Sleep-wake misperception. A comprehensive analysis of a large sleep lab cohort

OBJECTIVES Sleep-wake misperception has mainly been reported in insomnia patients. Conversely, the present study aimed to assess the prevalence and correlates of sleep-wake misperception in a large cohort of patients with various sleep-wake disorders, all diagnosed along the third version of the International Classification of Sleep Disorders. METHODS We retrospectively included 2738 patients examined by polysomnography, who in addition estimated upon awakening their total sleep time, sleep onset latency and Wake after sleep onset (WASO). We computed subjective-objective mismatch by the formula (subjective - objective value)/objective value ×100; negative and positive values indicated under- and overestimation, respectively. RESULTS In the entire sample, the magnitude of under- and overestimation of total sleep time was similar, but varied significantly between diagnostic groups, with insomnia and insufficient sleep syndrome showing the most pronounced underestimation and REM parasomnia and circadian rhythm disorders showing the most pronounced overestimation of total sleep time. In all diagnostic categories, a majority tended to overestimate their sleep onset latency and to underestimate the amount of WASO. Younger age was independently correlated with underestimation of total sleep time and WASO, and with overestimation of sleep onset latency. Overestimation of sleep onset latency independently correlated to an increased latency to N3 sleep stage on polysomnography. CONCLUSIONS While sleep-wake misperception is highly prevalent in all sleep-wake disorders, significant differences exist in magnitude of under- and overestimation between distinct diagnostic groups

Prevalence and predictors of fatigue in glioblastoma: a prospective study

Background The main goal of this study was to assess frequency, clinical correlates, and independent predictors of fatigue in a homogeneous cohort of well-defined glioblastoma patients at baseline prior to combined radio-chemotherapy. Methods We prospectively included 65 glioblastoma patients at postsurgical baseline and assessed fatigue, sleepiness, mean bedtimes, mood disturbances, and clinical characteristics such as clinical performance status, presenting symptomatology, details on neurosurgical procedure, and tumor location and diameter as well as pharmacological treatment including antiepileptic drugs, antidepressants, and use of corticosteroids. Data on fatigue and sleepiness were measured with the Fatigue Severity Scale and the Epworth Sleepiness Scale, respectively, and compared with 130 age- and sex-matched healthy controls. Results We observed a significant correlation between fatigue and sleepiness scores in both patients (r = 0.26; P = .04) and controls (r = 0.36; P < .001). Only fatigue appeared to be more common in glioblastoma patients than in healthy controls (48% vs 11%; P < .001) but not the frequency of sleepiness (22% vs 19%; P = .43). Female sex was associated with increased fatigue frequency among glioblastoma patients but not among control participants. Multiple linear regression analyses identified depression, left-sided tumor location, and female sex as strongest associates of baseline fatigue severity. Conclusions Our findings indicate that glioblastoma patients are frequently affected by fatigue at baseline, suggesting that factors other than those related to radio- or chemotherapy have significant impact, particularly depression and tumor localizatio

Reduced Regional NREM Sleep Slow-Wave Activity Is Associated With Cognitive Impairment in Parkinson Disease

Growing evidence implicates a distinct role of disturbed slow-wave sleep in neurodegenerative diseases. Reduced non-rapid eye movement (NREM) sleep slow-wave activity (SWA), a marker of slow-wave sleep intensity, has been linked with age-related cognitive impairment and Alzheimer disease pathology. However, it remains debated if SWA is associated with cognition in Parkinson disease (PD). Here, we investigated the relationship of regional SWA with cognitive performance in PD. In the present study, 140 non-demented PD patients underwent polysomnography and were administered the Montréal Cognitive Assessment (MoCA) to screen for cognitive impairment. We performed spectral analysis of frontal, central, and occipital sleep electroencephalography (EEG) derivations to measure SWA, and spectral power in other frequency bands, which we compared to cognition using linear mixed models. We found that worse MoCA performance was associated with reduced 1–4 Hz SWA in a region-dependent manner (F2, 687 =11.67, p < 0.001). This effect was driven by reduced regional SWA in the lower delta frequencies, with a strong association of worse MoCA performance with reduced 1–2 Hz SWA (F2, 687 =18.0, p < 0.001). The association of MoCA with 1–2 Hz SWA (and 1–4 Hz SWA) followed an antero-posterior gradient, with strongest, weaker, and absent associations over frontal (rho = 0.33, p < 0.001), central (rho = 0.28, p < 0.001), and occipital derivations, respectively. Our study shows that cognitive impairment in PD is associated with reduced NREM sleep SWA, predominantly in lower delta frequencies (1–2 Hz) and over frontal regions. This finding suggests a potential role of reduced frontal slow-wave sleep intensity in cognitive impairment in PD

