Specific biases for identifying facial expression of emotion in children and adolescents with conversion disorders

Recent advances in understanding the neurobiology of pediatric functional neurological disorder

INTRODUCTION

Functional neurological disorder (FND) is a neuropsychiatric disorder that manifests in a broad array of functional motor, sensory, or cognitive symptoms, which arise from complex interactions between brain, mind, body, and context. Children with FND make up 10%-20% of presentations to neurology services in children's hospitals and up to 20% of adolescents admitted to hospital for the management of intractable seizures.

AREAS COVERED

The current review focuses on the neurobiology of pediatric FND. The authors present an overview of the small but growing body of research pertaining to the biological, emotion-processing, cognitive, mental health, physical health, and social system levels.

EXPERT OPINION

Emerging research suggests that pediatric FND is underpinned by aberrant changes within and between neuron-glial (brain) networks, with a variety of factors - on multiple system levels - contributing to brain network changes. In pediatric practice, adverse childhood experiences (ACEs) are commonly reported, and activation or dysregulation of stress-system components is a frequent finding. Our growing understanding of the neurobiology of pediatric FND has yielded important flow-on effects for assessing and diagnosing FND, for developing targeted treatment interventions, and for improving the treatment outcomes of children and adolescents with FND.

Anger regulation in patients with functional neurological disorder: A systematic review

BACKGROUND

Functional neurological disorder (FND) has been associated with predisposing psychological factors, including dysregulation of anger-related processes. This paper provides a systematic review of the literature on anger regulation in FND. We evaluated anger-related research on patient self-report, observational, and laboratory based measures in FND. The review also addresses adverse childhood experiences and their relation with anger regulation, and the effects of therapies targeting anger regulation in FND.

METHODS

MEDLINE, EMBASE, and PsycINFO were searched for both quantitative and qualitative research, published in a peer-reviewed journal with a sample size of at least 5 (registered under Prospero protocol CRD42022314340).

RESULTS

A total of 2200 articles were identified. After screening, 54 studies were included in this review (k = 20 questionnaire-based studies, k = 12 laboratory studies, k = 21 using other methods, and k = 1 used both questionnaires and other methods) representing data of 2502 patients with FND. Questionnaire-based studies indicated elevated levels of state anger and trait hostility in patients with FND. Laboratory studies showed a higher tendency to avoid social threat cues, attentional bias towards angry faces, difficulties reliving anger, and preoccupation with frustrating barriers among FND patients versus controls. No specific childhood experiences were identified related to anger regulation in FND, and too few small and uncontrolled studies were available (k = 2) to assess the effects of anger-related interventions in FND. The overall quality of the studies was fair (k = 31) to poor (k = 18). Five studies (k = 5) were rated as having a good quality.

CONCLUSIONS

This review suggests that patients with FND have maladaptive anger regulation compared to individuals without FND. The findings also highlight the need for further research on the prevalence and consequences of anger-related processes in the development, diagnosis and treatment of FND.

Alexithymia and facial emotion recognition in patients with functional neurological disorder

OBJECTIVES

Patients with functional neurological disorder (FND) are known to have difficulties recognizing and processing emotions. Problems recognizing internal emotional states (alexithymia) are common in FND, but little is known about recognizing emotions expressed by other people. This study investigates whether patients with FND have higher levels of alexithymia and reduced facial emotion recognition compared to healthy controls.

METHODS

Patients with FND (n = 31, mean age=42.7 [SD=14.8] years, 54.8% women) were compared to healthy controls (n = 33, mean age=45.1 [SD=16.2] years, 63.6% women). The Bermond-Vorst Alexithymia Questionnaire (BVAQ) was used for the assessment of alexithymia and the Ekman 60 Faces Test (EFT) for facial emotion recognition.

RESULTS

Patients with FND had higher levels of alexithymia than healthy controls (BVAQ=71.8 [SD=19.8] versus 59.3 [SD=20.3], p = .02, Cohen's d=0.62). Facial emotion recognition did not significantly differ between FND patients and controls (EFT total score FND: 46.1 [SD=5.9], Controls: 47.5 [SD=5.5], p = .34, Cohen's d=0.24). Only recognition of surprise differed between patients and controls (FND: 8.4 [SD=1.8], Controls: 9.2 [SD=1.0), p = .03, Cohen's d= 0.56). Higher levels of alexithymia were associated with poorer facial emotion recognition, but this relationship was not statistically significant (FND: β= -0.20, p = .28; Controls: β=-0.03; p = .87).

