Ronald D. Chervin

Pediatric sleep questionnaire (PSQ): validity and reliability of scales for sleep-disordered breathing, snoring, sleepiness, and behavioral problems

Objective: To develop and validate questionnaire scales that can be used in research to investigate the presence of childhood SRBDs and prominent symptom complexes, including snoring, daytime sleepiness, and related behavioral disturbances.Background: Obstructive sleep-related breathing disorders (SRBDs) are common but usually undiagnosed among children. Methods to help identify SRBDs without the expense of polysomnography could greatly facilitate clinical and epidemiological research.Methods: Subjects were children aged 2-18 years who had polysomnographically-confirmed SRBDs (n=54) or appointments at either of two general pediatrics clinics (n=108). Parents completed a Pediatric Sleep Questionnaire which contained items under consideration for inclusion in desired scales.Results: Item reduction, based on data from a randomly selected 50% of the subjects (group A), produced a 22-item SRBD score that was strongly associated with diagnosis of an SRBD (P<0.0001) in a logistic regression model that accounted for age and gender. Diagnosis was also strongly associated with subscores for snoring (four items, P<0.0001), sleepiness (four items, P=0.0003), and behavior (six items, P<0.0001) among group A subjects. The scales performed similarly well among group B subjects, and among subjects of different ages and gender. In group A and B subjects, respectively, a selected criterion SRBD score produced a sensitivity of 0.85 and 0.81; a specificity of 0.87 and 0.87; and a correct classification for 86 and 85% of subjects. The scales showed good internal consistency and, in a separate sample (n=21), good test-retest stability.Conclusions: These scales for childhood SRBDs, snoring, sleepiness, and behavior are valid and reliable instruments that can be used to identify SRBDs or associated symptom-constructs in clinical research when polysomnography is not feasible.

Sleep-Disordered Breathing, Behavior, and Cognition in Children Before and After Adenotonsillectomy

OBJECTIVES. Most children with sleep-disordered breathing (SDB) have mild-to-moderate forms, for which neurobehavioral complications are believed to be the most important adverse outcomes. To improve understanding of this morbidity, its long-term response to adenotonsillectomy, and its relationship to polysomnographic measures, we studied a series of children before and after clinically indicated adenotonsillectomy or unrelated surgical care. METHODS. We recorded sleep and assessed behavioral, cognitive, and psychiatric morbidity in 105 children 5.0 to 12.9 years old: 78 were scheduled for clinically indicated adenotonsillectomy, usually for suspected SDB, and 27 for unrelated surgical care. One year later, we repeated all assessments in 100 of these children. RESULTS. Subjects who had an adenotonsillectomy, in comparison to controls, were more hyperactive on well-validated parent rating scales, inattentive on cognitive testing, sleepy on the Multiple Sleep Latency Test, and likely to have attention-deficit/hyperactivity disorder (as defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) as judged by a child psychiatrist. In contrast, 1 year later, the 2 groups showed no significant differences in the same measures. Subjects who had an adenotonsillectomy had improved substantially in all measures, and control subjects improved in none. However, polysomnographic assessment of baseline SDB and its subsequent amelioration did not clearly predict either baseline neurobehavioral morbidity or improvement in any area other than sleepiness. CONCLUSIONS. Children scheduled for adenotonsillectomy often have mild-to-moderate SDB and significant neurobehavioral morbidity, including hyperactivity, inattention, attention-deficit/hyperactivity disorder, and excessive daytime sleepiness, all of which tend to improve by 1 year after surgery. However, the lack of better correspondence between SDB measures and neurobehavioral outcomes suggests the need for better measures or improved understanding of underlying causal mechanisms.

