Higher Arousal Index Research Articles

Poor versus good sleepers in patients under treatment for sleep-related breathing disorders: better is not good enough

Dear editor Recently we published a retrospective study in this journal which reported the significant relationship between nocturnal awakening, respectively high arousal index, and fatigue in 410 patients with sleep disorders admitted to our sleep laboratory.1 In this study we noticed that Pittsburgh Sleep Quality Index (PSQI) mean values2 were lower in patients who have been treated for sleep-related breathing disorders (SRBD) compared with either treatment-naive SRBD patients, or with patients with periodic limb movement disorder (PLMD), restless legs syndrome (RLS), or insomnia. However, this study was not focused on PSQI values and we did not classify the patients into good and poor sleepers according to the established PSQI cut-off (less than or equal to versus greater than five). The PSQI was initially developed to screen impaired subjective sleep quality in patients with insomnia and depression, but today it is widely used in sleep medicine in general. We now report the results of a classification of our patients into good and poor sleepers according to their PSQI values, using the PSQI-cut-off of ≤ or >5 that we performed subsequent to our original study. To our knowledge, there have been to date only a few studies in this issue that have investigated the use of PSQI in obstructive sleep apnea (OSA) patients. These studies had inconsistent findings and small sample sizes. Macey et al3 did not find a significant relationship between the apnea-hypopnea-index per hour of sleep (AHI) and PSQI values in 49 untreated OSA patients. Chihara et al4 reported a significant improvement of PSQI values after auto-adjusting positive airway pressure (APAP) with flexible positive airway pressure (C-Flex) (n=29), but not with APAP alone (n=28) or APAP in combination with fixed inspiration/expiration pressure difference (A-Flex) (n=28). Mermigkis et al5 found no significant improvement of PSQI values before and after continuous positive airway pressure (CPAP) in a small sample of 12 patients.

Gündüz Aşırı Uykululuğu Olan ve Olmayan Obstrüktif Uyku Apneli Hastalarda Polisomnografik Değişkenlerin Karşılaştırılması

Objective: Excessive daytime sleepiness (EDS) is a common symptom in patients with obstructive sleep apnea (OSA), and the reason for this could not be fully elucidated. The aim of this study was to compare polysomnographic and demographic features of patients with OSA with or without EDS according to Epworth Sleepiness Scale (ESS). Material and Methods: A total of 82 adult patients who were diagnosed with OSA with polysomnography were retrospectively divided into 2 groups in terms of having EDS (ESS>10) or not (ESS≤10) according to ESS score. Results: Forty six patients had an ESS score >10. Patients with OSA suffering from sleepiness were younger (p=0.010), more obese (p=0.039), had higher arousal index (p=0.051) and apnea hypopnea index (AHI) (p=0.036) on polysomnography. There was no gender difference between two groups (p=0.423). Polysomnographic findings revealed that there were no differences in total sleep time, sleep efficiency or overall distribution of sleep stages (N1,N2, N3, REM), or nocturnal mean and minimum saturation (p=0.516, p=0.790, p=0.674, p=0.852, p=0.677, p=0.137, p=0.286, p=0.353, respectively). On multivariate regression analysis, arousal index, total AHI, and age were effective in determination of ESS score (p<0.001). Conclusion: OSA patients with EDS were younger and more obese when compared to OSA patients with no EDS. No single factor was effective for detection of EDS with ESS score. Rather, factors such as severity of OSA, arousal index, and age were collectively decisive.

Sertraline and periodic limb movements during sleep: an 8-week open-label study in depressed patients with insomnia

