Sleep spindle activity in children with obstructive sleep apnea as a marker of neurocognitive performance: A pilot study.

STUDY OBJECTIVES: To assess spindle activity as possible markers for neurocognitive consequences in children with mild obstructive sleep apnea. METHODS: Children aged 6-11 years diagnosed with mild OSA (i.e., an apnea hypopnea index <5.0) were recruited and compared with age and gender-matched healthy controls. Polysomnographic recordings were analyzed for sleep microstructure and spindle activity. All children completed also an intelligence test battery (i.e., the Wechsler intelligence test for children, 4th version). RESULTS: Nineteen children with OSA (13 boys, mean age 7.1 ± 1.4 y), and 14 controls (7 boys, mean age 8.1 ± 1.9 y) were included. Mean IQ was 110 ± 12 for the complete sample, in children with OSA 111 ± 13, and in controls 108 ± 12 (p = 0.602). Controls showed a higher spindle index in N2 stage than children with OSA: 143.0 ± 42.5 vs 89.5 ± 56.9, respectively (p = 0.003). Spindle index in NREM was strongly and significantly correlated with Verbal Comprehension Index (VCI), Working Memory Index (WMI), Processing Speed Index (PSI), and total IQ in children with OSA. CONCLUSIONS: Children with mild OSA demonstrate a different pattern of sleep spindle activity that seems to be linked with neurocognitive performance, especially concerning memory. Sleep spindle activity seems to be involved with mechanisms related with neurocognitive consequences in children with OSA.

Sleep-disordered breathing in children with Down syndrome: Usefulness of home polysomnography.

OBJECTIVE: To investigate the technical feasibility of unattended home polysomnography (HPSG) in children with Down syndrome. METHODS: Data from children with Down syndrome under 10 years of age referred to a diagnostic sleep study was analyzed. A full sleep-lab based polysomnography (PSG) or a HPSG with a portable device was performed. Uninterpretable HPSGs were defined as: recordings with (i) loss of ≥2 of the following channels: nasal flow, or thoracoabdominal sensors, or (ii) HPSG with less than 4h of artifact-free recording time or (iii) less than 4h SpO2 (peripheral capillary oxygen saturation) signal. RESULTS: A total of 44 children (68% males) were included in the study, with a mean age of 3.6 (0.1-10) years. PSG was performed in 8 cases and HPSG in 36 cases. Six HPSG recordings were classified as uninterpretable and had to be repeated. Age, gender and BMI were no significant predictors of uninterpretability of the HPSG. Obstructive sleep apnea (OSA) was present in 61% (n=27) of all subjects, and classified as mild, moderate, and severe in 43% (n=19), 11% (n=5), and 7% (n=3) of cases, respectively. Interpretable and technically acceptable HPSGs were obtained in 30 subjects (83%). Age, gender and BMI were no significant predictors for interpretability of the HPSG. DISCUSSION: This study demonstrates that a portable polysomnographic home device may be helpful for diagnosing OSA in children with Down syndrome. Considering the potential consequences of untreated OSA, this screening test may be helpful for early diagnosis of OSA in children with Down syndrome.

Diagnostic accuracy of the Spanish version of the Pediatric Sleep Questionnaire for screening of obstructive sleep apnea in habitually snoring children.

OBJECTIVES: We aimed to determine the diagnostic test accuracy of the Spanish version of the respiratory symptoms scale of the Pediatric Sleep Questionnaire (PSQ) in habitually snoring children for identifying obstructive sleep apnea (OSA). METHODS: Habitually snoring children referred for polysomnography (PSG) were recruited. Parents answered the PSQ prior to PSG. Based on an apnea-hypopnea index (AHI) >1.0 in PSG, children were divided into OSA and primary snorers. Correlations to PSG indices and diagnostic test accuracy measures were calculated. RESULTS: Of the 83 (n = 53 males, mean age 9.5 ± 3.6 years) habitually snoring children included, 35 had OSA. The previously validated PSQ cutoff value of 0.33 showed a specificity of 0.72 and sensitivity of 0.78. The PSQ score correlated significantly with the AHI rs = 0.313 (p-value = 0.004). Six items of the PSQ were significantly different between cases and controls. A subscale constructed on these six PSQ items concerning respiratory symptoms showed a good sensitivity (0.886) and an excellent negative likelihood ratio (0.261). PSQ was able to identify 89% of the children with OSA correctly. CONCLUSIONS: This version of the PSQ was able to identify children with OSA, separating them from those with primary snoring. The use of this simple, standardized questionnaire tool seems to be helpful and may improve clinical decision making in habitually snoring children.