A novel approach using actigraphy to quantify the level of disruption of sleep by in-home polysomnography: the MrOS Sleep Study: Sleep disruption by polysomnography

BackgroundThe “first-night effect” of polysomnography (PSG) has been previously studied; however, the ability to quantify the sleep disruption level has been confounded with the use of PSG on all nights. We used actigraphy to quantify disruption level and examined characteristics associated with disruption.MethodsTotally, 778 older men (76.2 ± 5.4 years) from a population-based study at six US centers underwent one night of in-home PSG. Actigraphy was performed on the PSG night and three subsequent nights. Actigraphically measured total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), and sleep onset latency (SOL) from the PSG night and subsequent nights were compared. Linear regression models were used to examine the association of characteristics and sleep disruption.ResultsOn average, sleep on the PSG night was worse than the following night (p < 0.05, TST 21 ± 85 min less, SE 2.3 ± 11.3% less, WASO 4.9 ± 51.8 min more, SOL 6.6 ± 56.2 min more). Sleep on the PSG night was significantly worse than that two and three nights later. Characteristics associated with greater sleep disruption on the PSG night included older age, higher apnea–hypopnea index, worse neuromuscular function, and more depressive symptoms. Minorities and men with excessive daytime sleepiness slept somewhat better on the PSG night.ConclusionsAmong older men, there was sleep disruption on the PSG night, which may lead to sleep time underestimation. The increase of sleep on the night after the PSG suggests that data from the second monitoring may overestimate sleep.     

Sleep disorders and daytime sleepiness in children with attention-deficit/hyperactivity disorder: A two-night polysomnographic study with a multiple sleep latency test

ObjectiveTo evaluate sleep macrostructure, sleep disorders incidence and daytime sleepiness in attention-deficit/hyperactivity disorder (ADHD) affected children compared with controls.MethodsThirty-one patients (26 boys, 5 girls, mean age 9.3 ± 1.7, age range 6–12 years) with ADHD diagnosed according to DSM-IV criteria, without comorbid psychiatric or other disorders, as never before pharmacologically treated for ADHD. The controls were 26 age- and sex-matched children (22 boys, 4 girls, age range 6–12 years, mean age 9.2 ± 1.5). Nocturnal polysomnography (PSG) was performed for two nights followed by the multiple sleep latency test (MSLT).ResultsNo differences between the two groups comparing both nights were found in the basic sleep macrostructure parameters or in the time (duration) of sleep onset. A first-night effect on sleep variables was apparent in the ADHD group. Occurrence of sleep disorders (sleep-disordered breathing [SDB], periodic limb movements in sleep [PLMS], parasomnias) did not show any significant differences between the investigated groups. A statistically significant difference (p = 0.015) was found in the trend of the periodic limb movement index (PLMI) between two nights (a decrease of PLMI in the ADHD group and an increase of PLMI in the control group during the second night). While the mean sleep latency in the MSLT was comparable in both groups, children with ADHD showed significant (sleep latency) inter-test differences (between tests 1 and 2, 1 and 4, 1 and 5, p < 0.01).ConclusionAfter the inclusion of adaptation night and exclusion of psychiatric comorbidities, PSG showed no changes in basic sleep parameters or sleep timing, or in the frequency of sleep disorders (SDB, PLMS) in children with ADHD compared with controls, thus not supporting the hypothesis that specific changes in the sleep macrostructure and sleep disturbances are connected with ADHD. A first-night effect on sleep variables was apparent only in the ADHD group. Though we found no proof of increased daytime sleepiness in children with ADHD against the controls, we did find significant vigilance variability during MSLT in the ADHD group, possibly a sign of dysregulated arousal.     

