Interoceptive awareness in patients with functional neurological symptoms

Re-PROGRAM: The evaluation of a brief intervention program for patients with functional seizures in an outpatient hospital setting

OBJECTIVE

Functional seizures (FS) account for 20%-25% of referrals to specialist epilepsy clinics. They are associated with major disability, increased mortality, and frequent and costly health care use. Current guidelines emphasize the importance of implementing clinical pathways to coordinate and deliver effective treatment, but there are few targeted evidence-based interventions that reliably improve patient outcomes, and treatment resources are limited. We conducted a retrospective evaluation of Re-PROGRAM, a novel, brief intervention for functional seizure patients, to assess its feasibility in an outpatient setting.

METHODS

Twenty-nine patients with FS undertook Re-PROGRAM between August 2020 and January 2022 at the Alfred Hospital Functional Seizures Clinic, Melbourne, Australia. The intervention comprised five 60-90-min consecutive weekly appointments via telehealth, where psychologists engaged patients in a structured program of seizure management skills, lifestyle modification, and behavioral activation strategies. Following the intervention, patient feedback was collected in routine clinical follow-up as well as with a 24-item self-report pre-/postintervention comparison questionnaire.

RESULTS

All 29 patients who enrolled in Re-PROGRAM completed the scheduled sessions. Of those who returned the postintervention questionnaire (n = 16), 15 reported a reduction in seizure frequency. Four patients were lost to follow-up. Of the remaining nine, eight reported seizure frequency reduction during clinical follow-up. Qualitative analysis of the feedback revealed the majority of patients reported reduced seizure duration, intensity, and bothersomeness, and patients felt improvements in their sense of control over seizures, confidence to use seizure control strategies, assertive communication, problem solving, coping skills, relationships with others, and their day-to-day functioning.

SIGNIFICANCE

This retrospective evaluation demonstrates the feasibility and acceptability of Re-PROGRAM as a brief intervention for individuals diagnosed with FS delivered in a clinical outpatient setting and warrants further investigation in larger scale, randomized controlled studies.

Functional Movement Disorder Is Associated with Abnormal Interoceptive Brain Activity: A Task-based Functional MRI Study

Background

Aberrant interoceptive processing has been hypothesized to contribute to the pathophysiology of functional neurological disorder, although findings have been inconsistent. Here, we utilized functional magnetic resonance imaging (fMRI) to examine neural correlates of interoceptive attention - the conscious focus and awareness of bodily sensations - in functional movement disorder (FMD).

Methods

We used voxelwise analyses to compare blood oxygenation level-dependent responses between 13 adults with hyperkinetic FMD and 13 healthy controls (HCs) during a task requiring attention to different bodily sensations and to an exteroceptive stimulus. Additionally, we examined between-group differences in self-reported measures of interoception and evaluated their relationship with neural activity.

Results

Interoceptive conditions (heartbeat, stomach and 'body', indicating sensations from the body part or limb affected in FMD participants) activated a network involving the precuneus, the posterior cingulate cortex (PCC) and caudate nucleus (CN) bilaterally, and the right anterior insula (aINS) (p <0.05, corrected). Group differences in brain activity were mainly driven by processing of disease-related interoceptive signals, which in the FMD group was associated with a broader neural activation than monitoring gastric interoception, while no group differences were detected during cardiac interoception. Differences based on interoceptive focus (body vs heartbeat and stomach) between FMD subjects and HCs were found in PCC, CN, angular gyrus, thalamus, and in the mid-insula (p <0.05, corrected).

Conclusions

This is, to our knowledge, the first study showing that FMD is associated with abnormal interoceptive processing in regions involved in monitoring body state, attentional focus, and homeostatic inference.

The multidimensional assessment of body representation and interoception in multiple sclerosis

BACKGROUND

The mental representation of the body (or body representation, BR) derives from the processing of multiple sensory and motor inputs and plays a crucial role in guiding our actions and in how we perceive our body. Fundamental inputs for BR construction come also from the interoceptive systems which refer to the whole bidirectional processes between the brain and the body. People with Multiple sclerosis (MS) show an abnormal multisensory integration which may compromise BR and interoception integrity. However, no study has evaluated possible deficits on distinct and dissociable dimensions of body representation (i.e., action-oriented, aBR; and a nonaction-oriented body representation, NaBR) and interoception (i.e., interoceptive accuracy, interoceptive sensibility, and interoceptive awareness) in MS.

OBJECTIVE

In the present study, we aimed to determine whether participants with MS present changes in BR and interoceptive dimensions.

METHODS

We performed comparison analyses on tasks and questionnaires tapping all BR and interoceptive dimensions between 36 people with relapsing-remitting MS (RRMS) and 42 healthy controls, and between 23 people with progressive MS (PMS) and 33 healthy controls.

RESULTS

Overall, patients with MS exhibited lower interoceptive accuracy than matched controls. The RRMS group also showed higher visceral interoceptive sensibility levels. No differences were found in BR accuracy measures, but the PMS reported longer response times when performing the aBR task.

CONCLUSION

These findings open a new issue on the role of inner-signal monitoring in the body symptomatology of MS and highlight the need for an accurate BR and interoceptive assessment in a clinical setting.

The body interior in anorexia nervosa: from interoception to conceptual representation of body interior

Background

Body image disorders are well documented in anorexia nervosa (AN); however, knowledge of interoceptive awareness (IA) in this population remains poor. This descriptive study investigated whether and how the representation of the interior of the body may have an impact on IA.

Methods

The representations and knowledge of the body interior were evaluated with a drawing task in 34 women with AN and 34 healthy controls (HCs). A lexicometric analysis was performed on the vocabulary used to describe the drawn body parts in a structured interview. It was assumed that the conceptual representation of the body interior could be affected by or influence IA. Thus, the relationship between IA, measured with the heartbeat task and the ischemia-induction test, and the drawings was explored. Other scales, such as those of body shape, awareness or satisfaction, were used to assess affective representations of the body.

Results

The drawing, lexicometric and IA results were similar in the two groups. No correlations were found among IA, body representation scores and representation level of body interior. Only the representation of bones by the AN group was significantly different.

Discussion

Increased visual attention to the skeleton or greater awareness of bone health could explain the stronger representation of bones in the AN group. The psychophysical therapy received by some AN participants (73%) did not seem to have influenced IA. Our results do not support a relationship between IA and the representation of the body interior.Clinical trial registration:https://clinicaltrials.gov/, identifier NCT03988218.

Loss and Return of Ticklishness in Functional Neurological Disorder

BACKGROUND

People with functional neurological disorder (FND) have abnormalities in sensory processing. Loss of ticklishness has been rarely reported.

OBJECTIVES

To describe associated clinical features in people with FND and loss of ticklishness and explore correlations with sensory changes.

METHODS

Retrospective audit of clinical letters of people diagnosed with FND in a tertiary clinic and further cases identified in a general neurology clinic.

RESULTS

Thirty-eight patients with loss of ticklishness are described, of which most had other functional sensory symptoms and signs. It was more often localized to one limb, rather than generalized, in those with pain or weakness. Dissociation for the affected body part was often described.

CONCLUSIONS

Loss of ticklishness in FND is frequently described and offers insights into mechanisms of agency, sensory processing and interoception, which are known to be altered in FND.

