The relationships between improvements in daytime sleepiness,fatigue and depression and psychomotor vigilance task testing with CPAP use in patients with obstructive sleep apnea

ObjectiveThe purpose of this study was to determine if the subjective improvements in daytime sleepiness, fatigue and depression experienced by patients with obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP) therapy predict an objective improvement in vigilance, and whether patients with mild-to-moderate OSA differ from patients with severe OSA in this regard.MethodsA total of 182 patients underwent psychomotor vigilance task (PVT) testing and measurements of subjective daytime sleepiness, fatigue and depression at baseline and after a minimum of one month of adherent CPAP use at an adequate pressure.ResultsPatients with both mild-to-moderate (n = 92) and severe (n = 90) OSA experienced improvements in subjective daytime sleepiness, fatigue and depression, but objective improvement in vigilance was only seen in patients with severe OSA. In patients with severe OSA, while a correlation was found between improvements in daytime sleepiness and some PVT parameters, changes in subjective daytime sleepiness, fatigue and depression scores were not predictive of objective improvement in vigilance while controlling for all these subjective symptoms and for age, gender, body mass index, apnea-hypopnea index/respiratory event index and total sleep time/total recording time with pulse oximetry below 90%.ConclusionsWe found no predictive relationship between subjective improvements in daytime sleepiness, fatigue and depression and objective vigilance with CPAP use in patients with OSA. These results suggest that subjective complaints of daytime impairment and objective measures of vigilance in patients with OSA should be assessed separately while evaluating the efficacy of CPAP therapy on daytime functioning.     

Evening and morning blood gases in patients with obstructive sleep apnea

BACKGROUND AND PURPOSE: The purpose of this study was to see if blood oxygen levels deteriorate overnight during obstructive sleep apnea (OSA). Before and after sleep, arterial blood gases (ABGs) in OSA subjects and controls were drawn during a diagnostic night, as well as during a continuous positive airway pressure (CPAP) night for the OSA subjects. PATIENTS AND METHODS: Subjects, both male and female, were referred to our sleep laboratory for symptoms of daytime somnolence. Subjects consisted of a control group (N=13) with a mean apnea hypopnea index (AHI) of 3.3 events/h and a study group (N=22) with a mean baseline AHI of 57 events/h. RESULTS: With the subject supine, resting room air ABGs were drawn at 'lights out' on the evening before (PM) nocturnal polysomnography and in the morning (AM) at discontinuation ('lights on') of the sleep study. In controls, PM PaO(2) (79.4+/-9.7 mmHg) was not significantly different from AM PaO(2) (80.2+/-8.9 mmHg, P=0.5). In apneic subjects, the PM PaO(2) was 78.7+/-7.2 mmHg compared to an AM PaO(2) of 72.6+/-8.3 mmHg (P<0.05). The AM PaO(2) after a night of CPAP treatment in the OSA subjects was 77.5+/-10.2 mmHg compared to the PM PaO(2) of 76.0+/-6.0 mmHg (NS). The PM and AM PaCO(2)s were not different in controls or in study subjects under baseline conditions. However, during titration with nasal CPAP, the PaCO(2) was significantly higher in the morning after CPAP treatment [43.1+/-4.8 vs. 46.1+/-4.8 mmHg, respectively (P<0.05)]. CONCLUSIONS: OSA subjects showed a fall in overnight resting oxygenation. This could be accounted for by overnight deterioration of gas exchange and is ameliorated by CPAP.     

Obstructive sleep apnea in children is associated with severity-dependent deterioration in overnight endothelial function

