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Introduction: Advances have been made in understanding the aetiology of functional neurological disorder (FND); however, its pathophysiological mechanisms have not been definitively demonstrated. Evidence suggests interacting roles for altered emotional processing and interoception, elevated autonomic arousal, and dissociation, but there is limited evidence demonstrating their causal influence on specific FND symptoms. Our superordinate aim is to elucidate potentially shared and distinct aetiological factors and mechanisms in two common FND subtypes, functional seizures (FS) and functional motor symptoms (FMS). Methods: This study has a multimodal, mixed between- and within-groups design. The target sample is 50 individuals with FS, 50 with FMS, 50 clinical controls (anxiety/depression), and 50 healthy controls. Potential aetiological factors (e.g., adverse life events, physical/mental health symptoms, dissociative tendencies, interoceptive insight/sensibility) will be assessed with a detailed medical history interview and self-report questionnaires. A laboratory session will include a neurocognitive battery, psychophysiological testing, cardiac interoception and time estimation tasks and an isometric handgrip task. A subsample will undergo magnetic resonance imaging, including structural, resting-state and task-based scans combined with psychophysiological recording. Remote monitoring with ecological momentary assessment and wearables will measure variability in FND symptoms and their potential predictors/correlates for ≥2 weeks in patients' daily lives. Longitudinal follow-ups at 3, 6, and 12-months will monitor longer-term outcomes in the clinical groups. Discussion: This study employs multimodal research methods to rigorously examine several putative mechanisms in FND, at subjective/experiential, behavioural, and physiological levels. The study will test causal hypotheses about the role of altered emotional processing, autonomic arousal, dissociation and interoception in the initiation or exacerbation of FND symptoms, directly comparing these processes in FS and FMS to healthy and clinical controls. This is the first study of its kind, with potential to reveal important targets for prevention and treatment of FND in future. [ABSTRACT FROM AUTHOR]

This study aimed to provide a preliminary assessment of objective and subjective neurocognitive functioning in individuals with functional motor symptoms (FMS) and/or functional seizures (FS). We tested the hypotheses that the FMS/FS group would display poorer objective attentional and executive functioning, altered social cognition, and reduced metacognitive accuracy. Individuals with FMS/FS (n = 16) and healthy controls (HCs, n = 17) completed an abbreviated CANTAB battery, and measures of intellectual functioning, subjective cognitive complaints, performance validity, and comorbid symptoms. Subjective performance ratings were obtained to assess local metacognitive accuracy. The groups were comparable in age (p = 0.45), sex (p = 0.62), IQ (p = 0.57), and performance validity (p-values = 0.10–0.91). We observed no impairment on any CANTAB test in this FMS/FS sample compared to HCs, although the FMS/FS group displayed shorter reaction times on the Emotional Bias task (anger) (p = 0.01, np2 = 0.20). The groups did not differ in subjective performance ratings (p-values 0.15). Whilst CANTAB attentional set-shifting performance (total trials/errors) correlated with subjective performance ratings in HCs (p-values<0.005, rs = −0.85), these correlations were non-significant in the FMS/FS sample (p-values = 0.10–0.13, rs-values = −0.46–0.50). The FMS/FS group reported more daily cognitive complaints than HCs (p = 0.006, g = 0.92), which were associated with subjective performance ratings on CANTAB sustained attention (p = 0.001, rs = −0.74) and working memory tests (p < 0.001, rs = −0.75), and with depression (p = 0.003, rs = 0.70), and somatoform (p = 0.003, rs = 0.70) and psychological dissociation (p-values<0.005, rs-values = 0.67–0.85). These results suggest a discordance between objective and subjective neurocognitive functioning in this FMS/FS sample, reflecting intact test performance alongside poorer subjective cognitive functioning. Further investigation of neurocognitive functioning in FND subgroups is necessary. [ABSTRACT FROM AUTHOR]

Functional neurological disorder (FND) represents a broad group of motor and sensory clinical symptoms which cannot be explained by other neurological diagnoses. Dissociation is considered a key mechanism in their development and maintenance. Despite psychological therapy being the recommended choice of treatment for FND, evidence for its effectiveness is in its infancy. This study explored the dissociative profile of forty-seven patients with FND and evaluated whether individual psychological therapy improved dissociative symptoms, psychological distress and general functioning among twenty-five adults with FND. Patients completed the Multiscale Dissociation Inventory, the EuroQol five-dimensional descriptive system, the General Anxiety Disorder-7 scale and the Patient Health Questionnaire-9. Our sample showed high levels of disengagement, depersonalization and memory disturbance at baseline. Treatment was associated with significant improvements in general functioning, and symptoms of dissociation and anxiety. Improvements in dissociative experiences were found to be possibly due to reduction in anxiety. Improvements in depression were the strongest predictor of improvements in general functioning. Limitations and areas for further research are discussed. [ABSTRACT FROM AUTHOR]

