Predictability modulates the affective and sensory-discriminative neural processing of pain

Knowing what is going to happen next, that is, the capacity to predict upcoming events, modulates the extent to which aversive stimuli induce stress and anxiety. We explored this issue by manipulating the temporal predictability of aversive events by means of a visual cue, which was either correlated or uncorrelated with pain stimuli (electric shocks). Subjects reported lower levels of anxiety, negative valence and pain intensity when shocks were predictable. In addition to attenuate focus on danger, predictability allows for correct temporal estimation of, and selective attention to, the sensory input. With functional magnetic resonance imaging, we found that predictability was related to enhanced activity in relevant sensory-discriminative processing areas, such as the primary and secondary sensory cortex and posterior insula. In contrast, the unpredictable more aversive context was correlated to brain activity in the anterior insula and the orbitofrontal cortex, areas associated with affective pain processing. This context also prompted increased activity in the posterior parietal cortex and lateral prefrontal cortex that we attribute to enhanced alertness and sustained attention during unpredictability. (c) 2006 Elsevier Inc. All rights reserved.This study was supported by grants from The Swedish Research Council (2003-5810), The family Hedlund Foundation and Karolinska Institutet. The project was finished in the context of Stockholm Brain Institute.info:eu-repo/semantics/publishedVersio

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Prior knowledge and present events in the brain

Our experience the world is dependent on both the surroundings and the brain. In other words, perception is a synthesis of incoming signals, internal state, and previous knowledge rather than a mere reflection of the environment. Prior knowledge can be engendered from cues in the present context, from previous experiences, or in a wider sense by evolutionary processes effected in the organization of the brain. Knowing what is going to happen modulates the extent to which aversiveness induces stress and anxiety. Predictability is also of importance since it may improve the accuracy and speed of sensory processing as well as behavioral responses. As for evolutionary relevant threats, a perceptual and behavioral system has been organized around a fear module generating instant responses even outside of awareness. Accordingly, brain regions with altered activities and functions complement each other in constituting a system that allows for perceptions, reactions and behavioral planning at different time scales. In this thesis, we investigate the influence of prediction on perception of somatosensory and aversive events and the differential neural processing of phobic and fear-relevant stimuli, as measured by functional magnetic imaging (fMRI) and positron emission tomography (PET). The network of activation and deactivation during anticipation of an expected somatosensory stimulus was found to be similar to that engaged during the actual sensory stimulation. These overlapping patterns of change furthers the idea that predictions are subserved by a neuronal network similar to that which subserves the processing of the actual sensory input. It also infers that anticipation may invoke a tonic top-down modulation of neural activity and in this way favor selective processing of relevant information. Correspondingly, predictive cues of painful stimuli that allowed for correct temporal estimation enhanced activity in relevant sensorydiscriminative processing areas. Absence of cues predicting painful stimuli augmented the negative experience as well as neuronal activity in areas associated with the affective component of pain processing, such as the anterior insula, the caudal anterior cingulate cortex, and the orbitofrontal cortex. This context also prompted increased activity in the posterior parietal cortex and lateral prefrontal cortex that we attribute to enhanced alertness and sustained attention during unpredictability. An affective cortical network along with the amygdala and the periaqueductal gray was also active in response to phobic relative to fear relevant (but nonfeared) stimuli. However, with non-conscious stimulus presentation only the amygdala was activated both to the phobic and fear relevant stimuli. With time to decide that the fear relevant stimuli in effect were not dangerous the dorsolateral prefrontal cortex was engaged, a region included in a system that has been identified in strategic selection of behavior and in inhibiting environmentally cued responses. These results thus reflect fast perceptual pathways favoring rapid responses to threat, top-down direction of attention contributing to enhancement of relevant information processing along with attenuation of anxiety and finally, activity in regions mediating goal-directed perception and behavior

How do children experience participating in a coeliac disease screening? A qualitative study based on children's written narratives

Aim: To explore how 12-year-old Swedish children experienced being involved in a coeliac disease (CD) screening. Methods: A qualitative approach was used to analyse short narratives written by children who had taken part in a school-based CD screening. Narratives were written after blood sampling, but prior to learning of the test results. Through an oscillation between the texts, codes, subcategories and four categories, a theme was generated describing the children's experience. Results: The theme "A Journey towards Confidence" captures the overall experience of the screening. It illustrates that, although some children faced fear or anxiety, overall they had or were provided tools allowing them to cope well and experience a journey towards confidence. The categories describe conditions that contributed to the experience. The first, being involved, reflects the importance of involvement in receiving information and deciding to participate. Being a "good citizen" refers to feeling a duty to help and a trust to be treated fairly. Being able to cope with the screening was influenced by the children's ability to manage sensations and support received. The last category, being able to balance risk, illustrates that the children were able to balance the risks of screening when they had a realistic understanding of the disease and their vulnerability and had tamed their anxiety. Conclusions: This study increases the understanding of how 12-year-old Swedish children experienced participating in a CD screening and describes conditions important for a positive experience. We show that, although some children faced anxiety, they had, or were provided with, tools allowing them to cope well and gain confidence