BackgroundRestorative sleep is expected to promote improved endothelial function (EF) in the morning compared to the evening. However, in adults with obstructive sleep apnea (OSA) EF is not only adversely affected, but it worsens during the night. Data in pediatric OSA are scarce, and overnight changes have not been explored. Therefore, we sought to examine potential associations between pediatric OSA and overnight changes in EF.Methods59 habitually snoring children with various degrees of sleep-disordered breathing (age range, 4–16 years) underwent EF assessment (reactive hyperemia test by EndoPAT, Itamar Medical, Israel) in the evening before and the morning after an overnight polysomnography (PSG). Two brachial occlusion periods (1 min and 5 min) also were tested. Potential associations between evening-to-morning changes in EF and polysomnographic parameters were explored.ResultsEvening-to-morning changes in children with OSA displayed severity-dependent deterioration of EF, and occlusions lasting 1 or 5 min during the reactive hyperemia test yielded similar findings.ConclusionsIn children deterioration in EF during the night significantly correlated with the severity of OSA. Furthermore, the reactive hyperemia test can be reliably performed with only 60 seconds of arterial flow occlusion in children. These findings support our hypothesis that similarly to adults, sleep apnea in children results in endothelial dysfunction (ED). We speculate that pediatric OSA is less commonly associated with cardiovascular complications possibly due to the shorter duration of the syndrome.     

Daytime leg pain after overnight continuous positive airway pressure titration

We report a case that showed transitional, severe emergent periodic limb movements during sleep (PLMS) in the first continuous positive airway pressure (CPAP) titration night and mild PLMS in the 3rd and 20th nights of CPAP titration in a 56-year-old woman after she was found to have severe obstructive sleep apnea (OSA). Severe PLMS in the initial CPAP night unexpectedly resulted in acute leg muscle soreness in the second morning. The case suggests that CPAP therapy in patients who suffer from severe OSA may provide a unique opportunity to look into the pathological mechanism of PLMS.     

Treating sleep apnea in Parkinson's disease with C-PAP: feasibility concerns and effects on cognition and alertness

BackgroundObstructive sleep apnea (OSA) is highly prevalent in Parkinson disease (PD) and is known to contribute to cognitive impairment and daytime sleepiness. We investigated feasibility of continuous positive airway pressure treatment (CPAP) and its effects on subjective daytime sleepiness and cognitive profile in PD plus OSA subjects in a longitudinal three months follow up study.MethodsSeventy (age 71.7 ± 7.6, disease duration 9.9 ± 12.3, UPDRS-III 33.7 ± 12.5, MMSE 25.3 ± 3.6; years of education 7.7 ± 3.2) out of 228 consecutive PD patients undergoing in-lab video-polysomnography were found to have obstructive sleep apnea. Thirty-six subjects accepted to titrate therapeutic CPAP. Video-polysomnography, neuropsychological battery evaluating different cognitive domains and subjective scales for daytime sleepiness were scheduled at baseline and after three months. All the patients were given educational informations relative to diagnosis of OSA and benefits of OSA treatment, and an individualized training with CPAP.ResultsTwenty-seven (75%) subjects dropped out of the study due to CPAP intolerance. No demographic or disease-related variables (in particular, severity of OSA), could be found between subjects who completed the study versus those who dropped out. Nine subjects completed the three-month follow up, and there were no significant changes in subjective sleepiness, neuropsychological scores and sleep structure (except for reduction in apnea/hypopnea index and a trend toward increase in stage N3 sleep).ConclusionOur data show that feasibility of CPAP treatment can be significantly threatened by overall attrition rates. Further studies should consider well-structured adherence promoting interventions. The actual role of OSA as a determinant of the profile of subjective daytime sleepiness and cognition in PD, and the effects of CPAP in PD need to be further studied.     

Relationship between reflux diseases and obstructive sleep apnea together with continuous positive airway pressure treatment efficiency analysis