Predictive Processing and the Pathophysiology of Functional Neurological Disorder

The contemporary neuroscience understanding of the brain as an active inference organ supports that our conscious experiences, including sensorimotor perceptions, depend on the integration of probabilistic predictions with incoming sensory input across hierarchically organized levels. As in other systems, these complex processes are prone to error under certain circumstances, which may lead to alterations in their outcomes (i.e., variations in sensations and movements). Such variations are an important aspect of functional neurological disorder, a complex disorder at the interface of brain-mind-body interactions. Thus, predictive processing frameworks offer fundamental mechanistic insights into the pathophysiology of functional neurological disorder. In recent years, many of the aspects relevant to the neurobiology of functional neurological disorder - e.g., aberrant motor and sensory processes, symptom expectation, self-agency, and illness beliefs, as well as interoception, allostasis, and emotion - have been investigated through the lens of predictive processing frameworks. Here, we provide an overview of the current state of research on predictive processing and the pathophysiology of functional neurological disorder.

Sleepiness and comorbid sleep disorders in functional motor disorders: a comparative study with central hypersomnia

Sleep symptoms, including excessive sleepiness, are frequently reported by patients with functional motor disorders (FMD). We aimed to classify the comorbid sleep disorders in FMD, and to investigate the relationship between subjective sleepiness and objective measures of hypersomnia, comparing them with data from people with central hypersomnia. A total of 37 patients (mean [SD] age 46.4 [11.2] years) with clinically definite FMD, and 17 patients (mean [SD] age 41.1 [11.6] years) with central hypersomnia underwent structured medical and sleep history, neurological examination, polysomnography, multiple sleep latency test (MSLT), and questionnaires assessing sleepiness, fatigue, and depression. In all, 23 patients with FMD (62%) reported excessive daytime sleepiness. Evidence of specific sleep disorders was identified in our cohort, with 35% having restless legs syndrome; 49% obstructive sleep apnea; and 8% periodic limb movements in sleep; however, the presence of these disorders was not correlated with subjective sleepiness. Patients with FMD with self-reported sleepiness reported higher fatigue (p = 0.002), depression (p = 0.002), and had longer sleep latencies in the MSLT (p < 0.001) compared to the patients with central hypersomnia. No correlation was found between subjective and objective sleepiness in either group. Fatigue positively correlated with self-reported sleepiness in patients with FMD (p < 0.001). This study did not find objective correlates of increased sleepiness in patients with FMD. While sleep abnormalities were found to be common in FMD, they were not correlated with self-reports of excessive sleepiness. Positive correlations between self-reported sleepiness and fatigue support the current unified model of non-motor symptoms in FMD.

Forearm bisection task suggests an alteration in body schema in patients with functional movement disorders (motor conversion disorders)

OBJECTIVES

To explore potential alterations of the Body Schema, the implicit sensorimotor representation of one's own body, in patients with Functional Movement Disorders (FMD, Motor Conversion Disorders), characterized by neurological symptoms of altered voluntary motor function that cannot be explained by typical medical conditions. This investigation is prompted by the potential dissociation from their reportedly intact sense of ownership.

METHODS

10 FMD patients and 11 healthy controls (HC) underwent the Forearm Bisection Task, aimed at assessing perceived body metrics, which consists in asking the subject, blindfolded, to repeatedly point at the perceived middle point of their dominant forearm with the index finger of their contralateral hand, and a psychometric assessment for anxiety, depression, alexithymia, and tendency to dissociation.

RESULTS

FMD patients bisected their forearm more proximally (with an increased shift towards their elbow equal to 7.5%) with respect to HC; average bisection point was positively associated with anxiety levels in the whole sample, and with the tendency to dissociation in the FMD group.

CONCLUSIONS

FMD patients perceive their forearm as shorter than HC, suggesting an alteration of their Body Schema. The Body Schema can go through short- and long-term updates in the life course, mainly related to the use of each body segment; we speculate that, despite FMD being a disorder of functional nature, characterized by variability and fluctuations in symptomatology, the lack of sense of agency over a body part might be interpreted by the nervous system as disuse and hence influence the Body Schema, as deficits of organic etiology do.

Thermosensation and emotion: Thermosensory accuracy in a dynamic thermal matching task is linked to depression and anxiety symptomatology

Interoception is related to the generation of bodily feelings and the awareness of ourselves as 'sentient beings', informing the organism about its bodily needs to guarantee survival. Previous studies have reported links among interoception, emotion processing, and mental health. For example, the alignment of interoceptive dimensions (i.e., accuracy, sensibility, awareness) can predict emotional symptoms, such as anxiety. Here, we aimed to investigate the relationship between the perception of a certain type of skin-mediated interoceptive signal, i.e., thermosensation, and self-reported depression, anxiety, and stress. One hundred seventy participants completed the Depression Anxiety Stress Scale (DASS-21) and a dynamic thermal matching task, a static temperature detection task, and a heartbeat counting task. Our results revealed that self-reported anxiety and depression were related to the perception of temperature on hairy and non-hairy skin, respectively: higher anxiety was related to better performance on the thermal matching task on the forearm, while higher depression was related to poorer performance on dynamic and static temperature tasks on the palm. Discrepancies between thermosensory accuracy and sensibility measures ('trait prediction error') were related to heightened anxiety, in line with previous studies. No significant correlations were found between DASS-21 scores and heartbeat counting accuracy. In conclusion, this study suggests that individual differences in thermosensory perception in different areas of the body are associated with self-reported anxiety and depression.

Increasing familiarity with the heartbeat counting task does not affect performance

BACKGROUND

Interoception is typically defined as the processing and perception of internal signals. A common evaluation of interoceptive abilities is the heartbeat counting task, during which participants count their heartbeats over a period of time. It has been argued recently, however, that performance in this task may reflect processes other than cardiac sensation.

OBJECTIVE

This study aimed to: 1) observe heartbeat counting task performance changes across multiple repetitions of the task; and 2) compare performance in the heartbeat counting task with that for a visual counting task to investigate generalised propensities for how uncertain stimuli are reported.

METHODS

Seventy-nine healthy participants performed seven blocks each of the heartbeat and visual counting tasks. Scores for each of the tasks were compared across blocks to identify any change in performance. Performance in the two tasks was then correlated. The study was preregistered at https://doi.org/10.17605/OSF.IO/GWAB7.

RESULTS

Heartbeat counting task performance did not change over blocks. In contrast, scores for the visual counting task reduced over time. A positive correlation was seen between performance in the two tasks (ρ(79) = .27).

CONCLUSION

Heartbeat counting task performance is stable across repetitions of the task, not changing with increasing familiarity. This suggests that non-interoceptive factors, such as beliefs, may be involved. The correlation between the heartbeat and visual counting tasks may point to a general propensity in counting uncertain stimuli across sensory domains. Together, these results raise questions about the interpretation of the heartbeat counting task as a measure of interoception.

Interoception in functional motor symptoms and functional seizures: Preliminary evidence of intact accuracy alongside reduced insight and altered sensibility

Altered interoception may be a pathophysiological mechanism in functional neurological disorder (FND). However, findings have been inconsistent across interoceptive dimensions in FND including functional motor symptoms (FMS) and seizures (FS). Here, individuals with FMS/FS (n = 17) and healthy controls (HC, n = 17) completed measures of interoceptive accuracy and insight (adapted heartbeat tracking task [HTT] with confidence ratings), a time estimation control task (TET) and the Multidimensional Assessment of Interoceptive Awareness-2 (MAIA-2) to assess interoceptive sensibility. The groups did not differ in interoceptive accuracy (p = 1.00, g = 0.00) or confidence (p = .99, g = 0.004), although the FMS/FS group displayed lower scores on the "Not-Distracting" (p < .001, g = 1.42) and "Trusting" (p = .005, g = 1.17) MAIA-2 subscales, relative to HCs. The groups did not differ in TET performance (p = .82, g = 0.08). There was a positive relationship between HTT accuracy and confidence (insight) in HCs (r = .61, p = .016) but not in FMS/FS (r = 0.11, p = .69). HTT confidence was positively correlated with MAIA-2 "Self-Regulation" (r = 0.77, p = .002) and negatively correlated with FND symptom severity (r = -0.84, p < .001) and impact (r = -0.86, p < .001) in FMS/FS. Impaired interoceptive accuracy may not be a core feature in FMS/FS, but reduced insight and altered sensibility may be relevant. Reduced certainty in self-evaluations of bodily experiences may contribute to the pathogenesis of FND symptoms.