BackgroundPrevious studies have reported that selective serotonin reuptake inhibitors (SSRIs) might induce or exacerbate periodic limb movements during sleep (PLMS). However, most of these studies were retrospective and cross-sectional studies with small sample sizes on a selective SSRI, fluoxetine. Because different SSRIs have different pharmacologic profiles, it was not certain if other SSRIs also might lead to PLMS. MethodsData were taken from an open-label 8-week trial of sertraline in depressive patients with insomnia (n=31). Depressed patients were administered sertraline 50mg at 8:00am on the first day, and the dosage was subsequently titrated up to a maximum of 200mg daily during the 8-week trial. All participants were tested by repeated polysomnography (PSG) (baseline, first day, 14th day, 28th day, and 56th day). Periodic leg movements (PLM) were visually counted and the PLM index (PLMI) was calculated. PLMS was defined as PLMI ⩾5, and significant PLMS was defined as PLMI ⩾15. ResultsCompared with baseline (PLMI, 3.6±1.5), all PLMI indices increased on the immediate administration of sertraline on the first day (PLMI, 5.1±3.9). From the 14th day onward, PLMI became stable and significantly higher than baseline and the first day (8.7±3.1 on the 14th day, 8.3±3.7 on the 28th day, and 8.5±3.6 on the 56th day; F[11.81]; P=.003). The clinical responses and PSG characteristics continuously improved during the 8-week trial. The PLMS group (PLMI ⩾5) had a higher arousal index (AI) than the non-PLMS group on the 14th day (9.4±5.5 vs 5.2±3.7; t test, 4.22; P=.03) and the 56th day (8.1±5.5 vs 4.3±3.7; z score, 3.11; P=.04); albeit, there was no significant clinical disturbances in the PLMS group. ConclusionsPLMS were increased during sertraline treatment, but only a few of the PLMS reached the significant level. This effect of sertraline on PLMS might be dosage dependent. Although the sertraline-induced PLMS did not seem to cause significant clinical disturbance, the PLMS group (PLMI ⩾5) had a higher AI than the non-PLMS group. Thus clinicians should pay more attention to PLMS during SSRI antidepressant treatment.

Snoring in a sitting position and neck circumference are predictors of sleep apnea in Chinese patients

Snoring is a common symptom among the adult population, and it is the most common complaint in patients with obstructive sleep apnea (OSA) syndrome. Patients who snore in a sitting position while taking a nap or sleeping may have a narrower upper airway. The aim of this study was to evaluate if snoring in a sitting position is a predictor of OSA in patients. We prospectively enrolled 166 SS+ (with a history of snoring in a sitting position) subjects and 139 SS- (who denied having a history of snoring in a sitting position) patients. All of the participants received questionnaires as well as a standard polysomnography thereafter. Patients with self-reported snoring in a sitting position (with a tilt position greater than 70°, SS+ group) had a higher body mass index as well as greater neck, waist, and buttock circumference and scored higher on the Epworth Sleepiness Scale. During the polysomnographic study, the SS+ group had a higher percentage of N1 sleep and lower percentage of N2 sleep. In addition, the SS+ group had a higher apnea-hypopnea index (AHI) as well as higher arousal index and oxygen desaturation index. The sensitivity and specificity of the SS+ group for OSA (defined as AHI ≥ 5) were 0.59 and 0.73, respectively, with a positive predictive value of 0.93. The likelihood ratio was 2.2. On the other hand, the sensitivity and specificity of the SS+ group for moderate to severe OSA (defined as AHI ≥ 15) were 0.82 and 0.48, respectively. Both SS+ and greater neck circumference have a high likelihood ratio for diagnosing OSA. In the present study, the symptoms of self-reported snoring in a sitting position and greater neck circumference can be useful clinical predictors of OSA in Chinese patients.

Characteristics of obstructive sleep apnea in patients with Parkinson's disease

Parkinson's disease (PD) patients frequently develop obstructive sleep apnea (OSA). In order to clarify the clinical significance of OSA in PD, we compared descriptive variables between PD patients with OSA (PD+OSA) and without (PD−OSA), and between the PD+OSA group and a group of OSA patients without PD (control OSA). The apnea hypopnea index (AHI) cutoff of 15 episodes/hour on polysomnogram (PSG) was used to assign 107 PD patients to groups; OSA-related symptoms and PSG findings were then compared. Demographic and PSG variables were compared between PD+OSA patients and 31 OSA controls.Twenty-four patients with PD (22.4%) were classified as PD+OSA. There were no significant differences in descriptive variables between the PD+OSA and PD−OSA groups. The PD+OSA group had a higher arousal index on PSG than the PD−OSA group, although the two groups had similar ESS scores. The PD+OSA patients had a lower respiratory arousal index and a smaller decrease in oxygen saturation than the control OSA group, despite having a similar AHI.The prevalence of OSA in PD did not differ from that in the general elderly population, indicating that the clinical significance of OSA as a contributor to daytime sleepiness in PD is low.