BackgroundObstructive sleep apnea (OSA) is known to be highly associated with reflux diseases. There is evidence that continuous positive airway pressure (CPAP) can decrease the clinical symptoms of gastroesophageal reflux (GER) in OSA patients, but whether CPAP can decrease nocturnal laryngopharyngeal reflux (LPR) episodes is still lack of strong evidence.ObjectiveTo investigate the efficiency of CPAP on LPR and the relationship between LPR, GER and OSA.Study designretrospective study.MethodsForty adult patients who had confirmed OSA by polysomnography and suspected LPR were enrolled. Their results of synchronous polysomnography and 24 h esophageal and oropharyngeal Dx-pH monitoring were analyzed. Twenty-seven OSA patients were treated with CPAP on the second night. The nocturnal reflux parameters with and without CPAP treatment were compared.Results15.0% and 42.5% of OSA patients were associated with LPR and GER through Dx-pH monitoring respectively. Nevertheless, more than one reflux attack falling below pH6.0 of oropharynx during sleep time was detected in 80.0% patients. There was a significant inverse correlation between the lowest/mean pH values of oropharynx and obstructive apnea index (OAI), so was the lowest pH values of esophagus. Significant positive correlation was calculated between the total number of reflux episodes below pH6.0 of oropharynx and apnea–hypopnea index (AHI)/OAI/hypopnea index (HI). A similar positive correlation was also significant between AHI/OAI and GER parameters. The assessment of the efficacy of CPAP treatment showed significant difference both in GER and LPR related parameter.ConclusionsOSA patients have a higher incidence of nocturnal LPR and GER. CPAP treatment can effectively reduce both GER and LPR attacks while disordered sleep events reduced in OSA patients.     

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.     

Residual sleep apnea on polysomnography after 3 months of CPAP therapy: Clinical implications,predictors and patterns

ObjectiveWe sought to determine the clinical implications, predictors and patterns of residual sleep apnea on continuous positive airway pressure (CPAP) treatment in patients with moderate-to-severe obstructive sleep apnea (OSA).MethodsWe performed a post hoc secondary analysis of data from a previously reported randomized trial. Sleepy patients with a high risk of moderate-to-severe OSA identified by a diagnostic algorithm were randomly assigned to standard CPAP titration during polysomnography (PSG) or ambulatory titration using auto-CPAP and home sleep testing. We observed them for 3 months and measured apnea–hypopnea index (AHI) on CPAP, Epworth sleepiness scale (ESS), sleep apnea quality of life index (SAQLI), CPAP pressure and objective CPAP compliance.ResultsSixty-one patients were randomized, 30 to the PSG group and 31 to the ambulatory group. Fifteen patients (25%) had residual sleep apnea (AHI >10/h on CPAP) with similar proportions in the PSG (7/30) and ambulatory (8/31) groups. Baseline variables including age, body mass index (BMI), ESS, SAQLI, respiratory disturbance index (RDI) and CPAP pressure did not differ between the groups. Outcomes including compliance were worse in patients with residual sleep apnea. Periodic breathing was prevalent among patients with residual sleep apnea.ConclusionsResidual sleep apnea is common in patients with moderate-to-severe OSA, despite careful CPAP titration, and is associated with worse outcomes.     

Clinical and polysomnographic characteristics and response to continuous positive airway pressure therapy in obstructive sleep apnea patients with nightmares

ObjectiveTo assess the characteristics of obstructive sleep apnea (OSA) patients with nightmares and the effects of continuous positive airway pressure (CPAP) therapy on nightmares.MethodsConsecutive patients referred with a clinical suspicion of OSA underwent attended overnight sleep studies. OSA and nightmares were diagnosed according to the American Academy of Sleep Medicine (AASM) criteria, and CPAP titration was performed in accordance with the AASM guidelines. A follow-up visit was performed 3 months later, and the patients with nightmares were divided into two groups: group 1 used CPAP with good compliance, whereas group 2 refused CPAP treatment and did not use other alternative treatments for OSA.ResultsThe study included 99 patients who had been diagnosed with OSA with nightmares. Their mean age was 47.2 ± 11.2 years, and they had a mean apnea–hypopnea index (AHI) of 36.5 ± 34.3/h. Also included were 124 patients with OSA without nightmares. The mean age of these patients was 45.4 ± 13.9 years, and they had a mean AHI of 40.2 ± 35/h. The patients with nightmares had a significantly higher AHI during rapid eye movement sleep (REM) compared with the patients without nightmares (51.7 ± 28.1 vs 39.8 ± 31.9/h). Logistic regression analysis revealed that the REM-AHI and interrupted sleep at night were independent predictors of nightmares in the OSA patients. Nightmares disappeared in 91% of the patients who used CPAP compared with 36% of patients who refused to use CPAP (p < 0.001).ConclusionNightmares in OSA patients are associated with a higher REM-AHI. CPAP therapy results in a significant improvement in nightmare occurrence.     