Findings of the Maintenance of Wakefulness Test and its relationship with response to modafinil therapy for residual excessive daytime sleepiness in obstructive sleep apnea patients adequately treated with nasal continuous positive airway pressure

ObjectiveWe aimed to examine the relationship between subjective and objective sleepiness in obstructive sleep apnea syndrome (OSAS) patients with residual sleepiness, and to determine whether baseline objective sleepiness severity predicts the response to modafinil therapy.MethodsData were obtained from a randomized, placebo-controlled modafinil (200 mg/day) study in Japanese OSAS patients with residual sleepiness receiving nasal continuous positive pressure (n-CPAP) treatment. We analyzed 50 participants whose subjective (Epworth Sleepiness Scale [ESS] total score) and objective (Maintenance of Wakefulness Test [MWT] sleep latency) sleepiness were evaluated before and after treatment. Subjects were dichotomized into two subgroups according to the mean baseline MWT sleep latency. ESS total score and MWT sleep latency changes after treatment were compared between the placebo and modafinil groups in both subgroups.ResultsThe mean baseline ESS total score and MWT sleep latency were 14.1 ± 2.8 and 14.2 ± 4.9 min, respectively; there was no significant correlation between these two variables. Patient characteristics were similar between the two subgroups (MWT sleep latency: <14 min, n = 23; ≥14 min, n = 27). In the <14-min subgroup, changes in ESS total score and MWT sleep latency after treatment were significantly greater in the modafinil group than in the placebo group (p = 0.005). In the ≥14-min subgroup, changes in these parameters did not differ between the treatment groups.ConclusionIn OSAS patients with residual sleepiness, the objective sleepiness level was not as high as expected, despite increased subjective sleepiness. Improvements in subjective and objective sleepiness seemed difficult to achieve with modafinil treatment among subjects with less objective sleepiness.     

Treatment of elderly primary insomnia patients with EVT 201 improves sleep initiation,sleep maintenance,and daytime sleepiness

ObjectiveTwo doses of EVT 201, a partial positive allosteric modulator of the GABA_A system, were evaluated in elderly primary insomnia patients with daytime sleepiness.Patients and methodsParticipants were 149 elderly patients with DSM-IV primary insomnia including evidence of daytime sleepiness (53 males, 96 females; mean age 71.3 yrs, range 65–86 yrs). A randomized, multicentre, double-blind, placebo-controlled, parallel-group design was used to assess the hypnotic efficacy of EVT 201 1.5 and 2.5 mg during seven consecutive nights. Polysomnography (PSG) was performed on nights 1, 6 and 7 of treatment. Daytime assessments on Day 8 included the multiple sleep latency test (MSLT), Rey Auditory Verbal Learning Test (RAVLT), Psychomotor Vigilance Task (PVT) and the Karolinska Sleepiness Scale (KSS). The primary endpoint was total sleep time (TST) and the key secondary endpoint was mean MSLT latency.ResultsCompared to placebo, EVT 201 1.5 and 2.5 mg increased TST (30.9, 56.4 min, respectively; p = 0.0001, p < 0.0001); reduced wake after sleep onset (WASO; ?15.2, ?36.1 min, respectively; p = 0.014, p < 0.0001); reduced latency to persistent sleep (LPS; ?15.9, ?19.9 min, respectively; p = 0.009, p = 0.001). The 2.5 mg dose also reduced WASO in hours 5–8 (?16.3 min, p = 0.001). Both doses also improved subjective sleep quality and usual subjective efficacy measures. A significantly longer mean MSLT latency was observed on Day 8 with both doses, compared to placebo (2 min increase; p = 0.03, both doses). The PVT, RAVLT, and POMS did not differ among treatment groups. No serious or unexpected treatment emergent adverse events were noted.ConclusionEVT 201 improved PSG measures of sleep onset and sleep maintenance and significantly reduced daytime physiological sleep tendency. These findings suggest that treatment of primary insomnia in older patients has the potential to improve daytime sleepiness as well as sleep.     

The influence of placebo administration on the first- night effect in patients with insomnia disorder

ObjectiveWe aimed to investigate the effects of placebo on the first-night effect (FNE) in insomniacs.MethodsIn sum, 36 patients with insomnia disorder who met the DSM-5 criteria were enrolled in this study. Sixteen patients with insomnia disorder were given two days of placebo intervention (placebo-administration group, PL). Twenty patients with insomnia disorder (drug-free group, DF) were not given any interventions. All participants underwent two consecutive nights of polysomnographic (PSG) testing in the sleep laboratory. Sleep diaries were recorded during one week at home before the PSG nights and on two subsequent nights.ResultsThe results demonstrated that compared with the DF group, sleep onset latency (SOL), time in bed (TIB) and wake after sleep onset (WASO) significantly increased and sleep efficiency (SE) significantly decreased in the first sleep lab night in the PL group (all p < 0.05). Moreover, compared with the second night, significant differences were observed in lower self-reported total sleep time (TST) and more subjective WASO during the first night in the PL group (all p < 0.05). However, no significant difference was found in the duration and percentage of N1, N2, N3 and REM between the two groups.ConclusionIn patients with insomnia disorder, placebo administration may increase the occurrence of worse sleep without causing a change in the duration and percentage of N1, N2, N3 and REM on the first sleep lab night. In some cases, a placebo may not serve as treatment but may result in a nocebo effect.     