CONCLUSIONS

The current data confirm prior observations that patients with FND have higher alexithymia levels than controls without FND. Difficulties recognizing emotions among patients with FND primarily involves recognition of internal emotional states rather than recognition of facially expressed emotions by others. These findings require replication in a larger and more divers sample.

Altered resting-state neural networks in children and adolescents with functional neurological disorder

•

FND in children commonly involves presentation with multiple neurological symptoms.

•

Children with FND show wide-ranging connectivity changes in resting-state neural networks.

•

Aberrant neural-networks changes are greater in children whose FND includes functional seizures.

•

Subjective distress, autonomic arousal, and HPA dysregulation contribute to network changes.

•

Children with FND (vs controls) report more subjective distress and more ACEs across the lifespan.

Objectives

Previous studies with adults suggest that aberrant communication between neural networks underpins functional neurological disorder (FND). The current study adopts a data-driven approach to investigate the extent that functional resting-state networks are disrupted in a pediatric mixed-FND cohort.

Methods

31 children with mixed FND and 33 age- and sex-matched healthy controls completed resting-state fMRI scans. Whole-brain independent component analysis (pFWE < 0.05) was then used to identify group differences in resting-state connectivity. Self-report measures included the Depression, Anxiety and Stress Scale (DASS-21) and Early Life Stress Questionnaire (ELSQ). Resting-state heart rate (HR) and cortisol-awakening response (CAR) were available in a subset.

Results

Children with FND showed wide-ranging connectivity changes in eight independent components corresponding to eight resting-state neural networks: language networks (IC6 and IC1), visual network, frontoparietal network, salience network, dorsal attention network, cerebellar network, and sensorimotor network. Children whose clinical presentation included functional seizures (vs children with other FND symptoms) showed greater connectivity decreases in the frontoparietal and dorsal attentional networks. Subjective distress (total DASS score), autonomic arousal (indexed by HR), and HPA dysregulation (attenuated/reversed CAR) contributed to changes in neural network connectivity. Children with FND (vs controls) reported more subjective distress (total DASS score) and more adverse childhood experiences (ACEs) across their lifespan.

Conclusions

Children with FND demonstrate changes in resting-state connectivity. Identified network alterations underpin a broad range of functions typically disrupted in children with FND. This study complements the adult literature by suggesting that FND in children and adolescents emerges in the context of their lived experience and that it reflects aberrant communication across neural networks.

A dimensional approach to functional movement disorders: Heresy or opportunity

Functional movement disorders (FMD) are a common and disabling neuropsychiatric condition, part of the spectrum of functional neurological/conversion disorder. FMD represent one of the most enigmatic disorders in the history of medicine. However, in the twenty years after the first report of distinctive abnormal brain activity associated with functional motor symptoms, there have been tremendous advances in the pathophysiologic understanding of these disorders. FMD can be characterized as a disorder of aberrant neurocircuitry interacting with environmental and genetic factors. These developments suggest that research on FMD could be better served by an integrative, neuroscience-based approach focused on functional domains and their neurobiological substrates. This approach has been developed in 'Research Domain Criteria' (RDoC) project, which promotes a dimensional approach to psychiatric disorders. Here, we use the RDoC conceptualization to review recent neuroscience research on FMD, focusing on the domains most relevant to these disorders. We discuss how the adoption of a similar integrative framework may facilitate the identification of the mechanisms underlying FMD and could also have potential clinical applicability.

Emotion attribution in intermittent explosive disorder

BACKGROUND

Accurate recognition of the emotions of others is an important part of healthy neurological development and promotes positive psychosocial adaptation. Differences in emotional recognition may be associated with the presence of emotional biases and can alter one's perception, thus influencing their overall social cognition abilities. The present study aims to extend our collective understanding of emotion attribution abnormalities in individuals with Intermittent Explosive Disorder (IED).

METHODS

Two-hundred and forty-two adults participated, separated into groups of those diagnosed with IED according to DSM 5 criteria, Psychiatric Controls (PC), and Healthy Controls (HC). Participants completed a modified version of the Emotional Attribution Task wherein they attributed an emotion to the main character of a short vignette.

