Altered functional connectivity of interoception in illness anxiety disorder

Mechanistic studies in pathological health anxiety: A systematic review and emerging conceptual framework

BACKGROUND

Pathological health anxiety (PHA) (e.g., hypochondriasis and illness anxiety disorder) is common in medical settings and associated with increased healthcare costs. However, the psychological and neurobiological mechanisms contributing to the development and maintenance of PHA are incompletely understood.

METHODS

We performed a systematic review to characterize the mechanistic understanding of PHA. PubMed, PsycINFO, and Embase databases were searched to find articles published between 1/1/1990 and 12/31/2022 employing a behavioral task and/or physiological measures in individuals with hypochondriasis, illness anxiety disorder, and PHA more broadly.

RESULTS

Out of 9141 records identified, fifty-seven met inclusion criteria. Article quality varied substantially across studies, and was overall inadequate. Cognitive, behavioral, and affective findings implicated in PHA included health-related attentional and memory recall biases, a narrow health concept, threat confirming thought patterns, use of safety-seeking behaviors, and biased explicit and implicit affective processing of health-related information among other observations. There is initial evidence supporting a potential overestimation of interoceptive stimuli in those with PHA. Neuroendocrine, electrophysiology, and brain imaging research in PHA are particularly in their early stages.

LIMITATIONS

Included articles evaluated PHA categorically, suggesting that sub-threshold and dimensional health anxiety considerations are not contextualized.

CONCLUSIONS

Within an integrated cognitive-behavioral-affective and predictive processing formulation, we theorize that sub-optimal illness and health concepts, altered interoceptive modeling, biased illness-based predictions and attention, and aberrant prediction error learning are mechanisms relevant to PHA requiring more research. Comprehensively investigating the pathophysiology of PHA offers the potential to identify adjunctive diagnostic biomarkers and catalyze new biologically-informed treatments.

The relationship between brain neural correlates, self-objectification, and interoceptive sensibility

Interoceptive sensibility refers to the tendency to focus on internal bodily states and the capacity to detect them. As the subjective dimension of interoception, interoceptive sensibility plays a key role in individuals' health. Self-objectification, a process by which individuals tend to adopt a third-person's perspective of their physical self, leads to decreased interoceptive sensibility. However, few studies regarding the neural basis of interoceptive sensibility and the underlying mechanism of the relationship between self-objectification and interoceptive sensibility have been conducted. In this study, we assessed the resting-state brain activity (fractional amplitude of low-frequency fluctuation, fALFF) and connectivity (resting-state functional connectivity, RSFC) of 442 college students. Whole-brain correlation analyses revealed that a higher level of interoceptive sensibility was linked to higher fALFF in the right inferior frontal gyrus (IFG) and left cerebellum and to lower fALFF in the left paracentral lobule and left superior/middle temporal gyrus. Interoceptive sensibility also was negatively associated with the RSFC between the right IFG and the right secondary somatosensory cortex (S2) and the right IFG and the ventral premotor cortex (VPC). These brain regions and connections are mainly responsible for switching attention to internal/external information and processing body-related somatosensory as well as sensory information. Mediation analyses suggested that the fALFF of the right IFG and the RSFC of IFG-S2 and IFG-VPC mediated the relationship between self-objectification and interoceptive sensibility. Overall, these results suggest that the IFG may be the neural marker of interoceptive sensibility and reveal several potential mediation models of the relationship between brain neural correlates and self-objectification and interoceptive sensibility.

Classification of Functional Movement Disorders with Resting-State Functional Magnetic Resonance Imaging

Introduction: Functional movement disorder (FMD) is a type of functional neurological disorder characterized by abnormal movements that patients do not perceive as self-generated. Prior imaging studies show a complex pattern of altered activity, linking regions of the brain involved in emotional responses, motor control, and agency. This study aimed to better characterize these relationships by building a classifier using a support vector machine to accurately distinguish between 61 FMD patients and 59 healthy controls using features derived from resting-state functional magnetic resonance imaging. Materials and Methods: First, we selected 66 seed regions based on prior related studies, then we calculated the full correlation matrix between them before performing recursive feature elimination to winnow the feature set to the most predictive features and building the classifier. Results: We identified 29 features of interest that were highly predictive of the FMD condition, classifying patients and controls with 80% accuracy. Several key features included regions in the right sensorimotor cortex, left dorsolateral prefrontal cortex, left cerebellum, and left posterior insula. Conclusions: The features selected by the model highlight the importance of the interconnected relationship between areas associated with emotion, reward, and sensorimotor integration, potentially mediating communication between regions associated with motor function, attention, and executive function. Exploratory machine learning was able to identify this distinctive abnormal pattern, suggesting that alterations in functional linkages between these regions may be a consistent feature of the condition in many FMD patients. Clinical-Trials.gov ID: NCT00500994 Impact statement Our research presents novel results that further elucidate the pathophysiology of functional movement disorder (FMD) with a machine learning model that classifies FMD and healthy controls correctly 80% of the time. Herein, we demonstrate how known differences in resting-state functional magnetic resonance imaging connectivity in FMD patients can be leveraged to better understand the complex pattern of neural changes in these patients. Knowing that there are measurable predictable differences in brain activity in patients with FMD may help both clinicians and patients conceptualize and better understand the illness at the point of diagnosis and during treatment. Our methods demonstrate how an effective combination of machine learning and qualitative approaches to analyzing functional brain connectivity can enhance our understanding of abnormal patterns of brain activity in FMD patients.

