JCSM Articles

AASM High School Topical Review in Sleep Science Contest Winners & Entries

Embracing Change, Responding to Challenge, and Looking Toward the Future

The Effect of Vestibular Stimulation in a Four-Hour Sleep Phase Advance Model of Transient Insomnia

Study Objectives: To determine if vestibular stimulation is an effective therapy for transient insomnia in a sleep phase advance model.
Design: Multi-site, double-blind, randomized, parallel-group, sham-controlled trial
Setting: This study was carried out at 6 sites in the United States.
Participants: 198 healthy normal sleepers.
Interventions: Bilateral electrical stimulation of the vestibular apparatus of the inner ear via electrodes on the skin of the mastoid process at a frequency of 0.5 Hz vs. sham stimulation
Results: We did not find a significant effect of treatment on our primary outcome variable, latency to persistent sleep onset (LPS). However, our planned analysis identified that the mean latency to sleep onset on the multiple sleep latency test was a significant covariate. This led us to carry out post hoc analyses, which showed a significant effect of treatment on LPS in those subjects with a mean MSLT sleep onset latency ≥ 14 minutes.
Conclusions: Vestibular stimulation did not have a therapeutic effect in a model of transient insomnia in the overall population studied. However, this study provides preliminary evidence that vestibular stimulation may shorten sleep onset latency compared with sham therapy in the subset of subjects with mean MSLT sleep onset latency ≥ 14 minutes.
Keywords: Transient insomnia, vestibular stimulation, sleep phase advance

Treatment of Insomnia in Depressed Insomniacs: Effects on Health-related Quality of Life, Objective and Self-Reported Sleep, and Depression

Study Objectives: Insomnia is associated with poor health related quality of life (HRQOL) in depressed patients. Prior clinical trials of hypnotic treatment of insomnia in depressed patients have shown improvement in HRQOL, but in these studies HRQOL was relegated to a secondary outcome, and objective measures of sleep were not undertaken.
Design: Double-blind, randomized, placebo-controlled clinical trial
Setting: Outpatient clinic and sleep laboratory
Patients: 60 depressed, insomniac outpatients
Interventions: one week of open-label fluoxetine (FLX), followed by 8 more weeks of FLX combined with either eszopiclone (ESZ) 3 mg or placebo at bedtime
Measurements: The primary HRQOL measure was the daily living and role functioning subscale (DLRF) of the Basis-32. Other measures included the Q-LES-Q, self-reported sleep, PSG, actigraphy, depression severity (HRSD)
Results: At the end of randomized treatment, patients receiving ESZ had lower (better) DLRF scores (0.81 ± 0.64) than those receiving placebo (1.2 ± 0.72), p = 0.01. The effect size for DLRF was 0.62, indicating a moderate effect. An advantage for ESZ was also seen in other measures of HRQOL, and most assessments of antidepressant efficacy and sleep. Women reported better end of treatment HRQOL scores than men.
Conclusions: ESZ treatment of insomnia in depressed patients is associated with multiple favorable outcomes, including superior improvement in HRQOL, depression severity, and sleep.
ClinicalTrials.gov Identifier: NCT00247624
Keywords: Insomnia, quality of life, depression, eszopiclone, polysomnography, actigraphy

Napping, Nighttime Sleep, and Cardiovascular Risk Factors in Mid-Life Adults

Study Objectives: To evaluate the relations between sleep characteristics and cardiovascular risk factors and napping behavior, and to assess whether daytime napping leads to subsequent better or worse sleep.
Methods: The sample consisted of 224 (African American, Caucasian, and Asian) middle-aged men and women. Sleep measures included nine nights of actigraphy and sleep diaries, sleep questionnaires, and one night of polysomnography to measure sleep disordered breathing.
Results: More frequent napping was associated with shorter nighttime sleep duration averaged across the nine nights of actigraphy (especially among African Americans), more daytime sleepiness, more pain and fatigue by diary, and increased body mass index and waist circumference. Shorter nighttime sleep duration was associated with taking a nap during the next day and taking a nap was associated with less efficient sleep the next night.
Conclusions: Napping in middle-aged men and women is associated with overall less nighttime sleep in African Americans and lower sleep efficiency as measured by actigraphy, and increased BMI and central adiposity. These findings point to the importance of measuring of napping in understanding associations of sleep with cardiovascular risk.
Keywords: Actigraphy, napping, obesity, cardiovascular risk factors