The Epworth Sleepiness Scale may not reflect objective measures of sleepiness or sleep apnea

Objective: To assess the validity of the Epworth Sleepiness Scale score (ES) as a measure of sleepiness among patients suspected or confirmed to have obstructive sleep apnea syndrome. Background: The ES is used with increasing frequency as a measure of excessive daytime sleepiness in part because several studies suggested that the ES correlates with mean sleep latency (MSL) on the Multiple Sleep Latency Test and with severity of sleep apnea among patients with that disorder. However, associations identified between the ES and other measures were not strong or consistent. Methods: The authors used regression models and retrospective data from a relatively large series of 237 patients to restudy how ES relates to MSL, to a simple self-rating of problem sleepiness (available for 141 patients), and to two polysomnographic measures of sleep apnea severity: the number of apneas or hypopneas per hour of sleep and the minimum recorded oxygen saturation. Results: The ES had a statistically significant association with self-rated problem sleepiness but not with MSL or measures of sleep apnea severity. Male gender, adjusted for potential confounding variables, had considerably more influence on the ES than did MSL or measures of sleep apnea severity. Conclusions: Our data suggest that the subjectively derived ES cannot be used as a surrogate for the objectively determined MSL.

Developmental aspects of sleep hygiene: Findings from the 2004 National Sleep Foundation Sleep in America Poll

OBJECTIVE To examine the associations between sleep hygiene and sleep patterns in children ages newborn to 10 years. The relationships between key features of good sleep hygiene in childhood and recognizable outcomes have not been studied in large, nationally representative samples. PARTICIPANTS AND METHODS A national poll of 1473 parents/caregivers of children ages newborn to 10 years was conducted in 2004. The poll included questions on sleep hygiene (poor sleep hygiene operationally defined as not having a consistent bedtime routine, bedtime after 9:00 PM, having a parent present when falling asleep at bedtime, having a television in the bedroom, and consuming caffeinated beverages daily) and sleep patterns (sleep onset latency, frequency of night wakings, and total sleep time). RESULTS Across all ages, a late bedtime and having a parent present when the child falls asleep had the strongest negative association with reported sleep patterns. A late bedtime was associated with longer sleep onset latency and shorter total sleep time, whereas parental presence was associated with more night wakings. Those children (ages 3+) without a consistent bedtime routine also were reported to obtain less sleep. Furthermore, a television in the bedroom (ages 3+) and regular caffeine consumption (ages 5+) were associated with shorter total sleep time. CONCLUSIONS Overall, this study found that good sleep hygiene practices are associated with better sleep across several age ranges. These findings support the importance of common US based recommendations that children of all ages should fall asleep independently, go to bed before 9:00 PM, have an established bedtime routine, include reading as part of their bedtime routine, refrain from caffeine, and sleep in bedrooms without televisions.

Decreased striatal dopaminergic innervation in REM sleep behavior disorder.

Article abstract—REM sleep behavior disorder (RBD) is a possible herald of neurodegenerative disorders with parkinsonism. The authors determined the density of striatal dopaminergic terminals with [11C]dihydrotetrabenazine PET in six elderly subjects with chronic idiopathic RBD and 19 age-appropriate controls. In subjects with RBD, there were significant reductions in striatal [11C]dihydrotetrabenazine binding, particularly in the posterior putamen.

Insomnia and hypnotic use, recorded in the minimum data set, as predictors of falls and hip fractures in Michigan nursing homes

Objectives: To examine the relationship between insomnia, hypnotic use, falls, and hip fractures in older people.

Sleep apnea in patients with transient ischemic attack and stroke A prospective study of 59 patients