An electrocardiogram-based analysis evaluating sleep quality in patients with obstructive sleep apnea

The study compares polysomnography (PSG) and cardiopulmonary coupling (CPC) sleep quality variables in patients with (1) obstructive sleep apnea (OSA) and (2) successful and unsuccessful continuous positive airway pressure (CPAP) response. PSGs from 50 subjects (32 F/18 M; mean age 48.4 ± 12.29 years; BMI 34.28 ± 9.33) were evaluated. OSA patients were grouped by no (n = 16), mild (n = 13), and moderate to severe (n = 20) OSA (apnea-hypopnea index (AHI) ≤ 5, >5-15, >15 events/h, respectively). Outcome sleep quality variables were sleep stages in non-rapid eye movement, rapid eye movement sleep, and high (HFC), low (LFC), very low-frequency coupling (VLFC), and elevated LFC broad band (e-LFCBB). An AHI ≤ 5 events/h and HFC ≥ 50 % indicated a successful CPAP response. CPC analysis extracts heart rate variability and QRS amplitude change that corresponds to respiration. CPC-generated spectrograms represent sleep dynamics from calculated coherence product and cross-power of both time series datasets. T tests differentiated no and moderate to severe OSA groups by REM % (p = 0.003), HFC (p = 0.007), VLFC (p = 0.007), and LFC/HFC ratio (p = 0.038) variables. The successful CPAP therapy group (n = 16) had more HFC (p = 0.003), less LFC (p = 0.003), and e-LFCBB (p = 0.029) compared to the unsuccessful CPAP therapy group (n = 8). PSG sleep quality measures, except the higher arousal index (p = 0.038) in the unsuccessful CPAP group, did not differ between the successful and unsuccessful CPAP groups. HFC ≥ 50 % showed high sensitivity (77.8 %) and specificity (88.9 %) in identifying successful CPAP therapy. PSG and CPC measures differentiated no from moderate to severe OSA groups and HFC ≥ 50 % discriminated successful from unsuccessful CPAP therapy. The HFC ≥ 50 % cutoff showed clinical value in identifying sleep quality disturbance among CPAP users.

Association between primary nocturnal enuresis and habitual snoring in children with obstructive sleep apnoea-hypopnoea syndrome

IntroductionNocturnal enuresis (NE) and obstructive sleep apnoea-hypopnoea syndrome (OSAHS) are common problems during childhood, and population studies have reported a significant correlation between them. This study aimed to assess whether habitual snoring, mouth breathing and daytime sleepiness are associated with increased incidence of NE in children with OSAHS.Material and methodsPolysomnography was performed in 42 children (66.7% males), 3.5-14.5 years old, who were evaluated for sleep-disordered breathing (SDB).ResultsFourteen out of 42 children (33.3%) presented mild, 16 out of 42 (38.1%) moderate and 12 out of 42 (28.6%) severe degree of OSAHS. Apnea hypopnea index (AHI) ranged between 1.30-94.20 (10.54 ±15.67) events per hour of sleep. Nocturnal enuresis was reported in 7/42 (16.7%) of them. The main observed symptoms were snoring (90.5%), restless sleep (81%), mouth breathing (71.4%), nasal congestion (76.2%), and difficulty in arousal (52.4%). A statistically significant association was found between NE and mouth breathing (p = 0.014) or nasal congestion (p = 0.005). Children with OSAHS and NE had a higher arousal index (8.14 ±8.05) compared with OSAHS children without NE (4.61 ±7.95) (p = 0.19, z = –1.28). Snorers had higher levels of AHI (11.02 ±16.37) compared with non-snorers (6.05 ±4.81) (p = 0.33, z = –0.96), and habitually snorers (23/42, 54.76%) were at greater risk of having NE (4/23) than were non-snorers (0/4, p = 0.36). However, the prevalence of enuresis was not related to the severity of OSAHS, expressed as AHI (p = 0.70).ConclusionsMouth breathing, nasal congestion and high threshold of arousal during sleep should be more carefully evaluated in cases of children with NE who do not respond to standard treatment and present SDB.