RESULTS

Participants with IED correctly identified anger stories and misattributed anger to non-anger stories significantly more often than PC and HC participants. They were also significantly less likely than HC participants to correctly identify "sad stories."

LIMITATIONS

We utilized self-report assessments in a community-recruited sample. Replication in a clinical is suggested.

CONCLUSIONS

Findings from this study support the validity of IED as a diagnostic entity and provide important information about how individuals with psychiatric disorders perceive and experience emotional cues.

Social aspects of life in patients with functional seizures: Closing the gap in the biopsychosocial formulation

The human, as a biological system, is an open system embedded within larger systems -including the family, culture, and socio-political environment. In this context, a patient with functional seizures (FS) is embedded in relationships, educational/professional institutions, culture, and society. Both connection to these broader systems and the quality of these connections, as well as the soundness of each system in and of itself, influence the health and well-being of patients in positive or negative ways. The social aspects of life are important determinants of health and quality of life across the lifespan. The current narrative review brings out several overarching themes in patients with FS. Sections on attachment, marriage, social networking, and stigma highlight the central roles of supportive and affirmative relationships across the lifespan. The section on education underscores the importance of keeping children and youth with FS connected within their school environments, as well as managing any barriers - learning difficulties, school response to FS events, stigma, etc.-that can diminish this connection. Finally, the sections on employment and driving highlight the value of being an active participant in one's society. In summary, FS impacts patients across most social aspects of life domains regardless of age - factors that are important when developing biopsychosocial formulations. This review concludes that the multidisciplinary management of FS requires careful assessment of social aspects of life in patients which can then be targeted for treatment, to improve their quality of life, facilitating recovery, and reducing the risk of relapse.

Impaired emotional and behavioural awareness and control in patients with dissociative seizures

BACKGROUND

Dissociative seizures (DS) are brief episodes of disrupted awareness and behavioural control that may resemble epileptic seizures. They are thought to arise in the context of impaired emotion processing and disinhibition. In a multi-perspective neuropsychological study, we aim to assess specific metacognitive traits and behavioural features involved in the affective and cognitive underpinnings of DS (emotion recognition and regulation, inhibition, interoception and sense of agency).

METHODS

Twenty prospectively recruited patients with video-EEG-confirmed DS and 20 healthy controls underwent comprehensive neuropsychological and psychiatric testing using validated questionnaires and structured interviews. Behavioural experimental data was obtained using a custom-made emotional go/no-go task, a digital Libet clock setup and a heartbeat counting paradigm.

RESULTS

Emotion recognition, as quantified in the emotional go/no-go task, was impaired in the DS group, and correlated with alexithymic traits. Behavioural inhibition, especially under conditions that would require emotion regulation, was also reduced in the emotional go/no-go task compared to controls and was correlated with neuropsychometric measures of emotion regulation. Data from the Libet clock experiment suggested impaired behavioural awareness in DS patients. No evidence of impaired interoceptive awareness was found in the heartbeat counting task.

CONCLUSION

These results represent comprehensive experimental evidence for alterations in emotional and behavioural awareness and control in patients with DS that yield empirical evidence for current psychopathological models. Our findings offer a more detailed understanding of key pathogenic factors in DS and provide theoretical support for recently developed cognitive-behavioural therapies for DS.

What Does Neuroscience Tell Us About the Conversion Model of Functional Neurological Disorders?

A dualistic mind-body understanding of functional neurological disorders (FNDs), also known as conversion disorders, has led to the view that the cause of the symptom should be either psychological (psychogenic) or physical (neurogenic-"organic"). One of the most influential psychological approaches is the Freudian model of conversion, which suggests that FNDs arise from a defense process in which emotional stress is converted into physical symptoms. This conversion theory has been challenged in recent years, accompanied by a shift in emphasis toward neuropathophysiological models of FND and away from historical psychological concepts. In this review, the authors consider the contemporary relevance of the conversion model from the neuroscientific perspective to reconcile the role of both psychological and biological factors in FND. A narrative review of recent neuroscientific findings pertaining to the conversion model of FND, encompassing neuroimaging, cognitive psychology, biological markers, and epigenetic studies, was performed. Research on the role of psychological stressors is discussed. Neurobiological mechanisms of repression of traumatic memories and their translation into physical symptoms are then explored. Finally, the role of physical symptoms as a potential protective defense mechanism against social stressors is considered. The authors argue that the conversion concept is consistent with recent neuroscientific research findings, and the model allows psychological and neurobiological concepts to be reconciled within a single account of FND that begins to resolve the dualistic mind-body dichotomy.

