Summary Sleep is known to be affected in space travel and in residents of the international space station. But little is known about the direct effects of gravity changes on sleep, if other factors, ...such as sleep conditions, are kept constant. Here, as a first exploration, we investigated sleep before and after exposure to short bouts of microgravity and hypergravity during parabolic flights. Sleep was measured through actigraphy and self‐report questionnaires in 20 healthy men and women before and after parabolic flight. Higher sleep fragmentation and more awakenings were found in the night after the flight as compared with the night before, which was discrepant from participants' reports showing better and longer sleep after the parabolic flight. Variable levels of experience with parabolic flights did not affect the results, nor did levels of scopolamine, a medication typically taken against motion sickness. Pre‐existing sleep problems were related to sleep fragmentation and wake after sleep onset by a quadratic function such that participants with more sleep problems showed lower levels of sleep fragmentation and nighttime awakenings than those with few sleep problems. These novel findings, though preliminary, have important implications for future research, directed at prevention and treatment of sleep problems and their daytime consequences in situations of altered gravity, and possibly in the context of other daytime vestibular challenges as well.
Summary
Despite cognitive behaviour therapy for insomnia (CBT‐I) being the first‐line intervention for the disorder, it is often not readily available to patients in need. The stepped care model ...(SCM) represents an approach to facilitating efficient and wide‐ranging provision of evidence‐based care to those with insomnia. The SCM reflects a pyramid of therapeutics based on CBT‐I gradually increasing in clinical intensity and addressing clinical complexity. By applying CBT‐I through the SCM it is hoped that the treatment gap can be bridged such that not only more patients can be reached, but that clinical resource can be more effectively distributed, with patients receiving more tailored care as needed. Nevertheless, this should not be done at the risk of a lower quality of care being offered, and high‐standard training for clinicians and scrutiny of non‐clinician led interventions remains important. As national health laws within European countries have substantial differences, the application of the SCM as it relates to the treatment of insomnia may be challenged by contrasting interpretations. In order that the SCM is appropriately implemented: (a) only evidence‐based CBT‐I treatments should be promoted within the model; (b) clinicians involved in SCM should be suitably qualified to offer CBT in general, and have appropriate further training in CBT‐I; (c) professionals involved in interventions not included in the SCM, but related to it, such as preventive and educational programmes, diagnostic procedures, and pharmacological treatments, should also have good knowledge of the SCM in order to promote correct allocation to the appropriate interventional step.
Background Dopaminergic drugs remain the mainstay of Parkinson’s disease therapy but often fail to improve cognitive problems such as impulsivity. This may be due to the loss of other ...neurotransmitters, including noradrenaline, which is linked to impulsivity and response inhibition. We therefore examined the effect of the selective noradrenaline reuptake inhibitor atomoxetine on response inhibition in a stop-signal paradigm. Methods This pharmacological functional magnetic resonance imaging study used a double-blinded randomized crossover design with low-frequency inhibition trials distributed among frequent Go trials. Twenty-one patients received 40 mg atomoxetine or placebo. Control subjects were tested on no-drug. The effects of disease and drug on behavioral performance, regional brain activity, and functional connectivity were analyzed using general linear models. Anatomical connectivity was examined using diffusion-weighted imaging. Results Patients with Parkinson’s disease had longer stop-signal reaction times, less stop-related activation in the right inferior frontal gyrus (RIFG), and weaker functional connectivity between the RIFG and striatum compared with control subjects. Atomoxetine enhanced stop-related RIFG activation in proportion to disease severity. Although there was no overall behavioral benefit from atomoxetine, analyses of individual differences revealed that enhanced response inhibition by atomoxetine was associated with increased RIFG activation and functional frontostriatal connectivity. Improved performance was more likely in patients with higher structural frontostriatal connectivity. Conclusions This study suggests that enhanced prefrontal cortical activation and frontostriatal connectivity by atomoxetine may improve response inhibition in Parkinson’s disease. These results point the way to new stratified clinical trials of atomoxetine to treat impulsivity in selected patients with Parkinson’s disease.
