Chronic sleep reduction is associated with academic achievement and study concentration in higher education students.

Inadequate sleep impairs cognitive function and has been associated with worse academic achievement in higher education students; however, studies that control for relevant background factors and include knowledge on sleep hygiene are scarce. This study examined the association of chronic sleep reduction (i.e. symptoms of chronic sleep reduction such as shortness of sleep, sleepiness and irritation), subjective sleep quality and sleep hygiene knowledge with academic achievement (grades and study credits) and study concentration among 1378 higher education students (71% female, mean age 21.73 years, SD = 3.22) in the Netherlands. Demographic, health, lifestyle and study behaviour characteristics were included as covariates in hierarchical regression analyses. After controlling for significant covariates, only chronic sleep reduction remained a significant predictor of lower grades (last exam, average in current academic year). Better sleep quality and sleep hygiene knowledge were associated with better academic achievement, but significance was lost after controlling for covariates, except for a remaining positive association between sleep hygiene beliefs and grades in the current academic year. Moreover, better sleep quality and lower scores on chronic sleep reduction were associated with better study concentration after controlling for significant covariates. To conclude, chronic sleep reduction is associated with academic achievement and study concentration in higher education students. Inadequate sleep hygiene knowledge is moderately associated with worse academic achievement. Future research should investigate whether sleep hygiene interventions improve academic achievement in students of higher education.

Oral appliance therapy versus nasal continuous positive airway pressure in obstructive sleep apnea: a randomized, placebo-controlled trial on psychological distress.

OBJECTIVES: The aim of this randomized placebo-controlled trail was to compare the effects of an objectively titrated mandibular advancement device (MAD) with those of nasal continuous positive airway pressure (nCPAP) and an intraoral placebo device on symptoms of psychological distress in OSA patients. MATERIALS AND METHODS: In a parallel design, 64 mild/moderate OSA patients (52.0 ± 9.6 years) were randomly assigned to an objectively titrated MAD, nCPAP, or an intraoral placebo appliance. All patients filled out the Symptom Checklist-90-Revised twice: one before treatment and one after 6 months of treatment. The Symptom Checklist-90-Revised is a multidimensional symptom inventory designed to measure symptomatic psychological distress over the past week. Linear mixed model analyses were performed to study differences between the therapy groups for the different dimensions of the Symptom Checklist-90-Revised over time. RESULTS: The MAD group showed significant improvements over time in the dimensions "somatization," "insufficiency of thinking and acting," "agoraphobia," "anxiety," "sleeping problems," and "global severity index" (F = 4.14-16.73, P = 0.048-0.000). These improvements in symptoms of psychological distress were, however, not significantly different from those observed in the nCPAP and placebo groups (P = 0.374-0.953). CONCLUSION: There is no significant difference between MAD, nCPAP, and an intraoral placebo appliance in their beneficial effects on symptoms of psychological distress. CLINICAL RELEVANCE: The improvement in psychological distress symptoms in mild/moderate OSA patients under MAD or nCPAP treatment may be explained by a placebo effect.

Time-linked concurrence of sleep bruxism, periodic limb movements, and EEG arousals in sleep bruxers and healthy controls.

OBJECTIVE: Sleep bruxism (SB) and periodic limb movements during sleep (PLMS) may have a common underlying neurophysiologic mechanism, especially in relation to the occurrence of sleep-related electroencephalographic (EEG) arousals. To test this hypothesis, three research questions were assessed. First, it was assessed whether PLMS events occur more frequently in SB patients than in individuals without SB. Second, the question was put forward whether the combined presence of SB and PLMS events is more common than that of isolated SB or PLMS events in a group of SB patients. Third, as to further unravel the possible role of EEG arousals in the underlying neurophysiologic mechanism of SB and PLMS, it was assessed in a group of SB patients whether combined SB/PLMS events with associated EEG arousals are more common than those without associated EEG arousals. Positive answers to these questions could suggest a common neurophysiological basis for both movement disorders. MATERIALS AND METHODS: Seventeen SB patients and 11 healthy controls were polysomnographically studied. SB, PLMS, and EEG arousals were scored. An association was noted when the occurrence was within a 3-s association zone. RESULTS: The PLMS index was higher in SB patients than in healthy controls (P < 0.001). Within the group of SB patients, the combined SB/PLMS index was higher than the isolated SB index (P < 0.001) and the isolated PLMS index (P = 0.018). Similarly, the combined SB/PLMS index with EEG arousal was higher than the combined SB/PLMS index without EEG arousal in SB patients (P < 0.001). CONCLUSION: The results of this study indicate that SB, PLMS, and EEG arousals commonly concur during sleep in a time-linked manner. CLINICAL RELEVANCE: SB and PLMS probably have a common underlying neurophysiological mechanism.

