Insomnia and somnolence in idiopathic RBD : a prospective cohort study

Although some sleep disorders are markers of prodromal Parkinson’s disease and dementia with Lewy bodies, it is unclear whether insomnia and somnolence can predict disease. We assessed a large cohort of patients with idiopathic rapid eye movement sleep behavior disorder and age/sex matched controls, comparing the Epworth sleepiness scale, the Insomnia Severity Index, the Pittsburgh Sleep Quality Index, and polysomnographic variables. In those with repeated scales, we assessed change over time. Finally, we assessed whether sleep abnormalities predicted defined neurodegenerative disease. The 151 patients (age = 65.9, 75% male) completed sleep scales and were included. Epworth scores were similar between patients and controls (7.0+/−4.6 vs. 7.2 +/−4.7, p = 0.77), and did not progress with time (change = +0.46+/−2.1, p = 0.45). Epworth scores were similar between those who developed neurodegenerative disease and those remaining disease-free (6.7+/−4.4 vs. 7.1+/−4.7, p = 0.70). Pittsburgh Index scores were higher in patients than controls (7.2+/−3.8 vs. 4.9+/−3.4, p = 0.004), mainly driven by the sleep disturbance/medication components (reflecting rapid eye movement sleep behavior disorder symptoms/treatment). Baseline Pittsburgh scores did not predict conversion to neurodegeneration, although sleep duration increased over time in those converting to neurodegenerative disease (+0.88+/−1.32 h, p = 0.014). Insomnia index scores were higher in patients than controls (10.0+/−5.5 vs. 6.35+/−4.66, p < 0.001), but declined over time (−1.43+/−5.09, p = 0.029) particularly in those converting to neurodegenerative disease. Finally, on polysomnogram, those with increased tonic rapid eye movement had higher risk of developing defined neurodegenerative disease (HR = 1.88, p = 0.039). In summary, we found that somnolence and insomnia do not predict neurodegeneration in idiopathic rapid eye movement sleep behavior disorder. As neurodegeneration progresses through prodromal stages, patients may have increasing sleep drive and duration

Placebo analgesia persists during sleep : an experimental study

Although placebo analgesia is a well-recognized phenomenon with important clinical implications, the possibility that placebo effects occur during sleep has received little attention. This experimental study examined whether responsiveness to acute heat pain stimuli applied during sleep could be reduced following a placebo conditioning procedure administered before sleep. Healthy individuals (n = 9) underwent polysomnographic recordings for one habituation night followed by one placebo analgesia night and one control night in counterbalanced order. Conditioning induced robust analgesia expectations before the placebo night. In the morning after the placebo night, participants reported less nocturnal pain, anxiety, and associated sleep disturbance (all p's < 0.05) compared to the control night. Furthermore, placebo induction produced a 10% reduction in brain arousals evoked by noxious stimuli during rapid-eye-movement (REM) sleep (p = 0.03), consistent with our previous findings suggesting that analgesia expectations are reprocessed during REM sleep. In contrast, arousals increased by 14% during slow wave sleep (SWS) (p = 0.02). In the morning after the last recording night, placebo testing administered as a manipulation check confirmed that typical placebo analgesic responses were produced during waking (p's < 0.05). These results suggest that analgesia expectations developed before sleep reduced nocturnal pain perception and subjective sleep disturbances and activated brain processes that modulate incoming nociceptive signals differentially according to sleep stage. These results need to be replicated in future studies exploring how analgesia expectations may be reactivated during different sleep stages to modulate nociceptive responses

A 12-week open-label, multicenter study evaluating the safety and patient-reported efficacy of sodium oxybate in patients with narcolepsy and cataplexy

