Sleep-disordered breathing, behavior, and cognition in children before and after adenotonsillectomy

Abstract

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.

Figure 1

The 105 subjects who participated in this study were identified as shown. Although a minority of non-participating families refused any discussion with investigators about the study and generated no basis for comparison to participants, some data were collected with permission by phone from many families who expressed willingness to hear about the study but later declined to participate. Comparisons between the 78 AT subjects whose data we report and those who did not participate (n = 136 to 173 whose data were available, depending on the variable in question), and separately between the 27 controls who participated and those who did not (n = 107 to 362), failed to reveal any statistically significant differences in gender, racial distribution, socioeconomic status (high = groups 3, 4, or 5 vs. low = groups 1 or 2), history of chronic tonsillitis, snoring frequency, or witnessed apneas. Participants were slightly older than non-participants in both the AT and control groups, by 0.5 years (p = 0.07) and 1.2 years (p = 0.01) respectively. Parents of 56% of the AT participants had behavioral concerns about their children, whereas only 40% of the non-participant AT parents had such concerns (p = 0.04). In contrast, identical percentages of control participants and non-participants (15% for each) had such concerns (p = 1.00).

Figure 2

Estimated least-squares means and their standard errors, obtained from repeated measures analysis of variance models, are shown for four study outcomes: rates of apneas and hypopneas (transformed), hyperactivity, attention, and sleepiness. Data are plotted for adenotonsillectomy (▲) and control subjects (■). Stars indicate significant (p<0.05) differences at baseline or one year, or significant time by group interaction (see Table 3).

Figure 3

Estimated least-squares means and their standard errors, obtained from repeated measures analysis of variance models, are shown for four study outcomes and three groups of subjects: adenotonsillectomy with obstructive sleep apnea (▲), adenotonsillectomy without sleep apnea (◆), and controls (■). Stars indicate significant (p<0.05) differences at baseline or one year, or significant time by group interaction (see Table 4).