Joyce A. Walsleben

Clinical Diagnosis of Pediatric Obstructive Sleep Apnea Validated by Polysomnography

The decision to perform tonsillectomy and adenoidectomy for treatment of pediatric obstructive sleep apnea syndrome is often made on a clinical basis without formal polysomnography. To examine the accuracy of the clinical diagnosis of pediatric obstructive sleep apnea syndrome, we prospectively evaluated 30 children with obstructive symptoms by a standardized history, physical examination, and review of a tape recording of breathing during sleep. On the basis of this clinical evaluation, patients were divided into three predictive groups: (1) definite obstructive sleep apnea syndrome, (2) possible obstructive sleep apnea syndrome, and (3) unlikely to have obstructive sleep apnea syndrome. Nocturnal polysomnography was used to determine the presence or absence of true sleep apnea. Ten of 18 (55.6%) patients predicted clinically to have definite obstructive sleep apnea syndrome had positive nocturnal polysomnographies. Two of six (33.3%) patients predicted to have possible obstructive sleep apnea syndrome had positive nocturnal polysomnographies. One of six (16.7%) patients predicted to be unlikely to have obstructive sleep apnea syndrome had a positive nocturnal polysomnography. Six nocturnal polysomnographies negative by conventional criteria were suspicious for apnea, but considering these positive for obstructive sleep apnea syndrome did not improve the specificity of the clinical prediction. Our results show that clinical assessment of obstructive sleep apnea syndrome in children is sensitive (92.3%) but not specific (29.4%) for making the diagnosis of obstructive sleep apnea syndrome as compared with nocturnal polysomnography and may contribute to the decision to obtain nocturnal polysomnography in specific circumstances.

Continuous positive airway pressure treatment of sleepy patients with milder obstructive sleep apnea: results of the CPAP Apnea Trial North American Program (CATNAP) randomized clinical trial.

RATIONALE Twenty-eight percent of people with mild to moderate obstructive sleep apnea experience daytime sleepiness, which interferes with daily functioning. It remains unclear whether treatment with continuous positive airway pressure improves daytime function in these patients. OBJECTIVES To evaluate the efficacy of continuous positive airway pressure treatment to improve functional status in sleepy patients with mild and moderate obstructive sleep apnea. METHODS Patients with self-reported daytime sleepiness (Epworth Sleepiness Scale score >10) and an apnea-hypopnea index with 3% desaturation and from 5 to 30 events per hour were randomized to 8 weeks of active or sham continuous positive airway pressure treatment. After the 8-week intervention, participants in the sham arm received 8 weeks of active continuous positive airway pressure treatment. MEASUREMENTS AND MAIN RESULTS The Total score on the Functional Outcomes of Sleep Questionnaire was the primary outcome measure. The adjusted mean change in the Total score after the first 8-week intervention was 0.89 for the active group (n = 113) and -0.06 for the placebo group (n = 110) (P = 0.006). The group difference in mean change corresponded to an effect size of 0.41 (95% confidence interval, 0.14-0.67). The mean (SD) improvement in Functional Outcomes of Sleep Questionnaire Total score from the beginning to the end of the crossover phase (n = 91) was 1.73 ± 2.50 (t[90] = 6.59; P < 0.00001) with an effect size of 0.69. CONCLUSIONS Continuous positive airway pressure treatment improves the functional outcome of sleepy patients with mild and moderate obstructive sleep apnea.

GREATER RISK OF ALZHEIMER’S DISEASE IN OLDER ADULTS WITH INSOMNIA

ACKNOWLEDGMENTS Conflict of Interest: This work was supported by the Fundamental Research Grant Scheme, Ministry of Higher Education, Malaysia. Dr. Noran N. Hairi’s work on this study was supported by the Public Service Department of Malaysia. The authors would like to express their appreciation to Dr. Siti Halimah Shaikh and all healthcare providers of Masjid Tanah Health Clinic, Ministry of Health, Malaysia, for their contributions to this research. Author Contributions: NNH: study concept, chief investigator, designing research protocol, data analysis, interpretation of data, and writing manuscript. AB, IM: conceptualization of research and data collection. RGC, VN, AB: critically editing of the manuscript. All authors read and approved the final manuscript. Sponsor’s Role: None.

Sleep latency on the maintenance of wakefulness test (MWT) for 530 patients with narcolepsy while free of psychoactive drugs