Increased sleep need and daytime sleepiness 6 months after traumatic brain injury: a prospective controlled clinical trial

In a controlled, prospective, electrophysiological study, Imbach et al. demonstrate increased sleep need and excessive daytime sleepiness 6 months after traumatic brain injury. Sleep is more consolidated after brain trauma, and an increase in sleep need is associated with intracranial haemorrhage. Trauma patients underestimate their increased sleep need and sleepines

Frequency and Correlates of Sleep Debt in St. Petersburg

Purpose During weekdays, many of us fail meeting their physiologic sleep need. During weekends, however, when given additional sleep opportunity, homeostatic sleep pressure will typically lead to longer bedtimes, manifesting the cumulative sleep debt. This study aims at examining the prevalence and determinants of sleep debt, as indicated by the presence of ≥ 2 h weekend bedtime prolongation, in a general population. Methods We studied 257 healthy subjects living in St. Petersburg, Russia. All participants indicated their habitual bedtimes during weekdays and weekends, and completed the Epworth Sleepiness Scale (ESS), Fatigue Severity Scale, Fatigue Impact Scale, Pittsburgh Sleep Quality Index, and Hospital Anxiety and Depression Scale. Results One-hundred-three participants (40%) exhibited a relevant sleep debt (≥ 2 h weekend–weekday difference in habitual bedtime). Compared to participants without sleep debt, the frequency of excessive daytime sleepiness (ESS score ≥ 11)—but not of fatigue, impaired sleep quality and mood disturbances—was higher in participants with sleep debt (21% vs. 10%, p = 0.01). Multiple regression analysis revealed younger age, higher ESS and lower body mass index as independent associates of sleep debt. Conclusions Sleep debt appeared to be very common among healthy subjects, and independently associated with younger age, higher ESS scores and lower BMI. However, the presence of sleep debt did not have an impact on fatigue or mood, as measured by validated questionnaires

Depression in myasthenia gravis: a heterogeneous and intriguing entity

BACKGROUND Depressive symptoms in myasthenia gravis (MG) are common, may mimic other disease features, and contribute to misdiagnosis and diagnostic delay. Nevertheless, the clinical determinants of depressive symptoms in MG remain poorly studied, in particular their overlap with fatigue. Moreover, studies in MG have rarely looked at distinct depression phenotypes. METHODS In 68 consecutive MG patients, we ascertained cognitive-affective and somatic depression with the Beck Depression Inventory (BDI), and also assessed age at disease onset, education, marital state, work ability, sleepiness, fatigue, and treatment modalities. Disease severity was graded according to the Myasthenia Gravis Foundation of America (MGFA) classification. RESULTS The prevalence of moderate-severe depression was 20.5%. While depression and fatigue showed large overlap (n = 37, 54.4%), only fatigue increased with disease severity, while BDI scores did not. Thymectomy was independently associated with lower BDI scores, but had no impact on fatigue. Total BDI scores were similar in patients with predominantly cognitive-affective and with predominantly somatic depression. However, ESS correlated only with cognitive-affective BDI, and younger age was independently associated with cognitive-affective BDI. Conversely, female sex and thymectomy were independently associated with somatic BDI. CONCLUSIONS Depression and fatigue are highly prevalent and largely overlapping comorbidities in MG, but only fatigue increased with disease severity, and only depression was milder in thymectomized patients. Comparative use of BDI subscales in MG reveals distinct depression phenotypes with distinct correlations to other disease features