Activation of Functional Brain Networks in Children With Psychogenic Non-epileptic Seizures

Objectives

Psychogenic non-epileptic seizures (PNES) have been hypothesized to emerge in the context of neural networks instability. To explore this hypothesis in children, we applied a graph theory approach to examine connectivity in neural networks in the resting-state EEG in 35 children with PNES, 31 children with other functional neurological symptoms (but no PNES), and 75 healthy controls.

Methods

The networks were extracted from Laplacian-transformed time series by a coherence connectivity estimation method.

Results

Children with PNES (vs. controls) showed widespread changes in network metrics: increased global efficiency (gamma and beta bands), increased local efficiency (gamma band), and increased modularity (gamma and alpha bands). Compared to controls, they also had higher levels of autonomic arousal (e.g., lower heart variability); more anxiety, depression, and stress on the Depression Anxiety and Stress Scales; and more adverse childhood experiences on the Early Life Stress Questionnaire. Increases in network metrics correlated with arousal. Children with other functional neurological symptoms (but no PNES) showed scattered and less pronounced changes in network metrics.

Conclusion

The results indicate that children with PNES present with increased activation of neural networks coupled with increased physiological arousal. While this shift in functional organization may confer a short-term adaptive advantage-one that facilitates neural communication and the child's capacity to respond self-protectively in the face of stressful life events-it may also have a significant biological cost. It may predispose the child's neural networks to periods of instability-presenting clinically as PNES-when the neural networks are faced with perturbations in energy flow or with additional demands.

Stress-system activation in children with chronic pain: A focus for clinical intervention

Accumulating evidence indicates that psychological and neurophysiological processes interconnect and interact to activate the body's stress system and to trigger and maintain functional somatic symptoms. This study used the Early Life Stress Questionnaire, Depression Anxiety Stress Scales and biological markers (heart rate, heart rate variability, skin conductance, C-reactive protein (CRP) titre, respiratory rate, and accuracy and reaction time in an emotion-face identification task), to examine childhood adversity, psychological distress and stress-system activation in 35 children and adolescents (23 girls and 12 boys, 9-17 years old) disabled by chronic pain (vs two groups of age- and sex-matched healthy controls). Patients reported more early-life stress (U = 798.5, p = .026) and more psychological distress (U = 978, p < .001). They showed activation of the autonomic system: elevated heart rate (U = 862.5, p = .003), elevated electrodermal activity (U = 804.5, p = .024) and lower heart rate variability in the time domain (U = 380.5, p = .007) and frequency domain (U = 409.5, p = .017). The group showed an upward shift of CRP titres (with 75th and 90th CRP percentiles of 4.5 and 10.5 mg/L, respectively), suggesting the activation of the immune-inflammatory system. Elevated CRP titres were associated with elevated heart rate (p = .028). There were no differences in respiratory rate or in accuracy and reaction time in the emotion-face identification task. The results indicate that interventions for children and adolescents with chronic pain need a multidisciplinary mind-body approach that concurrently addresses psychological distress, physical impairment and stress-system dysregulation.

Emotional processing in functional neurological disorder: a review, biopsychosocial model and research agenda

