurrence of leg movement (LM) activity during sleep characterized by low levels of periodicity. The aim of this study was to evaluate CAP and sleep LM activity in a group of children and adolescents with narcolepsy, to interpret the results under a developmental point of view and integrate this new information with data already available for adults. Thirteen young patients with narcolepsy/cataplexy were consecutively recruited for this study, together with 13 age- and sex-matched normal controls. Nocturnal polysomnography was carried out after a night of adaptation in a sleep laboratory room; sleep stages, CAP, and LMs were scored and evaluated following standard criteria. Narcoleptic patients showed shorter sleep onset and REM sleep latency, higher number of stage shifts and awakenings per hour of sleep, and higher percentage of wakefulness after sleep onset; CAP rate was found to be decreased in all NREM sleep stages (in particular CAP A1 subtypes) in narcoleptic patients who also showed significant higher values of all types of LMs (periodic or isolated), during both REM and NREM sleep; however, the most evident differences were found during REM sleep. The results of this study confirm that the sleep microstructure and LM activity changes observed in adulthood are already present and detectable in childhood and might have a role in the already known impaired prefrontal functioning of these subjects. The well-established orexin deficiency might be the unifying factor playing a major role in the modulation of CAP and LMs during sleep in children and adolescents with narcolepsy/cataplexy.

Development of NREM Sleep Instability-Continuity (Cyclic Alternating Pattern) in Healthy Term Infants Aged 1 to 4 months

To evaluate non-rapid eye movement (NREM) sleep instability, as measured by the cyclic alternating pattern (CAP), in the first months of life in a group of normal healthy infants, in order to obtain more information on the maturation of arousal mechanisms during NREM sleep and to set normative data of CAP parameters in this age range (from 1 to 4 months of life). Retrospective study. Sleep unit of an academic centre. Twenty-three healthy newborns and infants with a mean conceptional age (gestational age plus postnatal age) of 47.6 + 3.8 weeks, age range 42 to 55 weeks, 10 boys (43.47%), were studied while they slept in the morning between feedings, by means of a 3-hour video-electroencephalographic (EEG)-polygraphic recording. Sleep was visually scored for sleep architecture and CAP in a blinded fashion, using standard criteria. We found 3 different sleep EEG patterns in our infants, according to their age, and we subdivided the entire group into 3 subgroups. Group 1-Tracé alternant mixed with high-voltage slow activity included 9 subjects (3 boys), with a mean conceptional age of 43.9 +/- 1.3 weeks; Group 2 (high-voltage slow activity and rudimentary spindles) included 6 subjects (4 boys), with a mean conceptional age of 49.4 +/- 3.1 weeks; and Group 3 (slow-wave activity and spindles, scored as NREM sleep) included 8 subjects (3 boys), with a mean conceptional age of 50.4 +/- 2.9 weeks. CAP rate was 6.83 +/- 3.58 in infants belonging to Group 2 and increased to 12.91 +/- 2.21 in Group 3. We found a statistically significant higher A1 index in only Group 3. The relative percentages of the A1, A2, and A3 subtypes showed non significant changes with age. The duration of CAP events and the cortical and subcortical arousal indexes were not statistically different between Groups 2 and 3. With this study, we provide the first data on CAP analysis in infants from 1 to 4 months of life, and we found that there is a transitory period when trace alternant disappears and CAP events begin to occur. Furthermore, we suggest that the more appropriate time of life when CAP analysis can be first performed is related to the appearance of mature stage 2 NREM with spindles and slow delta waves mixed with theta waves, at approximately 3 months of life.

Analysis of NREM sleep in children with Prader–Willi syndrome and the effect of growth hormone treatment

Objectives Only few studies are available in the literature on sleep in children with Prader–Willi syndrome (PWS) and one single study analyzed the cyclic alternating pattern (CAP) in young adults with PWS, showing that patients with a higher proportion of A1 subtypes presented less severe GH deficiency. The aims of our study were to evaluate CAP in children with PWS compared to an age-matched control group and to evaluate the differences between PWS children with (GH+) and without (GH−) GH therapy. Methods Laboratory polysomnographic sleep recordings were obtained from 30 children with PWS (17 GH− and 13 GH+ patients) and 15 age-matched normal controls. Results Compared to controls, PWS children had a reduction of sleep efficiency, of sleep stage 2 and of REM sleep. GH− PWS patients showed a global decrease in total CAP rate during S1 and S2 but not in SWS. In GH+ PWS patients, SWS CAP rate and A1 index were increased vs. GH− children. Discussion The decrease in total CAP rate and all A subtypes might suggest the presence of a decreased NREM sleep instability in our PWS children and can be considered to be in agreement with the reported generalized hypoarousal state of PWS subjects. GH therapy is likely to increase CAP rate and A1 index during SWS in PWS patients.