Remitting narcolepsy? Longitudinal observations in a hypocretin-deficient cohort

Study Objective Narcolepsy type 1 (NT1) is considered a chronic, incurable disease. Excessive daytime sleepiness (EDS) is typically the most troublesome symptom, and more difficult to control by pharmacologic treatment than cataplexy. Although many NT1 patients are monitored by regular follow-ups, the purported relentless persistence of EDS has rarely been the object of longitudinal studies. Methods Retrospective analysis of 26 well-defined hypocretin-deficient NT1 patients who underwent longitudinal assessments of Epworth sleepiness scale (ESS) scores under stable pharmacotherapy. We present detailed case reports of four patients with unusual spontaneous improvement. Results Over a mean observation period of 5 years, changes in ESS scores between first and last examination were ≤4 points in 19 patients (73%). Three patients deteriorated by 5 points, four patients ameliorated by 7-11 points. Among the latter, subjective sleepiness resolved in all four patients, and three of them continued showing ESS scores 8 minutes), one of whom did not fall asleep during maintenance of wakefulness test. Multiple linear regression analysis identified higher cerebrospinal fluid (CSF) hypocretin level (p < 0.001) and absence of fragmented nighttime sleep (p = 0.001) as independent associates of EDS improvement. Conclusions The longitudinal course of NT1-related sleepiness is not invariably stable, but included spontaneous deterioration or improvement in 27%. Spontaneous improvement can persist after treatment discontinuation and resemble remission. Milder hypocretin deficiency and good nighttime sleep may predict a more favorable disease course

Narcolepsy type 2: A rare, yet existing entity

Because of unspecific diagnostic criteria, there is much controversy around narcolepsy type 2, its existence and its frequency. With this retrospective and purely descriptive study, we aimed to compare the frequency of narcolepsy type 2 compared to the well-described narcolepsy type 1, in a large (n = 3,782) retrospective sample from a single tertiary sleep centre. After 2 weeks washout of sleep-wake active medication, all patients with excessive daytime sleepiness (n = 1,392) underwent 2 weeks actigraphy, polysomnography and multiple sleep latency test, and all diagnoses were made along current diagnostic criteria. Narcolepsy type 1 was diagnosed in 91 patients, and 191 patients without cataplexy had multiple sleep latency test (MSLT) results indicating narcolepsy. After exclusion of shift work syndrome (n = 19), suspected insufficient sleep syndrome (n = 128), delayed sleep phase syndrome (n = 4) and obstructive sleep apnea (n = 34), six patients were diagnosed with narcolepsy type 2, of whom two patients later developed narcolepsy type 1. Altogether, our observations suggest that narcolepsy type 2 exists, but its frequency may be much lower compared to narcolepsy type 1. In addition, they emphasize the importance of scrupulously excluding other potential causes of sleepiness, if possible, with 2-week actigraphy and polysomnography

The eyes wake up: Screening for benign paroxysmal positional vertigo with polysomnography

OBJECTIVE: While positional nystagmus of benign paroxysmal positional vertigo (BPPV) has been shown to be detectable in electrooculography (EOG) tracings of polysomnography (PSG), the frequency of undiagnosed BPPV in patients referred for sleep-wake examination has never been investigated. METHODS: Prospective evaluation of positional nystagmus in 129 patients, referred to a neurological sleep laboratory for sleep-wake examination with PSG. Both in the evening and morning, patients had diagnostic positioning maneuvers under ongoing EOG-PSG registration, followed by visual inspection of EOG for positional nystagmus. RESULTS: In 19 patients (14.7%), we found patterns of positional nystagmus, typically appearing few seconds after changes in head position. In 9 of these patients (47%), the nystagmus was also provoked by the positioning maneuvers. Nystagmus only occurred during wakefulness, not during sleep. In a patient with severe cupulolithiasis, we observed disappearance of nystagmus while entering N1 sleep stage. Nocturnal positional nystagmus was independently associated with positive positioning maneuvers. CONCLUSIONS: Inspection of EOG-PSG demonstrated that positional nystagmus is common, occurring only when wake, and independently associated with positive positioning maneuvers. SIGNIFICANCE: By routinely searching for positional nystagmus in PSG, sleep physicians may substantially contribute to the identification of patients with so-far undiagnosed BPPV