Socioemotional self- and co-regulation in functional seizures: comparing high and low posttraumatic stress

Functional seizures (FS) are seizure-like symptoms without electroencephalogram (EEG)-based epileptic activity. Those with FS often show emotion-related dysfunction and disrupted interpersonal relationships, in which posttraumatic stress disorder symptoms (PTS) may play a role. We sought to better understand trauma comorbidities and socioemotional processes in FS, including affectionate touch, a form of social connection linked to emotion regulation and awareness. We administered questionnaires online to a community sample of 89 trauma-exposed FS participants (FS diagnoses were self-reported), 51 with and 38 without clinical-level PTS (FS-PTShi, FS-PTSlo) and 216 seizure-free matched trauma-exposed controls (TCs), 91 with and 125 without clinical-level PTS (TC-PTShi, TC-PTSlo) per the Posttraumatic Stress Disorder Symptom Checklist (PCL). As hypothesized, both FS-PTShi and FS-PTSlo reported more emotional avoidance (Brief Experiential Avoidance Questionnaire), more emotion regulation difficulties (Difficulties in Emotion Regulation Scale), and more perceived stress (Perceived Stress Scale) than PTS-matched counterparts. FS-PTShi also reported less reappraisal (Emotion Regulation Questionnaire), more loneliness (UCLA Loneliness Scale), and less frequent affectionate touch (Physical Affection Scale) during waking and surrounding sleep than TC-PTShi, whereas FS-PTSlo and TC-PTSlo did not differ. Neither FS group differed from PTS-matched controls in emotion suppression (Emotion Regulation Questionnaire) or comfort with social touch (Social Touch Questionnaire). Among FS, FS-PTShi reported more difficulties than FS-PTSlo on nearly all measures (non-significant trend for social support). Findings underscore potential synergistic effects of FS and PTS clinical symptoms in shaping experiences of one's emotions and social world, suggesting fostering meaningful connections with others, including via affectionate touch, is an important treatment target.

Functional neurological disorder: Clinical manifestations and comorbidities; an online survey

Functional Neurological Disorder (FND) is common and is often accompanied by multiple comorbid symptoms and conditions. There have been no large-scale studies exploring the change of its clinical manifestations and comorbidities. We used an online survey to assess FND patient characteristics, changes to fatigue, sleep and pain and comorbid symptoms and diagnoses, as well as treatment strategies. The survey was shared via the charities FND Action and FND Hope. 527 participants were included in the analysis. Most (97.3%) reported experiencing more than one core FND symptom. Many respondents reported associated pain (78.1%), fatigue (78.0%) and sleep disturbances (46.7%) before FND diagnosis which often increased thereafter. Rates of obesity were higher (36.9%) than in the general population. Obesity was associated with increased pain, fatigue and sleep difficulties. There was frequent weight gain after diagnosis. 50.0% of participants reported having other diagnoses prior to FND, while in 43.3% new comorbidities arise after FND diagnosis. Many respondents reported being dissatisfied with their care, expressing a wish for further follow-up from mental health (32.7%) and/or neurological services (44.3%). This large online survey further supports the phenotypic complexity of FND. High rates of pain, fatigue and sleep disturbance exist before diagnosis but monitoring for change is worthwhile. Our study identified major gaps in service provision; we highlight the importance of an open mind regarding change in symptoms; this could aid the early identification and management of co-morbidities, including obesity and migraine, which possibly have a negative impact on FND.

Effects of emotional contexts on respiratory attention task performance

Negative emotions have been found associated with high prevalence of respiratory disease and increased subjective feelings of dyspnea, while positive emotional stimulus has been suggested to alleviate dyspneic feelings. However, the extent to which different emotional contexts affect individuals' respiratory interoceptive attention was not clear. Therefore, the purpose of this study was to investigate the influences of emotional contexts on respiratory interoceptive accuracy, and the relationships between respiratory interoceptive accuracy and negative emotions as well as respiratory symptoms. Fifty-six healthy participants completed the self-reported questionnaires of depression, anxiety, and respiratory symptoms. During the experiment, the participants were instructed to watch one neutral and one positive affective picture series and mentally count the number of perceived occlusions (reported at the end of the trials). The Wilcoxon Signed-Rank test and Spearman's correlations were used to examine the effect of the emotional pictures and to explore the relationships between the level of emotional status or respiratory symptoms and respiratory interoceptive task performance. The significance level was set at p < 0.05. Our results did not show a significant difference in participants' occlusion counting task performance between the neutral and positive emotional context. However, Spearman's Rho correlation analysis revealed that depression level was negatively correlated with accuracy of the task performance in the neutral emotional context, and this relationship diminished in the positive emotional context. In summary, our study demonstrated that negative emotional status, especially depression, may lead to decreased respiratory interoceptive accuracy. Future studies are recommended to test the effect of positive emotional context on respiratory interoceptive task performance in individuals with clinical depression and anxiety.

Dysfunctional Networks in Functional Dystonia

Functional dystonia, the second most common functional movement disorder, is characterized by acute or subacute onset of fixed limb, truncal, or facial posturing, incongruent with the action-induced, position-sensitive, and task-specific manifestations of dystonia. We review neurophysiological and neuroimaging data as the basis for a dysfunctional networks in functional dystonia. Reduced intracortical and spinal inhibition contributes to abnormal muscle activation, which may be perpetuated by abnormal sensorimotor processing, impaired selection of movements, and hypoactive sense of agency in the setting of normal movement preparation but abnormal connectivity between the limbic and motor networks. Phenotypic variability may be related to as-yet undefined interactions between abnormal top-down motor regulation and overactivation of areas implicated in self-awareness, self-monitoring, and active motor inhibition such as the cingulate and insular cortices. While there remain many gaps in knowledge, further combined neurophysiological and neuroimaging assessments stand to inform the neurobiological subtypes of functional dystonia and the potential therapeutic applications.

Autism Spectrum Disorder May Be Highly Prevalent in People with Functional Neurological Disorders

Recent observations suggest that autism spectrum disorder (ASD) co-occurs in people with a functional neurological disorder (FND), but little systematic data are available on the relationship between FND and autism. The study aimed to assess the self-reported autistic traits via a standardized questionnaire and the prevalence of previously diagnosed ASD among people with FND and their 1st-degree relatives. We performed a survey of members of the patient organization FNDHope, using a self-completed questionnaire for screening for autistic traits and ASD: the adult autism subthreshold spectrum (AdAS spectrum). There were 344 respondents diagnosed with FND with a mean age of 39.8 ± 11.6 years (female sex 90%). Eight per cent of respondents volunteered a previous diagnosis of ASD, and 24% reported a 1st-degree relative with a formal diagnosis of ASD, mostly their children. We found that 69% of respondents had scores in the AdAS spectrum indicating a clinically significant ASD and 21% indicating autistic traits. Further studies are needed to provide more evidence regarding the prevalence of ASD in people with FND and how this may influence the aetiology, treatment selection and prognosis.

Emotional arousal in patients with functional movement disorders: A pupillometry study

OBJECTIVE

Pathophysiology explanations for functional movement disorders often assume a role for emotional hyperarousal. Pupillometry is a validated method for evaluation of emotional arousal by detecting changes in pupil size in response to emotional stimuli. In a case-control study design, we aimed to study objective and subjective emotional arousal using pupillometry and affective ratings. To assess attentional engagement by affective stimuli, we used videooculographic tracking of eye movement patterns (scanpath).