Delta sleep instability in children with chronic arthritis

The objective of the present study was to evaluate the expression of a cyclic alternating pattern (CAP) in slow wave sleep (SWS) in children with the well-defined chronic syndrome juvenile idiopathic arthritis (JIA). Twelve patients (9-17 years of age), 7 girls, with JIA were compared to matched controls by age, pubertal stage and gender. After one night of habituation in the sleep laboratory, sleep measurements were obtained by standard polysomnography with conventional sleep scoring and additional CAP analyses. The sleep parameters of the JIA and control groups were similar for sleep efficiency (91.1 +/- 6.7 vs 95.8 +/- 4.0), sleep stage in minutes: stage 1 (16.8 +/- 8.5 vs 17.8 +/- 4.0), stage 2 (251.9 +/- 41 vs 262.8 +/- 38.1), stage 3 (17.0 +/- 6.0 vs 15.1 +/- 5.7), stage 4 (61.0 +/- 21.7 vs 77.1 +/- 20.4), and rapid eye movement sleep (82.0 +/- 27.6 vs 99.0 +/- 23.9), respectively. JIA patients presented nocturnal disrupted sleep, with an increase in short awakenings, but CAP analyses showed that sleep disruption was present even during SWS, showing an increase in the overall CAP rate (P < 0.01). Overall CAP rate during non-rapid eye movement sleep was significantly higher in pediatric patients who were in chronic pain. This is the first study of CAP in pediatric patients with chronic arthritis showing that CAP analyses can be a powerful tool for the investigation of disturbance of SWS in children, based on sleep EEG visual analysis.

NREM sleep instability changes following rapid maxillary expansion in children with obstructive apnea sleep syndrome

Objective To evaluate NREM sleep microstructure in children with obstructive sleep apnea syndrome (OSAS) before and after one year of rapid maxillary expander (RME) treatment by means of the cyclic alternating pattern (CAP). Methods Nine children with OSAS aged 4–8 years (6 males, mean age 6.4 ± 1.97 years) and age-matched normal controls were included. All subjects underwent an overnight polysomnography in the sleep laboratory after one adaptation night, as a baseline evaluation; children with OSAS were recorded again after one year of RME treatment. Results After one year of treatment the OSAS group showed a longer duration of time in bed and sleep period time, a reduction in number of stage shifts compared to baseline recordings, and the apnea–hypopnea index decreased significantly. At baseline, the OSAS group had a higher CAP rate during slow-wave sleep and an increased A2 index compared to normal controls. After one year of RME application, children with OSAS showed an increase in CAP rate associated with an increase of A1 index during slow-wave sleep. Conclusions RME treatment almost normalized sleep architecture and improved sleep respiratory disturbances; however, sleep microstructure and respiratory parameters did not completely recover. The persistence of increased CAP rate in slow-wave sleep associated with an increase of A1 index might reflect a partial failure of orthodontic treatment. On the other hand, the rebound of A1 subtypes might be an indirect sign of an attempt to normalize sleep that has been disturbed by the respiratory events.

Effects of Zolpidem on Cyclic Alternating Pattern, an Objective Marker of Sleep Instability, in Japanese Patients with Psychophysiological Insomnia: A Randomized Crossover Comparative Study with Placebo

A placebo-controlled randomized crossover study to investigate the effects of zolpidem on sleep stability in Japanese insomniac patients was performed using the cyclic alternating pattern (CAP) rate, a polysomnographic marker that reflects sleep instability. Seventeen patients (5 M and 12 F, mean age: 40.4+/-13.6 years) who met the International Classification of Sleep Disorders (ICSD) criteria for psychophysiological insomnia were evaluated. During the first period, patients were administered the placebo on the first night, followed by either zolpidem or the placebo on the second night (treatment night). The second crossover period was conducted after a minimum 3-day observation. Improvement in the overnight CAP rate was the primary endpoint. Secondary endpoints included the CAP variables, conventional sleep variables, EEG arousals, subjective evaluation of sleep quality (measured by means of a visual analogue scale and the St. Mary's Hospital Sleep Questionnaire), and drug safety. Zolpidem significantly decreased the overnight CAP rate values (57.6 vs. 39.0%, p=0.009) and improved "sleep depth" (p=0.044) and "sleep quality" (p=0.023) subjective questionnaire scores. Zolpidem also significantly improved VAS (p=0.036). The amount of time spent in sleep stages 3+4 was significantly increased by zolpidem without affecting the amounts of stage 2 and rapid eye movement (REM) sleep. Significant negative correlations were found when the sleep quality score was matched to the CAP rate (p=0.022). No serious adverse events occurred during the study. In Japanese patients with psychophysiological insomnia, zolpidem increased sleep stability by significantly improving the overnight CAP rate. Zolpidem also improved sleep depth and sleep quality, both subjectively and objectively.