Validity of Activity-Based Devices to Estimate Sleep

Study Objectives: The aim of this study was to examine the feasibility of sleep estimation using a device designed and marketed to measure core physical activity.
Methods: Thirty adolescent participants in an epidemiological research study wore 3 actigraphy devices on the wrist over a single night concurrent with polysomnography (PSG). Devices used include Actical actigraph, designed and marketed for placement around the trunk to measure physical activity, in addition to 2 standard actigraphy devices used to assess sleep-wake states: Sleepwatch actigraph and Actiwatch actigraph. Sleep-wake behaviors, including total sleep time (TST) and sleep efficiency (SE), were estimated from each wrist-device and PSG. Agreements between each device were calculated using Pearson product movement correlation and Bland-Altman plots.
Results: Statistical analyses of TST revealed strong correlations between each wrist device and PSG (r = 0.822, 0.836, and 0.722 for Sleepwatch, Actiwatch, and Actical, respectively). TST measured using the Actical correlated strongly with Sleepwatch (r = 0.796), and even stronger still with Actiwatch (r = 0.955). In analyses of SE, Actical correlated strongly with Actiwatch (r = 0.820; p < 0.0001), but not with Sleepwatch (0.405; p = 0.0266). SE determined by PSG correlated somewhat strongly with SE estimated from the Sleepwatch and Actiwatch (r = 0.619 and 0.651, respectively), but only weakly with SE estimated from the Actical (r = 0.348; p = 0.0598).
Conclusions: The results from this study suggest that a device designed for assessment of physical activity and truncal placement can be used to measure sleep duration as reliably as devices designed for wrist use and sleep wake inference.
Keywords: Actigraphy, sleep, accelerometry, physical activity, polysomnography, validation

REM-related Obstructive Sleep Apnea: The Effect of Body Position

Study Objectives: To evaluate the effect of body position on REM-related obstructive sleep apnea (OSA) patients.
Design: Retrospective analysis.
Patients: 100 consecutive adult OSA patients (apnea-hypopnea index [AHI] ≥ 5) who had ≥ 10 min of REM sleep in both supine and lateral postures. REM-related OSA was defined by previously used criteria (REM AHI/Non-REM (NREM) AHI ≥ 2) and was compared with data from Not–REM-related OSA (REM AHI / NREM AHI < 2).
Measurements and Results: Most (93%) of the REM-related OSA patients (n = 45) had a mild–moderate syndrome, compared to 50.9% in the Not–REM-related OSA patients (n = 55). REM-related OSA patients had a lower apnea index (AI), AHI, supine and lateral AHI, and NREM AHI, but similar REM AHI compared to the Not–REM-related OSA group. For the entire group, the following sequence was observed: AHI REM supine > AHI NREM supine > AHI REM lateral > AHI NREM lateral. Also, for the REM-related and Not–REM-related OSA patients, the interaction between supine posture and REM sleep led to the highest AHI. However, the average length of apnea and hypopneas during REM sleep was similar in the supine and lateral postures.
Conclusions: During REM sleep, the supine position is associated with increased frequency but not increased duration of apneas and hypopneas. These body position effects prevail over the differences between REM-related and Not–REM-related OSA patients.
Keywords: Obstructive sleep apnea, REM sleep, body position

The Role of Single-Channel Nasal Airflow Pressure Transducer in the Diagnosis of OSA in the Sleep Laboratory

