Deborah L. Ruzicka

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.

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.

Objective Measures of Disordered Sleep in Fibromyalgia

Objective. Patients with fibromyalgia syndrome (FM) complain of inadequate sleep, which could contribute to common symptoms including sleepiness, fatigue, or pain. However, measures that consistently and objectively distinguish FM patients remain elusive. Methods. Fifteen women with FM and 15 age- and gender-matched controls underwent 3 nights of polysomnography; Multiple Sleep Latency Tests to assess sleepiness; testing of auditory arousal thresholds during non-REM stage 2 and stage 4 sleep; overnight assessment of urinary free cortisol; and analysis of 24-hour heart rate variability. Results. On the second night of polysomnography, women with FM in comparison to controls showed more stage shifts (p = 0.04) but did not differ significantly on any other standard polysomnographic measure or on the Multiple Sleep Latency Tests. Alpha EEG power during deep non-REM sleep, alone or as a proportion of alpha power during remaining sleep stages, also failed to distinguish the groups, as did auditory arousal thresholds. Urinary free cortisol did not differ between FM and control subjects in a consistent manner. However, decreased short-term heart rate variability (HRV) and especially ratio-based HRV among FM subjects suggested diminished parasympathetic and increased sympathetic activity, respectively. Other HRV measures suggested decreased complexity of HRV among the FM subjects. Conclusion. Standard measures of sleep, a gold-standard measure of sleepiness, quantified alpha-delta EEG power, auditory arousal thresholds, and urinary free cortisol largely failed to distinguish FM and control subjects. However, HRV analyses showed more promise, as they suggested both increased sympathetic activity and decreased complexity of autonomic nervous system function in FM.

Neuropsychological and behavioral functioning in children with and without obstructive sleep apnea referred for tonsillectomy.

Adenotonsillectomy (AT) is among the most common pediatric surgical procedures and is performed as often for obstructive sleep apnea (OSA) as for recurrent tonsillitis. This study compared behavioral, cognitive, and sleep measures in 27 healthy control children recruited from a university hospital-based pediatric general surgery clinic with 40 children who had OSA (AT/OSA+) and 27 children who did not have OSA (AT/OSA-) scheduled for AT. Parental ratings of behavior, sleep problems, and snoring, along with specific cognitive measures (i.e., short-term attention, visuospatial problem solving, memory, arithmetic) reflected greater difficulties for AT children compared with controls. Differences between the AT/OSA- and control groups were larger and more consistent across test measures than were those between the AT/OSA+ and control groups. The fact that worse outcomes were not clearly demonstrated for the AT/OSA+ group compared with the other groups was not expected based on existing literature. This counterintuitive finding may reflect a combination of factors, including age, daytime sleepiness, features of sleep-disordered breathing too subtle to show on standard polysomnography, and academic or environmental factors not collected in this study. These results underscore the importance of applying more sophisticated methodologies to better understand the salient pathophysiology of childhood sleep-disordered breathing.

Aggressive Behavior, Bullying, Snoring, and Sleepiness in Schoolchildren

BACKGROUND To assess whether urban schoolchildren with aggressive behavior are more likely than peers to have symptoms suggestive of sleep-disordered breathing. METHODS Cross-sectional survey of sleep and behavior in schoolchildren. Validated screening assessments for conduct problems (Connors rating scale), bullying behavior, and sleep-disordered breathing (pediatric sleep questionnaire) were completed by parents. Teachers completed Connors teacher rating scale. RESULTS Among 341 subjects (51% female), 110 (32%) were rated by a parent or teacher as having a conduct problem (T-score ⩾65) and 78 (23%) had symptoms suggestive of sleep-disordered breathing. Children with conduct problems, bullying, or discipline referrals, in comparison to non-aggressive peers, more often had symptoms suggestive of sleep-disordered breathing (each p<0.05). Children with vs. without conduct problems were more likely to snore habitually (p<0.5). However, a sleepiness subscale alone, and not a snoring subscale, predicted conduct problems after accounting for age, gender, a measure of socioeconomic status, and stimulant use. CONCLUSIONS Urban schoolchildren with aggressive behaviors may have symptoms of sleep-disordered breathing with disproportionate frequency. Sleepiness may impair emotional regulation necessary to control aggression.

