Data-driven analysis of simultaneous EEG/fMRI using an ICA approach

Due to its millisecond-scale temporal resolution, EEG allows to assess neural correlates with precisely defined temporal relationship relative to a given event. This knowledge is generally lacking in data from functional magnetic resonance imaging (fMRI) which has a temporal resolution on the scale of seconds so that possibilities to combine the two modalities are sought. Previous applications combining event-related potentials (ERPs) with simultaneous fMRI BOLD generally aimed at measuring known ERP components in single trials and correlate the resulting time series with the fMRI BOLD signal. While it is a valuable first step, this procedure cannot guarantee that variability of the chosen ERP component is specific for the targeted neurophysiological process on the group and single subject level. Here we introduce a newly developed data-driven analysis procedure that automatically selects task-specific electrophysiological independent components (ICs). We used single-trial simultaneous EEG/fMRI analysis of a visual Go/Nogo task to assess inhibition-related EEG components, their trial-to-trial amplitude variability, and the relationship between this variability and the fMRI. Single-trial EEG/fMRI analysis within a subgroup of 22 participants revealed positive correlations of fMRI BOLD signal with EEG-derived regressors in fronto-striatal regions which were more pronounced in an early compared to a late phase of task execution. In sum, selecting Nogo-related ICs in an automated, single subject procedure reveals fMRI-BOLD responses correlated to different phases of task execution. Furthermore, to illustrate utility and generalizability of the method beyond detecting the presence or absence of reliable inhibitory components in the EEG, we show that the IC selection can be extended to other events in the same dataset, e.g., the visual responses

The Relationship Between PSG and Morning/Evening Emotional Parameters in Patients With Insomnia Disorder and Good Sleepers

Objectives and Introduction: It is as yet unclear how polysomnographically determined sleep parameters determine emotional well-being both generally and particularly in patients with Insomnia Disorder (ID). ID is a frequent and disabling health condition associated with both day- and nighttime hyperarousal, linked to negative sleep-related ruminations as a cognitive component. Information on the immediate influence of objective sleep quality on emotional parameters is important for therapeutic approaches.Methods: The relationship between objective sleep parameters and two emotional questionnaire items obtained both for evening and morning, relaxation and emotional balance, was determined for both sleep lab nights in 161 ID patients and 161 age and gender matched good sleepers (retrospective sample from the Freiburg data base, 98 female, 63 male in each group, age ID: 42.16 ± 11.55, GSC: 41.91 ± 11.30 years). Multivariate mixed effects analysis, corrected for global influences of group, age and first/second night, was employed to determine between- and within-subject influences of sleep and emotional parameters.Results: Main effects: Within-subject, relaxation in the evening was strongly associated with sleep efficiency, REM latency and low arousal index in NREM sleep. No such influence was significant for emotional balance. Also between subjects, evening relaxation was related to increased sleep efficiency. Group interactions: Patients with larger relaxation values in the evening showed a larger reduction of the number of wake periods and the awakening index in NREM sleep than GSC subjects.Discussion: Unexpectedly, no general influence of emotional balance on sleep was found. The subjective feeling of relaxation, however, was associated with sleep efficiency, REM latency and low NREM sleep arousal index. While the first association may be obvious, a direct link to REM latency and NREM arousal index has not previously been shown. We could also directly observe that the number of wake periods in the PSG is more strongly influenced by evening relaxation in ID patients than in good sleepers, asserting the importance of sleep perception and attitude toward sleep in the therapeutic process

Ambulatory sleep scoring using accelerometers—distinguishing between nonwear and sleep/wake states