Rationale: Obstructive sleep apnea (OSA) is a common but underdiagnosed disorder. There is a need for validated simpler modalities such as single-channel monitors to assist diagnosis of OSA.
Study Objectives: To assess data sufficiency, agreement, and diagnostic accuracy of nasal airflow measured by a single-channel pressure transducer device (Flow Wizard, DiagnoseIT, Sydney, Australia) compared to attended full polysomnography (PSG) on the same night for OSA diagnosis.
Design: Cross-sectional study
Setting: Laboratory
Participants: Subjects with possible OSA referred to the sleep laboratory for PSG were eligible.
Methods: Nasal airflow was measured by a pressure transducer in the laboratory concurrently with PSG.
Results: Of 226 eligible subjects who consented, 221 (97.8%; 151 males, 70 females) completed the protocol. With nasal airflow measurement, 5.3% of subjects had insufficient data, compared with 2.2% on PSG. The mean difference between PSG AHI and NF RDI was −6.2 events/h with limits of agreement (± 2 standard deviation [SD]) of 17.0 events/hr. The accuracy of the Flow Wizard for diagnosing severe OSA (PSG AHI > 30) was very good (area under the ROC curve [AUC] 0.96; 95% confidence interval [CI] 0.92 to 0.99) and for diagnosing OSA (PSG AHI > 5) was good (AUC, 0.84; 95% CI, 0.77 to 0.90). There was no difference in the rate of data insufficiency and accuracy between males and females.
Conclusion: Nasal flow measured by a nasal pressure transducer has a low rate of data insufficiency, good agreement, and high accuracy compared to PSG for diagnosing OSA in the monitored sleep laboratory setting.
Keywords: Single-channel device, pressure transducer, obstructive sleep apnea, diagnosis, women

Diagnostic Accuracy of Split-Night Polysomnograms

Study Objectives: American Academy of Sleep Medicine (AASM) practice parameters indicate that split-night polysomnograms (SN-PSG) may be performed when the apnea hypopnea index (AHI) is ≥ 20 to 40, depending on clinical factors. The aim of this study was to determine the diagnostic accuracy of SN-PSG, including at the lower range of AHIs.
Methods: We reviewed 114 consecutive full-night PSGs (FN-PSG) performed at our center between August 2006 and November 2008 on subjects enrolled in studies in which obstructive sleep apnea (OSA) was the sleep disorder of interest. We compared the AHI from the first 2 hours (2hr-AHI) and 3 hours (3hr-AHI) of sleep with the “gold standard” AHI from FN-PSG (FN-AHI), considering OSA present if FN-AHI ≥ 5.
Results: The 2hr-AHI and 3hr-AHI correlated strongly with the FN-AHI (concordance correlation coefficient [CCC] = 0.93 and 0.97, respectively). After adjusting for percentage of sleep in stage REM sleep and in supine position, the correlation of 2 hr- and 3 hr-AHI with FN-AHI remained strong (0.92 and 0.96, respectively). The area under the receiver operating curves (AUC) for 2hr-AHI and 3hr-AHI using FN-AHI ≥ 5 were 0.93 and 0.95, respectively.
Conclusions: The AHI derived from the first 2 or 3 hours of sleep is of sufficient diagnostic accuracy to rule-in OSA at an AHI threshold of 5 in patients suspected of having OSA. This study suggests that the current recommended threshold for split-night studies (AHI ≥ 20 to 40) may be revised to a lower number, allowing for more efficient use of resources.
Keywords: Obstructive sleep apnea (OSA), polysomnography (PSG), split-night polysomnography, diagnostic accuracy

Severity of Obstructive Sleep Apnea is Related to Aldosterone Status in Subjects with Resistant Hypertension

Background: We previously described a significant correlation between plasma aldosterone concentration (PAC) and severity of obstructive sleep apnea (OSA) in patients with resistant hypertension. This investigation examines the relationship between aldosterone status and OSA in patients with resistant hypertensive—with and without hyperaldosteronism.
Methods and Results: One hundred and nine consecutive patients with resistant hypertension were prospectively evaluated with plasma renin activity (PRA), PAC, 24-hour urinary aldosterone excretion (UAldo), and polysomnography. Hyperaldosteronism (PRA < 1 ng·mL^-1·h^-1 and UAldo ≥ 12 µg/24-h) prevalence was 28% and OSA prevalence was 77%. In patients with hyperaldosteronism, OSA prevalence was 84%, compared with 74% in hypertensive patients with normal aldosterone levels. There were no significant differences in body mass index or neck circumference between aldosterone groups. PAC and UAldo were both significantly correlated with apnea-hypopnea index (AHI) in the high-aldosterone group (ρ = 0.568, p = 0.0009; ρ = 0.533, p = 0.002, respectively). UAldo correlated weakly with apnea-hypopnea index in the normal-aldosterone group, but there was no significant correlation between PAC and AHI in the normal-aldosterone group (ρ = 0.224, p = 0.049; ρ = 0.015, p = 0.898, respectively).
Conclusions: Our analysis of patients with resistant hypertension confirms a markedly high prevalence of OSA in this group. Furthermore, severity of OSA was greater in those patients with hyperaldosteronism and related to the degree of aldosterone excess. The correlation between OSA severity and aldosterone supports the hypothesis that aldosterone excess contributes to greater severity of OSA.
Keywords: Obstructive sleep apnea, aldosterone, resistant hypertension, sleep disorder, cardiovascular disease