Sleepiness in sleepwalking and sleep terrors: a higher sleep pressure?

ObjectiveTo identify the determinants of excessive daytime sleepiness in adults with sleepwalking or sleep terrors (SW/ST).MethodsWe collected the charts of all consecutive adult patients admitted from 2012 to 2014 for SW/ST. They had completed the Paris Arousal Disorders Severity Scale and the Epworth Sleepiness Scale, and had undergone one (n = 34) or two consecutive (n = 124) nocturnal videopolysomnographies. The demographic, clinical, and sleep determinants of excessive daytime sleepiness (defined as an Epworth Sleepiness Scale score of greater than 10) were analyzed.ResultsAlmost half (46.8%) of the 158 adult patients with SW/ST reported excessive daytime sleepiness. They had shorter sleep onset latencies (in night 1 and night 2), shorter REM sleep latencies, longer total sleep time, and higher REM sleep percentages in night 2, but no greater clinical severity of the parasomnia than patients without sleepiness. The level of sleepiness correlated with the same measures (sleep onset latency on both nights, REM sleep onset latency, and total sleep time in night 2), plus the latency to N3. In the regression model, higher sleepiness was determined by shorter sleep onset latency on night 1, lower number of awakenings in N3 on night 1, and higher total sleep time on night 2.ConclusionDaytime sleepiness in patients with SW/ST is not the consequence of disturbed sleep but is associated with a specific polygraphic phenotype (rapid sleep onset, long sleep time, lower numbers of awakenings on N3) that is suggestive of a higher sleep pressure that may contribute to incomplete arousal from N3.     

Acute effects of noninvasive ventilation on sleep physiology in patients with moderate to severe stable chronic obstructive pulmonary disease: a pilot study

Objective/backgroundChanges in sleep architecture in patients with Chronic Obstructive Pulmonary Disease (COPD) can be explained by a combination of physiological changes in breathing during sleep, with impairment of respiratory mechanics and reduction of arterial oxygenation. This study aimed to evaluate the acute effects of noninvasive ventilation (NIV) – compared to spontaneous breathing – on sleep latency and stages, and on the occurrence of sleep-related respiratory events, nocturnal hypoxemia, and changes in heart rate (HR) in patients with moderate to severe stable COPD.Patients/methodsPatients completed two polysomnography (PSG) studies: one during spontaneous breathing and one while receiving NIV in bilevel mode and with backup respiratory rate (RR.) setting. Sleepware G3 software was used for the analysis of PSG and pressure, volume, and ventilator flow curves × time.ResultsParticipants were 10 female patients with a mean age of 68.1 ± 10.2 years. NIV during sleep decreased sleep onset latency (17 ± 18.8 min vs 46.8 ± 39.5 min; p = 0.02), increased REM sleep time (41.2 ± 24.7 min vs 19.7 ± 21.7 min; p = 0.03), and decreased the obstructive apnea index (OAI) (0 vs 8.7 ± 18.8; p = 0.01). Lower mean HR (66.6 ± 4.1 bpm vs 70.6 ± 5.9 bpm; p = 0.03) and lower maximum HR (84.1 ± 7.3 bpm vs 91.6 ± 7.8 bpm; p = 0.03) were observed in PSG with NIV.ConclusionsThe use of NIV in patients with moderate to severe stable COPD while they were sleeping increased REM sleep time and decreased sleep onset latency, the number of obstructive respiratory events, and the mean and maximum HR.     

Sleep state misperception in schizophrenia: Are negative symptoms at work?