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 (rs = −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. [ABSTRACT FROM AUTHOR]

People with dissociative seizures (DS) report a range of difficulties in emotional functioning and exhibit altered responding to emotional facial expressions in experimental tasks. We extended this research by investigating subjective and autonomic reactivity (ratings of emotional valence, arousal and skin conductance responses [SCRs]) to general emotional images in 39 people with DS relative to 42 healthy control participants, whilst controlling for anxiety, depression, cognitive functioning and, where relevant, medication use. It was predicted that greater subjective negativity and arousal and increased SCRs in response to the affective pictures would be observed in the DS group. The DS group as a whole did not differ from controls in their subjective responses of valence and arousal. However, SCR amplitudes were greater in ‘autonomic responders’ with DS relative to ‘autonomic responders’ in the control group. A positive correlation was also observed between SCRs for highly arousing negative pictures and self‐reported ictal autonomic arousal, in DS ‘autonomic responders’. In the DS subgroup of autonomic ‘non‐responders’, differences in subjective responses were observed for some conditions, compared to control ‘non‐responders’. The findings indicate unaffected subjective responses to emotional images in people with DS overall. However, within the group of people with DS, there may be subgroups characterized by differences in emotional responding. One subgroup (i.e., ‘autonomic responders’) exhibit heightened autonomic responses but intact subjective emotional experience, whilst another subgroup (i.e., ‘autonomic non‐responders’) seem to experience greater subjective negativity and arousal for some emotional stimuli, despite less frequent autonomic reactions. The current results suggest that therapeutic interventions targeting awareness and regulation of physiological arousal and subjective emotional experience could be of value in some people with this disorder. [ABSTRACT FROM AUTHOR]

This study sought to extend knowledge about the previously reported preconscious attentional bias (AB) for facial emotion in patients with dissociative seizures (DS) by exploring whether the finding could be replicated, while controlling for concurrent anxiety, depression, and potentially relevant cognitive impairments. Patients diagnosed with DS (n = 38) were compared with healthy controls (n = 43) on a pictorial emotional Stroop test, in which backwardly masked emotional faces (angry, happy, neutral) were processed implicitly. The group with DS displayed a significantly greater AB to facial emotion relative to controls; however, the bias was not specific to negative or positive emotions. The group effect could not be explained by performance on standardized cognitive tests or self-reported depression/anxiety. The study provides additional evidence of a disproportionate and automatic allocation of attention to facial affect in patients with DS, including both positive and negative facial expressions. Such a tendency could act as a predisposing factor for developing DS initially, or may contribute to triggering individuals' seizures on an ongoing basis. Psychological interventions such as Cognitive Behavioral Therapy (CBT) or AB modification might be suitable approaches to target this bias in clinical practice. [ABSTRACT FROM AUTHOR]

Quantitative research has indicated that patients with dissociative seizures (DS) show altered responses to emotional stimuli, in addition to considerable emotional distress and dysregulation. The present study sought to further explore emotional processes in this population, to extend previous findings, and to provide a phenomenological insight into patients' perspectives on these issues. Semistructured interviews were carried out with 15 patients with DS, and the principles of interpretative phenomenological analysis (IPA) were adopted in data analysis. Key themes elicited included: i) general emotional functioning; ii) adverse (stressful/traumatic) life experiences; iii) the role of emotions in DS; iv) relating to others; and v) resilience, protective factors, and coping mechanisms. The clinical and theoretical implications of the findings are discussed. [ABSTRACT FROM AUTHOR]

Aims: To explore the acceptability and barriers to the introduction of nurse-led routine screening and brief interventions (SBI) for alcohol misuse on general in-patient hospital wards. Methods: Screening was introduced on an in-patient ward at three general hospitals. Screening rates, numbers of referrals to alcohol liaison nurses (ALNs), brief interventions conducted and patients’ access to specialist alcohol services at follow-up were measured. Semi-structured qualitative interviews were conducted to explore staff/patient attitudes. Findings: Screening rates ranged from 17.7% to 36.6% in the three wards. The highest rates of screening and positive screening scores were recorded on a gastrointestinal (GI) ward. Attitudes of staff and patients towards the SBI process were generally positive; however, a number of current barriers to its implementation were identified. Conclusions: In order for the SBI approach to be incorporated into routine procedures in in-patient medical settings it may be necessary to provide ongoing support and training from specialist alcohol workers, and to have mechanisms that ensure the screen remains part of routine nursing documentation. [ABSTRACT FROM AUTHOR]