Sleep findings and predictors of sleep desaturation in adult cystic fibrosis patients

Questions remain about the polysomnographic findings and the predictors for sleep desaturation in cystic fibrosis (CF) patients. Our study aimed to evaluate sleep parameters in a sample of adult CF patients comparing them with healthy controls and to determine the best predictors of sleep desaturation in CF patients with awake resting peripheral oxygen saturation (SpO(2)) ≥90%. In a cross-sectional study, with data collected prospectively, 51 clinically stable adult CF patients (mean age 25.1 ± 6.7years) and 25 age-matched controls underwent an overnight polysomnography and answered sleep questionnaires. CF patients had their pulmonary function, 6-min walk test, and echocardiography assessed. CF patients and control subjects had similar sleep architecture. However, CF patients had impaired subjective sleep quality and a higher arousal index than controls. The apnea-hypopnea index was similar in both groups, and only two CF patients (3.9%) fulfilled the criteria for obstructive sleep apnea syndrome. Sleep desaturation was more common in CF patients (29.4% vs 0%; p < 0.001). In a logistic regression model, we observed that awake resting SpO(2) was the single best variable associated with sleep desaturation in CF population (p < 0.001). The awake SpO(2) <94% had a sensitivity, specificity, positive and negative predictive value for sleep desaturation of, respectively, 93.3%, 100%, 100%, and 97.3%. CF patients had a worse subjective sleep quality and small changes in sleep architecture. In nonhypoxic, adult CF patients, sleep desaturation is common, is not associated with obstructive sleep events, and can be accurately predicted by awake resting SpO(2) <94%.

Daily sleep quality and mood as predictors of pain in children with juvenile polyarticular arthritis

Daily sleep quality and mood as predictors of pain in children with juvenile polyarticular arthritis

P03-394 - Quantitative electrophysiology during night- and daytime including electroencephalography and event-related potential EEG/ERP topography and tomography (LORETA) in hyperthyroidism

IntroductionIn contrast to the abundance of visual qualitative EEG reports in patho-endocrinology, there is a paucity of quantitative EEG findings.ObjectivesElectrophysiology may be utilized for differential diagnosis of hypersomnolence.AimsTo investigate long-term daytime sleepiness in a young female neurologist with the tentative diagnosis of narcolepsy in addition to moderate depression/anxiety and congenital thyroid hypoplasia treated with thyroxin.MethodsThree-night polysomnography, multiple sleep latency test (MSLT), visual EEG/ERP-mapping, LORETA, psychometrics and blood analyses were performed.ResultsPolysomnography revealed normal sleep efficiency and sleep architecture, but a high arousal index of up to 63/h TST. The MSLT showed a shortened mean sleep latency of 3.7 min. without REM-sleep onsets, objectifying the high Epworth Sleepiness score of 18. Visual EEG evaluation exhibited a fast alpha rhythm with intermittent theta and delta intrusions and paroxysmal activities. EEG-mapping showed an accelerated dominant frequency and ubiquitous increase in absolute (especially delta and beta) power, ERP revealed shortened N1 latency and very high amplitudes in all components (P300 &gt; 5 SD). LORETA demonstrated significant regional increases in delta, alpha-2 and beta-1 power in the anterior cingulate, orbital, ventromedial, dorsolateral prefrontal cortex and temporal cortex, predominantly right hemispherically. Psychometry showed increased anxiety (SAS) and depression (SDS) and reduced quality of life. Finally, hormonal analysis pointed to thyrotoxicosis factitia (ICD-10 E05.4).ConclusionDiagnostic investigations clearly elucidated the pathogenesis of the presenting diagnosis of organic hypersomnia triggered by increased sleep-microarousals due to thyrotoxicosis factitia. Discontinuation of hormone substitution led to a normalization process that will be discussed.

