Daytime sleepiness and polysomnography in obstructive sleep apnea patients

BackgroundExcessive daytime sleepiness (EDS) is the major complaint in subjects with obstructive sleep apnea syndrome (OSAS). However, EDS is not universally present in all patients with OSAS. The mechanisms explaining why some patients with OSAS complain of EDS whereas others do not are unknown.ObjectiveTo investigate polysomnographic determinants of excessive daytime sleepiness (EDS) in a large multicenter cohort of patients with obstructive sleep apnea (OSAS).MethodsAll consecutive patients with an apnea–hypopnea index greater than 5 h⁻¹ who were evaluated between 2003 and 2005. EDS was assessed using the Epworth Sleepiness Scale (ESS), and patients were considered to have EDS if the ESS was >10.ResultsA total of 1649 patients with EDS ((mean [±SD] Epworth 15 ± 3) and 1233 without EDS (Epworth 7 ± 3) were studied. Patients with EDS were slightly younger than patients without EDS (51 ± 12 vs 54 ± 13 years, p < 0.0001), had longer total sleep time (p < 0.007), shorter sleep latency (p < 0001), greater sleep efficiency (p < 0.0001) and less NREM sleep in stages 1 and 2 (p < 0.007) than those without EDS. Furthermore, patients with EDS had slightly higher AHI (p < 0.005) and arousal index (p < 0.001) and lower nadir oxygen saturation (p < 0.01).ConclusionsPatients with OSAS and EDS are characterized by longer sleep duration and increased slow wave sleep compared to those without EDS. Although patients with EDS showed a mild worsening of respiratory disturbance and sleep fragmentation, these results suggest that sleep apnea and sleep disruption are not the primary determinants of EDS in all of these patients.     

Periodic limb movements in sleep: Prevalence and associated sleepiness in the Wisconsin Sleep Cohort

Objectives

Periodic limb movements in sleep (PLMS) are thought to be prevalent in elderly populations, but their impact on quality of life remains unclear. We examined the prevalence of PLMS, impact of age on prevalence, and association between PLMS and sleepiness.

Periodic limb movements during sleep in alcohol dependent patients

Complaints of sleep disturbances are common among alcohol dependent patients during subacute abstinence. Recovered patients may show persistent sleep abnormalities for months or even years. In the present study we studied the issue whether periodic limb movements in sleep and disturbances of nocturnal respiration are more frequent in alcohol dependent patients than healthy subjects and may be of predictive value for sustained abstinence vs. relapse after withdrawal. Forty alcohol dependent patients spent three nights in the sleep laboratory at three time points: 2 to 3 weeks after withdrawal (T0) and at follow-up investigations 6 (T1) and 12 (T2) months after discharge from the hospital. Measurements of PLMS-arousal index and nocturnal respiration were performed during the first laboratory night of each measurement point. Alcohol dependent patients displayed a significantly enhanced PLMS-arousal index at T0 compared to age- and gender-matched healthy subjects, whereas no alterations of nocturnal respiration were found. The PLMS-arousal index at T0 was significantly elevated in patients who relapsed during the next 6 months compared to abstinent patients. In a discriminant function analysis the PLMS-arousal index classified 55 % of the patients correctly with respect to outcome after 6 months. It correctly predicted 80 % of abstainers and 44 % of the patients who relapsed. According to neurobiological models of the generation of PLMS and the etiopathology of alcohol dependence a genetically determined vulnerability of the dopaminergic system is discussed as a factor underlying an increased risk of relapse in a subgroup of alcohol dependent patients. Received: 14 November 2001 / Accepted: 7 May 2002     

Factors influencing subjective sleepiness in patients with obstructive sleep apnea syndrome