ObjectiveThis study investigates subjective and objective sleep quality to ascertain whether there is a sleep state misperception in schizophrenia patients, as well as analyze potential effect factors.MethodsA total of 148 inpatients with schizophrenia admitted to Beijing HuiLongGuan Hospital were enrolled in this study. The quality of objective sleep was assessed by polysomnography (PSG). On the second day after the successful completion of the PSG evaluation, an interview was arranged to collect patients' recorded subjective evaluation on sleep time, sleep latency, and wake times. Demographic information was collected from an interview, medical records were reviewed, and psychiatric symptoms were assessed using the Positive And Negative Symptom Scale (PANSS).ResultsThe main finding of this study was that schizophrenic patients exhibited sleep state misperception with a pattern of overestimation of total sleep time (TST) as well as sleep efficiency (SE), and an underestimation of sleep onset latency (SOL). Regarding the ± standard deviation of the differences between subjective and objective TST as a clinical acceptable range, the patients were divided into three groups: the overestimate group, the normal group, and the underestimate group. The differences of total PANSS score, especially the PANSS-N score in the overestimate group, the normal group and the underestimate group were significant, and there were significant differences between the overestimate group and the other groups.ConclusionA comprehensive evaluation of the subjective and objective sleep quality in patients with schizophrenia is needed, especially when negative symptoms are severe.     

Clinical significance of periodic limb movements during sleep: the HypnoLaus study

ObjectivePeriodic limb movements during sleep (PLMS) are prevalent in the general population, but their impact on sleep and association with cardiometabolic disorders are a matter of debate.MethodsData from 2162 participants (51.2% women, mean age 58.4 ± 11.1 years) of the population-based HypnoLaus study (Lausanne, Switzerland) were collected. Subjective sleep complaints and habits were assessed using the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale (ESS). Participants underwent a full polysomnography (PSG) at home and were evaluated for the presence of hypertension, diabetes, and metabolic syndrome.ResultsParticipants with a PLMS index (PLMSI) > 15/h (28.6% of the sample) had longer subjective sleep latency (18.6 ± 17.2 vs. 16.1 ± 14.3 min, p = 0.014) and duration (7.1 ± 1.2 vs. 6.9 ± 1.1 h, p < 0.001) than participants with PLMSI ≤ 15/h. At the PSG, they spent more time in stage N2 sleep (49.0 ± 11.2 vs. 45.5 ± 9.8%, p < 0.001), less in stage N3 (17.6 ± 8.2 vs. 20.6 ± 8.4%, p < 0.001) and in REM sleep (20.3 ± 6.4 vs. 22.4 ± 6.0%, p < 0.001), and exhibited longer REM latency (104.2 ± 70.2 vs. 91.7 ± 58.6 min, p < 0.001) and higher arousal index (26.5 ± 12.3 vs. 19.2 ± 9.7 n/h, p < 0.001). Participants with a PLMSI > 15/h had a lower ESS scores and higher prevalence of hypertension, diabetes, and metabolic syndrome. Multivariate analysis adjusting for confounding factors confirmed the independent association of PLMSI > 15/h with subjective sleep latency and duration, and with objective sleep structure disturbances. However, the associations with sleepiness and cardiovascular risk factors disappeared.ConclusionsIn our large middle-age European population-based sample, PLMSI > 15/h was associated with subjective and objective sleep disturbances but not with sleepiness, hypertension, diabetes, or metabolic syndrome.     

Bad sleep? Don't blame the moon! A population-based study

IntroductionThe aim of this study was to evaluate if there is a significant effect of lunar phases on subjective and objective sleep variables in the general population.MethodsA total of 2125 individuals (51.2% women, age 58.8 ± 11.2 years) participating in a population-based cohort study underwent a complete polysomnography (PSG) at home. Subjective sleep quality was evaluated by a self-rating scale. Sleep electroencephalography (EEG) spectral analysis was performed in 759 participants without significant sleep disorders. Salivary cortisol levels were assessed at awakening, 30 min after awakening, at 11 am, and at 8 pm. Lunar phases were grouped into full moon (FM), waxing/waning moon (WM), and new moon (NM).ResultsOverall, there was no significant difference between lunar phases with regard to subjective sleep quality. We found only a nonsignificant (p = 0.08) trend toward a better sleep quality during the NM phase. Objective sleep duration was not different between phases (FM: 398 ± 3 min, WM: 402 ± 3 min, NM: 403 ± 3 min; p = 0.31). No difference was found with regard to other PSG-derived parameters, EEG spectral analysis, or in diurnal cortisol levels. When considering only subjects with apnea/hypopnea index of <15/h and periodic leg movements index of <15/h, we found a trend toward shorter total sleep time during FM (FM: 402 ± 4, WM: 407 ± 4, NM: 415 ± 4 min; p = 0.06) and shorter-stage N2 duration (FM: 178 ± 3, WM: 182 ± 3, NM: 188 ± 3 min; p = 0.05).ConclusionOur large population-based study provides no evidence of a significant effect of lunar phases on human sleep.     