Effects of occlusal stabilization splints on obstructive sleep apnea: a randomized controlled trial.

AIMS: To assess the influence of occlusal stabilization splints on sleep-related respiratory variables in obstructive sleep apnea (OSA) patients. METHODS: Ten OSA patients (47.3 ± 11.7 years of age) received a stabilization splint in the maxilla. All patients underwent three polysomnographic recordings with their splint in situ, and three recordings without their splint in situ, using a randomized crossover design. RESULTS: Repeated-measures ANOVAs did not yield statistically significant differences in the Apnea-Hypopnea Index (AHI) or in the Epworth Sleepiness Scale (ESS), neither between the three nights without the stabilization splint (AHI: F = 2.757, P = .090; ESS: F = 0.153, P = .860) nor between the nights with the splint in situ (AHI: F = 0.815, P = .458; ESS: F = 0.231, P = .796). However, independent ANOVAs revealed that the mean AHI of the three nights with the stabilization splint in situ (17.4 ± 7.0 events/hour) was significantly higher than that of the nights without the splint in situ (15.9 ± 6.4 events/hour) (F = 7.203, P = .025). The mean increase in AHI with the splint in situ was 1.4 ± 1.7 (95% confidence interval = -1.9-4.7). No difference in ESS was found when both conditions were compared (F = 1.000, P = .343). CONCLUSION: The use of an occlusal stabilization splint is associated with a risk of aggravation of OSA; however, the effect size was small, which reduces the clinical relevance of the study.

Oral appliance therapy versus nasal continuous positive airway pressure in obstructive sleep apnea: a randomized, placebo-controlled trial.

BACKGROUND: Previous randomized controlled trials have addressed the efficacy of mandibular advancement devices (MADs) in the treatment of obstructive sleep apnea (OSA). Their common control condition, nasal continuous positive airway pressure (nCPAP), was frequently found to be superior to MAD therapy. However, in most of these studies, only nCPAP was titrated objectively but not MAD. To enable an unbiased comparison between both treatment modalities, the MAD should be titrated objectively as well. OBJECTIVE: The aim of the present study was to compare the treatment effects of a titrated MAD with those of nCPAP and an intra-oral placebo device. METHODS: Sixty-four mild/moderate patients with obstructive sleep apnea (OSA; 52.0 ± 9.6 years) were randomly assigned to three parallel groups: MAD, nCPAP and placebo device. From all patients, two polysomnographic recordings were obtained at the hospital: one before treatment and one after approximately 6 months of treatment. RESULTS: The change in the apnea-hypopnea index (ΔAHI) between baseline and therapy evaluation differed significantly between the three therapy groups (ANCOVA; p = 0.000). No differences in the ΔAHI were found between the MAD and nCPAP therapy (p = 0.092), whereas the changes in AHI in these groups were significantly larger than those in the placebo group (p = 0.000 and 0.002, respectively). CONCLUSION: There is no clinically relevant difference between MAD and nCPAP in the treatment of mild/moderate OSA when both treatment modalities are titrated objectively.

Long-term follow-up of a randomized controlled trial of oral appliance therapy in obstructive sleep apnea.

BACKGROUND: Long-term trials are needed to capture information regarding the persistence of efficacy and loss to follow-up of both mandibular advancement device (MAD) therapy and continuous positive airway pressure (CPAP) therapy. OBJECTIVES: The aim of the study was to compare these treatment aspects between MAD and nasal CPAP (nCPAP) in a 1-year follow-up. METHODS: Forty-three mild/moderate obstructive sleep apnea patients (52.2 ± 9.6 years) with a mean apnea-hypopnea index (AHI) of 20.8 ± 9.9 events/h were randomly assigned to two parallel groups: MAD (n = 21) and nCPAP (n = 22). Four polysomnographic recordings were obtained: one before treatment, one for the short-term evaluation, and two recordings 6 and 12 months after the short-term evaluation. Excessive daytime sleepiness (EDS) was also evaluated at the polysomnographic recordings. RESULTS: The initially achieved improvements in the AHI remained stable over time within both groups (p = 0.650). In the nCPAP group, the AHI improved 4.1 events/h more than in the MAD group (p = 0.000). The EDS values showed a gradual improvement over time (p = 0.000), and these improvements were similar for both groups (p = 0.367). In the nCPAP group, more patients withdrew from treatment due to side effects than in the MAD group. CONCLUSIONS: The absence of significant long-term differences in EDS improvements between the MAD and the nCPAP groups with mild/moderate obstructive sleep apnea may indicate that the larger improvements in AHI values in the nCPAP group are not clinically relevant. Moreover, nCPAP patients may show more problems in accepting their treatment modality than MAD patients.