The Association Among Lipoprotein-associated Phospholipase A2 Levels, Total Antioxidant Capacity and Arousal in Male Patients with OSA

The mechanisms of the increased cardiac and vascular events in patients with OSA are not well understood. Arousal which is an important component of OSA was associated with increased sympathetic activation and electrocardiographic changes which prone to arrhythmias. We planned to examine the association among arousal, circulating Lp-PLA2 and total antioxidant capacity in male patients with OSA. Fifty male patients with newly diagnosed OSA were enrolled the study. A full-night polysomnography was performed and arousal index was obtained. Lp-PLA2 concentrations were measured in serum samples with the PLAC Test. Total antioxidant capacity in patients was determined with Antioxidant Assay Kit. Arousal was positively correlated with LP-PLA2 levels (r=0.43, p=0.002) and was negatively correlated with total antioxidant capacity (r= -0.29, p=0.04). Elevated LP-PLA2 levels and decreased total antioxidant activities were found in the highest arousal quartile compared with the lowest and 2nd quartiles (p=0.02, p=0.05, respectively). LP-PLA2 was an independently predictor of arousal index in regression model (β=0.357, p=0.002) This study demonstrated a moderate linear relationship between arousal and LP-PLA2 levels. Also, total antioxidant capacities were decreased in the higher arousal index. Based on the study result, the patients with higher arousal index may be prone to vascular events.

Analysis of sleep characteristics in post-polio syndrome patients

The main post-polio syndrome (PPS) symptoms are new weakness, new atrophy, fatigue, pain and sleep disturbances. Polysomnography is the gold standard for sleep analysis. To analyze sleep patterns in PPS patients. Sixty patients (mean age 46.8+/-11.3 years) at the Federal University of São Paulo (UNIFESP/EPM) complaining of sleep disturbances were evaluated by means of polysomnography, performed at the Sleep Institute. Sleep efficiency was lower due to high sleep latency and arousal index. The apnea and hypopnea index (AHI) and the periodic limb movements (PLM) index were higher. Sleep architecture was also impaired. There were no abnormalities of oxygen saturation, carbon dioxide levels, respiratory rate or heart rate. New post-polio sleep disturbances were isolated symptoms. It appears that these symptoms were not due to post-polio features, but rather, that they were due to dysfunction of the surviving motor neurons in the brainstem. Abnormal dopamine production, which is responsible for many sleep-related breathing disorders and abnormal movements, may also have been implicated in the present findings.

Do differences in sleep architecture exist between persons with type 2 diabetes and nondiabetic controls?

It has been shown previously that the suppression of slow-wave sleep (SWS) markedly reduced insulin sensitivity and led to an impairment of glucose tolerance. We hypothesized that a decreased amount of SWS is a feature peculiar to subjects with type 2 diabetes. A retrospective case-control study analyzed polysomnographic recordings and covariate data of 22 type 2 diabetic and 22 nondiabetic subjects [n = 44; 8 women, 36 men, aged 57.5 +/- 5.5 years, body mass index (BMI) 33.8 +/- 5.9 kg/m(2), apnea-hypopnea index (AHI) 29.6 +/- 22.2 episodes/hr] matched individually for sex, race, age, BMI, and severity of sleep-related breathing disorders (SRBD). We assessed differences in sleep architecture between the study group and the control group. Primary end points included the percentage of total sleep time spent in each sleep stage. Despite similar age and severity of SRBD, subjects with type 2 diabetes demonstrated a significantly decreased amount of SWS (3.9 +/- 5.95% vs 8.4 +/- 4.57%; p = 0.012), increased percentage time in rapid eye movement sleep (24.1 +/- 12.14% vs 13.8 +/- 6.96%; p = 0.005), and higher arousal index (44.3 +/- 19.53/hr vs 35.7 +/- 12.67/hr; p = 0.037) compared to nondiabetic controls. After adjustment for sex, BMI, AHI, and smoking, age and presence of type 2 diabetes were independent predictors of the decreased SWS percentage (p = 0.001). Variables in this model accounted for 34% of the variance in the SWS percentage in our cohort. Results demonstrated distinct differences in sleep architecture in our cohort with decreased amounts of SWS in type 2 diabetes. These findings suggest that polysomnographic recognition of altered sleep architecture may be partially implicated in the early detection of persons with type 2 diabetes.