Nocturnal cognitive arousal is associated with objective sleep disturbance and indicators of physiologic hyperarousal in good sleepers and individuals with insomnia disorder

BackgroundCognitive arousal is central to models of sleep disturbance and insomnia, but findings remain mixed regarding whether cognitive arousal is associated with objective sleep disturbance and physiologic hyperarousal. This study explored associations of objective nocturnal wakefulness and indicators of physiologic hyperarousal with cognitive arousal in healthy sleepers and individuals with insomnia.MethodsIn sum, 52 adults (51.9% women; 18 with insomnia disorder, 34 healthy sleepers) underwent two overnight polysomnography (PSG) studies (adaptation + baseline nights) and a multiple sleep latency test (MSLT). Baseline depression was assessed and presleep cognitive arousal and somatic arousal were recorded for each night. Multivariate regression was used to evaluate associations of PSG sleep parameters with insomnia, cognitive arousal, and somatic arousal.ResultsAnalyses showed that high levels of nocturnal cognitive arousal were associated with prolonged sleep latency, lower sleep efficiency, and shorter total sleep time by PSG on both nights. An association between nocturnal cognitive arousal and wake after sleep onset was observed on night one only. Moreover, greater nocturnal cognitive arousal was associated with greater likelihood of obtaining short sleep and with longer MSLT sleep latencies. Insomnia diagnosis, depression, and somatic arousal were not associated with PSG sleep parameters or MSLT latency.ConclusionsHeightened cognitive arousal at night is linked to objective sleep disturbances and indicators of physiologic hyperarousal at night and during the day. For patients with insomnia, cognitive arousal may contribute to the 24-hr physiologic hyperarousal. Cognitive arousal may be a critical therapeutic target for severe or treatment-resistant sleep disturbance.     

Subjective sleep quality is poorly associated with actigraphy and heart rate measures in community-dwelling older men

ObjectivesThere has been a proliferation in the use of commercially-available accelerometry- and heart rate-based wearable devices to monitor sleep. While the underlying technology is reasonable at detecting sleep quantity, the ability of these devices to predict subjective sleep quality is currently unknown. We tested whether the fundamental signals from such devices are useful in determining subjective sleep quality.MethodsOlder, community-dwelling men (76.5 ± 5.77 years) enrolled in the Osteoporotic Fractures in Men Study (MrOS) participated in an overnight sleep study during which sleep was monitored with actigraphy (wrist-worn accelerometry) and polysomnography (PSG), including electrocardiography (N = 1141). Subjective sleep quality was determined the next morning using 5-point Likert-type scales of sleep depth and restfulness. Lasso and random forest regression models analyzed the relationship between actigraph-determined sleep variables, the shape of the activity patterns during sleep (functional principal component analysis), average heart rate, heart rate variability (HRV), demographics, and self-reported depression, anxiety, habitual sleep, and daytime sleepiness measures.ResultsActigraphy data, in combination with heart rate, HRV, demographic, and psychological variables, do not predict well subjective sleep quality (R² = 0.025 to 0.162).ConclusionsFindings are consistent with previous studies that objective sleep measures are not well correlated with subjective sleep quality. Developing validated biomarkers of subjective sleep quality could improve both existing and novel treatment modalities and advance sleep medicine towards precision healthcare standards.     