Background. Differentiating nonwear time from sleep and wake times is essential forthe estimation of sleep duration based on actigraphy data. To efficiently analyze large-scale data sets, an automatic method of identifying these three different states is re-quired. Therefore, we developed a classification algorithm to determine nonwear, sleepand wake periods from accelerometer data. Our work aimed to (I) develop a new patternrecognition algorithm for identifying nonwear periods from actigraphy data based onthe influence of respiration rate on the power spectrum of the acceleration signal andimplement it in an automatic classification algorithm for nonwear/sleep/wake states;(II) address motion artifacts that occur during nonwear periods and are known to causemisclassification of these periods; (III) adjust the algorithm depending on the sensorposition (wrist, chest); and (IV) validate the algorithm on both healthy individuals andpatients with sleep disorders. Methods. The study involved 98 participants who wore wrist and chest accelerationsensors for one day of measurements. They spent one night in the sleep laboratoryand continued to wear the sensors outside of the laboratory for the remainder of theday. The results of the classification algorithm were compared to those of the referencesource: polysomnography for wake/sleep and manual annotations for nonwear/wearclassification. Results. The median kappa values for the two locations were 0.83 (wrist) and 0.84(chest). The level of agreement did not vary significantly by sleep health (good sleepersvs. subjects with sleep disorders) (p=0.348,p=0.118) or by sex (p=0.442,p=0.456).The intraclass correlation coefficients of nonwear total time between the referenceand the algorithm were 0.92 and 0.97 with the outliers and 0.95 and 0.98 after theoutliers were removed for the wrist and chest, respectively. There was no evidence of anassociation between the mean difference (and 95% limits of agreement) and the meanof the two methods for either sensor position (wrist p=0.110, chest p=0.164), and themean differences (algorithm minus reference) were 5.11 [95% LoA−15.4–25.7] and1.32 [95% LoA−9.59–12.24] min/day, respectively, after the outliers were removed. Discussion. We studied the influence of the respiration wave on the power spectrum ofthe acceleration signal for the differentiation of nonwear periods from sleep and wakeperiods. The algorithm combined both spectral analysis of the acceleration signal and rescoring. Based on the Bland-Altman analysis, the chest-worn accelerometer showed better results than the wrist-worn accelerometer

Vitamin D Deficiency in Adult Patients with Schizophreniform and Autism Spectrum Syndromes: A One-Year Cohort Study at a German Tertiary Care Hospital

Introduction: Vitamin D has many immunomodulatory, anti-inflammatory, and neuroprotective functions, and previous studies have demonstrated an association between vitamin D deficiency and neuropsychiatric disease. The aim of our study was to analyze the prevalence of vitamin D deficiency in a one-year cohort of adult inpatients with schizophreniform and autism-spectrum syndromes in a naturalistic in-patient setting in Germany. Participants and methods: Our study was comprised of 60 adult schizophreniform and 23 adult high-functioning autism spectrum patients who were hospitalized Page: 2between January and December of 2015. We compared our findings with a historical German reference cohort of 3,917 adults using Pearson’s two-sided chi-squared test. The laboratory measurements of 25-hydroxyvitamin D2/3 (25(OH)vitamin D) were obtained using a chemiluminescence immunoassay. Results: In the schizophreniform group, we found decreased ( 30 ng/ml were observed in only 5% of the schizophreniform patients, 8.7% of the autism spectrum patients, and 21.9% of the healthy controls. Discussion: We found very high rates of 25(OH)vitamin D deficiency in both patient groups, and have discussed whether our findings might be related to alterations in the immunological mechanisms. Irrespective of the possible pathophysiological links between vitamin D deficiency and schizophrenia or autism spectrum disorders, a more frequent measurement of vitamin D levels seems to be justified in these patient groups. Further prospective, controlled, blinded, and randomized research should be conducted to analyze the effectiveness of vitamin D supplementation on the improvement of psychiatric symptoms

The Effects of Cognitive Behavioral Therapy for Insomnia on Multidimensional Perfectionism