Although sleep apnea (SA) appears to be a cardiovascular risk factor, little is known about its frequency in patients with transient ischemic attack (TIA) and stroke.We prospectively studied 59 subjects (26 women and 33 men; mean age, 62 years) with stroke (n = 36) or TIA (n = 23) with the use of a standard protocol that included assessment of snoring and daytime sleepiness (Epworth Sleepiness Score [ESS]), a validated SA score (Sleep Disorders Questionnaire [SDQ-SA]), and a severity of stroke score (Scandinavian Stroke Scale [SSS]). SA was considered clinically probable (P-SA) when habitual snoring was associated with an ESS of >10 or when SDQ-SA score was >or=to32 in women and >or=to36 in men. Polysomnography (PSG) was obtained in 36 subjects (group 1) a mean of 12 days after TIA or stroke. In 23 subjects (group 2), PSG was not available (n = 11), refused (n = 10), or inadequate (n = 2). Clinical and PSG data were compared with those obtained in 19 age- and gender-matched control subjects. Groups 1 and 2 were similar in mean age (61 versus 64 years), type of event (36% versus 44% TIA), reported habitual snoring (58% versus 52%), and P-SA (58% versus 50%). PSG showed SA (Apnea-Hypopnea Index [AHI], >or=to10) in 25 of 36 subjects (69%). The proportion of subjects with SA was similar in the TIA and stroke groups (69% versus 70%) and was well above the frequency found in our control group (15%). An AHI of >or=to20 and a minimal oxygen saturation of <85% were each found in 20 of 36 subjects (55%). Gender and age did not correlate with severity of SA. Subjects with habitual snoring, P-SA, or severe stroke (SSS of <30) had a significantly higher AHI (p < 0.05). The sensitivity of P-SA for SA was 64%, and the specificity was 67%. We conclude that SA has a high frequency in patients in the acute phase of TIA and stroke and SA cannot be predicted reliably on clinical grounds alone but is more likely in patients with habitual snoring, abnormal SDQ-SA, or severe stroke. NEUROLOGY 1996;47: 1167-1173