Actigraphy scoring for sleep outcome measures in chronic obstructive pulmonary disease

BackgroundActigraphy is commonly used to measure sleep outcomes so that sleep can be measured conveniently at home over multiple nights. Actigraphy has been validated in people with sleep disturbances; however, the validity of scoring settings in people with chronic medical illnesses such as chronic obstructive pulmonary disease remains unclear. The purpose of this secondary analysis was to compare actigraphy-customized scoring settings with polysomnography (PSG) for the measurement of sleep outcomes in people with chronic obstructive pulmonary disease who have insomnia.MethodsParticipants underwent overnight sleep assessment simultaneously by PSG and actigraphy at the University of Illinois of Chicago Sleep Science Center. Fifty participants (35 men and 15 women) with mild-to-severe chronic obstructive pulmonary disease and co-existing insomnia were included in the analysis. Sleep onset latency, total sleep time (TST), wake after sleep onset (WASO), and sleep efficiency (SE) were calculated independently from data derived from PSG and actigraphy. Actigraphy sleep outcome scores obtained at the default setting and several customized actigraphy settings were compared to the scored PSG results.ResultsAlthough no single setting was optimal for all sleep outcomes, the combination of 10 consecutive immobile minutes for sleep onset or end and an activity threshold of 10 worked well. Actigraphy overestimated TST and SE and underestimated WASO, but there was no difference in variance between PSG and actigraphy in TST and SE when the 10 × 10 combination was used. As the average TST and SE increased, the agreement between PSG and actigraphy appeared to increase, and as the average WASO decreased, the agreement between PSG and actigraphy appeared to increase.ConclusionResults support the conclusion that the default actigraphy settings may not be optimal for people with chronic obstructive pulmonary disease and co-existing insomnia.     

Sleep architecture in patients with Juvenile Myoclonic Epilepsy

AimThe aim is to analyze the sleep architecture using polysomnography (PSG) in patients with Juvenile Myoclonic Epilepsy (JME): (newly diagnosed and those on valproate drug) attending epilepsy clinic at Alexandria University Hospitals.MethodsThis study involved 20 patients with JME on valproate (age: 22.40 ± 5.80 years; M:F = 6:14), 20 newly diagnosed patients (age: 18.55 ± 6.0 years; M:F = 6:14), and 20 matched healthy controls (age: 22.10 ± 5.0 years; M:F = 6:14). Clinical assessment, electroencephalogram (EEG), evaluation with comprehensive sleep questionnaire, and PSG were done for all patients.ResultsPSG showed significant alterations in sleep architecture in the total JME group in the form of reduced mean sleep efficiency (p = 0.001¹), increased mean Rapid eye movement (REM) onset latency (p = 0.046¹), decrease mean REM percentage (p = 0.011¹), increased mean wakefulness after sleep onset (p = 0.018¹), increase the index of total arousal (p = 0.005¹), increased mean periodic limb movement index (P = 0.001¹), and reduced apnea hypopnea index (P = <0.001) in comparison to control group. Valproate treated group showed increased sleep efficiency (p = 0.040¹), decreased REM arousal index (P = 0.012), longer stage 3 (P = 0.038), and prolonged stage 2 (P = 0.049¹) than the newly diagnosed group.ConclusionsSleep architecture was significantly disturbed in JME, with improvement in sleep efficiency in valproate treated patients.     

The effects of transcranial direct current stimulation on sleep in patients with multiple sclerosis–A pilot study

BackgroundSleep complaints are commonly reported by patients with multiple sclerosis (PwMS). Several pharmacological and alternative interventions have been tried, but are usually faced by limited efficacy. Hence, exploring other methods such as transcranial direct current stimulation (tDCS), might be of interest. The aim of this study was to assess the effects of bifrontal tDCS on subjective (i.e., Epworth Sleepiness Scale (ESS)) and objective sleep measures (i.e., actigraphy).MethodsSeven patients completed the study. Patients randomly received two blocks of five daily sessions each in a crossover design (active and sham, with a washout interval of three weeks). The anode and cathode were placed over the left and right dorsolateral prefrontal cortices, respectively. Sleep assessment included ESS, sleep onset latency, total sleep duration, time in bed, sleep efficiency, waking after sleep onset, and number of awakenings.ResultsCompared to baseline scores (11.14 ± 4.06), significant decrease in ESS was obtained after active intervention (7.86 ± 4.18; p = 0.011), but not after sham intervention (9.57 ± 5.62; p = 0.142). No significant changes were observed with regards to actigraphy measures. Sessions were well tolerated, and no serious side-effects were reported at any time.ConclusionBifrontal tDCS resulted in significant improvement in daytime sleepiness, but did not yield any effect on objective sleep measures in PwMS. This discrepency might be explained by the modest association that could exist between objective and subjective sleep measures. In addition, it could be assumed that modulating objective sleep measures would require a larger sample size, more stimulation sessions, or modulation of other cortical areas.     