Objective: This study aimed to evaluate safety and efficacy of sodium oxybate (SXB) titrated to effect. Methods: SXB-naive patients who had participated in a randomized SXB clinical trial and had not been titrated to adequate clinical effect were initiated on open-label SXB at 4.5 g/night and titrated in 1.5-g increments to 6, 7.5, or 9 g/night or down to 3 g/night, based on individual clinical response. Treatment was 12 weeks; safety was the primary outcome. Efficacy was evaluated using the Narcolepsy Symptom Assessment Questionnaire (NSAQ), a five-point scale (“much improved” to “much worse”) that assessed changes from baseline in specific symptoms. Response was defined as “much improved” or “somewhat improved” overall at weeks 6 and 12. Results: Of 202 patients, 171 (85%) completed treatment; final doses were 3 g (n = 5), 4.5 g (n = 29), 6 g (n = 80), 7.5 g (n = 66), and 9 g (n = 22). Adverse events (AEs) were reported in 114 patients (56%), serious AEs in five (2%). The most common AEs were nausea (10%), headache (7%), and dizziness (5%). Response rate was 92% at week 6 and 90% at week 12; most patients reported improvements in all individual symptoms. Overall, 60% of patients rated their symptoms at 12weeks as “much improved,” and this improvement was dose dependent. Conclusions: The SXB safety profile was consistent with parent trials. Ninety percent of patients reported improvements as measured by the NSAQ

Sleep deprivation reveals altered brain perfusion patterns in somnambulism

BACKGROUND: Despite its high prevalence, relatively little is known about the pathophysiology of somnambulism. Increasing evidence indicates that somnambulism is associated with functional abnormalities during wakefulness and that sleep deprivation constitutes an important drive that facilitates sleepwalking in predisposed patients. Here, we studied the neural mechanisms associated with somnambulism using Single Photon Emission Computed Tomography (SPECT) with 99mTc-Ethylene Cysteinate Dimer (ECD), during wakefulness and after sleep deprivation. METHODS: Ten adult sleepwalkers and twelve controls with normal sleep were scanned using 99mTc-ECD SPECT in morning wakefulness after a full night of sleep. Eight of the sleepwalkers and nine of the controls were also scanned during wakefulness after a night of total sleep deprivation. Between-group comparisons of regional cerebral blood flow (rCBF) were performed to characterize brain activity patterns during wakefulness in sleepwalkers. RESULTS: During wakefulness following a night of total sleep deprivation, rCBF was decreased bilaterally in the inferior temporal gyrus in sleepwalkers compared to controls. CONCLUSIONS: Functional neural abnormalities can be observed during wakefulness in somnambulism, particularly after sleep deprivation and in the inferior temporal cortex. Sleep deprivation thus not only facilitates the occurrence of sleepwalking episodes, but also uncovers patterns of neural dysfunction that characterize sleepwalkers during wakefulness

EEG functional connectivity prior to sleepwalking : evidence of interplay between sleep and wakefulness

Study Objectives: Although sleepwalking (somnambulism) affects up to 4% of adults, its pathophysiology remains poorly understood. Sleepwalking can be preceded by fluctuations in slow-wave sleep EEG signals, but the significance of these pre-episode changes remains unknown and methods based on EEG functional connectivity have yet to be used to better comprehend the disorder. Methods: We investigated the sleep EEG of 27 adult sleepwalkers (mean age: 29 ± 7.6 years) who experienced a somnambulistic episode during slow-wave sleep. The 20-second segment of sleep EEG immediately preceding each patient’s episode was compared with the 20-second segment occurring 2 minutes prior to episode onset. Results: Results from spectral analyses revealed increased delta and theta spectral power in the 20 seconds preceding the episodes’ onset as compared to the 20 seconds occurring 2 minutes before the episodes. The imaginary part of the coherence immediately prior to episode onset revealed (1) decreased delta EEG functional connectivity in parietal and occipital regions, (2) increased alpha connectivity over a fronto-parietal network, and (3) increased beta connectivity involving symmetric inter-hemispheric networks implicating frontotemporal, parietal and occipital areas. Conclusions: Taken together, these modifications in EEG functional connectivity suggest that somnambulistic episodes are preceded by brain processes characterized by the co-existence of arousal and deep slee

Regional cerebral blood flow during wakeful rest in older subjects with mild to severe obstructive sleep apnea