Innovative approaches to service integration addressing the unmet needs of irritable bowel syndrome patients and new approaches for the needs of IBS patients

Background

Irritable bowel syndrome (IBS) is a common multifactorial condition that affects the large intestine and is characterized by chronic and relapsing abdominal pain and altered bowel habit. IBS is due to a combination of genetic, environmental and dietary factors. It's usually a lifelong problem very frustrating to live with and can have a big impact on quality of life, as single-agent therapy ra.

Objective

To analyze the approaches and solutions that address the social and health unmet needs of patients with IBS.

Design

A quantitative-qualitative approach was adopted in the current study to identify and specify key digital solution and high impact user scenarios applied to IBS patients, through an adaptation of the “Blueprint on Digital Transformation in Health and Care in an Ageing Society” persona methodology.

Settings

Digital health solutions bring the potential of supporting health interventions through mobile apps, wearable devices, telemedicine.

Patients

A Survey was administered to a group of patients in an anonymous form, and no need for Medical Ethical Committee approval was identified.

Interventions

The theoretical elaboration IBS personas was developed through an interdisciplinary Focus Group, which also mapped the pathway for the patient's management.

Main outcome

Three main needs were identified to be met to improve IBS patient's lifestyle: access to psychological support, mHealth solutions supporting diet and adapted physical activity, and home-based digital health support. mHealth intervention has been identified for diet adherence, physical exercise and psychological well-being. The process has been mapped and adapted to integrate the new solutions into the care pathway.

Limitation

Further research is needed to evaluate how mHealth services enable IBS patients to manage their conditions and improve their quality of life.

Conclusion

The person-centered approach was implemented through a multidisciplinary Focus group that enabled the identification of the need for a mHealth intervention.

Interoception and Obsessive-Compulsive Disorder: A Review of Current Evidence and Future Directions

Disrupted interoceptive processes are present in a range of psychiatric conditions, and there is a small but growing body of research on the role of interoception in obsessive-compulsive disorder (OCD). In this review, we outline dimensions of interoception and review current literature on the processing of internal bodily sensations within OCD. Investigations in OCD utilizing objective measures of interoception are limited and results mixed, however, the subjective experience of internal bodily sensations appears to be atypical and relate to specific patterns of symptom dimensions. Further, neuroimaging investigations suggest that interoception is related to core features of OCD, particularly sensory phenomena and disgust. Interoception is discussed in the context of treatment by presenting an overview of existing interventions and suggesting how modifications aimed at better targeting interoceptive processes could serve to optimize outcomes. Interoception represents a promising direction for multi-method research in OCD, which we expect, will prove useful for improving current interventions and identifying new treatment targets.

The Emerging Science of Interoception: Sensing, Integrating, Interpreting, and Regulating Signals within the Self

Interoception refers to the representation of the internal states of an organism, and includes the processes by which it senses, interprets, integrates, and regulates signals from within itself. This review presents a unified research framework and attempts to offer definitions for key terms to describe the processes involved in interoception. We elaborate on these definitions through illustrative research findings, and provide brief overviews of central aspects of interoception, including the anatomy and function of neural and non-neural pathways, diseases and disorders, manipulations and interventions, and predictive modeling. We conclude with discussions about major research gaps and challenges.