Functional neurological disorder (FND) is a common and highly disabling disorder, but its aetiology remains enigmatic. Conceptually, there has been reduced emphasis on the role of psychosocial stressors in recent years, with a corresponding increase in neurobiological explanations. However, a wealth of evidence supports the role of psychosocial adversities (eg, stressful life events, interpersonal difficulties) as important risk factors for FND. Therefore, there is a need to integrate psychosocial (environmental) and neurobiological factors (eg, sensorimotor and cognitive functions) in contemporary models of FND. Altered emotional processing may represent a key link between psychosocial risk factors and core features of FND. Here, we summarise and critically appraise experimental studies of emotional processing in FND using behavioural, psychophysiological and/or neuroimaging measures in conjunction with affective processing tasks. We propose that enhanced preconscious (implicit) processing of emotionally salient stimuli, associated with elevated limbic reactivity (eg, amygdala), may contribute to the initiation of basic affective/defensive responses via hypothalamic and brainstem pathways (eg, periaqueductal grey). In parallel, affect-related brain areas may simultaneously exert a disruptive influence on neurocircuits involved in voluntary motor control, awareness and emotional regulation (eg, sensorimotor, salience, central executive networks). Limbic-paralimbic disturbances in patients with FND may represent one of several neurobiological adaptations linked to early, severe and/or prolonged psychosocial adversity. This perspective integrates neurobiological and psychosocial factors in FND and proposes a research agenda, highlighting the need for replication of existing findings, multimodal sampling across emotional response domains and further examination of emotional influences on sensorimotor and cognitive functions in FND populations.

Processing of Emotion in Functional Neurological Disorder

Emotions have traditionally been considered crucial in the development of functional neurological disorder, but the evidence underpinning this association is not clear. We aimed to summarize evidence for association between functional neurological disorder and emotions as formulated by Breuer and Freud in their conception of hysterical conversion. Based on a systematic literature search, we identified 34 controlled studies and categorized them into four groups: (i) autonomic arousal, (ii) emotion-motion interactions, (iii) social modulation of symptoms, and (iv) bodily awareness in FND. We found evidence for autonomic dysregulation in FND; convergent neuroimaging findings implicate abnormal limbic-motor interactions in response to emotional stimuli in FND. Our results do not provide enough empirical evidence for social modulation of the symptoms, but there is a clinical support for the role of suggestion and placebo in FND. Our results provide evidence for abnormal bodily awareness in FND. Based on these findings, we propose that functional neurological symptoms are forms of emotional reactions shaped into symptoms by previous experience with illness and possibly reinforced by actual social contexts. Additional research should investigate the effect of social context on the intensity of functional neurological symptoms and associated brain regions.

"Motoring in idle": The default mode and somatomotor networks are overactive in children and adolescents with functional neurological symptoms

Objective

Children and adolescents with functional neurological symptom disorder (FND) present with diverse neurological symptoms not explained by a disease process. Functional neurological symptoms have been conceptualized as somatoform dissociation, a disruption of the brain's intrinsic organization and reversion to a more primitive level of function. We used EEG to investigate neural function and functional brain organization in children/adolescents with FND.

Method

EEG was recorded in the resting eyes-open condition in 57 patients (aged 8.5-18 years) and 57 age- and sex-matched healthy controls. Using a topographical map, EEG power data were quantified for regions of interest that define the default mode network (DMN), salience network, and somatomotor network. Source localization was examined using low-resolution brain electromagnetic tomography (LORETA). The contributions of chronic pain and arousal as moderators of differences in EEG power were also examined.

Results

Children/adolescents with FND had excessive theta and delta power in electrode clusters corresponding to the DMN-both anteriorly (dorsomedial prefrontal cortex [dmFPC]) and posteriorly (posterior cingulate cortex [PCC], precuneus, and lateral parietal cortex)-and in the premotor/supplementary motor area (SMA) region. There was a trend toward increased theta and delta power in the salience network. LORETA showed activation across all three networks in all power bands and localized neural sources to the dorsal anterior cingulate cortex/dmPFC, mid cingulate cortex, PCC/precuneus, and SMA. Pain and arousal contributed to slow wave power increases in all three networks.

Conclusions

These findings suggest that children and adolescents with FND are characterized by overactivation of intrinsic resting brain networks involved in threat detection, energy regulation, and preparation for action.

Emotion regulation strategies in trauma-related disorders: pathways linking neurobiology and clinical manifestations

Emotion regulation impairments with traumatic origins have mainly been studied from posttraumatic stress disorder (PTSD) models by studying cases of adult onset and single-incident trauma exposure. The effects of adverse traumatic experiences, however, go beyond the PTSD. Different authors have proposed that PTSD, borderline personality, dissociative, conversive and somatoform disorders constitute a full spectrum of trauma-related conditions. Therefore, a comprehensive review of the neurobiological findings covering this posttraumatic spectrum is needed in order to develop an all-encompassing model for trauma-related disorders with emotion regulation at its center. The present review has sought to link neurobiology findings concerning cortico-limbic function to the field of emotion regulation. In so doing, trauma-related disorders have been placed in a continuum between under- and over-regulation of affect strategies. Under-regulation of affect was predominant in borderline personality disorder, PTSD with re-experiencing symptoms and positive psychoform and somatoform dissociative symptoms. Over-regulation of affect was more prevalent in somatoform disorders and pathologies characterized by negative psychoform and somatoform symptoms. Throughout this continuum, different combinations between under- and over-regulation of affect strategies were also found.