Changes in neuropsychological and behavioral functioning in children with and without obstructive sleep apnea following Tonsillectomy.

The most common treatment for sleep disordered breathing (SDB) is adenotonsillectomy (AT). Following AT, SDB resolves in most cases, and gains in cognitive and behavior scores are consistently reported, although persistent neuropsychological deficits or further declines also have been noted. This study presents results of the comprehensive 1-year follow-up neuropsychological examinations for children in the Washtenaw County Adenotonsillectomy Cohort I (95% return rate). After adjusting for normal developmental and practice-effect related changes in control children, significant improvements 1 year following AT were noted in polysomnography and sleepiness, as well as parental reports of behavior, although cognitive outcomes were mixed. Children undergoing AT with and without polysomnography-confirmed obstructive sleep apnea improved across a range of academic achievement measures, a measure of delayed visual recall, short-term attention/working memory, and executive functioning, along with parental ratings of behavior. On the other hand, measures of verbal abstraction ability, arithmetic calculations, visual and verbal learning, verbal delayed recall, sustained attention, and another measure of visual delayed recall demonstrated declines in ability, while other measures did not improve over time. These findings call into question the expectation that AT resolves most or all behavioral and cognitive difficulties in children with clinical, office-based diagnoses of SDB.

Validation of the STOP- BANG Questionnaire among Patients Referred for Suspected Obstructive Sleep Apnea

BACKGROUND The STOP-BANG is a simple obstructive sleep apnea (OSA) screening tool, part questionnaire (STOP) and part demographic or physical measures (BANG), developed for use in preoperative surgical clinics. This study assessed sensitivity and specificity of the instrument among patients referred to a sleep disorders laboratory, and also its performance characteristics when BANG physical measures are patient-reported rather than measured. METHODS Adults referred for diagnostic polysomnography completed the STOP questions and answered four yes/no questions (BANG self-reported) about their body mass index (weight and height), age, neck circumference, and gender, which were also assessed by laboratory technologists (BANG-measured). RESULTS Among N=219 subjects (mean age 46.3 ± 13.9 [s.d.] years; 98 [44.8%] males) the sensitivity of the STOP-BANG measured for an apnea/hypopnea index (AHI, events per hour of sleep) >5, >15, and >30 was 82, 93, and 97% respectively. Corresponding negative predictive values were 44, 87, and 96%. Specificities were comparatively low (48, 40, and 33%). The STOP-BANG measured and STOP-BANG self-reported scores showed essentially equivalent test characteristics against polysomnography. CONCLUSIONS The STOP-BANG appears to have limited utility in a referred, sleep laboratory setting. Negative results help to identify some individuals as unlikely to have moderate-to-severe apnea, and may thereby prove useful in identification of patients who would benefit more from laboratory studies than home studies. A STOP-BANG in which all information is self-reported may be as effective as the original version, and has potential to facilitate research or community screening where good negative predictive value is required for an effective screening tool.

Polysomnography in children scheduled for adenotonsillectomy.

OBJECTIVE: Several studies suggest that a reliable diagnosis of childhood sleep-disordered breathing (SDB) requires polysomnography (PSG). We compared clinical and PSG-based diagnoses in children scheduled for adenotonsillectomy (AT). Parent responses on a validated Pediatric Sleep Questionnaire were used to determine which symptoms could help identify children with clinical diagnoses of SDB but normal PSG. STUDY DESIGN AND SETTING: Thirty-four children aged 5.0 to 12.9 years and scheduled for AT to treat clinically diagnosed sleep-disordered breathing underwent laboratory-based PSG. Results were scored by 3 different criteria: 1) >1 obstructive apnea (2 breaths or longer) per hour of sleep; 2) >5 apneas or hypopneas per hour of sleep; or 3) >1 apnea, hypopnea, or respiratory event–related arousal per hour of sleep. RESULTS: Depending on the criterion used, the PSG documented SDB from a minimum of 18/34 subjects (53%, for criterion I) to as many as 30/34 subjects (88%, for criterion III). Among symptoms studied, absence of daytime mouth breathing and habitual snoring were most helpful in identification of children who had no evidence of SDB on PSG, by criterion I (Chi-square, P < 0.05). The absence of other common symptoms, such as “loud snoring” or “trouble breathing” at night, were not helpful. CONCLUSION: Children with clinical diagnoses of SDB may not consistently meet PSG criteria for this disorder. Questions about daytime mouth breathing and habitual snoring might help clinicians recognize children who would not have SDB on objective testing. SIGNIFICANCE: Clinical identification of SDB confirmable on PSG could be improved. However, available outcome data do not yet clarify whether clinical or PSG criteria best identify children likely to suffer morbidity from SDB. EBM rating: C.