The aim of the present paper was to clarify the factors influencing subjective daytime sleepiness in patients with obstructive sleep apnea syndrome (OSAS). Subjects included 230 adult male OSAS patients aged 20-73 years. Single and multiple linear regression analyses were performed to estimate the association between the Epworth Sleepiness Scale (ESS) and the following variables: Minnesota Multiphasic Personality Inventory (MMPI), Self-Rating Depression Scale (SDS), age, body mass index (BMI), sleep duration during the preceding month and apnea-hypopnea index (AHI). Single linear regression analysis showed that age had a negative association with ESS score, while BMI, AHI, SDS, hypochondriasis (Hs), hysteria, psychopathic deviant, psychasthenia, schizophrenia and hypomania on the MMPI had a positive association with ESS score. However, the other remaining parameters such as nocturnal sleep duration during the preceding month, depression, masculinity-femininity, paranoia, social introversion on the MMPI had no statistical association with ESS score. Multiple linear regression analysis with stepwise elimination method was applied to choose the significant factors associated with ESS. It was found that three variables including age, AHI and Hs scores were independent factors influencing ESS score. The R(2) for the model was 0.14, suggesting that these factors account for 14% of possible variance of subjective daytime sleepiness of OSAS patients. These results suggest that subjective daytime sleepiness in patients with OSAS may be influenced not only by the severity of respiratory disorder indices but also by certain personality characteristics affecting Hs score and by age.     

Daytime sleepiness and automobile accidents in patients with obstructive sleep apnea syndrome

Abstract We evaluated the rate of automobile accidents and daytime sleepiness using the Epworth sleepiness scale (ESS) in 44 patients with obstructive sleep apnea syndrome (OSAS). We defined the automobile accident score as a sum of two points for every one automobile accident and one point for every near-miss accident. Automobile accidents and near-misses were found in 54.5% and 50.0% in patients with OSAS. Automobile accident score was significantly correlated with the ESS score ( r = 0.56, P < 0.01). Our findings suggest that ESS score may be useful in detecting patients with the potential risk of automobile accidents associated with daytime sleepiness.     

Restless legs syndrome and periodic limb movements during sleep in a patient with obstructive sleep apnea

A case of moderate obstructive sleep apnea in which effective treatment with continuous positive airway pressure did not reduce excessive daytime sleepiness was described. Polysomnography with tibial muscles activity recording revealed frequent periodic limb movements in sleep (PLMS) with sleep fragmentation. PLMS index was 13.6/h of sleep. Clonazepam combined with iron and magnesium supplementation reduced limb movements, excessive daytime sleepiness and improved the patient's mood. Causes of PLMS and treatment options are discussed. PLMS and restless legs syndrome (RLS) should be considered in the differential diagnosis of excessive daytime sleepiness.     

Periodic limb movements in sleep and periodic limb movement disorder

Neurological Sciences - Previously referred to as “nocturnal myoclonus”, periodic limb movements in sleep (PLMS) is regarded as a distinct nosologic entity, although it overlaps a great...     

Persistent sleepiness in CPAP treated obstructive sleep apnea patients: evaluation and treatment

Nasal continuous positive airway pressure (CPAP) is an effective treatment for most patients with obstructive sleep apnea syndrome (OSAS), improving sleepiness, cognitive function and mood. A number of patients, however, complain about persistent sleepiness after CPAP. In these cases another clinical history should be carried out to confirm the diagnosis of OSAS, to check CPAP compliance and to exclude associated conditions such as poor sleep hygiene, depression, narcolepsy or idiopathic hypersomnia. If necessary, a full polysomnography (PSG) followed by a multiple sleep latency test or even a full PSG with CPAP titration should be performed. Experimental data in animals suggest that long-term intermittent hypoxia related to the apneic events could deteriorate the brain structures that regulate alertness. This impairment, if present in humans, could be another reason for residual sleepiness after CPAP. Modafinil has been shown to reduce subjective sleepiness after CPAP in OSAS patients. Further studies are warranted to clarify the way in which CPAP modifies sleepiness.     

Causes of excessive daytime sleepiness in hypercapnic and normocapnic obstructive sleep apnea patients

Daytime sleepiness assessed using the Epworth sleepiness scale (ESS) and polysomnography results were compared in 43 patients with obstructive sleep apnea (OSA) with concomitant chronic hypercapnia (PaCO2 53 +/- 6 mmHg), and in 58 patients with the OSA syndrome accompanied by normocapnia (PaCO2 < or = 45 mmHg, mean 39 +/- 3 mmHg). The OSA patients with hypercapnia were more sleepy than those with normocapnia (ESS 18 +/- 7 vs 15 +/- 7, p < 0.05), but apnea index values were similar in both groups (54 +/- 20 and 49 +/- 17). The following parameters of electrophysiological sleep structure were obtained in the hypercapnic OSA patients: sleep stage 1: 66 +/- 28%, stage 2: 28 +/- 27%, stage 3 + 4: 1 +/- 1%, REM sleep 5 + 6% of the total sleep time, while in the OSA patients with normocapnia: stage 1: 39 +/- 19%, stage 2: 28 +/- 27%, stage 3 + 4: 2 +/- 2%, and REM sleep 6 +/- 7% of the total sleep time. Stage 1 NREM sleep was found to be longer, and stage 2 NREM--shorter in hypercapnic than in normocapnic OSA patients (p < 0.01). CONCLUSION: Increased daytime sleepiness in both groups patients with the OSA syndrome is due to sleep fragmentation as well as to deficiency of deep and paradoxical sleep (almost absent deep sleep and extremely shortened REM sleep). Hypercapnic OSA patients' more marked sleepiness may result from a more pronounced disturbance of their sleep macrostructure, with a considerable predomination of stage I NREM sleep.     