Psychogenic non-epileptic seizures in children and adolescents: Part II - explanations to families, treatment, and group outcomes

Psychogenic non-epileptic seizures (PNES) - time-limited disturbances of consciousness and motor-sensory control, not accompanied by ictal activity on electroencephalogram (EEG) - are best conceptualized as atypical neurophysiological responses to emotional distress, physiological stressors and danger. Patients and families find the diagnosis of PNES difficult to understand; the transition from neurology (where the diagnosis is made) to mental health services (to which patients are referred for treatment) can be a bumpy one. This study reports how diagnostic formulations constructed for 60 consecutive children and adolescents with PNES were used to inform both the explanations about PNES that were given to them and their families and the clinical interventions that were used to help patients gain control over PNES. Families were able to accept the diagnosis of PNES and engage in treatment when it was explained how emotional distress, illness and states of high arousal could activate atypical defence responses in the body and brain - with PNES being an unwanted by-product of this process. Patients and their families made good use of therapeutic interventions. A total of 75% of children/adolescents (45/60) regained normal function and attained full-time return to school. Global Assessment of Functioning scores increased from 41 to 67 ( t(54) = 10.09; p < .001). Outcomes were less favourable in children/adolescents who presented with chronic PNES and in those with a chronic, comorbid mental health disorder that failed to resolve with treatment. The study highlights that prompt diagnosis, followed by prompt multidisciplinary assessment, engagement, and treatment, achieves improved outcomes in children/adolescents with PNES.

Psychogenic non-epileptic seizures in children and adolescents: Part I - Diagnostic formulations

Psychogenic non-epileptic seizures (PNES) are a nonspecific, umbrella category that is used to collect together a range of atypical neurophysiological responses to emotional distress, physiological stressors and danger. Because PNES mimic epileptic seizures, children and adolescents with PNES usually present to neurologists or to epilepsy monitoring units. After a comprehensive neurological evaluation and a diagnosis of PNES, the patient is referred to mental health services for treatment. This study documents the diagnostic formulations - the clinical formulations about the probable neurophysiological mechanisms - that were constructed for 60 consecutive children and adolescents with PNES who were referred to our Mind-Body Rehabilitation Programme for treatment. As a heuristic framework, we used a contemporary reworking of Janet's dissociation model: PNES occur in the context of a destabilized neural system and reflect a release of prewired motor programmes following a functional failure in cognitive-emotional executive control circuitry. Using this framework, we clustered the 60 patients into six different subgroups: (1) dissociative PNES (23/60; 38%), (2) dissociative PNES triggered by hyperventilation (32/60; 53%), (3) innate defence responses presenting as PNES (6/60; 10%), (4) PNES triggered by vocal cord adduction (1/60; 2%), (5) PNES triggered by activation of the valsalva manoeuvre (1/60; 1.5%) and (6) PNES triggered by reflex activation of the vagus (2/60; 3%). As described in the companion article, these diagnostic formulations were used, in turn, both to inform the explanations of PNES that we gave to families and to design clinical interventions for helping the children and adolescents gain control of their PNES.

Grey matter abnormalities in children and adolescents with functional neurological symptom disorder

Objective

Functional neurological symptom disorder refers to the presence of neurological symptoms not explained by neurological disease. Although this disorder is presumed to reflect abnormal function of the brain, recent studies in adults show neuroanatomical abnormalities in brain structure. These structural brain abnormalities have been presumed to reflect long-term adaptations to the disorder, and it is unknown whether child and adolescent patients, with illness that is typically of shorter duration, show similar deficits or have normal brain structure.