Perfectionism is related to insomnia and objective markers of disturbed sleep. This study examined whether multidimensional perfectionism is related to dysfunctional beliefs about sleep, sleep-effort, pre-sleep arousal, and polysomnography-determined markers of sleep amongst individuals with insomnia. The effects of cognitive behavioral therapy for insomnia (CBT-I) on perfectionism was also examined. This was a secondary analysis of a randomized controlled trial on CBT-I. Forty-three insomnia patients were randomized to treatment (receiving CBT-I) or waitlist control groups. Sleep was recorded using polysomnography at baseline. Participants completed measures of perfectionism, dysfunctional beliefs about sleep, sleep-effort and pre-sleep arousal at baseline and post-treatment. Total perfectionism scores and doubts about action, concern over mistakes and personal standards were each significantly related to increased sleep effort, pre-sleep arousal and dysfunctional beliefs about sleep at baseline. Patients receiving treatment displayed increased total perfectionism scores post-treatment d=.49. In those receiving treatment, levels of organization d=.49 and parental expectations d=.47 were significantly increased post-treatment, relative to baseline. In line with the literature, our results confirm that perfectionism is related to insomnia. Here, insomnia was related to increased sleep effort, pre-sleep arousal and dysfunctional beliefs about sleep. The propensity to maintain a high standard of order and organization may be elevated following CBT-I, considering the treatment protocol expects patients to strictly adhere to a set of clearly defined rules. Levels of parental expectations may be increased following CBT-I since the patient-therapist-relationship may trigger implicitly expectations in the patients which are reminiscent of their relationship to their parents

Co-ordination of brain and heart oscillations during non-rapid eye movement sleep

Oscillatory activities of the brain and heart show a strong variation across wakefulness and sleep. Separate lines of research indicate that non‐rapid eye movement (NREM) sleep is characterised by electroencephalographic slow oscillations (SO), sleep spindles, and phase–amplitude coupling of these oscillations (SO–spindle coupling), as well as an increase in high‐frequency heart rate variability (HF‐HRV), reflecting enhanced parasympathetic activity. The present study aimed to investigate further the potential coordination between brain and heart oscillations during NREM sleep. Data were derived from one sleep laboratory night with polysomnographic monitoring in 45 healthy participants (22 male, 23 female; mean age 37 years). The associations between the strength (modulation index [MI]) and phase direction of SO–spindle coupling (circular measure) and HF‐HRV during NREM sleep were investigated using linear modelling. First, a significant SO–spindle coupling (MI) was observed for all participants during NREM sleep, with spindle peaks preferentially occurring during the SO upstate (phase direction). Second, linear model analyses of NREM sleep showed a significant relationship between the MI and HF‐HRV (F = 20.1, r (2) = 0.30, p < 0.001) and a tentative circular‐linear correlation between phase direction and HF‐HRV (F = 3.07, r (2) = 0.12, p = 0.056). We demonstrated a co‐ordination between SO–spindle phase–amplitude coupling and HF‐HRV during NREM sleep, presumably related to parallel central nervous and peripheral vegetative arousal systems regulation. Further investigating the fine‐graded co‐ordination of brain and heart oscillations might improve our understanding of the links between sleep and cardiovascular health

Cognitive behavioural therapy for insomnia does not appear to have a substantial impact on early markers of cardiovascular disease: A preliminary randomized controlled trial

According to the World Health Organization, cardiovascular diseases are the leading cause of death in the world. Therefore, early prevention of these diseases is a public health priority. Epidemiological data suggest that insomnia may be a modifiable risk factor for cardiovascular diseases. A randomized controlled trial in a sample of insomnia patients without cardiovascular disease was conducted to investigate the effects of insomnia treatment on early markers of cardiovascular diseases assessed by 24‐hr ambulatory blood pressure, heart rate and heart rate variability monitoring, and morning fasting blood samples. Forty‐six patients with insomnia disorder were randomized to cognitive behavioural therapy for insomnia (CBT‐I; n = 23) or a waitlist control condition (n = 23). Contrary to the hypothesis, intention‐to‐treat analyses did not show any significant treatment effects on early markers of cardiovascular disease (d = 0.0–0.6) despite successful insomnia treatment (d = 1.3). Potential methodological and conceptual reasons for these negative findings are discussed. Future studies might include larger sample sizes that are at risk of cardiovascular diseases and focus on other cardiovascular markers