Effects of an oral appliance with different mandibular protrusion positions at a constant vertical dimension on obstructive sleep apnea.

The aim of the study was to assess the influence of four mandibular protrusion positions, at a constant vertical dimension, on obstructive sleep apnea (OSA). Seventeen OSA patients (49.2 +/- 8.5 years) received an adjustable mandibular advancement device (MAD). The patients underwent four polysomnographic recordings with their MAD in situ at, in random order, 0%, 25%, 50%, and 75% of the maximum protrusion. The mean apnea-hypopnea index (AHI) values of the patients differed significantly between the protrusion positions (P < 0.000). The 25% protrusion position resulted in a significant reduction of the AHI with respect to the 0% position, while in the 50% and 75% positions, even lower AHI values were found. The number of side effects was larger starting at the 50% protrusion position. We therefore recommend coming to a weighted compromise between efficacy and side effects by starting a MAD treatment in the 50% protrusion position.

Oral appliance therapy versus nasal continuous positive airway pressure in obstructive sleep apnea: A randomized, placebo-controlled trial on temporomandibular side-effects.

PURPOSE: To assess the differences in the frequency of clinical signs of temporomandibular disorder (TMD) pain and mandibular function impairment between mandibular advancement device (MAD) and nasal continuous positive airway pressure (nCPAP) therapies in obstructive sleep apnea (OSA) patients at baseline and after 6 month of treatment. METHODS: This study concerns a secondary analysis of a randomized placebo-controlled trial in which different treatment effects of an objectively titrated MAD were compared with those of nCPAP and an intra-oral placebo appliance in a parallel design. Sixty-four mild to severe OSA patients (52.0 ± 9.6 years) were randomly assigned to these three groups. All patients underwent a shortened functional examination of their masticatory system at baseline and after 6 months to establish the presence of clinical signs of TMD pain. Mandibular function impairment was assessed with a questionnaire. RESULTS: Clinical signs of TMD pain were only rarely present at baseline and therapy evaluation. No significant differences were found between the three groups in the (low) frequency of clinical signs of TMD pain at both time points (p = .401-.176). In addition, the (low) scores of mandibular function impairment did not differ between the three groups either, neither at baseline (p = .744) nor after 6 months (p = .359). CONCLUSIONS: A low frequency of clinical signs of TMD pain in mild to severe OSA patients was found after 6 months, regardless of treatment with MAD or nCPAP. In addition, no difference in mandibular function impairment was observed between the different treatment modalities.

Variability in the apnea-hypopnea index and its consequences for diagnosis and therapy evaluation.

BACKGROUND: The apnea-hypopnea index (AHI) is frequently used to recognize obstructive sleep apnea (OSA) and to evaluate therapy. OBJECTIVES: The aim of this study was to determine the AHI variability during a 10-week period, and to discuss its consequences for diagnosis and therapy evaluation. METHODS: Fifteen OSA patients (50.8 +/- 11.2 years) underwent four polysomnographic (PSG) recordings, with a mean interval between recordings of 3.3 weeks. RESULTS: No differences were found in the average AHI values of the four PSG recordings (p = 0.985). Nevertheless, pooling all data of the 15 participants yielded a smallest detectable difference for AHI of 12.8. Linear regression between the individual means and standard deviations (SDs) of AHI showed that participants with a higher AHI tended to have a higher SD (p < 0.044). CONCLUSIONS: These results suggest a considerable intra-individual variability in AHI recordings. Hence, a single-night recording can only recognize OSA when the AHI lies outside a cutoff band surrounding the AHI cutoff point. AHI variability should also be taken into account when evaluating OSA therapy. In this context, it should be noted that it is mainly the approach that we would like to convey to the reader and not the cutoff values per se.

ERP amplitude and latency in breast cancer survivors treated with adjuvant chemotherapy.