Sleep phenotypes of intellectual disability: A polysomnographic evaluation in subjects with Down syndrome and Fragile-X syndrome

Objective To analyze sleep architecture and NREM sleep alterations by means of the Cyclic Alternating Pattern (CAP) in children with Down syndrome (DS) and Fragile-X syndrome (fraX), the two most common causes of inherited mental retardation, in order to find out eventual alterations of their sleep microstructure related to their mental retardation phenotypes. Methods Fourteen patients affected by fraX (mean age 13.1 years) and 9 affected by Down syndrome (mean age 13.8 years) and 26 age-matched normal controls were included. All subjects underwent overnight polysomnography in the sleep laboratory, after one adaptation night and their sleep architecture and CAP were visually scored. Results FraX subjects showed a reduced time in bed compared to DS subjects, whereas DS subjects showed a lower sleep efficiency, a higher percentage of wakefulness after sleep onset, and a reduced percentage of stage 2 NREM compared to the other groups. Furthermore, DS and fraX subjects, compared to normal controls, showed a higher percentage of stage 1 NREM and a lower percentage of REM sleep. FraX subjects showed the most disrupted sleep microstructure with low total CAP rate and CAP rate in S2 NREM. Both patient groups showed a lower percentage of A1 and higher percentage of A2 and A3 compared to normal controls. Conclusions The analysis of CAP might be able to disclose new important findings in the sleep architecture of children with mental retardation and might characterize sleep microstructural patterns of the different phenotypes of intellectual disability. Significance The NREM sleep microstructure alterations found in our subjects, associated with the reduction in REM sleep percentage, seem to be distinctive features of intellectual disability.

NREM sleep instability in children with sleep terrors: The role of slow wave activity interruptions

Objective To evaluate NREM sleep instability, as measured by the cyclic alternating pattern (CAP), in children with sleep terrors (ST) vs. normal controls. Methods Ten boys (mean age: 8.5 years, range 5–13) meeting the following inclusion criteria: (a) complaint of ST several times a month, (b) a history of ST confirmed by a third person, and (c) a diagnosis of ST according to the ICSD-2 criteria. Eleven age-matched control children with parental report of at least 8.5 h of nightly sleep, absence of known daytime consequences of sleep disorders were recruited by advertisement from the community. Sleep was visually scored for sleep macrostructure and CAP using standard criteria. Results Sleep macrostructure showed only a significantly increased number of awakenings per hour and reduced sleep efficiency in ST subjects. CAP parameters analysis revealed several significant differences in ST vs. controls: an increase of total CAP rate in SWS, of A1 index in SWS and of the mean duration of A phases while B phases had a decreased duration, exclusively in SWS. The normalized CAP interval-distribution graphs showed significant differences in SWS with interval classes 10 ⩽ i < 35 s higher in children with ST and intervals classes above 50 s higher in normal controls. Conclusions Children with ST showed faster alternations of the amplitude of slow EEG bursts during SWS. This abnormally fast alternation of the EEG amplitude in SWS is linked to the frequent intrusion of CAP B phases interrupting the continuity of slow delta activity and could be considered as a neurophysiological marker of ST. Significance This abnormal alternation of the EEG amplitude in SWS is associated with the occurrence of parasomnias and might be considered as a neurophysiological marker of disorders of arousal.

Role of Continuous Positive Airway Pressure Therapy on the Pathogenesis of Sleep-Related Frontal Lobe Epilepsy in a Child With Obstructive Sleep Apnea Syndrome

We describe an obese child with severe obstructive sleep apnea syndrome in whom nocturnal frontal lobe seizures developed within a week after therapy was started with continuous positive airway pressure. The video polysomnographic study after the onset of nocturnal episodes showed 3 seizures: 2 starting from slow-wave sleep when he was sleeping with continuous positive airway pressure, and 1 from stage 2 non-rapid eye movement sleep when he was sleeping without continuous positive airway pressure. Cyclic alternating pattern analysis during the video polysomnography recorded after the onset of nocturnal seizures disclosed a high cyclic alternating pattern rate during slow-wave sleep, and the recording obtained after antiepileptic therapy began showed a low cyclic pattern analysis rate. In this child, we describe the non-rapid eye movement sleep instability induced by continuous positive airway pressure therapy might have had a role in triggering the nocturnal seizures.