Method

High-resolution, three-dimensional T1-weighted magnetic resonance images (MRIs) were acquired in 25 patients (aged 10–18 years) and 24 healthy controls. Structure was quantified in terms of grey matter volume using voxel-based morphometry. Post hoc, we examined whether regions of structural difference related to a measure of motor readiness to emotional signals and to clinical measures of illness duration, illness severity, and anxiety/depression.

Results

Patients showed greater volumes in the left supplementary motor area (SMA) and right superior temporal gyrus (STG) and dorsomedial prefrontal cortex (DMPFC) (corrected p < 0.05). Previous studies of adult patients have also reported alterations of the SMA. Greater SMA volumes correlated with faster reaction times in identifying emotions but not with clinical measures.

Conclusions

The SMA, STG, and DMPFC are known to be involved in the perception of emotion and the modulation of motor responses. These larger volumes may reflect the early expression of an experience-dependent plasticity process associated with increased vigilance to others' emotional states and enhanced motor readiness to organize self-protectively in the context of the long-standing relational stress that is characteristic of this disorder.

•

We used high-resolution MRI to investigate brain structure in children presenting with acute functional neurological symptom disorder (FND).

•

Patients had multiple antecedent stressors, a long-standing history of relational stress and at-risk attachment strategies.

•

Patients had greater volumes in the SMA—where motor-, cognitive-, and emotion-processing signals interact to influence motor function.

•

FND may involve experience-dependent changes in brain structure alongside experience-dependent changes in brain function.

The respiratory control of carbon dioxide in children and adolescents referred for treatment of psychogenic non-epileptic seizures

Psychogenic non-epileptic seizures (PNES) are a common problem in paediatric neurology and psychiatry that can best be understood as atypical responses to threat. Threats activate the body for action by mediating increases in arousal, respiration, and motor readiness. In previous studies, a range of cardiac, endocrine, brain-based, attention-bias, and behavioral measures have been used to demonstrate increases in arousal, vigilance, and motor readiness in patients with PNES. The current study uses respiratory measures to assess both the motor readiness of the respiratory system and the respiratory regulation of CO₂. Baseline respiratory rates during clinical assessment and arterial CO₂ levels during the hyperventilation component of routine video electroencephalogram were documented in 60 children and adolescents referred for treatment of PNES and in 50 controls. Patients showed elevated baseline respiratory rates [t(78) = 3.34, p = .001], with 36/52 (69%) of patients [vs. 11/28 (39%) controls] falling above the 75th percentile (χ² = 6.7343; df = 1; p = .009). Twenty-eight (47%) of patients [vs. 4/50 (8%) controls] showed a skewed hyperventilation-challenge profile—baseline PCO₂ <36 mmHg, a trough PCO₂ ≤ 20 mmHg, or a final PCO₂ <36 mmHg after 15 min of recovery—signaling difficulties with CO₂ regulation (χ² = 19.77; df = 1; p < .001). Children and adolescents with PNES present in a state of readiness-for-action characterized by high arousal coupled with activation of the respiratory motor system, increases in ventilation, and a hyperventilation-challenge profile shifted downward from homeostatic range. Breathing interventions that target arousal, decrease respiratory rate, and normalize ventilation and arterial CO₂ may help patients shift brain–body state and avert PNES episodes.

Cortical arousal in children and adolescents with functional neurological symptoms during the auditory oddball task

OBJECTIVE

Stress, pain, injury, and psychological trauma all induce arousal-mediated changes in brain network organization. The associated, high level of arousal may disrupt motor-sensory processing and result in aberrant patterns of motor function, including functional neurological symptoms. We used the auditory oddball paradigm to assess cortical arousal in children and adolescents with functional neurological symptom disorder.

METHOD

Electroencephalogram (EEG) data was collected in fifty-seven children and adolescents (41 girls; 16 boys, aged 8.5-18 years) with acute functional neurological symptoms and age- sex- matched controls during a conventional auditory oddball task. The high-resolution fragmentary decomposition technique was used to analyse the amplitude of event-related potentials (ERPs) to target tones at midline sites (Fz, Cz, and Pz).

RESULTS

Compared to age- and sex-matched controls, and across all three midline sites, children and adolescents with functional neurological symptoms showed increased amplitude of all ERP components (P50, N100, P200, N200, and P300) (t-value range 2.28-8.20; p value-range 0.023 to < 0.001) to the emotionally-neutral auditory stimulus.