Accuracy and Linearity of Positive Airway Pressure Devices: A Technical Bench Testing Study

Study Objectives: To analyze the accuracy and linearity of different CPAP devices outside of the manufacturers’ own quality control environment.
Methods: Accuracy (how well readings agree with the gold standard) and linearity were evaluated by comparing programmed pressure to measured CPAP pressure using an instrument established as the gold standard. Comparisons were made centimeter-by-centimeter (linearity) throughout the entire programming spectrum of each device (from 4 to 20 cm H₂O).
Results: A total of 108 CPAP devices were tested (1836 measurements); mean use of the devices was 956 hours. Twenty-two of them were new. The intra-class correlation coefficient (ICC) decreased from 0.97 at pressures programmed between 4 and 10 cm H₂O, to 0.84 at pressures of 16 to 20 cm H₂O. Despite this high ICC, the 95% agreement limit oscillated between −1 and 1 cm H₂O. This same behavior was observed in relation to hours of use: the ICC for readings taken on devices with < 2,000 hours of use was 0.99, while that of the 50 measurements made on devices with > 6,000 hours was 0.97 (the agreement limit oscillated between −1.3 and 2.5 cm H₂O). “Adequate adjustments” were documented in 97% of measurements when the definition was ± 1 cm H₂O of the programmed pressure, but this index of adequate adjustment readings decreased to 85% when the ± 0.5 cm H₂O criterion was applied.
Conclusions: In general, the CPAP devices were accurate and linear throughout the spectrum of programmable pressures; however, strategies to assure short- and long-term equipment reliability are required in conditions of routine use.
Keywords: Sleep apnea, CPAP, accuracy, linearity, quality control, stability

Polysomnographic Characteristics of a Referred Sample of Children with Sickle Cell Disease

Study Objectives: To describe polysomnographic parameters and their clinical correlates in a referred sample of children with sickle cell disease (SCD).
Methods: This was a retrospective medical record review of 55 consecutive children aged 2-18 years with SCD (hemoglobin [Hb] SS and Hb SC genotypes) undergoing polysomnography for evaluation of sleep disordered breathing. Polysomnography values were compared between SCD genotypes, 4 age groups, and adenotonsillectomy status using descriptive and nonparametric statistics.
Results: Obstructive sleep apnea (OSA) was diagnosed in 38/55 (69%) children. Polysomnographic parameters differed significantly between Hb SS and Hb SC genotypes only on arterial oxyhemoglobin saturation (SpO₂; 95.2 ± 3.8 vs. 98.0 ± 0.8, respectively, p < 0.01) and percent of sleep time below SpO₂ 90% (T₉₀; 8.0 ± 22.0 vs. 0.01 ± 0.02, respectively, p < 0.05). Increasing age was associated with decreasing SpO₂ (rho = −0.282, p < 0.05), obstructive apnea-hypopnea index (OAHI; rho = −0.364, p < 0.01), total arousal index (rho = −0.272, p < 0.05) and respiratory arousal index (rho = −0.349, p < 0.01). Periodic limb movements in sleep (PLM) averaged 4.7 ± 8.8/h, with a PLM index > 5/h in 5/17 children without OSA. Post- adenotonsillectomy, 8/10 children had OSA, but compared to untreated OSA-positive children they had a lower mean OAHI (4.4 ± 5.5 vs. 8.9 ± 12.5) and a lower T90 (1.6 ± 4.2 vs. 9.2 ± 24.9).
Conclusions: Both OSA and PLMs were common in children with SCD. Children with Hb SS experienced more severe nocturnal oxygen desaturation than did those with Hb SC. Post-adenotonsillectomy, most children had OSA, although they experienced fewer obstructive respiratory events and less severe nocturnal oxygen desaturation than did untreated OSA-positive children.
Keywords: Adenoidectomy, tonsillectomy, child, adolescent, sickle cell disease, obstructive sleep apnea, periodic limb movement disorder, polysomnography