METHODS

Twenty-five female patients with functional movement disorders (mean age: 40.9 [SD 12.7] years) and 23 age matched healthy female controls participated in the study. Using infrared high-resolution eye-tracker, both pupil size and eye movement pattern in response to emotionally charged erotic, adventure, threat, victim, and neutral pictures were recorded along with subjective ratings of emotional valence and arousal of the presented pictures.

RESULTS

A between-group comparison showed significantly smaller pupil dilation to adventure stimuli compared to neutral stimuli in patients compared to controls (P < 0.004, bootstrap, uncorr., adj. η2 = 0.00). No significant difference in pupillary response to other stimuli and scanpath parameters was found between the groups. Patients rated significantly lower emotional arousal to erotic pictures than controls (P < 0.001, bootstrap, uncorr., adj. η2 = 0.09).

CONCLUSION

This study did not find evidence of autonomous or subjective emotional hyperarousal. The mismatch between objective autonomic measures and subjective arousal ratings in patients is of pathophysiological interest and in line with recent findings of impaired interoception in functional movement disorders.

Interoceptive accuracy and bias in somatic symptom disorder, illness anxiety disorder, and functional syndromes: A systematic review and meta-analysis

Somatic symptom disorder, illness anxiety disorder, and functional syndromes are characterized by burdensome preoccupation with somatic symptoms. Etiological models propose either increased interoceptive accuracy through hypervigilance to the body, or decreased and biased interoception through top-down predictions about sensory events. This systematic review and meta-analysis summarizes findings of 68 studies examining interoceptive accuracy and 8 studies examining response biases in clinical or non-clinical groups. Analyses yielded a medium population effect size for decreased interoceptive accuracy in functional syndromes, but no observable effect in somatic symptom disorder and illness anxiety disorder. The overall effect size was highly heterogeneous. Regarding response bias, there was a small significant effect in somatic symptom disorder and illness anxiety disorder. Our findings strengthen the notion of top-down factors that result in biased rather than accurate perception of body signals in somatic symptom disorder and illness anxiety disorder.

The relationship between interoception and agency and its modulation by heartbeats: an exploratory study

Interoception, the sense of the internal physiological state of the body, theoretically underpins aspects of self-representation. Experimental studies link feelings of body ownership to interoceptive perception, yet few studies have tested for association between the sense of agency and interoceptive processing. Here, we combined an intentional binding paradigm with cardiac measures of interoceptive processing (behavioural performance on a heartbeat discrimination task, and effects of timing within the cardiac cycle) in twenty-six non-clinical participants as an exploratory study. We found performance accuracy on the heartbeat discrimination task correlated positively with the intentional binding effect, an index of sense of agency (β = 0.832, p = 0.005), even after controlling for effects of age, sex, educational level, heart rate, heart rate variability and time accuracy. The intentional binding effect was enhanced during cardiac systole (compared to diastole) in individuals with greater heartbeat discrimination accuracy (β = 0.640, p = 0.047). These findings support the proposal that interoception contributes to mechanisms underlying the emergence of sense of agency.

Clinical overlap between functional neurological disorders and autism spectrum disorders: a preliminary study

Functional neurological disorders (FNDs) and autism spectrum disorders (ASDs) share common features in terms of deficits in emotion regulation and recognition, sensory sensitivity, proprioception and interoception. Nevertheless, few studies have assessed their overlap. We recruited 21 patients with FNDs, 30 individuals with ASDs without intellectual disabilities and 45 neurotypical adults (NA). Participants completed: the Autism Quotient (AQ); the Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R); and a questionnaire assessing functional neurological symptoms (FNS). ASDs participants also completed the Sensory Perception Quotient-Short Form (SPQ-SF35), assessing sensory sensitivity. In the FNDs sample, no patient scored above the clinical cut-off at the AQ and the 19% scored above the cut-off at the RAADS-R, a prevalence similar to the one we found in NA (15.6%; both p > 0.05). The 86.7% of participants with ASDs reported at least one FNS, a prevalence significantly higher than the NA one (35.6%, p < 0.001). In the ASDs sample, tactile hypersensitivity was found to be a risk factor for functional weakness (OR = 0.74, p = 0.033) and paraesthesia (OR = 0.753, p = 0.019). In conclusions, FNDs individuals did not present autistic traits more than NA, but ASDs individuals presented a higher number of FNSs than NA; this rate was associated with higher sensory sensitivity, especially in the touch domain.

Precentral gyrus and insula responses to stress vary with duration to diagnosis in functional seizures

OBJECTIVE

This study was undertaken to determine whether undiagnosed illness duration (time between functional seizures [FS] onset and diagnosis) is linked to differences in neural response and functional connectivity during processing of stressful experiences.

METHODS

Forty-nine participants with traumatic brain injury preceding the onset of FS confirmed by video-electroencephalography were recruited prospectively. Participants completed psychiatric symptom assessments before undergoing functional magnetic resonance imaging (fMRI) with an acute psychosocial stress task. Linear mixed effects (LME) analyses identified significant interactions between the factors of group (early vs. delayed diagnosis) and time lag to diagnosis on neural responses to stressful math performance and auditory feedback (corrected α = .05). Functional connectivity analysis utilized clusters from initial LME analyses as seed regions to determine significant interactions between these factors on network functional connectivity.

RESULTS

Demographic and psychiatric symptom measures were similar between early (n = 25) and delayed (n = 24) groups. Responses to stressful math performance within the left anterior insula and functional connectivity between the anterior insula seed region and a precentral gyrus cluster were significantly negatively correlated with time lag to diagnosis for the early but not the delayed FS diagnosis group. There was no correlation between fMRI findings and psychiatric symptoms.

SIGNIFICANCE

This study indicates that aberrant left anterior insula activation and its functional connectivity to the precentral gyrus underlie differences in processing of stressful experiences in patients with delayed FS diagnosis. Follow-up comparisons suggest changes are associated with undiagnosed illness duration rather than psychiatric comorbidities and indicate a potential mechanistic association between neuropathophysiology, response to stressful experiences, and functional neuroanatomy in FS.

Hypermobile spectrum disorders symptoms in patients with functional neurological disorders and autism spectrum disorders: A preliminary study

Autism spectrum disorders (ASDs) and functional neurological disorders (FNDs) share some clinical characteristics such as alexithymia, sensory sensitivity and interoceptive issues. Recent evidence shows that both the disorders present symptoms compatible with a diagnosis of hypermobile Ehlers-Danlos Syndrome and hypermobile spectrum disorders (hEDS/HSD), a heterogeneous group of heritable connective tissue disorders characterized by joint hypermobility, skin hyperextensibility, and tissue fragility. Here we compared the prevalence of hEDS/HSD-related symptoms in a group of patients with FNDs, of people with ASDs without intellectual disabilities, and a non-clinical comparison group (NC). Twenty patients with FNDs, 27 individuals with ASDs without intellectual disabilities and 26 NC were recruited and completed the Self-reported screening questionnaire for the assessment of hEDS/HSD-related symptoms (SQ-CH). We found that 55% of the patients with FNDs, 44.4% of the individuals with ASDs and 30.8% of NC scored above the cut-off at the SQ-CH; SQ-CH scores of both FNDs and ASDs group were significantly higher than the NC group's ones. In conclusion, both ASDs and FNDs individuals present hEDS/HSD-related symptoms in a higher number than the general population. Imputable mechanisms include (i) overwhelming of executive functions with consequent motor competence impairment for ASDs individuals, and (ii) exacerbation of FNDs symptoms by physical injury and chronic pain due to abnormal range of joint mobility. Moreover, we speculated that the amygdala and the anterior cingulate cortex circuitry might be responsible for the imbalances at the proprioceptive, interoceptive, and emotional levels.