Upper Airway Sleep-Disordered Breathing in Women

Most surveys of the obstructive sleep apnea syndrome have emphasized the predominance of the syndrome in men, and the few reports [1-3] describing adult women with this syndrome have emphasized its frequent association with massive obesity. Previous reports have suggested that the appearance of the obstructive sleep apnea syndrome is 10 to 20 times more common in men than in women. Recently, however, a survey of the general population aged 30 to 60 years by Young and colleagues [4] concluded that sleep-disordered breathing or obstructive sleep apnea associated with excessive daytime sleepiness has a prevalence of 4% in middle-aged men and of 2% in middle-aged women; Gislason and colleagues [5] estimated the prevalence at 2.5% for women in Iceland aged 40 to 59 years. The discrepancy between previous estimates of the prevalence of sleep-disordered breathing in women and these recent reports suggests that sleep-disordered breathing in women is underdiagnosed. We studied the clinical presentation and consequences of sleep-disordered breathing in a large sample of women seen during the past 4 years at the Stanford Sleep Disorders Clinic for symptoms of excessive daytime sleepiness. Methods Participants All women 18 years of age and older who contacted the clinic between 1988 and 1993 with symptoms of daytime tiredness, daytime fatigue, or daytime sleepiness were identified using our computerized clinic database. Inclusion Criteria For study inclusion, participants must have had a complete sleep-wake evaluation and a complete report in their chart that included the results of polygraphic evaluation. All participants included in our study had daytime sleepiness, based on either a score of 9 or more on the Epworth sleepiness scale [6, 7] or a score of 8 minutes or less on the multiple sleep latency test [8]. Nocturnal recordings included an electroencephalogram, an electrooculogram, a chin and a leg electromyogram (one lead), measurements of body position, and monitoring of respiration. Breathing patterns during sleep had to have indicated the presence of partial or complete upper airway obstruction. Initially, we looked for obstructive patterns that lasted 10 seconds and for a respiratory disturbance index (the number of apneas and hypopneas per hour of sleep) of 5 or more. In 1991, however, it was shown that clinical consequences could be seen with a respiratory disturbance index of less than 5, even in the absence of classically defined hypopneas. In this group of affected participants (with a respiratory disturbance index < 5), flow remains more or less constant, but breathing effort (as reflected by esophageal pressure) is substantially increased, leading to arousals on the electroencephalograms (the upper airway resistance syndrome) [9]. From this point on, we included participants with obstructive patterns of a shorter duration (one to two obstructed breaths) that induced sleep disturbances and daytime symptoms but who had a respiratory disturbance index of less than 5. The abnormal breathing patterns may have been shown by different means, from the use of complex protocols involving a facemask and pneumotachometer to simpler protocols that used measurements of esophageal pressure (Pes) with inductive respiratory plethysmography, monitoring of airflow, pulse oximetry, microphone monitoring, and intercostal electromyography (Figure 1). The minimum accepted protocol for inclusion involved monitoring of airflow, inductive plethysmography, and pulse oximetry, with the addition of Pes measurements after 1991. Finally, participants had to have shown clinical improvement in response to treatment using nasal continuous positive airway pressure (or nasal bilevel positive airway pressure in obese participants with a body mass index > 36.0 kg/m2). Figure 1. Polygraph showing a progressive increase in respiratory effort over time in a woman with symptoms of sleep-disordered breathing. Exclusion Criteria After reviewing their chart and test results, we excluded patients with sleepiness, a history of cataplexy, and two or more periods of sleep onset with rapid eye movement on the multiple sleep latency test. These patients were diagnosed as having narcolepsy. Patients with sleepiness and specific organic disorders (repetitive nocturnal epileptic seizures, brain tumor, neuromuscular disorders, untreated hypothyroidism) were also excluded. Patients with sleepiness and specific congenital or genetic defects or both (for example, trisomy 21 and substantial craniomandibular abnormalities such as the Hurler, the Hunter, the Traecher-Collin, and the Pierre Robin syndromes and other neurocrestopathies) were excluded even if their daytime sleepiness was related to an upper airway problem during sleep. Patients with major, noncongenital craniofacial deformities (particularly those associated with mandibular involvement) were also excluded, as were patients with psychiatric mood disorders in whom daytime somnolence was clearly a symptom of depression. All other participants 18 years and older were considered for the study and had polygraphic investigation. Selection of Controls Women with Insomnia We selected 60 women with insomnia, aged 18 years or older, who were seen during the same period as the index cases to serve as a control group. Use of this group as a control allowed us to compare the severity of the symptoms of these two groups of women with different sleep disorders. The control participants reported insomnia of at least 6 months duration; all were diagnosed with psychophysiologic insomnia on the basis of interviews, questionnaires, sleep logs, actigraphy, and nocturnal polygraphic recordings [10]. The control group was subdivided into six age groups (18 to 30 years, 31 to 40 years, 41 to 50 years, 51 to 60 years, 61 to 70 years, and > 70 years). Ten women were in each age group. Women with insomnia were examined successively in order of first clinic visit. When a woman met the criteria for any group, she was selected as an appropriate control for the breathing disorders group. The upper limit of normal weight for women in the control and index groups was defined as 26.8 kg/m2 [11]. A participant was considered overweight if her body mass index was more than 27.0 kg/m2 [11]. Participants in the control and sleep-disordered breathing groups were matched for weight on the basis of the above classifications and for menopausal status. Exact matching for obesity was difficult. Our two most obese controls with insomnia had body mass indices of 35.0 kg/m2 and 32.5 kg/m2,respectively, whereas our heaviest case patient with sleep-disordered breathing had a body mass index of 59.0 kg/m2. Men with Insomnia We selected 100 men who had been diagnosed during the past 3 years with upper airway sleep-disordered breathing as a second control group. Controls in this group met the same inclusion and exclusion criteria as female participants. Male controls were matched with case patients for body mass index (2 kg/m2) and respiratory disturbance index (<5 or 5). Exact matching for obesity was easy; we were able to match the men with the womens index group for highest body mass index. Geographic Distribution of Participants The Stanford Sleep Disorders Clinic has a high visibility locally and nationally and has frequent exposure in the media. Forty percent of the patients seen at the clinic are self-referred. These patients come to the Clinic for various reasons: Some have already seen sleep specialists and want second opinions, some are seeking different treatment options, and some have used the telephone book and come because our location is convenient. Twenty-five percent of our patients are referred by surgeons after consultation for a snoring problem; 35% are referred by general practitioners, internists, and pulmonary physicians who may be part of a health maintenance organization or a preferred provider organization that includes Stanford Medical Center as part of its referral list. Collected Variables and Analysis Data on the three groups of participants were collected from interviews. We used the Sleep Questionnaire and Assessment of Wakefulness, a previously validated questionnaire covering sleep-wake symptoms, past and present sleep-wake history, medical history, and drug intake [12, 13]. The sleep specialist reviewed answers to the questionnaire at the time of the patients interview. Demographic, familial, and social histories are also included in this sleep questionnaire and in the clinic administrative questionnaire, and these data were used in our analysis. Body mass index [14], neck circumference [15-18], and fatty distribution [19] were taken from records of the initial evaluation (done within 1 month of polysomnography). Upper airway anatomy was examined, and a diagram of anatomic abnormalities of the region was made on a standard form. In women, hormonal status was derived from their histories, and, if necessary, a follicle-stimulating hormone test was done after determining whether the women were receiving hormonal treatment (including birth control pills or estrogen as prophylaxis for osteoporosis). Daytime sleepiness indices and sleep variables for statistical analysis before and after treatment were collected from the monitored nights. Data and Statistical Analyses All participants were given a number, and their data were processed anonymously. Histograms were generated to describe the overall group of participants. Simple, descriptive statistics were generated using the Statview statistical computer package (Abacus Concepts, Inc., Berkeley, California). Correlation matrices were obtained. We did linear and multiple regression analyses to evaluate the effect of independently collected variables on dependent variables, such as respiratory disturbance index. Analysis of variance (ANOVA) was used for analyses of noncontinuous variables, and ANOVAs were also used, in conjunction with nonparametric statistics, to compare d