OBJECTIVE: Neurocognitive problems that were observed in a number of breast cancer survivors treated with adjuvant chemotherapy initiated a series of EEG studies to examine the neurophysiological basis of these deficits. The aim of the present study was to examine the effects of various regimens of adjuvant chemotherapy on the N1 and P3 component of the event-related potential (ERP) in breast cancer patients 3-6 years after treatment. METHODS: Fifty-three breast cancer patients treated with various chemotherapy regimens were compared to 23 stage I breast cancer patients not treated with chemotherapy. An auditory oddball task was used to study the amplitude, latency and structure of the potential field of the N1 and P3. RESULTS: Patients treated with chemotherapy showed lower P3 amplitudes than patients not treated with chemotherapy. Differences were also observed in P3 latency between patients treated with different chemotherapy regimens. CONCLUSIONS: Our results indicate a general effect of all chemotherapy regimens under study on P3 amplitude and a more specific chemotherapeutic effect on P3 latency. SIGNIFICANCE: The present study provides evidence for the notion that different chemotherapy regimens have different effects on brain functioning.

Effects of high-dose and conventional-dose adjuvant chemotherapy on long-term cognitive sequelae in patients with breast cancer: an electrophysiologic study.

BACKGROUND: The mechanisms underlying cognitive deficits found in a number of patients with breast cancer treated with adjuvant chemotherapy are still unclear. In the current study, we used a combination of measures of brain electric activity and cognitive performance during information processing to elucidate the origin of these cognitive deficits. PATIENTS AND METHODS: Twenty-nine patients at high risk with breast cancer treated with adjuvant conventional-dose cyclophosphamide/epirubicin/5-fluorouracil or adjuvant high-dose cyclophosphamide/thiotepa/carboplatin were compared with 23 patients with stage I breast cancer not treated with chemotherapy approximately 4 years after completion of treatment. We studied reaction times and the amplitudes and latencies of the P3, an electrophysiologic index of information processing, in a task with different conditions related to input, central, and output processing of information. RESULTS: The amplitude of the P3 component was significantly reduced in patients with breast cancer treated with high-dose cyclophosphamide/thiotepa/carboplatin compared with patients with breast cancer not treated with chemotherapy. We observed no significant differences in reaction times and P3 latency between the treatment groups. CONCLUSION: Our data show electrophysiologic alterations in patients with breast cancer treated with high-dose chemotherapy 4 years after completion of treatment. The observed P3 reduction might be a result of suboptimal phasic cortical arousal and problems with the allocation of processing resources in these patients.

Controlled assessment of the efficacy of occlusal stabilization splints on sleep bruxism.

AIMS: To assess the efficacy of occlusal stabilization splints in the management of sleep bruxism (SB) in a double-blind, parallel, controlled, randomized clinical trial. METHODS: Twenty-one participants were randomly assigned to an occlusal splint group (n = 11; mean age = 34.2 +/- 13.1 years) or a palatal splint (ie, an acrylic palatal coverage) group (n = 10; mean age = 34.9 +/- 11.2 years). Two polysomnographic recordings that included bilateral masseter electromyographic activity were made: one prior to treatment, the other after a treatment period of 4 weeks. The number of bruxism episodes per hour of sleep (Epi/h), the number of bursts per hour (Bur/h), and the bruxism time index (ie, the percentage of total sleep time spent bruxing) were established as outcome variables at a 10% maximum voluntary contraction threshold level. A general linear model was used to test both the effects between splint groups and within the treatment phase as well as their interaction for each outcome variable. RESULTS: Neither occlusal stabilization splints nor palatal splints had an influence on the SB outcome variables or on the sleep variables measured on a group level. In individual cases, variable outcomes were found: Some patients had an increase (33% to 48% of the cases), while others showed no change (33% to 48%) or a decrease (19% to 29%) in SB outcome variables. CONCLUSION: The absence of significant group effects of splints in the management of SB indicates that caution is required when splints are indicated, apart from their role in the protection against dental wear. The application of splints should therefore be considered at the individual patient level.

[Putting sleep disorders in context]. / Plaats slaapproblemen in de juiste context.

The new guidelines show many improvements when compared to the previous set. However, there still are several shortcomings. These mainly involve a lack of discussion of the increasing problem of sleep deprivation in western societies, and a non-consistent use of the terms "fatigue" and "excessive daytime sleepiness".

[Chronic insomnia: not always psychophysiological]. / Chronische insomnie: niet altijd psychofysiologisch.