Sex differences in interoceptive accuracy: A meta-analysis

Interoceptive accuracy, the ability to correctly perceive internal signals arising from the body, is thought to be disrupted in numerous mental and physical health conditions. Whilst evidence suggests poorer interoceptive accuracy in females compared to males, raising the possibility that interoceptive differences may relate to sex differences in mental and physical health, results concerning sex differences in interoceptive accuracy are mixed. Given such ambiguity, this meta-analysis aimed to establish the presence or absence of sex differences in interoceptive accuracy across cardiac, respiratory, and gastric domains. A review of 7956 abstracts resulted in 93 eligible studies. Results demonstrated superior accuracy in males across cardiac, but not gastric, tasks, while findings on respiratory tasks were mixed. Effect sizes were consistent across cardiac tasks, but instability and/or moderate heterogeneity was observed across other domains, likely due to the small number of eligible studies. Despite such limitations, results indicate the possibility of sex differences across interoception tasks and domains. Methodological limitations concerning the influence of physiological factors, and directions for future research are discussed.

Subjective versus objective measures of distress, arousal and symptom burden in patients with functional seizures and other functional neurological symptom disorder presentations: A systematic review

Symptoms and functioning can be measured subjectively using self-report measures or objectively, based on physiological changes. This raises the question whether subjective and objective measures are closely correlated and - if not - whether one is more accurate or meaningful than the other, especially in patients with Functional Seizures (FS) or other Functional Neurological Symptom Disorders (FND), where subjective and objective observations may be thought particularly likely to deviate. This systematic review explores these questions focussing on measures of distress, arousal and symptom burden. Eighteen studies (12 FS, 6 other FND) capturing 396 FND patients were included. Eleven reported no correlation between subjective and objective measures. Only four studies reported significant correlations (r's = -0.74-0.59, p's < 0.05). The small number of studies and diverse methodologies do not provide conclusive answers to the questions posed. Given that subjective and objective measures capture different aspects of current state or function, a combination of measurement approaches is likely to provide optimal information about patients' health state. In view of the attentional and perceptual alterations implicated in FND, the difference between objective and subjective measures may represent an interesting observation in its own right.

Sensory integration in interoception: Interplay between top-down and bottom-up processing

Although the neural systems supporting interoception have been outlined in general, the exact processes underlying the integration of visceral signals still await research. Based on the predictive coding concept, we aimed to reveal the neural networks responsible for the bottom-up (stimulus-dependent) and top-down (model-dependent) processing of interoceptive information. In a study of 30 female participants, we utilized two classical body perception experiments-the rubber hand illusion and a heartbeat detection task (cardioception), with the latter being implemented in fMRI settings. We interpreted a stronger rubber hand illusion, as measured by higher proprioceptive drift, as a tendency to rely on actual sensory experience, i.e., bottom-up processing, while lower proprioceptive drift served as an indicator of the prevalence of top-down, model-based influences. To reveal the bottom-up and top-down processes in cardioception, we performed a seed-based connectivity analysis of the heartbeat detection task, using as seeds the areas with known roles in sensory integration and entering proprioceptive drift as a covariate. The results revealed a left thalamus-dependent network positively associated with proprioceptive drift (bottom-up processing) and a left amygdala-dependent network negatively associated with drift (top-down processing). Bottom-up processing was related to thalamic connectivity with the left frontal operculum and anterior insula, anterior cingulate cortex, hypothalamus, right planum polare and right inferior frontal gyrus. Top-down processing was related to amygdalar connectivity with the rostral prefrontal cortex and an area involving the left frontal opercular and anterior insular cortex, with the latter area being an intersection of the two networks. Thus, we revealed the neural mechanisms underlying the integration of interoceptive information through the interaction between the current sensory experience and internal models.

Maladaptive schemas of patients with functional neurological symptom disorder

BACKGROUND

The psychological underpinnings of functional neurological symptom disorders (FNSD) remain poorly understood. A disintegration of explicit and implicit information processing in patients with FNSD has previously been suggested; however, this suggestion has so far received little empirical support. Trauma and maladaptive schemas probably reinforce disintegration in FNSD. The present study explored the occurrence of maladaptive schemas and investigated the impact of trauma-related maladaptive schemas in patients with FNSD.

METHODS

Forty-eight FNSD patients were assessed at the start of treatment using the Young Schema Questionnaire (YSQ-2) to explore maladaptive schemas. The Life Event Checklist (LEC-5) and the PTSD Checklist for DSM-5 (PCL-5) were used to explore trauma states, and the Sickness Impact Profile (SIP-68) was used to measure health dysfunction.

RESULTS

The self-sacrifice schema scored within a clinically relevant range where no increased scores were found in other maladaptive schemas. Linear regression models showed a positive association between mistrust/abuse and severity of health dysfunction.

DISCUSSION

Results suggest that maladaptive schemas play a modest role in FNSD at the start of treatment. It is suggested to examine the occurrence of maladaptive schemas in FNS-disordered patients with a longitudinal design.

Diseases, Disorders, and Comorbidities of Interoception

Interoception, the sense of the body's internal physiological state, underpins homeostatic reflexes, motivational states, and sensations contributing to emotional experiences. The continuous nature of interoceptive processing, coupled to behavior, is implicated in the neurobiological construction of the sense of self. Aberrant integration and control of interoceptive signals, originating in the brain and/or the periphery, can perturb the whole system. Interoceptive abnormalities are implicated in the pathophysiology of psychiatric disorders and in the symptomatic expression of developmental, neurodegenerative, and neurological disorders. Moreover, interoceptive mechanisms appear central to somatic disorders of brain-body interactions, including functional digestive disorders, chronic pain, and comorbid conditions. The present article provides an overview of disorders of interoception and suggests future directions for better understanding, diagnosis, and management of these disorders.

Disrupted Dorsal Mid-Insula Activation During Interoception Across Psychiatric Disorders

OBJECTIVE

Maintenance of bodily homeostasis relies on interoceptive mechanisms in the brain to predict and regulate bodily state. While altered neural activation during interoception in specific psychiatric disorders has been reported in many studies, it is unclear whether a common neural locus underpins transdiagnostic interoceptive differences.

METHODS

The authors conducted a meta-analysis of neuroimaging studies comparing patients with psychiatric disorders with healthy control subjects to identify brain regions exhibiting convergent disrupted activation during interoception. Bibliographic, neuroimaging, and preprint databases through May 2020 were searched. A total of 306 foci from 33 studies were extracted, which included 610 control subjects and 626 patients with schizophrenia, bipolar or unipolar depression, posttraumatic stress disorder, anxiety, eating disorders, or substance use disorders. Data were pooled using a random-effects model implemented by the activation likelihood estimation algorithm. The preregistered primary outcome was the neuroanatomical location of the convergence of peak voxel coordinates.

RESULTS

Convergent disrupted activation specific to the left dorsal mid-insula was found (Z=4.47, peak coordinates: -36, -2, 14; volume: 928 mm3). Studies directly contributing to the cluster included patients with bipolar disorder, anxiety, major depression, anorexia, and schizophrenia, assessed with task probes including pain, hunger, and interoceptive attention. A series of conjunction analyses against extant meta-analytic data sets revealed that this mid-insula cluster was anatomically distinct from brain regions involved in affective processing and from regions altered by psychological or pharmacological interventions for affective disorders.

CONCLUSIONS

These results reveal transdiagnostic, domain-general differences in interoceptive processing in the left dorsal mid-insula. Disrupted mid-insular activation may represent a neural marker of psychopathology and a putative target for novel interventions.