CONCLUSIONS

Our findings add to a growing literature indicating that a baseline state of high arousal may be a precondition for generating functional neurological symptoms, a finding that helps explain why a range of psychological and physiological stressors can trigger functional neurological symptoms in some patients. Interventions that target cortical arousal may be central to the treatment of paediatric patients with functional neurological symptom disorder.

Reduction of autonomic regulation in children and adolescents with conversion disorders

OBJECTIVE

Conversion symptoms--functional neurological disturbances of body function--occur in association with extreme arousal, often in the context of emotional distress. The mechanisms that determine how and why such symptoms occur remain unknown. In this study, we used cardiac measures to assess arousal and cardiac autonomic regulation in children and adolescents who presented with acute conversion symptoms.

METHODS

Heart rate was recorded in 57 children and adolescents (41 girls; 8.5-18 years old) with acute conversion symptoms and 57 age- and sex-matched healthy controls, during a resting condition and then during tasks involving cognitive and emotional activation. Arousal and autonomic regulation were assessed by measures of heart rate and heart rate variability. Psychological measures included attachment and emotional distress.

RESULTS

Children and adolescents with conversion symptoms displayed higher autonomic arousal than did the controls, both at baseline and during task conditions (higher heart rate: baseline mean [standard deviation] = 82 [9.49] versus 74 [10.79] beats/min, p < .001; lower root mean squared successive differences-heart rate variability: 45.35 [27.97] versus 58.62 [25.69] ms(2), p = .012; and lower high-frequency heart rate variability: 6.50 [1.19] versus 7.01 [0.95] ln[ms(2)] p = .017), and decreased autonomic regulation (attenuation of heart rate increases across tasks). The baseline pattern of increased autonomic arousal was especially pronounced in children with coercive-preoccupied patterns of attachment. Autonomic measures were not correlated with measures of emotional distress.

CONCLUSIONS

High autonomic arousal may be a precondition for generating conversion symptoms. Functional dysregulations of the cardiac, respiratory, and circulatory systems may mediate fainting episodes and nonepileptic seizures, and aberrant patterns of functional connectivity between motor areas and central arousal systems may be responsible for generating motor conversion symptoms.

Emotion-motion interactions in conversion disorder: an FMRI study

Objectives

To evaluate the neural correlates of implicit processing of negative emotions in motor conversion disorder (CD) patients.

Methods

An event related fMRI task was completed by 12 motor CD patients and 14 matched healthy controls using standardised stimuli of faces with fearful and sad emotional expressions in comparison to faces with neutral expressions. Temporal changes in the sensitivity to stimuli were also modelled and tested in the two groups.

Results

We found increased amygdala activation to negative emotions in CD compared to healthy controls in region of interest analyses, which persisted over time consistent with previous findings using emotional paradigms. Furthermore during whole brain analyses we found significantly increased activation in CD patients in areas involved in the ‘freeze response’ to fear (periaqueductal grey matter), and areas involved in self-awareness and motor control (cingulate gyrus and supplementary motor area).

Conclusions

In contrast to healthy controls, CD patients exhibited increased response amplitude to fearful stimuli over time, suggesting abnormal emotional regulation (failure of habituation / sensitization). Patients with CD also activated midbrain and frontal structures that could reflect an abnormal behavioral-motor response to negative including threatening stimuli. This suggests a mechanism linking emotions to motor dysfunction in CD.

Functional somatic symptoms in childhood and adolescence

PURPOSE OF REVIEW

Functional somatic symptoms (FSS) are common in children and adolescents, but explanatory models that synthesize research findings are lacking. This article reviews the studies published from January 2012 to March 2013 that investigate the neurophysiological mechanisms that may underlie FSS.

RECENT FINDINGS

Studies from diverse medical disciplines suggest that FSS are associated with functional differences in hypothalamic-pituitary-adrenal function, imbalances in vagal-sympathetic tone, upregulation of immune-inflammatory function, and primed cognitive-emotional responses that serve to amplify reactivity to threatening stimuli, thereby contributing to the subjective experience of somatic symptoms.

SUMMARY

FSS appear to reflect dysregulations of the stress system. When seemingly disparate research findings are interpreted together within an overarching 'stress-system' framework, a coherent explanatory model begins to emerge.