Background Brain mechanisms of chronic insomnia, a highly prevalent condition, have barely been investigated. We demonstrate here a decrease in orbitofrontal gray matter (GM) volume that strongly ...correlates with the severity of complaints. Methods In a case-control study, optimized voxel-based morphometry was used to compare the regional brain volumes of 24 medication-free chronic primary insomnia patients (age range 52–74 years, 17 women), carefully selected to exclude psychiatric comorbidity, with those of 13 matched control subjects without sleep problems (age range 50–76 years, 9 women). Additionally, the correlation of regional volumes with insomnia severity was investigated. Results Patients had a smaller volume of GM in the left orbitofrontal cortex, strongly correlating ( r = −.71) with the subjective severity of insomnia. Furthermore, reduced GM volume was found in the anterior and posterior precuneus. Patients did not show increased GM volume in any area. No group differences were found for white matter volume. Conclusions This is the first voxel-based morphometry study showing structural brain correlates of insomnia and their relation with insomnia severity. Functional roles of the affected areas in decision-making and stimulus processing might better guide future research into the poorly understood condition of insomnia.
Impulsivity is common in Parkinson's disease even in the absence of impulse control disorders. It is likely to be multifactorial, including a dopaminergic 'overdose' and structural changes in the ...frontostriatal circuits for motor control. In addition, we proposed that changes in serotonergic projections to the forebrain also contribute to response inhibition in Parkinson's disease, based on preclinical animal and human studies. We therefore examined whether the selective serotonin reuptake inhibitor citalopram improves response inhibition, in terms of both behaviour and the efficiency of underlying neural mechanisms. This multimodal magnetic resonance imaging study used a double-blind randomized placebo-controlled crossover design with an integrated Stop-Signal and NoGo paradigm. Twenty-one patients with idiopathic Parkinson's disease (46-76 years old, 11 male, Hoehn and Yahr stage 1.5-3) received 30 mg citalopram or placebo in addition to their usual dopaminergic medication in two separate sessions. Twenty matched healthy control subjects (54-74 years old, 12 male) were tested without medication. The effects of disease and drug on behavioural performance and regional brain activity were analysed using general linear models. In addition, anatomical connectivity was examined using diffusion tensor imaging and tract-based spatial statistics. We confirmed that Parkinson's disease caused impairment in response inhibition, with longer Stop-Signal Reaction Time and more NoGo errors under placebo compared with controls, without affecting Go reaction times. This was associated with less stop-specific activation in the right inferior frontal cortex, but no significant difference in NoGo-related activation. Although there was no beneficial main effect of citalopram, it reduced Stop-Signal Reaction Time and NoGo errors, and enhanced inferior frontal activation, in patients with relatively more severe disease (higher Unified Parkinson's Disease Rating Scale motor score). The behavioural effect correlated with the citalopram-induced enhancement of prefrontal activation and the strength of preserved structural connectivity between the frontal and striatal regions. In conclusion, the behavioural effect of citalopram on response inhibition depends on individual differences in prefrontal cortical activation and frontostriatal connectivity. The correlation between disease severity and the effect of citalopram on response inhibition may be due to the progressive loss of forebrain serotonergic projections. These results contribute to a broader understanding of the critical roles of serotonin in regulating cognitive and behavioural control, as well as new strategies for patient stratification in clinical trials of serotonergic treatments in Parkinson's disease.
Abstract
Study objectives
Emotional reactivity to negative stimuli has been investigated in insomnia, but little is known about emotional reactivity to positive stimuli and its neural representation.
...Methods
We used 3 Tesla functional magnetic resonance imaging (fMRI) to determine neural reactivity during the presentation of standardized short, 10- to 40-seconds, humorous films in patients with insomnia (n = 20, 18 females, aged 27.7 +/− 8.6 years) and age-matched individuals without insomnia (n = 20, 19 females, aged 26.7 +/− 7.0 years) and assessed humor ratings through a visual analog scale. Seed-based functional connectivity was analyzed for the left and right amygdalas (lAMYG and rAMYG, respectively) networks: group-level mixed-effects analysis (FLAME; FMRIB Software Library FSL) was used to compare amygdala connectivity maps between groups.