Early-life trauma endophenotypes and brain circuit-gene expression relationships in functional neurological (conversion) disorder

Functional neurological (conversion) disorder (FND) is a neuropsychiatric condition whereby individuals present with sensorimotor symptoms incompatible with other neurological disorders. Early-life maltreatment (ELM) is a risk factor for developing FND, yet few studies have investigated brain network-trauma relationships in this population. In this neuroimaging-gene expression study, we used two graph theory approaches to elucidate ELM subtype effects on resting-state functional connectivity architecture in 30 patients with motor FND. Twenty-one individuals with comparable depression, anxiety, and ELM scores were used as psychiatric controls. Thereafter, we compared trauma endophenotypes in FND with regional differences in transcriptional gene expression as measured by the Allen Human Brain Atlas (AHBA). In FND patients only, we found that early-life physical abuse severity, and to a lesser extent physical neglect, correlated with corticolimbic weighted-degree functional connectivity. Connectivity profiles influenced by physical abuse occurred in limbic (amygdalar-hippocampal), paralimbic (cingulo-insular and ventromedial prefrontal), and cognitive control (ventrolateral prefrontal) areas, as well as in sensorimotor and visual cortices. These findings held adjusting for individual differences in depression/anxiety, PTSD, and motor phenotypes. In FND, physical abuse also correlated with amygdala and insula coupling to motor cortices. In exploratory analyses, physical abuse correlated connectivity maps overlapped with the AHBA spatial expression of three gene clusters: (i) neuronal morphogenesis and synaptic transmission genes in limbic/paralimbic areas; (ii) locomotory behavior and neuronal generation genes in left-lateralized structures; and (iii) nervous system development and cell motility genes in right-lateralized structures. These circuit-specific architectural profiles related to individual differences in childhood physical abuse burden advance our understanding of the pathophysiology of FND.

Feasibility and effects of a chair-based yoga program for adults with neurodisability

Purpose: This study focuses on exploring the feasibility and the effects of practicing chair-based yoga for 10 weeks on health-related quality of life (HRQoL) and interoceptive body awareness (BA) in adults with neurodisability and moderate to severe physical dependence.Materials and Methods: A pre- and post-testing control group design was followed. Participants were 34 service users at a rehabilitation center. The intervention group (IG, n = 17, 53% men, mean age of 48.6 ± 11.4 years) took part in the 10-week chair-based yoga program. The control group (CG, n = 17, 53% men, mean age of 53.1 ± 11.0 years) received usual care. The outcome measures were feasibility (recruitment rate, attrition, completion rate, adherence, participation, safety and tolerability), HRQoL (WHOQoL-BREF questionnaire), and BA (the Multidimensional Assessment of Interoceptive Awareness, MAIA). Participants in the IG completed a questionnaire to measure their personal experience of participating in the program.Results and Conclusions: This study provides implications for a 10-week chair-based yoga program as a feasible, well-tolerated, and safe intervention, reinforced by the participants' retrospective judgment. Compared to the CG, the program produced statistically significant improvements over BA, such as subscales of MAIA Noticing (p = .031, Hedges g_s = 0.76), Emotional Awareness (p < .001, Hedges g_s = 1.68), and Trusting (p = .036, Hedges g_s = 0.74), but not HRQoL, for the IG. Chair-based yoga programs could be a rehabilitation strategy in the socio-health care of a varied population with physical mobility impairments leading to wheelchair use.Implications for RehabilitationA 10-week chair-based yoga intervention was shown to be a feasible, well-tolerated, and safe therapy which allowed people of varying abilities to participate equitable.Chair-based yoga can help people with moderate to severe physical dependence due to neurodisability to improve their interoceptive body awareness.Chair-based yoga does not have a significant impact on the health-related quality of life of this sample of participants.

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.

One's Interoception Affects the Representation of Seeing Others' Pain: A Randomized Controlled qEEG Study

Objective

This research demonstrates that interoceptive attentiveness (IA) can modulate cortical oscillations related to the emotional and cognitive representations of observing pain in others.

Methods

Twenty participants were required to observe painful/nonpainful stimuli in an individual versus the interactive condition during the recording of the electroencephalogram. The sample was divided into experimental (EXP) and control (CTR) groups, and the EXP group was explicitly required to direct the attention on its interoceptive correlates while observing the stimuli.

Results

Mixed repeated measures, analyses of variance, were applied to each EEG frequency band. Significant findings were obtained mainly for theta and beta bands for the two groups. A hemispheric lateralisation effect was found, with right lateralisation of the theta band for the EXP group when observing painful stimuli and enhanced left activation of theta and beta bands for the CTR group when observing nonpainful stimuli. For both groups, frontal cortical regions were significantly sensitive to social scenarios, while posterior parietal activation was found for stimuli depicting the individual condition.

Conclusions

The results suggest that IA might enhance the emotional representation of painful stimuli, highlighting their negative and unpleasant features in the EXP group, while the attention of the CTR group was mainly drawn to nonpainful stimuli in social and individual conditions, with a positive valence. The role of frontal regions in the processing of social stimuli through social cognition, inducing emotional mirroring and requiring deeper analysis of the social context, was underlined. We propose that IA could be trained for promoting emotion regulation and empathic response.

Exploring three levels of interoception in people with functional motor disorders

INTRODUCTION

A three-level model of interoception has recently been defined. We aim to study the interoceptive processing in individuals with functional motor disorder (FMD).

METHODS

Twenty-two patients with FMD were compared to 23 healthy controls. They underwent a protocol measuring different levels of interoception including: accuracy (a heart-beat tracking task), awareness (participant's confidence level) and sensibility (the Body Awareness Questionnaire-BAQ). Depression, anxiety and alexithymia were assessed by means of validated clinical scales.

RESULTS

The FMD group showed a lower cardiac interoceptive accuracy and sensibility than healthy controls but they did not differ in terms of awareness (p = 0.03 and 0.005 respectively). They were aware of their poor performance in the accuracy task. Cardiac interoceptive accuracy positively correlated with the BAQ sub-scales "Predict Body Reaction" (r = 0.49, p = 0.001) and "Sleep-Wake Cycle" (r = 0.52, p < 0.001). A mediation analysis showed a significant indirect effect of group on cardiac interoceptive accuracy through BAQ "Predict Body Reaction" (b = -2.95, 95% BCa CI[-7.2;-0.2]). The direct effect of group on "Predict Body Reaction" was still significant (b = - 6.95, p = 0.02, 95% CI[-13.18;-0.73]).

CONCLUSIONS

People with FMD have impaired cardiac interoceptive accuracy and sensibility but no difference in metacognitive interoception compared to healthy controls.

Interoception and stress in patients with Functional Neurological Symptom Disorder

INTRODUCTION

Research suggests that patients with Functional Neurological Symptom Disorder (pwFND) struggle to identify their own emotions and associated physiological cues (interoceptive sensitivity, IS). However, it is not known how this deficit interacts with stress. This study aimed to assess IS in pwFND at baseline and following stress induction, and relate the findings to self-reported emotion processing difficulties.

METHODS

Twenty-six pwFND and 27 healthy controls performed the Heart Beat Detection Task pre- and post-stress induction with the Cold Pressor Test. Participants also completed questionnaires assessing anxiety (GAD-7) and depressive symptomology (PHQ-9), as well as emotion processing (EPS-25).

RESULTS

Patients reported deficits in emotion processing (p < . 001) and had lower IS (p = .032) than healthy controls. IS improved following stress induction across both groups (p = .003) but patients' IS was lower than that of healthy controls' pre-and post-stress induction. Exploratory analyses revealed that patients reporting sensory symptoms had lower IS at baseline than patients who did not.

CONCLUSION

Our findings suggest that pwFND are relatively impaired in the identification of their emotions at baseline and following stress induction. This may be related to the experience of functional sensory symptoms and has implications for the psychological treatment of emotion dysregulation in this population.

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.