Balancing health benefits and social sacrifices : a qualitative study of how screening-detected celiac disease impacts adolescents' quality of life

Background Celiac disease often goes undiagnosed. Mass screening might be an option to reduce the public health burden of untreated celiac disease. However, mass screening is still controversial since it is uncertain whether the benefits of early detection outweigh the possible negative consequences. Before implementation of screening programs, the experiences of those being identified as cases should be considered. The aim of our study was to explore how screening-detected celiac disease impacts adolescents' quality of life, as perceived by themselves and their parents. Methods All adolescents (n = 145) with screening-detected celiac disease found in a Swedish screening study, and their parents, were invited to share their experiences in a qualitative follow-up study. In total, we have information on 117 (81%) of the adolescents, either from the adolescents themselves (n = 101) and/or from their parent/s (n = 125). Written narratives were submitted by 91 adolescents and 105 parents. In addition, 14 focus group discussions involving 31 adolescents and 43 parents were conducted. Data was transcribed verbatim and analyzed based on a Grounded Theory framework. Results The screening-detected celiac disease diagnosis had varying impact on quality of life that related both to changes in perceived health and to the adolescents' experiences of living with celiac disease in terms of social sacrifices. Changes in perceived health varied from "healthy as anyone else with no positive change" to "something was wrong and then changed to the better", whereas experiences of living with celiac disease ranged from "not a big deal" to "treatment not worth the price". Perceptions about living with celiac disease and related coping strategies were influenced by contextual factors, such as perceived support from significant others and availability of gluten-free products, and were developed without a direct relation to experiencing changes in perceived health. Conclusions Screening-detected celiac disease has varying impact on adolescents' quality of life, where their perceived change in health has to be balanced against the social sacrifices the diagnosis may cause. This needs to be taken into account in any future suggestion of celiac disease mass screening and in the management of these patients.This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.</p

Health-related quality-of-life in children with coeliac disease, measured prior to receiving their diagnosis through screening

Objective To compare the health-related quality-of-life (HRQoL) of children with screening-detected coeliac disease (CD), before they learned of their diagnosis, with that of children without CD and in those previously diagnosed with CD. Methods In a cross-sectional CD screening study ('ETICS': Exploring the Iceberg of Coeliacs in Sweden), of 10,041 Swedish 12-year-olds invited, 7567 (75%) consented to participate, and 7208 (72%) children without previously diagnosed CD had serological markers analysed. Before the screening results were known, 7218 children (72%) and 6524 of their parents (65%) answered questionnaires. Questionnaires included the Swedish child-friendly pilot version of the EQ-5D instrument and proxy version of the EQ-5D instrument, which are generic tools used to describe HRQoL. Results We found no significant difference in HRQoL between the groups of children with screening-detected CD, without CD, and those previously diagnosed with CD. Conclusion The HRQoL reported by 12-year-olds with screening-detected CD, before they learned of their diagnosis, was not worse than that of the children without CD or those previously diagnosed with CD. Thus, mass screening for CD should not be justified on the basis that children with unrecognized CD have a poor HRQoL. However, because these children rated their HRQoL before diagnosis and treatment, they may not have recognized or perceived symptoms as severe enough to seek medical attention which demonstrates how difficult clinical/active case finding can be. Mass screening may still, therefore, be considered if the aim is early detection and prevention of future complications

Is mass screening for coeliac disease a wise use of resources? A health economic evaluation

Background: Living with undiagnosed symptomatic coeliac disease is connected with deteriorated health, and persons with coeliac disease often wait a long time for their diagnosis. A mass screening would lower the delay, but its cost-effectiveness is still unclear. Our aim was to determine the cost-effectiveness of a coeliac disease mass screening at 12 years of age, taking a life course perspective on future benefits and drawbacks. Methods: The cost-effectiveness was derived as cost per quality-adjusted life-year (QALY) using a Markov model. As a basis for our assumptions, we mainly used information from the Exploring the Iceberg of Celiacs in Sweden (ETICS) study, a school-based screening conducted in 2005/2006 and 2009/2010, where 13,279 12-year-old children participated and 240 were diagnosed with coeliac disease, and a study involving members of the Swedish Coeliac Association with 1031 adult participants. Results: The cost for coeliac disease screening was 40,105 Euro per gained QALY. Sensitivity analyses support screening based on high compliance to a gluten-free diet, rapid progression from symptom-free coeliac disease to coeliac disease with symptoms, long delay from celiac disease with symptoms to diagnosis, and a low QALY score for undiagnosed coeliac disease cases. Conclusions: A coeliac disease mass screening is cost-effective based on the commonly used threshold of 50,000 Euro per gained QALY. However, this is based on many assumptions, especially regarding the natural history of coeliac disease and the effects on long-term health for individuals with coeliac disease still eating gluten