Out-of-step: brain-heart desynchronization in anxiety disorders

Imaging studies in anxiety disorders (AD) show abnormal functional connectivity primarily in the salience network (SN), somatomotor network (SMN), and default mode network (DMN). However, it is not clear how precisely these network changes occur including their relation to psychopathological symptoms. Here, we show that the functional networks affected in AD overlap with cortical regions that receive visceral inputs (the so-called central/visceral autonomic network). Focusing on cardiac afferents, we suggest that network changes in AD may be due to reduced phase synchronization between ongoing neural and cardiac activity. This neuro-cardiac desynchronization occurs due to the abnormal phase resetting of neural activity at the onset of each heartbeat, as measured by a lower intertrial coherence and heartbeat-evoked potential. Biochemically, cardiac afferents reach subcortical serotonergic raphe nuclei and noradrenergic locus coeruleus (among others) which, in turn, are known to reciprocally modulate the DMN and SMN/SN on the cortical level. Consistent with the network changes in AD, decreases in serotonergic and noradrenergic activity are known to increase connectivity in both SMN and SN while, at the same time, they decrease DMN connectivity. SMN and SN increases, in turn, lead to increased emotional arousal/anxiety and bodily awareness whereas decreased DMN connectivity leads to an unstable sense-of-self in AD. Finally, we integrate our proposal with interoceptive predictive processing models suggesting neuro-cardiac desynchronization as a mechanism for "noisy" bottom-up information leading to a persistently uncertain bodily state in top-down models. In sum, integrating theories on active interference and hyperarousal, we propose a precise neuro-cardiac and biochemically -driven mechanisms for key psychopathological symptoms of AD.

Intrinsic functional brain connectivity patterns underlying enhanced interoceptive sensibility

BACKGROUND

Cumulative evidence has suggested that brain regions including the bilateral insula and the anterior cingulate cortex play critical roles in the processing of interoceptive information. However, the brain functional connectivity patterns underlying interoceptive sensibility (IS) and their role in the relationship between IS and self-reported bodily symptoms remain unknown. We aimed to investigate the intrinsic functional connectivity patterns associated with IS and how this modulates the relationship between IS and self-reported bodily symptoms.

METHODS

Resting-state functional magnetic resonance imaging was used to test the intrinsic large-scale functional connectivity in 459 healthy subjects. IS and self-reported bodily symptoms were assessed by questionnaires.

RESULTS

Individuals with greater IS had a stronger tendency to report bodily symptoms. Higher IS was correlated with decreased ventral anterior insula-superior temporal gyrus, dorsal anterior cingulate cortex-middle frontal cortex and amygdala-medioventral occipital cortex connectivity. The large-scale functional connectivity of cingulo-opercular task control network (CON)-default mode network, CON-subcortical network and CON-dorsal attention network moderated the association between IS and bodily symptoms.

LIMITATIONS

The Body Perception Questionnaire mainly reflects the self-perceived tendency to focus on negatively-valenced interoceptive sensations. Future research should distinguish neutral and negative IS in order to make the definition of IS clearer.

CONCLUSIONS

This study suggests that IS may be related to impaired intrinsic functional connectivity between brain areas related to multisensory integration and cognitive-affective control, resulting in increased vigilance-attention to bodily signals. These findings offer new empirical evidence for a better understanding of the intricate relationships between interoception and symptom reporting.

Insula shows abnormal task-evoked and resting-state activity in first-episode drug-naïve generalized anxiety disorder

BACKGROUND

Interoception is associated with neural activity in the insula of healthy humans. On the basis of the somatic symptoms in generalized anxiety disorder (GAD), especially abnormal heartbeat perception, we hypothesized that abnormal activity in the insula was associated with interoceptive awareness in patients with GAD.

METHODS

We investigated the psychological correlates of interoceptive awareness in a sample of 34 patients with first-onset, drug-naïve GAD and 30 healthy controls (HCs). Furthermore, we compared blood oxygenation level-dependent responses between the two groups during a heartbeat perception task to assess task-evoked activity and its relationship with psychological measures. We also examined between-group differences in insular subregions resting-state functional connectivity (rsFC), and its relationship with anxiety severity.

RESULTS

Patients with GAD had significantly higher body perception scores than HCs. They also exhibited greater task-evoked activity in the left anterior insula, left posterior insula, and right anterior insula during interoceptive awareness than HCs. Left anterior insula activity was positively correlated with body awareness in patients with GAD, and rsFC between the left anterior insula and left medial prefrontal gyrus was negatively correlated with somatic anxiety severity.

CONCLUSIONS

Investigating a sample of first-episode, drug-naïve patients, our study demonstrated abnormal interoceptive awareness in patients with GAD and that this was related to abnormal anterior insular activity during both rest and task. These results shed new light on the psychological and neural substrates of somatic symptoms in GAD, and they may serve to establish abnormal interoceptive awareness as a neural and psychological marker of GAD.

Microstructural Changes in Motor Functional Conversion Disorder: Multimodal Imaging Approach on a Case

BACKGROUND

Functional motor conversion disorders are characterized by neurological symptoms unrelated to brain structural lesions. The present study was conducted on a woman presenting motor symptoms causing motor dysfunction, using advanced multimodal neuroimaging techniques, electrophysiological and neuropsychological assessment.