Sleep Disorders in Patients with Breast Cancer Based on Polysomnographic Data.

Abstract Background. Complaints of sleep disturbances are common in patients with breast cancer and may affect their quality of life. Insomnia, fatigue, and sleep fragmentation were previously reported in these patients. However, no studies reported polysomnographic data to elucidate the etiology of these symptoms. We hypothesized that patients with breast cancer will have considerable abnormalities on their monitored overnight sleep studies including sleep disordered breathing, periodic leg movement, and spontaneous arousals.Methods. Data from sleep studies were prospectively collected from cancer patients who undergo a sleep study at the MD Anderson Sleep Center and who consented to participate. All breast cancer patients who underwent a poylsomnogram between 1/30/2007 and 4/1/2009 and signed informed consent were identified. The prospectively collected data included demographics, breast cancer clinical data and treatment, as well as polysomnographic data.Results. Sixty-nine patients (68 female, 1 male) were identified with breast cancer. All patients underwent a formal sleep consultation. The median age was 56 (range: 38 to 75 years), and the median body mass index (BMI) was 33 kg/m2 (21 to 52).Tumor characteristics were as follows: 55 patients (80%) had invasive ductal carcinoma, 8 (12%) had invasive lobular carcinoma, 5 with ductal carcinoma in situ (7%), and 1 unknown (1%). ER/PR was positive in 44 patients (64%), and HER-2 positive in 9 patients (13%). Five patients (7%) had stage 0, 12 (17%) had stage I, 30 (44%) had stage II, 12 (17%) had stage III, and 10 (15%) had stage IV disease. Twenty-four patients (35%) had completed treatment, 10 patients (15%) were receiving chemotherapy, and 34 patients (50%) were receiving hormonal therapy.Fifty-one patients (74%) were referred for daytime sleepiness and fatigue, 11 (16%) for sleep apnea symptoms, 1 (1%) for pulmonary hypertension and 6 (9%) for insomnia. In 55 patients (81%), the median Epworth Sleepiness Score 12 (4 to 21) was consistent with excessive daytime sleepiness.Sleep fragmentation was noted in all patients with a median sleep efficiency of 86% (36% to 98%) and a median Arousal Index of 33 arousals/hour of sleep (7 to 118). Furthermore, the median percentages of delta sleep (deep sleep) and REM sleep were notably diminished at 1% and 13% respectively. Sleep disordered breathing was noted with a median Apnea Hypopnea Index (AHI) of 10 apneas and hypopneas/hour of sleep (0 to 68). Only 2 patients were noted to have significant periodic limb movements with arousals. There was no difference in these abnormalities between treatment groups (chemotherapy, hormonal therapy, or no treatment).Conclusions. This is the first report of polysomnographic data in breast cancer patients. Our data show that sleep disordered breathing (obstructive sleep apnea) is a cause of sleep disturbance in a number of these patients. Conversely, periodic leg movement was not common among these patients. Of interest, the high Arousal Index indicates a high frequency of spontaneous arousals not explained by apnea or hypopnea and these findings did not vary across treatment types. These findings show unique abnormalities in the sleep architecture of breast cancer patients that are provoking and warrant further study. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5036.

Severe obstructive sleep apnea: Sleepy versus nonsleepy patients

To compare demographic and polysomnographic data of sleepy versus nonsleepy severe obstructive sleep apnea (OSA) patients according to the Epworth Sleepiness Scale (ESS). Retrospective cohort. Six hundred forty-four consecutive severe (apnea-hypopnea index [AHI] >or= 30) adult OSA patients who underwent a polysomnographic evaluation in our sleep disorders unit. ESS data were available in 569 (88.3%). Three hundred twenty-seven (57.5%) patients had ESS > 10. Sleepy severe OSA patients are slightly younger and more obese than nonsleepy patients. These sleepy patients have shorter sleep latency and lower percentage of slow wave sleep. They consistently show a higher AHI, both supine and lateral AHI, have a higher number of short arousals, and a higher arousal index. They also have higher snoring loudness in the supine and both lateral positions and a lower minimal SaO(2) in rapid eye movement and non-rapid eye movement sleep. After adjusting for confounders, a logistic regression model points to apnea index as a significant prognostic factor for excessive daytime sleepiness. Severe OSA sleepy patients have a syndrome that is significantly more severe than nonsleepy patients. Sleepy patients have worse sleep-related breathing parameters, and their sleep patterns are lighter and more fragmented than nonsleepy patients. Apnea index appears as an important prognostic factor for excessive daytime sleepiness.