Cognitive Function in Patients with Sleep Apnea after Acute Nocturnal Nasal Continuous Positive Airway Pressure (CPAP) Treatment: Sleepiness and Hypoxemia Effects

Abstract

Patients with sleep apnea are typically hypersomnolent during the daytime and may demonstrate higher order cognitive dysfunction. A persistent problem in interpreting impaired neuropsychological test performance in such patients is whether the observed deficits can be explained wholly by impaired vigilance. We examined 37 sleep apnea patients prior to and immediately subsequent to successful sleep apnea treatment with nasal continuous positive airway pressure (CPAP). Patients were evaluated immediately after morning awakening in the sleep lab. A brief neuropsychological evaluation, was administered at that time. Following this, alertness was measured with a 30-min polysomnographically determined sleep latency test. Both tests (approximately 50 min in duration) were performed once following a baseline (diagnostic) night in the sleep lab and once in the morning following a CPAP (therapeutic) night in the lab. Subgroup analyses indicted that while vigilance impairment can account for some of the decreased test performance seen in sleep apnea (auditory verbal learning) the effects of severe nocturnal hypoxemia appear to affect other functions (sustained attention in repetitive arithmetic calculations) that were not easily modified by treatment. Thus, performance on the recall trial of the Rey Auditory Verbal Learning Test increased from pre-CPAP to post-CPAP for the increased alertness group but decreased significantly for the decreased alertness group. On the Wilkinson Addition Test, non-hypoxemic patients showed statistically significant improvement in problems correctly solved from pre-CPAP to post-CPAP, but the hypoxemic patients showed only a marginal increase. These results are compatible with other studies suggesting that patients having sleep apnea may incur deficits as a result of both decreased vigilance and hypoxemia, and that at least some of these deficits are immediately reversible.     

Effect of below-the-knee compression stockings on severity of obstructive sleep apnea

BackgroundOvernight fluid shift from the legs to the neck may narrow the upper airway and contribute to obstructive sleep apnea (OSA) pathogenesis. We hypothesized that below-the-knee compression stockings will decrease OSA severity in a general OSA population by decreasing daytime leg fluid accumulation and overnight fluid shift and increasing upper-airway size.MethodsPatients with OSA (apnea–hypopnea index ≥10) were randomized to wear compression stockings during the daytime or to a control group for 2 weeks. Overnight polysomnography with measurement of leg and neck fluid volumes and upper-airway cross-sectional area before and after sleep was performed at baseline and follow-up. The primary outcome was change in the apnea–hypopnea index.ResultsTwenty-two patients randomized to compression stockings and 23 to control completed the study. The apnea–hypopnea index decreased significantly more in the compression stockings than in the control group (from 32.4 ± 20.0 to 23.8 ± 15.5 vs. from 31.2 ± 25.0 to 30.3 ± 23.8, p = 0.042), in association with a significantly greater reduction in the overnight decrease in leg fluid volume (p = 0.028), and a significantly greater increase in morning upper-airway cross-sectional area (p = 0.006). Overnight change in neck fluid volume was unchanged.ConclusionThese observations suggest that in, a general OSA population, below-the-knee compression stockings decrease OSA severity modestly via attenuation of overnight fluid shift and consequent upper-airway dilatation.     

Long-term adherence to continuous positive airway pressure therapy in non-sleepy sleep apnea patients

ObjectiveThe effectiveness of continuous positive airway pressure (CPAP) therapy greatly depends on consistent use. However, data regarding adherence in non-sleepy obstructive sleep apnea (OSA) patients are scarce. The aim of this study was to assess long-term adherence and predictors of CPAP compliance in a large sample of non-sleepy OSA patients.MethodsWe conducted a prospective, multicenter study comprising 357 non-sleepy patients (Epworth Sleepiness Scale score <11) with moderate-to-severe OSA (apnea–hypopnea index [AHI] of ≥20) who began CPAP therapy between May 2004 and May 2006; follow-up ended in May 2009. Non-compliance was scored as CPAP dropout or average cumulative CPAP use of <4 hours per night. Multivariate Cox regression analysis was performed to identify independent predictors of poor CPAP adherence.ResultsPatients were followed up for a median of four years (interquartile range [IQR] = 3.0–4.4). At the end of the study period, 230 patients (64.4%) fulfilled the criteria for good CPAP compliance, whereas 127 patients (35.6%) were considered non-compliant. The median CPAP use was five hours per night (interquartile range = 2.18–6.25). Multivariate analysis showed that interactions between the AHI and the percentage of nighttime spent with an O₂ saturation of <90% (TC90) (p = 0.010) and between the AHI and hypertension at baseline (p = 0.029) predicted long-term compliance with CPAP.ConclusionThis study demonstrates that CPAP treatment is feasible in non-sleepy, moderate-to-severe OSA patients. Good CPAP adherence was predicted by greater OSA severity as measured by both the AHI and TC90 and by the presence of hypertension at baseline in patients with higher AHI levels.     