METHODS

The patient underwent fluorodeoxyglucose-positron emission tomography-computed tomography (FDG-PET-CT) and functional magnetic resonance imaging (fMRI) with both task and resting-state paradigms and was compared with 11 healthy matched controls. To test differences in structural parameters, Bayesian comparison was performed. To test differences in functional parameters, a first- and second-level analysis was performed in task fMRI, while a seed-to-seed analysis to evaluate the connections between brain regions and identify intersubject variations was performed in resting-state fMRI.

RESULTS

FDG-PET showed two patterns of brain metabolism, involving the cortical and subcortical structures. Regarding the diffusion data, microstructural parameters were altered for U-shape fibers for the hand and feet regions. Resting-state analysis showed hypoconnectivity between the parahippocampal and superior temporal gyrus. Neurophysiological assessment showed no alterations. Finally, an initial cognitive impairment was observed, paralleled by an anxiety and mild depressive state.

CONCLUSIONS

While we confirmed no structural alterations sustaining this functional motor disorder, we report microstructural changes in sensory-motor integration for both the hand and feet regions that could functionally support clinical manifestations.

The Self and its World: A Neuro-Ecological and Temporo-Spatial Account of Existential Fear

The current international crisis situation caused by the COVID-19 pandemic is having a strong psychological impact on our subjectivities. We are constantly threatened by the danger of i) being infected, ii) infecting other people, and (iii) by the loss of social relation. Departing from these premises, we here aim to investigate the psychological and neurodynamics of this complex phenomenon. First, we discuss about recent psychological and neuronal findings on fear and its disorders, related to an unbalanced intero-exteroceptive processing and emotional regulation. Secondly we move to the psychological and neuronal dynamics of self and others characterized by a temporo-spatial alignment with the world. Due to the neural overlap of emotion and self and the deep-reaching neuro-ecological layers of self, emotional feelings like fear and anxiety cannot be detached and dissociated from the world; they signify the world–brain relation, and, more specifically, our self-other relation. The deepest neuro-ecological and neuro-social layers of self are threatened by the loss of subjectivity, which is manifest in our loss of body and thus the fear of dying, and the loss of intersubjectivity that surfaces in our fear of infecting others, which reflect the intimate anchorage of the self with the world. In our opinion the pandemic of COVID-19 deeply affect our sense of self and its spatio-temporal neuronal dynamics providing the prerequisites for the manifestation of fear and existential anxiety, thus disrupting the brain-world relation with significant repercussions on our psyche and on our daily lives.

Validation of an electronic version of the Self-Awareness Questionnaire in English and Italian healthy samples

OBJECTIVES

Interoception is a general sensitivity to bodily sensations that informs motivational processes and behaviours. Interoceptive abilities seem to be impaired in several clinical conditions, and the development of new pragmatic instruments to assess subjective components of interoception are crucially needed. An easy to use paper and pencil questionnaire measuring sensitivity to bodily sensations was validated in an Italian sample (Self-Awareness Questionnaire; SAQ).

METHODS

In the present study, we created and evaluated an electronic version of the SAQ in Italian and English language.

RESULTS

Psychometric properties of both electronic versions of the SAQ were validated in an Italian (n = 206) and an English (n = 275) sample, using factorial analyses. Differences in factorial structures observed between the two samples were discussed in terms of cultural impact on emotional regulation and bodily sensations processing.

CONCLUSIONS

The electronic version of SAQ in English and Italian provides a pragmatic and validated tool to evaluate bodily signal sensitivity in clinical settings, informing the development of a new therapy targeting interoceptive processes, in a wide range of psychopathological conditions.

The role of mid-insula in the relationship between cardiac interoceptive attention and anxiety: evidence from an fMRI study

Interoception refers to the perception of the internal bodily states. Recent accounts highlight the role of the insula in both interoception and the subjective experience of anxiety. The current study aimed to delve deeper into the neural correlates of cardiac interoception; more specifically, the relationship between interoception-related insular activity, interoceptive accuracy, and anxiety. This was done using functional magnetic resonance imaging (fMRI) in an experimental design in which 40 healthy volunteers focused on their heartbeat and anxious events. Interoceptive accuracy and anxiety levels were measured using the Heartbeat Perception Task and State Trait Anxiety Inventory, respectively. The results showed posterior, mid and anterior insular activity during cardiac interoception, whereas anxiety-related activation showed only anterior insular activity. Activation of the anterior insula when focused on cardiac interoception was positively correlated to state and trait anxiety levels, respectively. Moreover, the mid-insular activity during the cardiac attention condition not only related to individuals’ interoceptive accuracy but also to their levels of state and trait anxiety, respectively. These findings confirm that there are distinct neural representations of heartbeat attention and anxious experience across the insular regions, and suggest the mid-insula as a crucial link between cardiac interoception and anxiety.