Adherence to sleep restriction therapy – An evaluation of existing measures

Summary: Sleep restriction, a key element of cognitive behavioural therapy for insomnia, involves considerable behavioural changes in patients' lives, leading to side‐effects like increased daytime sleepiness. Studies on sleep restriction rarely report adherence, and when assessed it is often limited to the average number of therapy sessions attended. This study aims to systematically evaluate different measures of adherence to cognitive behavioural therapy for insomnia and their relationship with treatment outcome. This is a secondary analysis of data from a randomized controlled trial investigating cognitive behavioural therapy for insomnia (Johann et al. (2020) Journal of Sleep Research, 29, e13102). The sample included 23 patients diagnosed with insomnia according to DSM‐5 criteria who underwent 8 weeks of cognitive behavioural therapy for insomnia. The following adherence measures based on sleep diary data were used: number of sessions completed; deviations from agreed time in bed; average percentage of patients deviating from bedtime by 15, 30 or 60 min; variability of bedtime and wake‐up time; change in time in bed from pre‐ to post‐assessment. Treatment outcome was assessed using the Insomnia Severity Index. Multiple regression models were employed, and insomnia severity was controlled for. Results showed that none of the adherence measures predict insomnia severity. Baseline insomnia severity, dysfunctional thoughts and attitudes about sleep, depression or perfectionism did not predict adherence. The limited variance in the outcome parameter due to most patients benefiting from treatment and the small sample size may explain these findings. Additionally, using objective measures like actigraphy could provide a better understanding of adherence behaviour. Lastly, the presence of perfectionism in patients with insomnia may have mitigated adherence problems in this study

Cognitive behavioral therapy for insomnia in patients with mental disorders and comorbid insomnia: A systematic review and meta-analysis.

Almost 70% of patients with mental disorders report sleep difficulties and 30% fulfill the criteria for insomnia disorder. Cognitive behavioral therapy for insomnia (CBT-I) is the first-line treatment for insomnia according to current treatment guidelines. Despite this circumstance, insomnia is frequently treated only pharmacologically especially in patients with mental disorders. The aim of the present meta-analysis was to quantify the effects of CBT-I in patients with mental disorders and comorbid insomnia on two outcome parameters: the severity of insomnia and mental health. The databases PubMed, CINHAL (Ebsco) und PsycINFO (Ovid) were searched for randomized controlled trials on adult patients with comorbid insomnia and any mental disorder comparing CBT-I to placebo, waitlist or treatment as usual using self-rating questionnaires as outcomes for either insomnia or mental health or both. The search resulted in 1994 records after duplicate removal of which 22 fulfilled the inclusion criteria and were included for the meta-analysis. The comorbidities were depression (eight studies, 491 patients), post-traumatic stress disorder (PTSD, four studies, 216 patients), alcohol dependency (three studies, 79 patients), bipolar disorder (one study, 58 patients), psychosis (one study, 50 patients) and mixed comorbidities within one study (five studies, 189 patients). The effect sizes for the reduction of insomnia severity post treatment were 0.5 (confidence interval, CI, 0.3-0.8) for patients with depression, 1.5 (CI 1.0-1.9) for patients with PTSD, 1.4 (CI 0.9-1.9) for patients with alcohol dependency, 1.2 (CI 0.8-1.7) for patients with psychosis/bipolar disorder, and 0.8 (CI 0.1-1.6) for patients with mixed comorbidities. Effect sizes for the reduction of insomnia severity were moderate to large at follow-up. Regarding the effects on comorbid symptom severity, effect sizes directly after treatment were 0.5 (CI 0.1-0.8) for depression, 1.3 (CI 0.6-1.9) for PTSD, 0.9 (CI 0.3-1.4) for alcohol dependency in only one study, 0.3 (CI -0.1 - 0.7, insignificant) for psychosis/bipolar, and 0.8 (CI 0.1-1.5) for mixed comorbidities. There were no significant effects on comorbid symptoms at follow-up. Together, these significant, stable medium to large effects indicate that CBT-I is an effective treatment for patients with insomnia and a comorbid mental disorder, especially depression, PTSD and alcohol dependency. CBT-I is also an effective add-on treatment with the aim of improving mental health in patients with depression, PTSD, and symptom severity in outpatients with mixed diagnoses. Thus, in patients with mental disorders and comorbid insomnia, given the many side effects of medication, CBT-I should be considered as a first-line treatment