Effect of continuous positive airway pressure on regional cerebral blood flow in patients with severe obstructive sleep apnea syndrome

ObjectivesObstructive sleep apnea (OSA) is commonly associated with neural and cognitive deficits induced by recurrent hypoxemia and sleep fragment. The aims of this study were to use statistical parametric mapping (SPM) to analyze changes in regional cerebral blood flow (rCBF) in untreated patients with severe OSA before and after nasal continuous positive airway pressure (CPAP) treatment, examine the impact of OSA-related variables on rCBF, and assess the therapeutic effect of nasal CPAP treatment.MethodsThirty male patients with severe OSA underwent brain single photon emission computed tomography (SPECT) scans twice before and after nasal CPAP treatment for ≥6 months, whereas 26 healthy controls underwent a single SPECT scan. The rCBF differences were compared between two OSA sub-groups (untreated and treated) and the control group, and correlations between rCBF differences and clinical parameters were analyzed.ResultsCompared with the controls, the untreated OSA patients showed a significantly lower rCBF in multiple brain areas. After the treatment, partial reversal of the rCBF decreases was observed in the limbic and prefrontal areas. Moreover, complete reversal of the rCBF decreases was observed in the medial orbitofrontal, angular and cerebellar areas. Significant improvements in some clinical and polysomnographic variables (Epworth Sleepiness Scale, apnea–hypopnea index, CPAP duration, and arousal index) paralleled the rCBF changes after the treatment.ConclusionsDecreased rCBF in severe OSA was significantly reversible by CPAP treatment and correlated with the improvements in the apnea–hypopnea index, arousal index, CPAP duration and Epworth Sleepiness Scale. These results suggest that long-term CPAP treatment improves rCBF in areas responsible for executive, affective, and memory function.     

Reduced overnight consolidation of procedural learning in chronic medicated schizophrenia is related to specific sleep stages

We previously reported that patients with schizophrenia failed to demonstrate normal sleep-dependent improvement in motor procedural learning. Here, we tested whether this failure was associated with the duration of Stage 2 sleep in the last quartile of the night (S2q4) and with spindle activity during this epoch. Fourteen patients with schizophrenia and 15 demographically matched controls performed a motor sequence task (MST) before and after a night of polysomnographically monitored sleep. Patients showed no significant overnight task improvement and significantly less than controls, who did show significant improvement. While there were no group differences in overall sleep architecture, patients showed significant reductions in fast sigma frequency power (45%) and in spindle density (43%) during S2q4 sleep at the electrode proximal to the motor cortex controlling the hand that performed the MST. Although spindle activity did not correlate with overnight improvement in either group, S2q4 sleep duration in patients significantly correlated with the plateau level of overnight improvement seen at the end of the morning testing session, and slow wave sleep (SWS) duration correlated with the delay in reaching this plateau. SWS and S2q4 sleep each predicted the initial level of overnight improvement in schizophrenia, and their product explained 77% of the variance, suggesting that both sleep stages are necessary for consolidation. These findings replicate our prior observation of reduced sleep-dependent consolidation of motor procedural learning in schizophrenia and link this deficit to specific sleep stages. They provide further evidence that sleep is an important contributor to cognitive deficits in schizophrenia.     

