Identification of Sleep-Disordered Breathing in Children

The purpose of this research is to study and improve the methods used to detect childhood breathing problems during sleep that can affect daytime behavior at home and school. Early diagnosis of these sleep disorders may allow doctors to treat children at a time when the consequences can still be reversed.

BACKGROUND:

Sleep-disordered breathing (SDB) affects at least 1 to 3 percent of children. Associated morbidity can include inattentive and hyperactive behavior, disruptive behavior disorders, cognitive deficits, and excessive daytime sleepiness. Sleep specialists recommend that children undergo polysomnography to confirm SDB, especially before undergoing treatment, which often involves an adenotonsillectomy. Unfortunately, such testing is rarely performed either before or after surgery. Available data suggest that a clinical diagnosis of SDB does not predict polysomnographic results reliably. However, the extent to which polysomnographic results predict morbidity, and especially treatable morbidity, is not well known. The main goal of the proposed research, therefore, is to study and improve methods for identification of childhood SDB that carries reversible morbidity.

DESIGN NARRATIVE:

Researchers will examine the utility of polysomnography in a group of children scheduled to undergo adenotonsillectomy for clinical indications, and a group of matched control subjects. Initial evaluations, before surgery in the first group, will be compared to results of identical evaluations 6 months later in this controlled nonrandomized trial. Outcomes will be provided by well-validated assessments of behavior, psychiatric status, cognition, and sleepiness. Explanatory variables will include standard clinical and polysomnographic information, and data from two newer techniques. The first, nasal pressure monitoring, shows increased sensitivity for events that characterize SDB, but few results and no outcome data have been reported from use of this method in children. The second is an innovative signal processing algorithm developed by the investigators to show that cortical electroencephalogram (EEG) activity changes in synchrony with non-apneic respiratory cycles in children with SDB. Preliminary data suggest that the magnitude of respiratory cycle-related EEG changes (RCREC) varies with SDB severity, diminishes after SDB treatment, and improves prediction of neurobehavioral outcomes. The specific aims of the proposed research are to show that 1) nasal pressure monitoring, in comparison to standard measures of airflow, improves prediction of neurobehavioral response to adenotonsillectomy; 2) RCREC, in comparison to standard visually-scored EEG-based arousals, do likewise; 3) polysomnographic SDB measures, including nasal pressure monitoring and RCREC, add useful information to that derived from office-based assessments; and 4) polysomnography after adenotonsillectomy can identify clinically relevant residual SDB in some children.

Eligibility Criteria:
Inclusion Criteria:

* Assent of child (if over the age of 9 or younger but able to understand the nature of the study)
* At least one parent or guardian must sign an informed consent
* Child must be either a healthy volunteer or scheduled for an adenotonsillectomy for any reason
* Children scheduled for adenotonsillectomies must be referred to the program by a treating otolaryngologist who practices at the University of Michigan or St. Joseph Mercy Hospital in Ann Arbor, Michigan

Exclusion Criteria:

* Mental or physical limitations that would prevent proper interpretation of neurobehavioral tests
* Medical history that could confound interpretation of EEG or behavioral data, including epilepsy, psychiatric diagnoses (other than disruptive behavior disorders), head trauma with loss of consciousness for more than 30 seconds, or chronic medication use (e.g., benzodiazepines, other hypnotics, or antihistamines)
* Current treatment by a physician or past surgical treatment for SDB
* A known medical condition that carries independent high risk of SDB (e.g., Pierre Robin syndrome, Down syndrome, or neuromuscular disorders) or excessive daytime sleepiness (e.g., narcolepsy)
* Inability to schedule polysomnography, a Multiple Sleep Latency Test, and neurobehavioral testing before the surgical date
* Determination by any of the patient's physicians that sleep testing is required before surgery can be scheduled (to avoid the possibility that study enrollment itself could affect ability to complete the study)
* Prior enrollment of a sibling in the study
* Expectation that the child will no longer have convenient access to University of Michigan facilities within 6 months or expectation of further surgery within that period

Additional exclusion criteria for healthy volunteers include:

* Any history of adenoidectomy or tonsillectomy
* Plans for either procedure in the future
* History of habitual snoring
* History of large (uninfected) tonsils
* History of recurrent throat infection that might be grounds for adenotonsillectomy (three episodes in each of 3 years, five episodes in each of 2 years, or seven episodes in one year)