Objectives: To evaluate changes in regional cerebral blood flow (rCBF) during wakeful rest in older subjects with mild to severe obstructive sleep apnea (OSA) and healthy controls, and to identify markers of OSA severity that predict altered rCBF. Design: High-resolution 99mTc-HMPAO SPECT images during wakeful rest. Setting: Research sleep laboratory affiliated with a University hospital. Participants: Fifty untreated OSA patients aged between 55 and 85 years divided into mild, moderate and severe OSA and 20 age-matched healthy controls. Interventions: N/A Measurements: Using statistical parametrical mapping, rCBF was compared between groups and correlated with clinical, respiratory and sleep variables. Results: Whereas no rCBF change was observed in mild and moderate groups, participants with severe OSA had reduced rCBF compared to controls in the left parietal lobules, precentral gyrus, bilateral postcentral gyri, and right precuneus. Reduced rCBF in these regions and in areas of the bilateral frontal and left temporal cortex was associated with more hypopneas, snoring, hypoxemia, and sleepiness. Higher apnea, micro-arousal, and body mass indexes were correlated to increased rCBF in the basal ganglia, insula, and limbic system. Conclusions: While older individuals with severe OSA had hypoperfusions in the sensorimotor and parietal areas, respiratory variables and subjective sleepiness were correlated with extended regions of hypoperfusion in the lateral cortex. Interestingly, OSA severity, sleep fragmentation and obesity correlated with increased perfusion in subcortical and medial cortical regions. Anomalies with such a distribution could result in cognitive deficits and reflect impaired vascular regulation, altered neuronal integrity, and/or undergoing neurodegenerative processes

Evaluation of qualityof-life in patients with narcolepsy treated with sodium oxybate : use of the 36-item short-form health survey in a clinical trial

Introduction The present post hoc analysis was designed to evaluate health-related quality of life (HRQoL) using the 36-item Short Form Health Status Survey (SF-36) during an 8-week trial of sodium oxybate (SXB). Methods SF-36 was assessed in a phase 3 placebo-controlled trial in patients with narcolepsy (N = 228) randomized to placebo or SXB in doses of 4.5, 6, or 9 g nightly for 8 weeks. Changes from baseline in SF-36 (last observation carried forward) were compared between SXB and placebo, and effect sizes (ES) were estimated. Results Baseline SF-36 values were lower than normative values for the US general population. After 8 weeks of treatment, mean (±standard deviation) improvement from baseline on the Physical Component Summary (PCS) was significantly greater with SXB 9 g/night than placebo (6.3 ± 9.1 vs. 1.5 ± 6.2; p = 0.005), with moderate ES; no significant difference was found between the SXB and placebo groups on the Mental Component Summary. SXB 9 g/night resulted in significantly (p < 0.05) greater improvements than placebo in Physical Functioning (4.4 ± 9.2 vs. 1.0 ± 8.0), General Health (GH; 3.1 ± 7.0 vs. 0.4 ± 6.8), and Social Functioning (6.8 ± 16.8 vs. 1.1 ± 9.6). All SXB doses resulted in significant improvement (p < 0.05) relative to placebo for Vitality, with moderate ES. No significant differences versus placebo were observed for Role–Physical, Role–Emotional, or Mental Health domains. Conclusion Treatment with SXB was associated with a dose-dependent improvement in HRQoL, with the 9-g nightly dose demonstrating a positive impact on PCS and individual SF-36 domains of Vitality, GH, and Physical and Social Functioning

Correlation of changes in patient-reported quality of life with physician-rated global impression of change in patients with narcolepsy participating in a clinical trial of sodium oxybate : a post hoc analysis