Placebo and modafinil effect on sleepiness in obstructive sleep apnea

INTRODUCTION: Previous studies have evaluated the effect of modafinil on residual excessive daytime sleepiness (EDS) in patients with obstructive sleep apnea syndrome (OSAS) under effective CPAP treatment. Even though those trials also used placebo groups, we suppose that the placebo effect might influence the patients' response to modafinil. METHODS: Twenty sleepy patients with OSAS under CPAP treatment were selected. All of them had Epworth Sleepiness Scale (ESS) >10. Following baseline evaluation (T1), all subjects were instructed to take placebo for 7 days. After this single-blind placebo phase and second evaluation (T2), patients were randomly allocated to placebo or modafinil treatment for 21 days in a double-blind protocol. Patients underwent a final evaluation (T3) on the last day of drug intake. The evaluations at T1, T2 and T3 consisted of: medical and laboratory examinations, nocturnal polysomnography, ESS, maintenance of wakefulness test (MWT) and complex reaction time (CRT-NY). In addition, in T2 and T3 the change of illness severity scale (CGI-C) and the evaluation of quality of life (SF-36) were applied. RESULTS: The comparison between the two groups during the three periods studied, showed the following results: in the modafinil group, ESS score did not change during the initial placebo period, but there was a significant reduction during the modafinil treatment period (p=0.0006); in the placebo group a significant reduction occurred during the initial placebo period (p=0.05), and no further change was observed in the treatment (placebo) period. A significant difference was found between the two groups after the placebo period (T2) (p=0.02). Three patients (33%) of the modafinil group and 9 patients (81%) of the placebo group were classified as placebo-responsive (X2: p=0.039). In the treatment period, reaction time was significantly reduced in the modafinil group compared to the placebo group (p<0.02). There was a trend toward improvement in overall clinical condition and also in some domains of SF-36 in the modafinil group. CONCLUSION: In summary, our study confirms that modafinil used adjunctively with CPAP therapy improves subjective daytime sleepiness in patients with OSAS who were regular users of CPAP therapy but still experienced sleepiness. Moreover, it could help in the improvement of objective measures of behavioral alertness and reduce functional impairments. The usefulness of a blinded placebo period for systematic investigation of placebo role in studies based on subjective response is a point that should be considered in this type of drug trial.     

The Epworth sleepiness scale in the identification of obstructive sleep apnea

The Epworth sleepiness scale (ESS) is often used clinically to screen for the manifestations of the behavioral morbidity associated to obstructive sleep apnea (OSA). The purpose of this study was to assess the sensitivity of the ESS in the identification of OSA, as defined by an elevated apnea-hypopnea index. A retrospective chart review of 268 consecutive patients diagnosed with OSA at a multidisciplinary sleep medicine clinic was conducted. The ESS obtained a relatively low sensitivity (66%) in the identification of an apnea-hypopnea index of 5 and above at the suggested cutoff of 10 and increased to 76% at 8. The results of the study showed only fair discriminatory ability of the ESS as a screener for OSA. A score of 8 (instead of 10) is suggested as the cutoff among clinic populations being screened for a sleep disorder.     