Relational and affective neuroscience: a quiet revolution in psychiatric and psychotherapeutic practice

We consider some advances in relational and affective neuroscience and related disciplines that attempt to resolve some fundamental aspects of the mind–brain problem. We consider the key role of affect in generating consciousness and in meeting our essential survival needs; the neural correlates of relating; how self and other are represented in the brain and awareness of self and other is generated through interoceptive predictive processes. We describe some leading models of the generation and purpose of consciousness, linking theories of affective and cognitive consciousness. We discuss psychiatric and psychotherapeutic innovations arising from this research, new integrated biopsychosocial interventions and the obstacles to be overcome in applying these models in practice.

What is it like to live with a functional movement disorder? An interpretative phenomenological analysis of illness experiences from symptom onset to post-diagnosis

OBJECTIVES

With few empirically supported treatments, functional movement disorders (FMD) can be challenging to manage. To enable service providers to better support people with FMD, this study sought to understand the lived experience of FMD: to gain insight into how individuals make sense of their experience from symptom onset through medical evaluation and diagnosis to post-diagnostic adaptation.

DESIGN

An interpretative phenomenological analysis (IPA) of patient accounts of living with FMD.

METHODS

Eight participants were recruited from a UK teaching hospital adult neurology service: seven females, varying in age (20s-70s), FMD symptom type (tremor, dystonia, and tics), and time to diagnosis (10 - 192 months). Semi-structured interviews facilitated participant accounts of key events. Interviews lasted 75-125 minutes and were transcribed verbatim.

RESULTS

Three super-ordinate themes were apparent. The first covered the experiences of onset ('Something is wrong with me'), including loss of control - with the affected body part often described as a separate entity - threats to identity and disturbance in relationships. 'At last! What now?' outlined the bittersweet experience of diagnosis and of treatments. Third, 'Living my life with it' incorporated ongoing experiences of coping with symptoms. While some continued to struggle with the emotional impact of symptoms, others developed a compassionate relationship with their self and maintained satisfying activities.

CONCLUSIONS

FMD has a significant impact on patients' relationships with themselves and others, which in turn affects well-being. These findings suggest some nuanced additions to interventions (diagnosis, psychotherapy, physiotherapy, public education.).

Neural activity in functional movement disorders after inpatient rehabilitation

Functional movement disorders (FMD) are a common source of disability in neurology.While treatment of FMD can reduce motor severity and disability, the neural mechanisms implicated in such a response remain unclear. We aimed to investigate neural changes in patients with FMD after a one-week multidisciplinary motor retraining (MoRe) treatment program. Fourteen FMD patients completed an emotional Go/No-Go fMRI task before and after MoRe treatment. Standardized pre- and post-treatment videos were rated for motor severity by a blinded reviewer using the psychogenic movement disorder rating scale (PMDRS). PMDRS scores before and after treatment were used for whole-brain regression. PMDRS scores were significantly reduced after MoRe treatment. Worse severity prior to treatment was associated with greater primary motor cortex (M1) activation at baseline and a larger response to treatment. Globally, increased connectivity between bilateral amygdala and premotor regions was observed following treatment. Lower post-treatment PMDRS scores were associated with increased connectivity between amygdala and ventromedial prefrontal cortex, whereas higher post-treatment PMDRS scores (and poorer treatment response) were associated with increased connectivity between amygdala and M1. Motor retraining in FMD may reorganize activity and connectivity in emotion processing and motor planning networks, with shifts in amygdala connectivity from posterior to frontal/prefrontal regions.

A framework for understanding the pathophysiology of functional neurological disorder

The symptoms of functional neurological disorder (FND) are a product of its pathophysiology. The pathophysiology of FND is reflective of dysfunction within and across different brain circuits that, in turn, affects specific constructs. In this perspective article, we briefly review five constructs that are affected in FND: emotion processing (including salience), agency, attention, interoception, and predictive processing/inference. Examples of underlying neural circuits include salience, multimodal integration, and attention networks. The symptoms of each patient can be described as a combination of dysfunction in several of these networks and related processes. While we have gained a considerable understanding of FND, there is more work to be done, including determining how pathophysiological abnormalities arise as a consequence of etiologic biopsychosocial factors. To facilitate advances in this underserved and important area, we propose a pathophysiology-focused research agenda to engage government-sponsored funding agencies and foundations.

Functional neurological movements in children: Management with a psychological approach

AIM

To develop a cognitive behavioural treatment (CBT) approach that included novel attention training components to support symptom management in children with a primary diagnosis of Functional Movement Disorder (FMD).

METHOD

Eighteen children (9 male and 9 female) with a mean age of 13 years (sd = 2.46, range 10-18 years) were assessed and completed CBT with novel attention training components. Treatment outcomes were measured using the Child Global Assessment Scale (CGAS) which was administered at baseline and post-treatment.

RESULTS

Scores on the CGAS improved significantly post-treatment (p < 0.001) with all participants showing significant change in functioning on the basis of the Reliable Change Index (RCI), with clinically significant change across classification boundaries.

INTERPRETATION

This case series provides support for the use of CBT with attention training components for the management of FMD. Larger trials are necessary to identify which individual treatment components are most effective and to better understand and quantify response to treatment. Future clinical treatment studies would benefit from the inclusion of objective measures of interoception and attentional focus.

Dissociation and interoception in functional neurological disorder

Introduction: We aimed to examine susceptibility to dissociation and the impact of dissociation on interoceptive processing in individuals with functional neurological disorder (FND). We hypothesised that dissociative states would be elevated and interoceptive accuracy and awareness impaired at baseline in people with FND, and that such differences would be exacerbated following acute dissociation. Methods: Nineteen adults with FND were compared to 20 healthy controls. A modified heart-beat tracking task measured interoceptive accuracy and awareness (confidence) before and after a validated dissociation induction procedure. An exteroceptive processing control task was included. Mann-Whitney tests and r-values (effect size) were computed for between-group comparisons. Results: The FND group displayed elevated dissociation at baseline (p = 0.001, r = 0.528) compared to controls which increased following dissociation-induction (p < 0.001, r = 0.663). Interoceptive accuracy did not differ between groups at baseline (p = 0.967, r = 0.009); however, the FND group had lower accuracy scores post-induction (p = 0.021, r = 0.379). A negative correlation (trend) between change scores for dissociation and interoceptive accuracy was noted (r_s = -0.411, p = 0.057). Confidence ratings on interoceptive and exteroceptive processing tasks were lower in the FND group (p-values < 0.05 or <0.01, r-values 0.331-0.489). Conclusions: Individuals with FND experienced greater susceptibility to dissociation, metacognitive deficits and impaired interoceptive accuracy than controls after acute dissociation.

The association of different interoceptive dimensions with functional gastrointestinal symptoms

The aim of the current cross-sectional studies was to investigate the association of interoceptive dimensions with irritable bowel syndrome-related functional gastrointestinal symptoms using a multimethod approach. Two studies were conducted in Hungarian volunteers. Study 1 involved questionnaires regarding interoceptive sensibility. In Study 2, an experimental task was additionally used for the measurement of interoceptive accuracy. Reporters of high functional gastrointestinal symptoms were characterised by an increased perception of different somatic sensations together with a reduced trust in bodily signals. Our results support the hypothesis that there are interactions between interoceptive dimensions in the production of functional somatic symptoms. A data accessibility statement is included.

Trait and state interoceptive abnormalities are associated with dissociation and seizure frequency in patients with functional seizures

OBJECTIVE

Dissociative traits represent a disturbance in selfhood that may predispose to, and trigger, functional seizures (FSs). The predictive representation and control of the internal physiological state of the body (interoception) are proposed to underpin the integrity of the sense of self ("minimal selfhood"). Therefore, discrepancies between objective and subjective aspects of interoception may relate to symptom expression in patients with FSs. Here, we tested whether individual differences in trait measures of interoception relate to dissociative symptoms, and whether state interoceptive deficits predict FS occurrence.

