Marco Del Pozzo

Sleep clinical record: an aid to rapid and accurate diagnosis of paediatric sleep disordered breathing

Overnight polysomnography (PSG) is an expensive procedure which can only be used in a minority of cases, although it remains the gold standard for the diagnosis of sleep disordered breathing (SDB). The objective of this study was to develop a simple, PSG-validated tool to screen SDB, thus reducing the use of PSG. For every participant we performed PSG and a sleep clinical record was completed. The sleep clinical record consists of three items: physical examination, subjective symptoms and clinical history. The clinical history analyses behavioural and cognitive problems. All three items were used to create a sleep clinical score (SCS). We studied 279 children, mean±sd age 6.1±3.1 years, 63.8% male; 27.2% with primary snoring and 72.8% with obstructive sleep apnoea (OSA) syndrome. The SCS was higher in the OSA syndrome group compared to the primary snoring group (8.1±9.6 versus 0.4±0.3, p<0.005), correlated with apnoea/hypopnoea index (p=0.001) and had a sensitivity of 96.05%. Positive and negative likelihood ratios were 2.91 and 0.06, respectively. SCS may effectively be used to screen patients as candidates for PSG study for suspected OSA syndrome, and to enable those with a mild form of SDB to receive early treatment.

Diagnosis of Pediatric Obstructive Sleep Apnea Syndrome in Settings With Limited Resources

IMPORTANCE Although polysomnographic (PSG) testing is the gold standard for the diagnosis of obstructive sleep apnea syndrome (OSAS) in children, the number of pediatric sleep laboratories is limited. Developing new screening methods for identifying OSAS may reduce the need for PSG testing. OBJECTIVE To evaluate the combined use of the sleep clinical record (SCR) and nocturnal oximetry testing for predicting PSG results in children with clinically suspected OSAS. DESIGN, SETTING, AND PARTICIPANTS Prospective study over 10 months. A cohort of 268 consecutive children (mean [SD], age 6 [3] years) referred for clinically suspected OSAS was studied at a pediatric sleep center at a university hospital. Children with disorders other than adenotonsillar hypertrophy or obesity were excluded. MAIN OUTCOMES AND MEASURES Mild OSAS (obstructive apnea-hypopnea index [AHI], 1-5 episodes/h) and moderate-to-severe OSAS (AHI, >5 episodes/h) were the main outcome measures. Sleep clinical record scores greater than or equal to6.5 were considered positive, as were McGill oximetry scores (MOS) greater than 1, and these positive scores were the main explanatory variables in our study. Each participant was evaluated by the SCR, followed by pulse oximetry test the first night and PSG test in the sleep laboratory the second night. RESULTS Of the total participants, 236 (88.1%) were diagnosed with OSAS, 236 (88.1%) had a positive SCR score, and 50 (18.7%) had a positive MOS. Participants with positive SCR scores had significantly increased risk of an AHI greater than or equal to 1 (adjusted odds ratio [AOR], 9.3; 95% CI, 3.7-23.2; P < .001). Children with an MOS greater than 1 were significantly more likely to have an AHI greater than 5 episodes/h than children with an MOS equal to 1 (AOR, 26.5; 95% CI, 7.8-89.2; P < .001). A positive SCR score had satisfactory sensitivity (91.9%) and positive predictive value (91.9%) but limited specificity (40.6%) and negative predictive value (40.6%) for OSAS. An MOS greater than 1 had excellent specificity (97.4%) and positive predictive value (94%) but low sensitivity (39.2%) and fair negative predictive value (60.8%) for moderate-to-severe OSAS among children with a positive SCR score. The combination of SCR scores and MOS correctly predicted primary snoring, mild OSAS, or moderate-to-severe OSAS in 154 of 268 (57.4%) participants. CONCLUSIONS AND RELEVANCE The combined use of the SCR score and nocturnal oximetry results has moderate success in predicting sleep-disordered breathing severity when PSG testing is not an option.

The cooccurrence of interictal discharges and seizures in pediatric sleep-disordered breathing

Studies in the literature data have shown that the prevalence of obstructive sleep apnea (OSA) in children with epilepsy is high and that treatment for OSA leads to a reduction in the number of seizures; by contrast, few studies have demonstrated an increased prevalence of interictal epileptiform discharges (IEDs) or epilepsy in children with sleep-disordered breathing (SDB). The aim of the present study was to confirm the high prevalence of IEDs or epilepsy in a large sample of children with SDB and to collect follow-up data. Children were recruited prospectively and underwent their first video-polysomnography (video-PSG) for SDB in a teaching hospital sleep center. Of the 298 children who fulfilled the diagnostic criteria for sleep-disordered breathing, 48 (16.1%) children were found to have IEDs, three of these 48 children were also found to have nocturnal seizures (two females diagnosed with rolandic epilepsy and a male diagnosed with frontal lobe epilepsy). Only 11 subjects underwent a second video-PSG after 6months; at the second video-PSG, the IEDs had disappeared in six subjects, who also displayed a reduced AHI and an increased mean overnight saturation. Thirty-eight of the 250 children without IEDs underwent a second video-PSG after 6months. Of these 250 children, four, who did not display any improvement in the respiratory parameters and were found to experience numerous stereotyped movements during sleep, were diagnosed with nocturnal frontal lobe epilepsy. Our study confirms the high prevalence of IEDs in children with SDB. Follow-up data indicate that they may recede over time, accompanied by an improvement of sleep respiratory parameters.

Autonomic imbalance during apneic episodes in pediatric obstructive sleep apnea

OBJECTIVES To investigate the activity of the autonomic nervous system (ANS) during sleep in children with obstructive sleep apnea (OSA), in order to detect a possible cardiac ANS imbalance analyzing heart rate variability (HRV). METHODS 43 subjects between 4 and 12 years of age (7.26 ± 2.8 years), undergoing a diagnostic assessment for OSA were evaluated. A time domain index (R-apnea index) was developed to evaluate HRV strictly related to obstructive events during sleep. Poincaré plot of RR intervals during the whole night was calculated. RESULTS R-apnea index was negatively correlated with apnea hypopnea index (AHI) (r=-0.360, p=0.028). AHI and the duration of the disease were the only variables that were significantly correlated with R-apnea index. Three groups were subsequently created according to polysomnographic findings considering AHI. R-apnea index resulted significantly lower in patient with severe OSA compared to primary snoring/mild OSA subjects (p<0.05). Looking at Poincaré plot, SD1 showed a diminishing trend with severity of OSA, however not reaching statistical significance. CONCLUSIONS Our findings suggest an autonomic impairment in OSA children evidenced by the altered HRV both in the very short term (R-apnea index) and in short term (SD1). SIGNIFICANCE R-apnea index is an easy and cheap method to undelay early ANS imbalance.