The impact of obstructive sleep apnea and daytime sleepiness on work limitation

BackgroundMany patients with obstructive sleep apnea (OSA) participate in the work force. However, the impact of OSA and sleepiness on work performance is unclear.MethodsTo address this issue, we administered the Epworth Sleepiness Scale (ESS), the Work Limitations Questionnaire (WLQ), and an occupational survey to patients undergoing full-night polysomnography for the investigation of sleep-disordered breathing. Of 498 patients enrolled in the study, 428 (86.0%) completed the questionnaires. Their mean age ± standard deviation (SD) was 49 ± 12years, mean body mass index (BMI) was 31 ± 7 kg/m² mean apnea hypopnea index (AHI) was 21 ± 22 events/h, and mean ESS score was 10 ± 5. Subjects worked a mean of 39 ± 18 h per week. The first 100 patients to complete the survey were followed up at two years.ResultsIn the group as a whole, there was no significant relationship between severity of OSA and the four dimensions of work limitation. However, in blue-collar workers, significant differences were detected between patients with mild OSA (AHI 5–15/h) and those with severe OSA (AHI > 30/h) with respect to time management (limited 23.1% of the time vs. 43.8%, p = 0.05) and mental/personnel interactions (17.9% vs. 33.0%, p = 0.05). In contrast, there were strong associations between subjective sleepiness (as assessed by the ESS) and three of the four scales of work limitation. That is, patients with an ESS of ⩽5 had much less work limitation compared to those with an ESS ⩾18 in terms of time management (19.7% vs. 38.6 %, p < 0.001), mental-interpersonal relationships (15.5% vs. 36.0%, p < 0.001) and work output (16.8% vs. 36.0%; p < 0.001). Of the group followed up, 49 returned surveys and 33 who were using continuous positive airway pressure (CPAP) showed significant improvements between the initial and second follow-up in time management (26% vs. 9%, p = 0.0005), mental-interpersonal relationships (16% vs. 11.0%, p = 0.014) and work output (18% vs. 10%; p < 0.009).ConclusionWe have demonstrated a clear relationship between excessive sleepiness and decreased work productivity in a population referred for suspected sleep-disordered breathing. Screening for sleepiness and sleep-disordered breathing in the workplace has the potential to identify a reversible cause of low work productivity.     

The impact of obstructive sleep apnea and daytime sleepiness on work limitation

BACKGROUND: Many patients with obstructive sleep apnea (OSA) participate in the work force. However, the impact of OSA and sleepiness on work performance is unclear. METHODS: To address this issue, we administered the Epworth Sleepiness Scale (ESS), the Work Limitations Questionnaire (WLQ), and an occupational survey to patients undergoing full-night polysomnography for the investigation of sleep-disordered breathing. Of 498 patients enrolled in the study, 428 (86.0%) completed the questionnaires. Their mean age+/-standard deviation (SD) was 49+/-12 years, mean body mass index (BMI) was 31+/-7 kg/m(2) mean apnea hypopnea index (AHI) was 21+/-22 events/h, and mean ESS score was 10+/-5. Subjects worked a mean of 39+/-18 h per week. The first 100 patients to complete the survey were followed up at two years. RESULTS: In the group as a whole, there was no significant relationship between severity of OSA and the four dimensions of work limitation. However, in blue-collar workers, significant differences were detected between patients with mild OSA (AHI 5-15/h) and those with severe OSA (AHI>30/h) with respect to time management (limited 23.1% of the time vs. 43.8%, p=0.05) and mental/personnel interactions (17.9% vs. 33.0%, p=0.05). In contrast, there were strong associations between subjective sleepiness (as assessed by the ESS) and three of the four scales of work limitation. That is, patients with an ESS of 5 had much less work limitation compared to those with an ESS 18 in terms of time management (19.7% vs. 38.6 %, p<0.001), mental-interpersonal relationships (15.5% vs. 36.0%, p<0.001) and work output (16.8% vs. 36.0%; p<0.001). Of the group followed up, 49 returned surveys and 33 who were using continuous positive airway pressure (CPAP) showed significant improvements between the initial and second follow-up in time management (26% vs. 9%, p=0.0005), mental-interpersonal relationships (16% vs. 11.0%, p=0.014) and work output (18% vs. 10%; p<0.009). CONCLUSION: We have demonstrated a clear relationship between excessive sleepiness and decreased work productivity in a population referred for suspected sleep-disordered breathing. Screening for sleepiness and sleep-disordered breathing in the workplace has the potential to identify a reversible cause of low work productivity.     