Integrated Cognitive and Neuromotor Rehabilitation in Multiple Sclerosis: A Pragmatic Study

Background: Few studies examined the effects of combined motor and cognitive rehabilitation in patients with multiple sclerosis (MS). The present prospective, multicenter, observational study aimed to determine the efficacy of an integrated cognitive and neuromotor rehabilitation program versus a traditional neuromotor training on walking, balance, cognition and emotional functioning in MS patients.

Methods: Sixty three MS patients were selected and assigned either to the Integrated Treatment Group (ITG; n = 32), receiving neuropsychological treatment (performed by ERICA software and paper–pencil tasks) complemented by conventional neuromotor rehabilitation, or to the Motor Treatment Group (n = 31) receiving neuromotor rehabilitation only. The intervention included two 60-min sessions per week for 24 weeks. At baseline and at end of the training all patients underwent a wide-range neuropsychological, psychological/emotional, and motor assessment.

Results: At baseline the two groups did not differ for demographic, neuropsychological, psychological/emotional, and motor features significantly. After rehabilitation, only ITG group significantly (p-corrected for False Discovery Rate) improved on test tapping spatial memory, attention and cognitive flexibility, as well as on scales assessing depression and motor performance (balance and gait). A regression analysis showed that neuropsychological and motor improvement was not related to improvements in fatigue and depression.

Conclusion: The present study demonstrated positive effects in emotional, motor, and cognitive aspects in MS patients who received an integrated cognitive and neuromotor training. Overall, results are supportive of interventions combining motor and cognitive training for MS.

Interoception in Psychiatric Disorders: A Review of Randomized, Controlled Trials with Interoception-Based Interventions

Interoception, or the process of sensing, interpreting, and integrating internal bodily signals, has increasingly been the subject of scientific research over the past decade but is still not well known in clinical practice. The aim of this article is to review clinical treatment interventions that use interoception, to synthesize the current research knowledge, and to identify the gaps where future research is needed. We conducted a comprehensive literature search on randomized, controlled trials that both include interoception in treatment interventions for individuals with psychiatric disorders and measure aspects of interoception using self-report measures. Out of 14 randomized, controlled trials identified, 7 found that interventions with interoception were effective in ameliorating symptoms. These studies included individuals with anxiety disorders, eating disorders, psychosomatic disorders, and addictive disorders. All of the intervention studies with positive clinical outcomes also demonstrated changes on interoceptive measures; however, these measures were often related to specific illness symptoms. Interoception may be a mechanism of action in improving clinical symptomatology, though studies incorporating general, symptom-independent interoceptive measures remain scarce. To further our understanding of the role interoception has in psychiatric disorders and their treatment, more studies integrating interoceptive measures are needed, along with a clearer definition of interoceptive terms used.

Neural correlates of interoception: Effects of interoceptive focus and relationship to dimensional measures of body awareness

Interoception has been defined as the sensing of the physiological condition of the body, with interoceptive sensibility (IS) characterizing an individual's self-reported awareness of internal sensation. IS is a multidimensional construct including not only the tendency to be aware of sensation but also how sensations are interpreted, regulated, and used to inform behavior, with different dimensions relating to different aspects of health and disease. Here we investigated neural mechanisms of interoception when healthy individuals attended to their heartbeat and skin temperature, and examined the relationship between neural activity during interoception and individual differences in self-reported IS using the Multidimensional Scale of Interoceptive Awareness (MAIA). Consistent with prior work, interoception activated a network involving insula and sensorimotor regions but also including occipital, temporal, and prefrontal cortex. Differences based on interoceptive focus (heartbeat vs skin temperature) were found in insula, sensorimotor regions, occipital cortex, and limbic areas. Factor analysis of MAIA dimensions revealed 3 dissociable components of IS in our dataset, only one of which was related to neural activity during interoception. Reduced scores on the third factor, which reflected reduced ability to control attention to body sensation and increased tendency to distract from and worry about aversive sensations, was associated with greater activation in many of the same regions as those involved in interoception, including insula, sensorimotor, anterior cingulate, and temporal cortex. These data suggest that self-rated interoceptive sensibility is related to altered activation in regions involved in monitoring body state, which has implications for disorders associated with abnormality of interoception. Hum Brain Mapp 38:6068-6082, 2017. © 2017 Wiley Periodicals, Inc.