Sleep architecture and NREM alterations in children and adolescents with Asperger syndrome.

To analyze sleep in children with Asperger syndrome (AS) by means of standard sleep questionnaires, to evaluate sleep architecture and NREM sleep alterations by means of cyclic alternating pattern (CAP) and to correlate objective sleep parameters with cognitive behavioral measures. Cross-sectional study involving validated sleep questionnaires, neuropsychological scales, and PSG recording. Sleep medicine center. Eight children with AS, 10 children with autism, and 12 healthy control children. N/A. Children with AS had a higher prevalence of problems of initiating sleep and daytime sleepiness. Sleep architecture parameters showed minor differences between the 3 groups. CAP parameters showed an increased percentage of A1 and a decreased percentage of A2 subtypes in subjects with AS vs. controls. All A subtype indexes (number per hour of NREM sleep) were decreased, mostly in sleep stage 2 but not in SWS. With respect to children with autism, subjects with AS showed increased CAP rate in SWS and A1 percentage. In subjects with AS, verbal IQ had a significant positive correlation with total CAP rate and CAP rate in SWS and with global and SWS A1 index. The percentage of A2 negatively correlated with full scale IQ, verbal and performance IQ. CBCL total score correlated positively with CAP rate and A1 index while externalizing score correlated negatively with A3%. This study shows peculiar CAP modifications in children with AS and represents an attempt to correlate the quantification of sleep EEG oscillations with the degree of mental ability/disability.

Impaired cortical and autonomic arousal during sleep in multiple system atrophy

Objective Periodic limb movements during sleep (PLMS) in Restless Legs Syndrome (RLS) are associated with arousals and stereotyped EEG and heart rate (HR) changes. We investigated PLMS-related EEG and HR variations in multiple system atrophy (MSA) in order to detect possible abnormalities in cortical and autonomic arousal responses. Methods Ten patients with MSA were contrasted against ten patients with primary RLS. Cortical (EEG) and autonomic (HR) variations associated with PLMS during NREM sleep were analysed by means of Fast Fourier Transform and HR analysis. In addition, we analysed the cyclic alternating pattern (CAP) during sleep, CAP representing a measure of the spontaneous arousal oscillations during NREM sleep. Results PLMS in RLS were associated with tachycardia and spectral EEG variations, beginning about 2 s before the onset of PLMS, and peaking 1–4 s after. The HR and spectral EEG variations were strikingly reduced or absent in MSA. MSA patients also had significantly lower CAP rate compared to RLS patients. Conclusions Blunted HR and EEG spectral changes adjacent to PLMS indicated impaired cortical and autonomic arousal responses during sleep in MSA patients. Significance PLMS, when present, may represent a useful means to study the arousal responses during sleep.

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.

Sleep in children with autistic spectrum disorder: A questionnaire and polysomnographic study

Objective To evaluate sleep in children with autistic spectrum disorder (ASD) by means of sleep questionnaires and polysomnography; moreover, to analyze their cyclic alternating pattern (CAP). Methods Thirty-one patients with ASD (28 males, 3 females, aged 3.7–19 years) and age-matched normal controls were included. ASD children were evaluated by a standard sleep questionnaire that consisted of 45 items in a Likert-type scale covering several areas of sleep disorders and by overnight polysomnography in the sleep laboratory after one adaptation night. Results The questionnaire results showed that parents of ASD children reported a high prevalence of disorders of initiating and maintaining sleep, enuresis, repetitive behavior when falling asleep, and daytime sleepiness. Polysomnographically, ASD children showed reduced time in bed, total sleep time, sleep period time and rapid eye movement (REM) latency. ASD subjects had a CAP rate during slow-wave sleep (SWS) lower than normal controls, together with a lower percentage of A1 subtypes. Conclusions ASD children questionnaires showed a higher percentage of disorders of initiating and maintaining sleep than normal controls; this was not completely confirmed by sleep staging. CAP measures showed subtle alterations of NREM sleep which could be detected with an appropriate methodology of analysis. The reduction of A1 subtypes during SWS might play a role in the impairment of cognitive functioning in these subjects.