Change in frequency of periodic limb movements during sleep with usage of continuous positive airway pressure in obstructive sleep apnea syndrome

There is evidence that visuo-spatial capacity can become overloaded when processing a secondary visual task (Dual Task, DT), as occurs in daily life. Hence, we investigated the influence of the visuo-spatial interference in the identification of emotional facial expressions (EFEs) in early stages of Parkinson's disease (PD). We compared the identification of 24 emotional faces that illustrate six basic emotions in, unmedicated recently diagnosed PD patients (16) and healthy adults (20), under two different conditions: a) simple EFE identification, and b) identification with a concurrent visuo-spatial task (Corsi Blocks). EFE identification by PD patients was significantly worse than that of healthy adults when combined with another visual stimulus.     

Periodic limb movements and other movement disorders in sleep: neuropsychiatric dimensions

Movement disorders such as Parkinson's disease and Tourette's syndrome, primarily manifest during wakefulness, intrude into sleep. There are some disorders, however, such as periodic limb movements in sleep, restless legs syndrome, paroxysmal nocturnal dystonia, bruxism, and somnambulism, which occur primarily during sleep. The diagnosis and management of these disorders pose a challenge to neuropsychiatric practice, not only because they may be difficult to distinguish from other neuropsychiatric disorders, but also because psychiatric disorders are often co-morbid with them. Study of these disorders is necessary for an understanding of the interaction of sleep and movement, and how disturbance in one may affect the other.     

Antioxidant capacity in obstructive sleep apnea patients

OBJECTIVES: Obstructive sleep apnea syndrome (OSA) results in oxygen desaturation and arousal from sleep. Free oxygen radicals are highly reactive molecules, which can be produced by the OSA phenomenon known as hypoxia/reoxygenation. Hypoxic conditions, such as OSA, may also result in transient depletion of cellular reductants, which constitute a main line of antioxidant defense. Both apneas and hypopneas usually end in arousal, where reoxygenation causes the production of reactive oxygen species (free radicals). Living organisms have developed complex antioxidant systems to counteract reactive oxygen species and to reduce their damage. We evaluated the antioxidant capacity in serum from OSA patients and healthy people in order to confirm the hypothesis that there is a relationship between oxidative stress and OSA. MATERIALS AND METHODS: A physician interviewed 25 participants, determining age, smoking habits and symptoms such as excessive daytime sleepiness and snoring. Physical examination and polysomnography were performed during patients' hospitalization. Antioxidant capacity was measured in blood samples by Trolox Equivalent Antioxidant Capacity assay. RESULTS: Seventeen out of 25 subjects had an apnea/hypopnea index (AHI) greater than 10 (OSA group). The measurement of antioxidant capacity did not differ between the OSA patients and our healthy sample (of 25 subjects, seven with an AHI less than 10). Furthermore, patients with severe OSA (AHI >20, N=14) had linearly negative correlation between antioxidant capacity in their blood samples and AHI (R=-0.551, P=0.041). CONCLUSIONS: Reduced antioxidant capacity in serum is an index of excessive oxidative stress. Patients with severe OSA have reduced values of antioxidant capacity.     

Hypercoagulability in patients with obstructive sleep apnea

BACKGROUND: Obstructive sleep apnea (OSA) has been linked to cardiovascular complications such as stroke and myocardial infarction. Previous studies demonstrate that OSA patients show elevated fibrinogen levels and increased platelet aggregation that are reversed with 1 night of nasal continuous positive airway pressure treatment (NCPAP). Questioning overall coagulability in OSA, we examined whole blood coagulability in 11 chronically NCPAP treated OSA subjects, 22 previously untreated OSA subjects, and in 16 of these after 1 night of NCPAP treatment. PATIENTS AND METHODS: During full polysomnography, subjects from each group had blood drawn prior to bedtime (21:00 h) and upon waking in the morning (07:00 h). RESULTS: Untreated OSA patients had faster P.M. clotting times than chronically treated OSA patients (3.33+/-0.31 versus 6.12+/- 0.66 min, P<0.05 by ANOVA). A.M. values showed similar results (4.31+/- 0.34 min versus 7.08+/-0.52 min, P<0.05 by ANOVA) for the respective groups. One overnight treatment with nasal CPAP did not produce a significant change in A.M. whole blood coagulability (4.35 +/-0.43 to 5.31+/-0.53 min; n=16; P=0.1) in 16 treated subjects. CONCLUSIONS: These data indicate a relationship between obstructive sleep apnea and blood hypercoagulability status that appears to be reversed by chronic NCPAP treatment. These data suggest that NCPAP might protect against the development of cardiovascular complications in OSA patients.