OBJECTIVES To compare maintenance of wakefulness test (MWT) data gathered at baseline in the course of two, multicenter studies on the therapeutic efficacy of modafinil with published MWT norms. METHODS The MWT is a procedure that uses electrophysiological measures to determine the ability to remain awake while sitting in a quiet, darkened room. The test consists of 4 20 min trials conducted 4 times at 2 h intervals commencing 2 h after awakening from a night of sleep. MWT data were gathered at baseline in the course of two, multicenter studies on the therapeutic efficacy of modafinil. Subjects were 17-68 year old men (n = 239) and women (n = 291) diagnosed with narcolepsy according to the International Classification of Sleep Disorders (ICSD). All patients were free of psychoactive medication for a minimum of 14 days. RESULTS Mean MWT sleep latency was 6.0 +/- 4.8 min. However, the mean for the first MWT trial was 7.0 min which was longer that the means for the following 3 trials (5.8, 5.6 and 5.7 min, respectively). The 4 distributions of the individual MWT trials were similar and adequately summarized by the distribution of the average MWT sleep latency. As a group, patients with narcolepsy were less able to remain awake than normals; only 8 of 530 (1.5%) patients were able to remain awake on 4 20 min MWT trials compared with 35 of 64 (54.7%) normals in another study. However, using a mean MWT sleep latency of 12 min (the 5th percentile for normals) as the lowest cut-point for normalcy, 15% of patients with narcolepsy appeared to have an unimpaired ability to remain awake. CONCLUSIONS The diagnosis of narcolepsy did not always predict inability to remain awake on the MWT. Age, gender and the duration of illness did not predict ability to remain awake. Patients with severe cataplexy and other ancillary symptoms were least able to remain awake on MWT trials. Patients who used tobacco and caffeine moderately had the lowest MWT sleep latencies relative to patients with heavy and light use.

Comparison of the maintenance of wakefulness test (MWT) to a modified behavioral test (OSLER) in the evaluation of daytime sleepiness

The objectives were to evaluate the correlation between sleep onset as defined by the Oxford sleep resistance (OSLER) test and by simultaneous electroencephalography (EEG) and to determine the correlation between sleep latencies measured by the OSLER test and maintenance of wakefulness test (MWT) performed on the same day. This was a prospective, cross‐sectional study carried out in a tertiary‐care university‐based sleep laboratory. Participants were 11 consecutive subjects presenting to the sleep center with clinical indications for nocturnal polysomnography and MWT. The interventions included MWT and OSLER test. Mean sleep latencies for the OSLER and MWT in each subject were closely correlated (ICC = 0.94, [Intra‐class correlation]P < 0.05). Sleep latency by OSLER and simultaneous measurement of EEG also had excellent agreement (ICC = 0.91) with a bias of −0.97 min. The OSLER test is a practical and reliable tool for evaluating daytime sleepiness when compared with the MWT. No obvious systematic adaptation was seen during sequential OSLER test performance. Given its portability and minimal technical requirements, the OSLER test may be useful for large‐scale applications in the evaluation of daytime wakefulness and vigilance.

Response to CPAP withdrawal in patients with mild versus severe obstructive sleep apnea/hypopnea syndrome.

BACKGROUND Patients with obstructive sleep apnea/hypopnea syndrome (OSAHS), even those generally compliant with CPAP therapy, often intermittently discontinue CPAP. STUDY OBJECTIVE Examine the impact of CPAP withdrawal on sleep, sleep disordered breathing (SDB), and daytime function in subjects with varying severity of OSAHS. PATIENTS AND INTERVENTIONS Forty-two subjects (26M/16 F) with OSAHS (AHI4% = 45.2 ± 35.5/h pretreatment) on CPAP for 4 months were evaluated on the second night of CPAP withdrawal. Sleep architecture, SDB indices, and subjective/objective daytime function were assessed pretreatment, on CPAP therapy, and after CPAP withdrawal. Comparisons were made between pretreatment and CPAP withdrawal for the entire group, and for subgroups of mild/moderate (AHI4% < 30/h, n = 22) and severe (AHI4% > 30/h, n = 20) SDB. RESULTS Overall, and for mild/moderate subjects, SDB indices returned to pretreatment values on CPAP withdrawal but with fewer apneas and more hypopneas/RERAs. For severe SDB, the event frequency (AI, AHI4%, and RDI) was lower and O2 desaturation was improved on CPAP withdrawal. Across SDB severity, sleep architecture showed lower %REM (15.6% vs 12.9%, P = 0.009) on the CPAP withdrawal compared to pretreatment. Stanford Sleepiness Score, MSLT, and PVT measures were not significantly different between pretreatment and CPAP withdrawal. CONCLUSIONS Over a wide range of SDB severity CPAP withdrawal results in recurrence of SDB, albeit with less severe O2 desaturation. Subjective/objective daytime function returned to pretreatment levels. Sleep architecture changes on CPAP withdrawal (acute SDB) may reflect reduced sleep pressure compared to pretreatment chronic SDB. Our data suggest detrimental effects of even brief withdrawal of CPAP in subjects with both mild and severe OSAHS. CITATION Young LR; Taxin ZH; Norman RG; Walsleben JA; Rapoport DM; Ayappa I. Response to CPAP withdrawal in patients with mild versus severe obstructive sleep apnea/hypopnea syndrome. SLEEP 2013;36(3):405-412.

A likelihood based computer approach to conventional scoring of sleep

We describe a computer algorithm for scoring sleep stages from polysomnographic records. Our algorithm is based on the likelihood of correct detection of features and the relative impact these features have on decisions necessary to implement R&K rules. We compared results of the computerized scoring to that done manually by 2 experienced scorers. Epoch-by-epoch agreement between computer and humans was 83.4% and between humans was 86.7%. Patterns of misscores were similar. The computer was also able to characterize ambiguity by comparing the probabilities of the two most likely stage scores for each epoch.