Esophageal Pressures, Polysomnography, and Neurobehavioral Outcomes of Adenotonsillectomy in Children

BACKGROUND Esophageal pressure monitoring during polysomnography in children offers a gold-standard, “preferred” assessment for work of breathing, but is not commonly used in part because prospective data on incremental clinical utility are scarce. We compared a standard pediatric apnea/hypopnea index to quantitative esophageal pressures as predictors of apnea-related neurobehavioral morbidity and treatment response. METHODS Eighty-one children aged 7.8 ± 2.8 (SD) years, including 44 boys, had traditional laboratory-based pediatric polysomnography, esophageal pressure monitoring, multiple sleep latency tests, psychiatric evaluations, parental behavior rating scales, and cognitive testing, all just before clinically indicated adenotonsillectomy, and again 7.2 ± 0.8 months later. Esophageal pressures were used, along with nasal pressure monitoring and oronasal thermocouples, not only to identify respiratory events but also more quantitatively to determine the most negative esophageal pressure recorded and the percentage of sleep time spent with pressures lower than -10 cm H(2)O. RESULTS Both sleep-disordered breathing and neurobehavioral measures improved after surgery. At baseline, one or both quantitative esophageal pressure measures predicted a disruptive behavior disorder (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-defined attention-deficit/hyperactivity disorder, conduct disorder, or oppositional defiant disorder) and more sleepiness and their future improvement after adenotonsillectomy (each P < .05). The pediatric apnea/hypopnea index did not predict these morbidities or treatment outcomes (each P > .10). The addition of respiratory effort-related arousals to the apnea/hypopnea index did not improve its predictive value. Neither the preoperative apnea/hypopnea index nor esophageal pressures predicted baseline hyperactive behavior, cognitive performance, or their improvement after surgery. CONCLUSIONS Quantitative esophageal pressure monitoring may add predictive value for some, if not all, neurobehavioral outcomes of sleep-disordered breathing.

The face of sleepiness: improvement in appearance after treatment of sleep apnea.

STUDY OBJECTIVES Anecdote but no formal evidence suggests that facial appearance improves after hypersomnolent patients with obstructive sleep apnea are treated. We investigated whether masked volunteer raters can identify post- rather than pre-treatment images as looking more alert, and whether impressions are predicted by any objective changes on highly precise 3-dimensional digital photogrammetry. METHODS Participants included 20 adults with obstructive sleep apnea on polysomnography and excessive sleepiness on Epworth Sleepiness Scales. Photogrammetry was performed before and after ≥ 2 months of adherent use of positive airway pressure. Twenty-two raters then assessed pre- and post-treatment facial images, paired side-by-side in random order. RESULTS Subjects included 14 men and 6 women, with mean age 45 ± 11 (SD) years and mean baseline apnea/hypopnea index of 26 ± 21. The 22 raters twice as often identified post-treatment rather than pre-treatment images to look more alert (p = 0.0053), more youthful (p = 0.026), more attractive (p = 0.0068), and more likely to reflect the treated state (p = 0.015). Photogrammetry documented post-treatment decreases in forehead surface volume and decreased infraorbital and cheek redness, but no narrowing of the interpalpebral fissure. Decreased deep NREM sleep at baseline, and pre- to post-treatment decrements in facial redness showed promise as predictors of improved subjective ratings for alertness. CONCLUSIONS Patients with obstructive sleep apnea are perceived to appear more alert, more youthful, and more attractive after adherent use of positive airway pressure. Objective changes in facial surface volume and color were identified. Post-treatment decrements in redness may inform subjective impressions of improved alertness.