Results
fMRI seed-based analysis of the amygdala revealed stronger neural reactivity in patients with insomnia than in controls in several brain network clusters within the reward brain network, without humor rating differences between groups (p = 0.6). For lAMYG connectivity, cluster maxima were in the left caudate (Z = 3.88), left putamen (Z = 3.79), and left anterior cingulate gyrus (Z = 4.11), whereas for rAMYG connectivity, cluster maxima were in the left caudate (Z = 4.05), right insula (Z = 3.83), and left anterior cingulate gyrus (Z = 4.29). Cluster maxima of the rAMYG network were correlated with hyperarousal scores in patients with insomnia only.
Conclusions
The presentation of humorous films leads to increased brain activity in the neural reward network for patients with insomnia compared with controls, related to hyperarousal features in patients with insomnia, in the absence of humor rating group differences. These novel findings may benefit insomnia treatment interventions.
Clinical trial
The Sleepless Brain: Neuroimaging Support for a Differential Diagnosis of Insomnia (SOMNET). ClinicalTrials.gov identifier: NCT02821234; https://clinicaltrials.gov/ct2/show/NCT02821234.
Sleep before learning benefits memory encoding through unknown mechanisms. We found that even a mild sleep disruption that suppressed slow-wave activity and induced shallow sleep, but did not reduce ...total sleep time, was sufficient to affect subsequent successful encoding-related hippocampal activation and memory performance in healthy human subjects. Implicit learning was not affected. Our results suggest that the hippocampus is particularly sensitive to shallow, but intact, sleep.
Insomnia symptoms are frequent during peripartum and are considered risk factors for peripartum psychopathology. Assessing and treating insomnia and related conditions of sleep loss during peripartum ...should be a priority in the clinical practice. The aim of this paper was to conduct a systematic review on insomnia evaluation and treatment during peripartum which may be useful for clinicians. The literature review was carried out between January 2000 and May 2021 on the evaluation and treatment of insomnia during the peripartum period. The PubMed, PsycINFO, and Embase electronic databases were searched for literature published according to the PRISMA guidance with several combinations of search terms “insomnia” and “perinatal period” or “pregnancy” or “post partum” or “lactation” or “breastfeeding” and “evaluation” and “treatment.” Based on this search, 136 articles about insomnia evaluation and 335 articles on insomnia treatment were found and we conducted at the end a narrative review. According to the inclusion/exclusion criteria, 41 articles were selected for the evaluation part and 22 on the treatment part, including the most recent meta-analyses and systematic reviews. Evaluation of insomnia during peripartum, as for insomnia patients, may be conducted at least throughout a clinical interview, but specific rating scales are available and may be useful for assessment. Cognitive behavioral therapy for insomnia (CBT-I), as for insomnia patients, should be the preferred treatment choice during peripartum, and it may be useful to also improve mood, anxiety symptoms, and fatigue. Pharmacological treatment may be considered when women who present with severe forms of insomnia symptoms do not respond to nonpharmacologic therapy.
Summary
Virtual reality and simulation tools enable us to assess daytime functioning in environments that simulate real life as close as possible. Simulator sickness, however, poses a problem in the ...application of these tools, and has been related to pre‐existing health problems. How sleep problems contribute to simulator sickness has not yet been investigated. In the current study, 20 female chronic insomnia patients and 32 female age‐matched controls drove in a driving simulator covering realistic city, country and highway scenes. Fifty percent of the insomnia patients as opposed to 12.5% of controls reported excessive simulator sickness leading to experiment withdrawal. In the remaining participants, patients with insomnia showed overall increased levels of oculomotor symptoms even before driving, while nausea symptoms further increased after driving. These results, as well as the realistic simulation paradigm developed, give more insight on how vestibular and oculomotor functions as well as interoceptive functions are affected in insomnia. Importantly, our results have direct implications for both the actual driving experience and the wider context of deploying simulation techniques to mimic real life functioning, in particular in those professions often exposed to sleep problems.
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