OBJECTIVE: To determine the sensitivity, specificity and the positive and negative predictive value of taking a detailed sleep history for making the diagnosis of psychophysiological insomnia. DESIGN: Retrospective case file study. METHOD: We examined 767 patients referred to the Amsterdam Centre for Sleep and Wake Disorders, and who underwent polysomnography for the first time between 1 January and 31 December 2010. We compared the probable diagnosis made following history-taking with the final diagnosis made after polysomnography. In this we differentiated between organic and non-organic insomnia. The sensitivity, specificity, positive and negative predictive values of the sleep history were calculated. RESULTS: In 24.8% of the 303 patients whose histories did not indicate organic insomnia, polysomnography showed there to be an organic cause. Primary causes were obstructive sleep apnoea (13.2%), upper airway resistance syndrome (5.4%), and periodic limb movement disorder (4.0%) or a combination of these. In the histories of 464 patients there were indications that the insomnia had an organic cause and in 325 of them this was confirmed by polysomnography. The sensitivity of detailed history taking to psychophysiological insomnia was 62.1%, the specificity 81.3%, the positive predictive value was 75.2% and the negative predictive value was 70.0%. In patients under the age of 40 with a score on the Epworth sleepiness scale < 10 (i.e. no hypersomnolence), a BMI < 25 kg/m2 and indications of psychophysiological insomnia, organic insomnia could not be demonstrated, with the exception of one parasomnia. CONCLUSION: History-taking only meant that the organic cause was missed in a substantial percentage of patients with insomnia, in particular in older patients with hypersomnolence and a high BMI.

Acetaminophen for self-reported sleep problems in an elderly population (ASLEEP): study protocol of a randomized placebo-controlled double-blind trial.

BACKGROUND: The prevalence of sleep disorders increases with age. Sleep disorders may have serious health implications and may be related to serious underlying diseases. Many older people use hypnotics, like benzodiazepines, although these medications have serious side effects and often lead to habituation. Acetaminophen is one of the most frequently used off-label drugs for sleep disorders, although little is known about its effects. Our objective is to investigate whether acetaminophen is effective in treating self-reported sleep disorders in older people. METHODS/DESIGN: Participants, aged 65 years or older (n=150), who have sleep disorders will be randomized for treatment with either acetaminophen 1000 mg or placebo, once daily at bedtime in a double-blind design. Eligible patients should be able to give informed consent, should not be cognitively impaired (Minimal Mental State Examination (MMSE) score≥20), should not have pain, and should not use acetaminophen on a regular basis because of pain complaints. The study will take three weeks to complete. During these three weeks, the participants register their sleep behavior in a sleep diary. The participants will use the study medication during the second and third week. The primary endpoint will be the self-reported sleep disorders at the end of week three, as measured by means of the Insomnia Severity Index (ISI). To validate these subjective sleep parameters against objectively measured indices of the sleep-wake pattern, we will measure the periods of wakefulness and sleep in a subgroup of participants, using an actigraph worn on the wrist during the entire study period. DISCUSSION: The proposed study will contribute to our knowledge about the treatment of sleep disorders in an older population. There is a need for treatments for sleep disorders without serious adverse effects. Acetaminophen might be a simple and inexpensive alternative for the regimes that are currently used with older people. TRIAL REGISTRATION: The Netherlands National Trial Register NTR2747.

Electrophysiological correlates of information processing in breast-cancer patients treated with adjuvant chemotherapy.

Cognitive deficits are found in a number of breast-cancer patients who have undergone adjuvant (Cyclophosphamide, Methotrexate, and 5-Fluorouracil (CMF)) chemotherapy, but the underlying mechanisms are still unclear. The objective of this study is to investigate information processing in these patients with concurrent registration of brain activity. Twenty-six breast-cancer patients treated with adjuvant CMF chemotherapy and a control group of 23 stage I breast-cancer patients not treated with chemotherapy were examined. Mean time since treatment for the CMF patients was 5.1 years after the last CMF course, and for the control patients 3.6 years after termination of radiotherapy. An information processing task was administered with concurrent EEG registration. Reaction times and the amplitudes and latencies of an Event Related Potential component (P3) in different task conditions related to input, central, and output processing of information were studied. Significant differences in latency and amplitude of the P3 component were found between the treatment groups with an earlier and reduced P3 in the chemotherapy group. Patients treated with chemotherapy had longer reaction times (although not significantly different) than the control group on all task conditions. Our data provide further evidence for long-term neurocognitive problems in breast-cancer patients treated with adjuvant (CMF) chemotherapy and offer new information regarding abnormalities in brain functioning in these patients.