Subjective nocturnal symptoms have different associations with depressive symptoms and anxiety than with daytime sleepiness in patients with obstructive sleep apnea

BackgroundWe determined the relationships among the subjective symptoms of sleep apnea and daytime sleepiness, depressive symptoms, and anxiety in adults with obstructive sleep apnea (OSA).MethodsWe developed the Subjective Apnea Severity Questionnaire (SASQ) to measure subjective OSA symptoms during the night and on waking in the morning. Construct validity and reliability were assessed. The Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI), and State Scale of State Trait Anxiety Inventory (STAI-S) were applied. Multiple linear regression analyses were performed, and the results were adjusted for several confounders.ResultsA total of 337 OSA patients were included. The SASQ consists of eight items with three domains. Cronbach's α for the SASQ was 0.657. The mean SASQ score was 1.35 ± 0.59. Symptoms related to nocturnal breathing difficulties were associated with polysomnographic (PSG) respiratory parameters. In the adjusted models, total SASQ scores were associated with ESS scores but not with BDI or STAI-S scores. Unlike other symptom groups, nocturnal breathing difficulties tended toward a positive relationship with ESS scores (p = 0.076), but were negatively related to BDI scores (p = 0.003) and STAI-S scores (p = 0.012). Symptoms related to nocturnal awakening or morning waking were either positively related or unrelated to ESS, BDI, and STAI-S scores.ConclusionsThe subjective OSA symptoms measured via the SASQ were associated with daytime sleepiness in adults with OSA, but not with depressive symptoms or anxiety. Nocturnal breathing difficulties were positively related to daytime sleepiness, but negatively related to depressive symptoms and anxiety.     

Nocturia is an independent predictive factor of prevalent hypertension in obstructive sleep apnea patients

ObjectiveThe aim of this study was to determine whether nocturia is an independent predictor for prevalent hypertension in obstructive sleep apnea (OSA).MethodsWe analyzed data from a national prospective clinical cohort of OSA patients participating in the French national prospective registry. Anthropometric data, comorbidities, OSA severity, and number of voids/night were included in multivariate analyses to determine the independent variables associated with prevalent hypertension.ResultsA total of 22,674 OSA patients were included, of which 11,332 were hypertensive. The prevalence of hypertension among OSA patients was about 1.3 times higher in patients suffering from nocturia at 61.45% versus 46.52% in hypertensive and non-hypertensive OSA patients (p <0.001). There was a significant positive relationship between hypertension and the severity of nocturia beyond two voids/night: two voids/night versus none: odds ratio (OR) = 1.270 (95% confidence interval (CI) = 1.175; 1.372), three voids/night versus none: OR = 1.422 (95% CI = 1.293; 1.565), and four voids/night versus none: OR = 1.575 (95% CI = 1.394; 1.781). The strength of the association was enhanced in patients over 64 years of age.ConclusionsNocturia is a strong independent predictor of prevalent hypertension in OSA. This association exhibited a “dose–response” relationship beyond two voids/night. The resolution of nocturia after continuous positive airway pressure (CPAP) treatment might be an important outcome to consider for the response of hypertension to CPAP.     

CPAP therapy in patients with mild OSA: implementation and treatment outcome

Objectives: To determine continuous positive airway pressure (CPAP) treatment compliance and reversal of excessive daytime sleepiness in patients with mild OSA.Background: CPAP therapy is the most widely accepted and used intervention in patients with a diagnosis of obstructive sleep apnea (OSA). There are, however, no widely accepted protocols to help guide the rational use of CPAP therapy. Patients with mild OSA (respiratory event index (REI) >5 or 相似文献   

Sleep spindle activity correlates with implicit statistical learning consolidation in untreated obstructive sleep apnea patients