Sleep state distribution of obstructive events in children: is obstructive sleep apnoea really a rapid eye movement sleep‐related condition?

Obstructive sleep apnoea (OSA) in children is commonly considered to occur predominantly in rapid eye movement (REM) sleep, but clinical experience suggests that this is not universally the case. We hypothesized that there would be a subgroup of children with OSA who have non-REM (NREM) predominance of obstructive events and that these children share certain clinical characteristics. Thus, we aimed to compare the obstructive apnoea-hypopnoea index (OAHI) in REM versus NREM sleep and to assess factors influencing the distribution of events by sleep state. Polysomnography (PSG) recordings of 102 children aged 0-18 years with moderate to severe OSA (OAHI >or=5 h(-1)) were reviewed. OAHI was calculated separately for REM and NREM sleep. A REM predominance index (RPI) was determined using log transformation [RPI = log (REM OAHI + 0.5) - log (NREM OAHI + 0.5)] and compared with possible influencing factors using multiple linear regression. Analysis showed that obstructive events were more common in REM sleep (median REM OAHI 21.4 h(-1), median NREM OAHI 8.3 h(-1), P < 0.001). Mean RPI was significantly greater than zero (P = 0.003). However, a substantial minority of children (30.4%) had a higher NREM than REM OAHI. The factors that were related significantly to NREM predominance were older age (P = 0.02), higher arousal index (P < 0.001) and higher SpO(2) nadir (P < 0.001). Our findings demonstrate that while OSA is a REM sleep-related problem in the majority of children, there is a significant subset of children with NREM predominance of obstructive events. This finding highlights the importance of considering sleep state distribution of events in studies of the pathophysiology and outcomes of OSA in childhood.

Polysomnographic and Health-related Quality of Life Correlates of Restless Legs Syndrome in the Sleep Heart Health Study

Sleep disturbance is the primary clinical morbidity of restless legs syndrome (RLS). To date, sleep disturbance in RLS has been measured in (1) clinical samples with polysomnography (PSG) or (2) population-based samples by self-report. The objective of this study was to analyze sleep by PSG in a population-based sample with symptoms of RLS. Cross-sectional observational study. Community-based. 3433 older men and women. None. RLS was evaluated using an 8-item self-administered questionnaire based on NIH diagnostic criteria and required symptoms occurring > or = five times per month and associated with at least moderate distress. Health-related quality of life (HRQOL) was determined using the SF-36. Unattended, in-home PSG was performed. Data were assessed using general linear models with adjustment for demographic, health-related variables, and apnea-hypopnea index (AHI). Subjects with RLS had longer adjusted mean sleep latency (39.8 vs 26.4 min, P < 0.0001) and higher arousal index (20.1 vs 18.0, P = 0.0145) than those without RLS. Sleep latency increased progressively as the frequency of RLS symptoms increased from 5-15 days per month to 6-7 days per week. No differences in sleep stage percentages were observed between participants with and without RLS. Subjects with RLS also reported poorer HRQOL in all physical domains as well as in the Mental Health and Vitality domains. These novel PSG data from a nonclinical, community-based sample of individuals with RLS document sleep disturbance in the home even in individuals with intermittent symptoms.