Topiramate Responsive Exploding Head Syndrome

Exploding head syndrome is a rare phenomenon but can be a significant disruption to quality of life. We describe a 39-year-old female with symptoms of a loud bang and buzz at sleep onset for 3 years. EEG monitoring confirmed these events occurred in transition from stage 1 sleep. This patient reported improvement in intensity of events with topiramate medication. Based on these results, topiramate may be an alternative method to reduce the intensity of events in exploding head syndrome.
Keywords: Topiramate, exploding head syndrome, auditory sleep starts

Joubert Syndrome Associated with Severe Central Sleep Apnea

We report on a patient with mental retardation and chronic hypercapnic respiratory failure who was found to have severe central apnea and periodic breathing while undergoing an evaluation of low oxygen saturation during wakefulness at rest. Magnetic resonance imaging of the brain, which was performed to uncover potential causes for the central sleep apnea, revealed a “molar tooth sign” consistent with the diagnosis of Joubert syndrome. Joubert syndrome-related disorders are autosomal-recessive disorders characterized by diffuse hypotonia, developmental delay, abnormal respiratory patterns, and the pathognomonic neuroradiologic finding of a molar tooth sign. Adaptive servoventilation failed to correct the central apneas or the periodic breathing. Treatment with bilevel positive airway pressure in S/T mode led to resolution of the central events, improvement in sleep quality, and normalization of the oxygen saturation during wakefulness.
Keywords: Joubert syndrome, respiratory failure, central apnea, adaptive servo-ventilation, bilevel positive airway pressure

Best Practice Guide for the Treatment of Nightmare Disorder in Adults

Summary of Recommendations: Prazosin is recommended for treatment of Posttraumatic Stress Disorder (PTSD)-associated nightmares. Level A
Image Rehearsal Therapy (IRT) is recommended for treatment of nightmare disorder. Level A
Systematic Desensitization and Progressive Deep Muscle Relaxation training are suggested for treatment of idiopathic nightmares. Level B
Venlafaxine is not suggested for treatment of PTSD-associated nightmares. Level B
Clonidine may be considered for treatment of PTSD-associated nightmares. Level C
The following medications may be considered for treatment of PTSD-associated nightmares, but the data are low grade and sparse: trazodone, atypical antipsychotic medications, topiramate, low dose cortisol, fluvoxamine, triazolam and nitrazepam, phenelzine, gabapentin, cyproheptadine, and tricyclic antidepressants. Nefazodone is not recommended as first line therapy for nightmare disorder because of the increased risk of hepatotoxicity. Level C
The following behavioral therapies may be considered for treatment of PTSD-associated nightmares based on low-grade evidence: Exposure, Relaxation, and Rescripting Therapy (ERRT); Sleep Dynamic Therapy; Hypnosis; Eye-Movement Desensitization and Reprocessing (EMDR); and the Testimony Method. Level C
The following behavioral therapies may be considered for treatment of nightmare disorder based on low-grade evidence: Lucid Dreaming Therapy and Self-Exposure Therapy. Level C
No recommendation is made regarding clonazepam and individual psychotherapy because of sparse data.
Keywords: Nightmare disorder, nightmares, prazosin, clonidine, cyproheptadine, nefazodone, trazodone, olanzapine, topiramate, risperidone, cortisol, tricyclics, fluvoxamine, triazolam, nitrazepam, phenelzine, aripiprazole, gabapentin, venlafaxine, clonazepam, cognitive behavioral therapy, imagery rehearsal therapy, lucid dreaming therapy, sleep dynamic therapy, exposure relaxation and rescripting therapy, hypnosis, self-exposure therapy, systematic desensitization, progressive deep muscle training, psychotherapy, testimony method

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Associations Between Narcolepsy and Consumption of Alcohol and Caffeinated Beverages Among Genetically Susceptible Individuals: A Population-Based Case-Control Study

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