Conduct problems and symptoms of sleep disorders in children.

OBJECTIVE Conduct problems and hyperactivity are frequent among children referred for sleep-disordered breathing (SDB), restless legs syndrome, or periodic leg movements during sleep (PLMS), but children not referred to sleep centers have received little study. METHOD Parents of children aged 2 to 14 years were surveyed at two general clinics between 1998 and 2000. A Pediatric Sleep Questionnaire generated validated scores for SDB and PLMS. The Conners Parent Rating Scale (CPRS-48) produced an age- and sex-adjusted Conduct Problem Index (CPI) and Hyperactivity Index. RESULTS Parents of about 1,400 children were approached; those of 872 (62%) completed the surveys. Bullying and other specific aggressive behaviors were generally two to three times more frequent among 114 children at high risk for SDB than among the remaining children. An association between high CPI and SDB scores (p <.0001) retained significance after adjustment for sleepiness, high Hyperactivity Index, stimulant use, or PLMS scores. Analogous results were obtained for the association between high CPI and PLMS scores. CONCLUSIONS Conduct problems were associated with symptoms of SDB, restless legs syndrome, and PLMS. Although these results cannot prove a cause-and-effect relationship, assessment for sleep disorders may provide a new treatment opportunity for some aggressive children.

REM sleep behavior disorder is related to striatal monoaminergic deficit in MSA

Objective: To explore the neurochemical basis of REM sleep behavior disorder (RBD) in multiple-system atrophy (MSA). Methods: In 13 patients with probable MSA, nocturnal, laboratory-based polysomnography was used to rate the severity of REM atonia loss by the percentage of REM sleep with tonically increased electromyographic (EMG) activity and the percentage of REM sleep with phasic EMG bursts. PET with (+)-[11C]dihydrotetrabenazine ([11C]DTBZ) was employed to measure the density of striatal monoaminergic terminals and SPECT with (−)-5-[123I]iodobenzovesamicol ([123I]IBVM) to measure the density of thalamic cholinergic terminals. Data in the patient group were compared with data from 15 normal control subjects scanned with [11C]DTBZ and 12 with [123I]IBVM. Results: Age and gender distributions were similar in patient and normal control groups. The MSA subjects showed decreased mean [11C]DTBZ binding in the striatum (p < 0.0001) and decreased [123I]IBVM binding in the thalamus (p < 0.001). Moreover, in the MSA group, striatal [11C]DTBZ binding was inversely correlated with the severity of REM atonia loss (p = 0.003). Thalamic [123I]IBVM binding, however, was not correlated to the severity of REM atonia loss. Conclusion: Decreased nigrostriatal dopaminergic projections may contribute to RBD in MSA.