Catathrenia,a REM predominant disorder of arousal?

ObjectivesCatathrenia is an uncommon and poorly understood disorder, characterized by groaning during sleep occurring in tandem with prolonged expiration. Its classification, pathogenesis, and clinical relevance remain debated, substantially due to the limited number of cases reported to date. We report a series of consecutive cases of catathrenia, their clinical and polysomnographic characteristics, and their subsequent management.MethodsConsecutive patients with catathrenia who had undergone full polysomnography in our institution over a 5.5-year period were included. Catathrenia events (CEs) were examined in clusters, which formulated catathrenia periods (CPs). The relationships between CPs, sleep stage distribution, electroencephalogram (EEG) arousals, and other sleep parameters were assessed, along with the clinical presentation and management of catathrenic patients.ResultsA total of 427 CPs were identified in 38 patients, 81% arising from rapid eye movement (REM) sleep. EEG arousals preceded or coincided with the onset of 84% of CPs, which were of longer duration than those not associated with an arousal (57.3 ± 56.8 vs. 32.2 ± 29.4 s, p < 0.001). Each CE had a characteristic airflow signal, with inspiration preceding a protracted expiration and a brief more rapid exhalation, followed by deep inspiration. Although the majority of patients were referred on the basis of bed partner complaints, 44.7% complained of daytime sleepiness. Continuous positive airway pressure therapy and sleep-consolidating pharmacotherapy led to subjective improvement, but were limited by poor long-term adherence.ConclusionsIn the largest series of catathrenia patients reported to date, we found that this rare disorder is characterized by a distinct breathing pattern and arises predominantly from REM sleep, with arousals almost uniformly preceding or coinciding with the onset of CPs.     

Are NREM sleep characteristics associated to subjective sleep complaints after mild traumatic brain injury?

IntroductionSleep complaints are common after mild traumatic brain injury (mTBI). While recent findings suggest that sleep macro-architecture is preserved in mTBI, features of non-rapid eye movement (NREM) sleep micro-architecture including electroencephalography (EEG) spectral power, slow waves (SW), and sleep spindles could be affected. This study aimed to compare NREM sleep in mTBI and healthy controls, and explore whether NREM sleep characteristics correlate with sleep complaints in these groups.MethodsThirty-four mTBI participants (mean age: 34.2 ± 11.9 yrs; post-injury delay: 10.5 ± 10.4 weeks) and 29 age-matched controls (mean age: 32.4 ± 8.2 yrs) were recruited for two consecutive nights of polysomnographic (PSG) recording. Spectral power was computed and SW and spindles were automatically detected in three derivations (F3, C3, O1) for the first three sleep cycles. Subjective sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI).ResultsmTBI participants reported significant poorer sleep quality than controls on the PSQI and showed significant increases in beta power during NREM sleep at the occipital derivation only. Conversely, no group differences were found in SW and spindle characteristics. Interestingly, changes in NREM sleep characteristics were not associated with mTBI estimation of sleep quality.ConclusionsCompared to controls, mTBI were found to have enhanced NREM beta power. However, these changes were not found to be associated with the subjective evaluation of sleep. While increases in beta bands during NREM sleep may be attributable to the occurrence of a brain injury, they could also be related to the presence of pain and anxiety as suggested in one prior study.     