Introduction: Narcolepsy patients report lower health-related quality of life (HRQoL) than the general population, as measured by the Short Form-36 Health Survey (SF-36). This analysis evaluated whether changes in SF-36 correlated with physician-rated Clinical Global Impression of Change (CGI-C). Methods: Data were from 209 of 228 narcolepsy patients participating in an 8-week clinical trial of sodium oxybate. Changes from baseline for SF-36 subscales (Physical Functioning, Role Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role Emotional, and Mental Health) and the summary scores were evaluated for correlation with CGI-C overall and by treatment group. Correlations were calculated using the Pearson product-moment correlation coefficient (r). Results: Correlations described an inverse relationship in scores, but a direct relationship in improvement; lower CGI-C scores (i.e., better) were associated with higher SF-36 subscale scores (i.e., improved HRQoL). Moderate and significant correlations were observed for Vitality (r = -0.464; P\0.0001) and Role Physical (r = -0.310; P\0.0001) subscales, but weak correlations were observed with other subscales including summary scores. Correlations were stronger at higher sodium oxybate doses for most SF-36 subscales. Conclusion: Some aspects of HRQoL, measured by the SF-36, may be associated with narcolepsy. In particular, Vitality (indicative of energy and tiredness) and Role Physical (impact of physical function on daily roles) moderately correlated with overall change in status observed by clinicians. However, lack of strong correlations between SF-36 and CGI-C indicates differences in patient and clinician perspectives of disease, and suggest a need for broader assessment of the impact of narcolepsy and its treatment on patients

Short-term heart rate variability in a population-based sample of 10-year-old children

Heart rate variability (HRV) is a non-invasive quantitative marker of cardiac autonomic function derived from continuous electrocardiogram (ECG) recordings. Normative HRV values and development factors have not been established in pediatric populations. The objective was to derive referent time- and frequency-domain HRV values for a population-based sample of children. Children aged 9-11 years (N = 1,036) participated in the Québec Longitudinal Study of Child Development cohort cardiovascular health screening. Registered nurses measured anthropometrics (height, weight) and children wore an ambulatory Holter monitor to continuously record an ECG signal. HRV variables included time (SDNN, pNN50, RMSSD, SDANN) and frequency (HF, LF, LF/HF ratio) domain variables. Normative HRV values, stratified by age, sex, and heart rate, are presented. Greater heart rate (β avg = -0.60, R avg (2) = 0.39), pubertal maturation (β avg = -0.11, R avg (2) = 0.01), later ECG recording times (β avg = -0.19, R avg (2) = 0.07), and higher diastolic blood pressure (β avg = -0.11, R avg (2) = 0.01) were significantly associated with reduced HRV in 10-year-old children. The normative HRV values permit clinicians to monitor, describe, and establish pediatric nosologies in primary care and research settings, which may improve treatment of diseases associated with HRV in children. By better understanding existing values, the practical applicability of HRV among clinicians will be enhanced. Lastly, developmental (e.g., puberty) and procedural (e.g., recording time) factors were identified that will improve recording procedures and interpretation of results

Gray matter hypertrophy and thickening with obstructive sleep apnea in middle-aged and older adults

Rationale: Obstructive sleep apnea causes intermittent hypoxemia, hemodynamic fluctuations, and sleep fragmentation, all of which could damage cerebral gray matter that can be indirectly assessed with neuroimaging. Objectives: To investigate whether markers of obstructive sleep apnea severity are associated with gray matter changes among middle-aged and older individuals. Methods: Seventy-one subjects (ages: 55 to 76; apnea–hypopnea index: 0.2 to 96.6 events/h) were evaluated with magnetic resonance imaging. Two techniques were used: 1) voxel-based morphometry, which measures gray matter volume and concentration; 2) FreeSurfer automated segmentation, which estimates the volume of predefined cortical/subcortical regions and cortical thickness. Regression analyses were performed between gray matter characteristics and markers of obstructive sleep apnea severity (hypoxemia, respiratory disturbances, sleep fragmentation). Measurements and Main Results: Subjects had few symptoms, i.e. sleepiness, depression, anxiety and cognitive deficits. While no association was found with voxel-based morphometry, FreeSurfer revealed increased gray matter with obstructive sleep apnea. Higher levels of hypoxemia correlated with increased volume and thickness of the left lateral prefrontal cortex as well as increased thickness of the right frontal pole, the right lateral parietal lobules, and the left posterior cingulate cortex. Respiratory disturbances positively correlated with right amygdala volume while more severe sleep fragmentation was associated with increased thickness of the inferior frontal gyrus. Conclusions: Gray matter hypertrophy and thickening were associated with hypoxemia, respiratory disturbances, and sleep fragmentation. These structural changes in a group of middle-aged and older individuals may represent adaptive/reactive brain mechanisms attributed to a presymptomatic stage of obstructive sleep apnea