Objective/BackgroundThe aim of this study was to examine the relationship between overnight consolidation of implicit statistical learning with spindle frequency EEG activity and slow frequency delta power during non-rapid eye movement (NREM) sleep in obstructive sleep apnea (OSA).Patients/MethodsForty-seven OSA participants completed the experiment. Prior to sleep, participants performed a reaction time cover task containing hidden patterns of pictures, about which participants were not informed. After the familiarisation phase, participants underwent overnight polysomnography. 24 h after the familiarisation phase, participants performed a test phase to assess their learning of the hidden patterns, expressed as a percentage of the number of correctly identified patterns. Spindle frequency activity (SFA) and delta power (0.5–4.5 Hz), were quantified from NREM electroencephalography. Associations between statistical learning and sleep EEG, and OSA severity measures were examined.ResultsSFA in NREM sleep in frontal and central brain regions was positively correlated with statistical learning scores (r = 0.41 to 0.31, p = 0.006 to 0.044). In multiple regression, greater SFA and longer sleep onset latency were significant predictors of better statistical learning performance. Delta power and OSA severity were not significantly correlated with statistical learning.ConclusionsThese findings suggest spindle activity may serve as a marker of statistical learning capability in OSA. This work provides novel insight into how altered sleep physiology relates to consolidation of implicitly learnt information in patients with moderate to severe OSA.     

Obstructive sleep apnea in narcolepsy

Study objectivesNarcolepsy and obstructive sleep apnea syndrome (OSAS) are two conditions associated with excessive daytime sleepiness (EDS). They may coexist in the same patient but the frequency of this association and its clinical significance is unknown. The presence of obstructive sleep apnea (OSA) in a narcoleptic patient may interfere with the diagnosis of narcolepsy. The aim of the study was to determine the prevalence of OSA in narcolepsy.Design and settingUniversity hospital sleep clinic series of narcoleptic patients diagnosed with nocturnal polysomnography and multiple sleep latency test. Patients were systematically interviewed evaluating narcoleptic and OSAS features and their response to continuous positive airway pressure (CPAP) treatment when applied.PatientsOne hundred and thirty-three patients with narcolepsy.ResultsThirty-three patients (24.8%) had an apnea–hypopnea index greater than 10 with a mean index of 28.5 ± 15.7. Ten of them were initially diagnosed only with OSAS and the diagnosis of narcolepsy was delayed 6.1 ± 7.8 years until being evaluated in our center for residual EDS after CPAP therapy. In the remaining 23 patients, narcolepsy and OSA were diagnosed simultaneously. Cataplexy occurred with similar frequency in both groups. EDS did not improve in 11 of the 14 patients who were treated with CPAP. The presence of OSA was associated with male gender, older age and higher body mass index.ConclusionsOSA occurs frequently in narcolepsy and may delay the diagnosis of narcolepsy by several years and interfere with its proper management. In patients with OSA, cataplexy should be actively looked for to exclude the presence of narcolepsy. Treatment with CPAP does not usually improve EDS in narcoleptics with OSA.     

Predictors of CPAP adherence following stroke and transient ischemic attack

ObjectiveContinuous positive airway pressure (CPAP) has been shown to improve functional, motor and cognitive outcomes in post-stroke obstructive sleep apnea (OSA). However, rates of CPAP adherence are often low and factors impacting CPAP adherence remain under-explored. Our objective was to determine predictors of CPAP adherence in patients who had a stroke or transient ischemic attack (TIA).MethodsWe screened 313 stroke/TIA patients for OSA using in-hospital polysomnography or the ApneaLink home sleep apnea test. Potential predictors were recorded at baseline and adherence to CPAP was recorded during a six-month follow-up visit. Selected variables from our univariate analyses were included in multivariate regression models to determine predictors of CPAP adherence. For our logistic regression analyses, CPAP adherence (CPAP use of ≥4 h per night) was the dependent outcome variable. In our linear regression analyses, total CPAP use per week (recorded in hours) was the dependent outcome variable.ResultsEighty-eight patients (mean age 67.81 ± 13.09 years, 69.32% male, mean body mass index 27.93 ± 5.23 kg/m²) were diagnosed with OSA, prescribed CPAP, and assessed for adherence at a six-month follow-up visit. In these 88 patients, 46 (52.27%) were adherent with CPAP therapy. From our regression models, two significant predictors of CPAP adherence were identified: greater functional status (p = 0.04) and not endorsing daytime tiredness (p = 0.047) post-stroke/TIA.ConclusionPatients with greater functional capacity and those with less daytime fatigue demonstrated stronger adherence to CPAP therapy. Our findings may facilitate future treatment strategies for enhancing CPAP adherence in the vulnerable stroke/TIA population.