METHODS

Forty-one participants with FSs and 30 controls completed questionnaire ratings of dissociation, and measures of (1) interoceptive accuracy (IA)-objective performance on heartbeat detection tasks; (2) trait interoceptive sensibility-subjective sensitivity to internal sensations (using the Porges Body Perception Questionnaire); and (3) state interoceptive sensibility-subjective trial-by-trial measures of confidence in heartbeat detection. Interoceptive trait prediction error (ITPE) was calculated from the discrepancy between IA and trait sensibility, and interoceptive state prediction error (ISPE) from the discrepancy between IA and state sensibility.

RESULTS

Patients with FSs had significantly lower IA and greater trait interoceptive sensibility than healthy controls. ITPE was the strongest predictor of dissociation after controlling for trait anxiety and depression in a regression model. ISPE correlated significantly with FS frequency after controlling for state anxiety.

SIGNIFICANCE

Patients with FSs have disturbances in interoceptive processing that predict both dissociative traits reflecting the disrupted integrity of self-representation, and the expression of FSs. These findings provide insight into the pathophysiology of functional neurological disorder, and could lead to novel diagnostic and therapeutic approaches.

An Active Inference Approach to Interoceptive Psychopathology

Interoception refers to the process by which the nervous system senses and integrates signals originating from within the body, providing a momentary mapping of the body's internal landscape and its relationship to the outside world. Active inference is based on the premise that afferent sensory input to the brain is constantly shaped and modified by prior expectations. In this review we propose that interoceptive psychopathology results from two primary interoceptive dysfunctions: First, individuals have abnormally strong expectations of the situations that elicit bodily change (i.e., hyperprecise priors), and second, they have great difficulty adjusting these expectations when the environment changes (i.e., context rigidity). Here we discuss how these dysfunctions potentially manifest in mental illness and how interventions aimed at altering interoceptive processing can help the brain create a more realistic model of its internal state.

EMDR as an Adjunctive Psychological Therapy for Patients With Functional Neurological Disorder: Illustrative Case Examples

Functional neurological disorder (FND) is a common diagnosis in neurology clinics, and there is some evidence psychological therapy can be of benefit. Eye movement desensitization and reprocessing therapy (EMDR) is a well-evidenced treatment for posttraumatic stress disorder (PTSD), and there is increasing evidence that it is beneficial for other conditions. EMDR is a therapy designed to focus on distressing memories, and therefore can be used for non-PTSD presentations where distressing memories are relevant. There is a small amount of case study evidence that EMDR can be used successfully with FND presentations and comorbid PTSD. This article describes two illustrative case examples of people diagnosed with FND who have distressing memories relevant to their presentation. Presenting functional symptoms included functional non-epileptic attacks and functional sensory symptoms. Psychological treatment-as-usual plus EMDR resulted in improvements for both cases and demonstrated that EMDR is a promising additional treatment option for FND presentations, appropriately selected. Recommendations regarding further research are made.

Sensory Processing Difficulties in Functional Neurological Disorder: A Possible Predisposing Vulnerability?

BACKGROUND

Functional neurological disorder (FND) is a prevalent neuropsychiatric condition characterized by sensorimotor difficulties. Patients with FND at times report that sensory experiences trigger and/or exacerbate their symptoms. Sensory processing difficulties are also commonly reported in other psychiatric disorders frequently comorbid in FND, suggesting that contextualizing sensory profiles in FND within a biopsychosocial model may be clinically relevant.

OBJECTIVE

To address this literature gap, we conducted a retrospective cohort study to examine sensory processing patterns and their relationship to other neuropsychiatric characteristics in patients with FND.

METHODS

A retrospective chart review design was used to investigate sensory processing patterns, established with the Adolescent/Adult Sensory Profile self-report questionnaire, in 44 patients with FND. Univariate analyses of cross-sectional screening tests followed by multivariate linear regression analyses were performed to identify clinical factors associated with sensory processing scores in the FND cohort.

RESULTS

Compared to normative data, most patients with FND reported sensory processing tendencies toward low registration, sensory sensitivity, and sensation avoiding. In multivariate regression analyses, the presence of a lifetime anxiety disorder independently predicted elevated low registration scores, while female gender and number of current medications independently predicted increased sensory sensitivity scores. In uncorrected univariate analyses only, individuals with psychogenic nonepileptic seizures were more likely to report increased sensory sensitivity and elevated low registration.

CONCLUSION

These preliminary findings support sensory processing difficulties in some patients with FND. Prospective and large sample size studies are needed to investigate relationships between sensory processing profiles and neuropsychiatric comorbidities, FND subtypes, and treatment outcomes.

Raised visual contrast thresholds with intact attention and metacognition in functional motor disorder

Functional motor disorders (FMDs) are distinguished by signs that lack congruence with recognised patterns of organic disease and show inconsistency over time. Their pathophysiology is poorly understood, but there is evidence that irregularities in perceptual and cognitive processing lie at the heart of these conditions. Here, we draw on a predictive coding account of functional neurological disorders to study perceptual decision-making in three groups: 20 patients with FMDs (14 with functional movements and 6 with functional weakness), 20 with phenotypically-matched organic motor disorders, and 20 age-matched healthy controls. We examine four cognitive domains with putative roles in FMD pathogenesis: attention, expectations, sensory processing (perceptual sensitivity), and metacognition (introspective evaluation of performance). We augmented a dual-task paradigm, manipulating the visual contrast required for target detection to examine these domains in one design. With sensory input (stimulus contrast) psychometrically adjusted to staircase target detection at a fixed level for all groups, the FMD group exhibited statistically equivalent attentional, expectational and metacognitive processing to healthy controls. However, we demonstrate Bayesian evidence and a frequentist trend that FMD patients require higher visual contrast than controls to maintain the same detection sensitivity (BF₁₀ = 8.1, p_holm = .066). This was statistically equivalent to the visual contrast required by the organic group, and unlikely to be accounted for by medication use or comorbid psychopathology. The organic group showed differences in processing of attention and expectations for target detection that were not observed in either healthy controls or the functional group. The distinctive behavioural profile of FMDs may arise from abnormalities in basic sensory processing, while higher attentional, expectational and metacognitive mechanisms remain intact. Conceptualising functional neurological disorders under a predictive coding account may consolidate and refine existing pathophysiological theories about them.

Interoceptive awareness in focal brain-damaged patients

BACKGROUND

Interoception is the basic process enabling evaluation of one's own internal state of body, but its alteration in brain-damaged patients has not been adequately investigated. Our study aimed to investigate awareness of visceral and somatosensorial sensations in brain-damaged patients with unilateral stroke.

METHODS

Sixty patients (22 with left brain damage, LP; 25 with right brain damage without neglect, RPN-; and 13 with right brain-damage and extrapersonal and/or personal neglect, RPN+) and 45 healthy controls (HC) completed the Self-Awareness Questionnaire (SAQ), a self-report tool for assessing interoceptive awareness with two domains related to visceral (VD) and somatosensory feelings (SD), respectively.

RESULTS

Comparing the SAQ subdomains scores between three groups of patients (LP, RPN-, and RPN+) and HC, we found that RPN+ had significantly lower scores on VD than HC and LP, whereas no significant difference was found on scores of SD between groups.

CONCLUSION

Our results support the hypothesis of a right-hemispheric dominance for "interoceptive neural network" suggesting that processing of visceral sensations would be located mainly in the right hemisphere. Therefore, a careful assessment of interoceptive awareness in clinical practice would be useful to improve rehabilitation and to engage patients with deficit of interoceptive awareness in developing greater accuracy of body signals.