Spectrum of Polysomnographic Abnormalities in Children With Epilepsy

This study sought to evaluate polysomnographic abnormalities in a cohort of 40 children with epilepsy who underwent a sleep study because of various sleep complaints. Retrospective analyses included polysomnographic variables, antiepileptic drugs, type of epilepsy, and seizure control. The subgroup with epilepsy and obstructive sleep apnea syndrome was compared with 11 children who manifested uncomplicated obstructive sleep apnea syndrome. Thirty-three patients (83%) exhibited snoring (42.5%), sleep-disordered breathing (obstructive hypoventilation, 12.5%; obstructive sleep apnea, 20%; and upper-airway resistance syndrome, 7.5%), or periodic limb movements of sleep (10%). Children with poor seizure control demonstrated significantly lower sleep efficiency, a higher arousal index, and a higher percentage of rapid-eye-movement sleep compared with children who were seizure-free or exhibited good seizure control. Patients with epilepsy and obstructive sleep apnea had significantly a higher body mass index, longer sleep latency, a higher arousal index, and a lower apnea-hypopnea index, but significantly more severe desaturation compared with patients with uncomplicated obstructive sleep apnea. A significant proportion of children with epilepsy referred for polysomnography with diverse sleep problems manifest sleep-disordered breathing, including obstructive sleep apnea syndrome.

Central Sleep Apnea on Commencement of Continuous Positive Airway Pressure in Patients With a Primary Diagnosis of Obstructive Sleep Apnea-Hypopnea

Central sleep apnea (CSA) may occur in patients with snoring and obstructive sleep apnea-hypopnea (OSAH) during commencement of continuous positive airway pressure (CPAP) therapy. The presence of CSA may limit the effectiveness of CPAP therapy. The aims of this study were to assess the prevalence of CSA amongst patients starting CPAP for OSAH and to identify possible predictors of this condition. We reviewed the polysomnograms (PSGs) and clinical records of 99 consecutive patients with a primary diagnosis of OSAH who were referred for an in-laboratory CPAP titration study. Patients with a CSA Index of > or =5 per hour at or near (+/-1 cm H2O) prescribed CPAP level formed the CSA-CPAP group. The remaining patients made up the noCSA-CPAP group. Demographic, baseline and CPAP titration PSG variables were compared between the 2 two groups. 13 subjects (13.1%) had CSA-CPAP. Patients with and without CSA-CPAP did not differ with respect to age or body mass index. 46% of patients with CSA-CPAP had CSA on their baseline PSGs compared with 8% in the noCSA-CPAP group (p <0.01). CSA-CPAP patients also had a higher apnea-hypopnea index (72.1 vs. 52.7 p = 0.02), a higher arousal index (43.3 vs. 29.2 p <0.01), and a higher mixed apnea index (6.8 vs. 1.3 p = 0.03), on their baseline PSGs. Therapeutic CPAP could not be determined in 2 CSA-CPAP patients due to a very high frequency (of severe) central apneas. In the remaining 11, the CPAP prescription to eliminate obstructive events was higher than in the noCSA-CPAP group (11.0 vs. 9.3 p = 0.08). AHI was greater both at or near prescribed CPAP (48.8 vs. 6.7 p <0.01) and overall (47.4 vs. 14.9 p <0.01). A history of ischemic heart disease or heart failure was more frequent amongst patients with CSA-CPAP than those without (p = 0.03). A significant minority of patients with a primary diagnosis of OSAH have either emergence or persistence of CSA on CPAP. Risk factors include male sex, history of cardiac disease, and CSA on baseline PSG.

Periodic leg movements in narcolepsy patients: impact on sleep architecture

We assessed the effect of periodic leg movements (PLMs) on sleep architecture in narcolepsy patients by comparing sleep patterns in narcoleptics of comparable age with and without PLMs. Patients diagnosed with narcolepsy between January 1999 and December 2005 were divided into those with PLM index >or= 5/hr and <5/hr. Each patient underwent polysomnographic recording followed by a multiple sleep latency test (MSLT). There were 47 patients, of mean age 28.9 +/- 1.8 years, 31 (66%) with PLM index >or= 5/hr and 16 (34%) with PLM index <5/hr. Arousal index, PLM arousals and total number of arousals were all significantly higher in narcoleptics with PLM index >or= 5/hr than in those with PLM index <5/hr. Significant correlations were found between PLM index and arousal index, stage shifts, Stage 1 and average sleep latency on MSLT. Our findings demonstrated that narcolepsy patients with PLMs have a higher arousal index and increased PLM arousals compared with narcolepsy patients without PLMs. The contribution of the above to the perceived sleep quality and daytime sleepiness is not clear.