Alteration in polysomnographic profile in ‘migraine without aura’ compared to healthy controls

ObjectiveStudies related to sleep macroarchitecture in migraines are far and few between. We studied the polysomnographic (PSG) abnormalities in subjects of ‘migraine without aura’ as compared to healthy controls.MethodsThirty patients of ‘migraine without aura’ were prospectively recruited. The frequency and severity of headaches was assessed using the migraine disability assessment score (MIDAS). Patients were evaluated for their sleep quality and excessive daytime sleepiness with the Pittsburgh sleep quality index (PSQI) and Epworth sleepiness scale (ESS), respectively. Their overnight PSGs were compared with 32 healthy controls who were group matched for age.ResultsThe mean age of the cases (33.5 ± 8.6 years) and controls (30.2 ± 9.6 years) was comparable. There was a female preponderance among the migraineurs (80%). The sleep efficiency was significantly lower in the cases as compared to the controls (P = 0.003). Stage 4 sleep (p = 0.008) and total NREM sleep (p = 0.001) was also significantly less in the cases as compared to the controls. Sleep onset (p = 0.021) and stage 1 latency (p = 0.048) was significantly prolonged in cases as compared to controls.ConclusionsThis study showed significantly lower sleep efficiency, prolonged sleep onset latency, lesser stage 4 and NREM sleep, and more number of total awakenings in migraineurs compared to the controls. Further studies are required to detect whether these abnormalities are due to migraine per se or associated comorbidities.     

Validation of a novel sleep-quality questionnaire to assess sleep in the coronary care unit: a polysomnography study

IntroductionThe sleep of patients admitted to coronary care unit (CCU) may be compromised. A feasible and cost-effective tool to evaluate sleep in this scenario could provide important data. The aim of this study was to evaluate sleep with a questionnaire developed specifically for the CCU and to validate it with polysomnography (PSG).MethodsNinety-nine patients (68% male; 56 ± 10 years old) with acute coronary syndrome were included. PSG was performed within 36 h of admission. A specific 18-question questionnaire (CCU questionnaire) was developed and applied after the PSG. Cronbach's alpha test was used to validate the questionnaire. The Spearman test was used to analyze the correlation between the PSG variables and the questionnaire, and the Kruskal–Wallis test was used to compare the PSG variables among patients with good, regular, or poor sleep.ResultsThe total sleep time was 265 ± 81 min, sleep efficiency 62 ± 18%, REM sleep 10 ± 7%, apnea/hypopnea index 15 ± 23, and the arousal index 24 ± 15. Cronbach's alpha test was 0.69. The CCU questionnaire showed correlation with the sleep efficiency evaluated by PSG (r: 0.52; p < 0.001). Sleep quality was divided into three categories according to the CCU questionnaire: patients with good sleep had a sleep efficiency of 72 ± 9%, better than those with a regular or poor sleep (60 ± 16% and 53 ± 20%, respectively; p < 0.01).ConclusionThe CCU questionnaire is a feasible and reliable tool to evaluate sleep in the CCU, showing correlation with the PSG sleep efficiency.     

Neurocognitive function in patients with residual excessive sleepiness from obstructive sleep apnea: a prospective,controlled study

ObjectiveThis study aimed to evaluate neurocognitive function in adult patients with residual excessive sleepiness (RES) after appropriate treatment of obstructive sleep apnea (OSA) with CPAP and good adherence to treatment.MethodsThis was a prospective controlled study. We included patients of both sexes, aged 35–60 years with OSA and an apnea–hypopnea index >20 ev/h, effectively treated with CPAP, but with a residual Epworth Sleepiness Scale score ≥11. The control group consisted of OSA patients adequately treated with CPAP who did not present with excessive sleepiness after treatment. Both groups underwent the following evaluations: polysomnography, multiple sleep latency testing, depression symptoms, and cognitive assessment.ResultsRegarding baseline characteristics, the data were matched for age, years of study, and body mass index. Long-term memory result did not show a significant difference between the two groups (RES group 4.7 ± 2.0; control group 6.5 ± 1.9; p = 0.08). The executive functions were the most affected, with alterations in Wisconsin test, number of categories (RES group: 1.6 ± 1.4; control group: 3.0 ± 1.4; p = 0.01), and semantic verbal fluency test (RES group: 13.6 ± 3.3; control group: 16.9 ± 4.3; p = 0.04).ConclusionIn summary, the mean depression scale score in the group with residual excessive sleepiness was significantly higher than that in the control group. Patients with residual excessive sleepiness showed impairment of executive functions but no impairments in other cognitive domains.