Background and purpose Methods Results Conclusions Cognitive complaints are common in functional neurological disorder (FND), but it is unclear whether objective neurocognitive deficits are present. This systematic review summarized validated/standardized cognitive test performance in FND samples across cognitive domains.Embase, PsycInfo and MEDLINE were searched from inception to 15 May 2023, combining terms for FND and cognitive domains (e.g., attention, memory, executive functioning). Studies included a range of FND phenotypes (seizures, motor, cognitive disorder, mixed), compared to healthy or clinical controls. Risk of bias was assessed with the modified Newcastle–Ottawa Scale and a qualitative synthesis/narrative review of cognitive performance in FND was conducted. Test performance scores were extracted, and random effects meta‐analyses were run where appropriate. This review was registered on PROSPERO, CRD42023423139.Fifty‐six studies including 2260 individuals with FND were eligible. Although evidence for some impairments emerged across domains of executive functioning, attention, memory and psychomotor/processing speed, this was inconsistent across studies and FND phenotypes. Common confounds included group differences in demographics, medication and intellectual functioning. Only 24% of studies objectively assessed performance validity. Meta‐analyses revealed higher scores on tests of naming (g = 0.67, 95% confidence interval [CI] 0.50, 0.84) and long‐term memory (g = 0.43, 95% CI 0.13, 0.74) in functional seizures versus epilepsy, but no significant differences in working (g = −0.08, 95% CI −0.44, 0.29) or immediate (g = 0.25, 95% CI −0.02, 0.53) memory and cognitive flexibility (g = −0.01, 95% CI −0.29, 0.28).There is mixed evidence for objective cognitive deficits in FND. Future research should control for confounds, include tests of performance validity, and assess relationships between objective and subjective neurocognitive functioning. [ABSTRACT FROM AUTHOR]

Identification of clinical features that might distinguish psychogenic nonepileptic seizures (PNES) from epileptic seizures (ES) is of value for diagnosis, management, and understanding of both conditions. Previous studies have shown that patients' descriptions of their seizures reflect differences in content and delivery. We aimed to compare verbal descriptions of PNES and ES using a mixed-methods approach. We analyzed data from semi-structured interviews in which patients with video-electroencephalography (EEG)-confirmed ES (n = 30) or PNES (n = 10) described their seizures. Two masked raters independently coded the transcripts for relevant psychological categories and discrepancies that were noted and resolved. Additional analyses were conducted using the Linguistic Inquiry and Word Count system. The identified phenomena were descriptively compared, and inferential analyses assessed group differences in frequencies. A logistic regression analysis examined the predictive power of the most distinctive phenomena for diagnosis. As compared with ES, PNES reported longer seizures, more preseizure negative emotions (e.g., fear), anxiety symptoms (e.g., arousal, hyperventilation), altered vision/olfaction, and automatic behaviors. During seizures, PNES reported more fear, altered breathing, and dissociative phenomena (depersonalization, impaired time perception). Epileptic seizures reported more self-injurious behavior. Postseizure, PNES reported more fear and weeping and ES more amnesia and aches. The predictive power when including these variables was 97.5%. None of the single predictor variables was significant. The few but consistent linguistic differences related to the use of some pronouns and references to family. Although no single clinical feature definitively distinguishes PNES from ES, several features may be suggestive of a PNES diagnosis, including longer duration, negative emotion (i.e., fear) throughout the events, preseizure anxiety, ictal dissociation, and postseizure weeping. Fewer reports of ictal self-injury and postseizure amnesia and aches may also indicate the possibility of PNES. • No single feature distinguished PNES from ES. • Psychogenic nonepileptic seizures reported longer seizures, more negative emotions, and anxiety. • Epileptic seizures reported more ictal self-injury, postseizure amnesia, and aches. • Epileptic seizures used more words related to "he/she," "they," and "family." [ABSTRACT FROM AUTHOR]

Objectives: We report routinely collected outcome data from an 8-week outpatient rehabilitative therapy program. The aims of the intervention were to (1) reduce symptom severity and (2) improve functional mobility in adults with functional neurological disorder (FND). Methods: The program delivered individual physiotherapy, cognitive behavioral therapy (CBT) and self-management sessions, group physiotherapy, and psychoeducation. Outcome measures included the Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI-II), Work and Social Adjustment Scale (WSAS), 10-Meter Walk Test (10MWT), Timed Up and Go (TUG), and Berg Balance Scale (BBS). Data were analyzed retrospectively in accordance with routine service evaluation. Wilcoxon signed-rank tests assessed changes in outcomes between weeks 1 and 8 for all patients completing treatment (n = 45). For patients who attended the 3-month follow-up (n = 31), Friedman's ANOVA assessed overall change in outcomes over time. Post hoc Wilcoxon signed-rank tests compared pairs of time-points (Weeks 1, 8, and 3-month follow-up). Results: Analyses of patients completing the program revealed significant improvements in scores between week 1 and week 8. Excluding the BBS, there were statistically significant improvements in all outcomes between weeks 1 and 8 and between weeks 1 and 3-month follow-up. Discussion: This outpatient therapy program provided effective treatment for FND. Patients reported reduced anxiety, depression, and functional impairment, as well as improved performance on most physiotherapy measures. [ABSTRACT FROM AUTHOR]

(2) When MT filled out the Depression, Anxiety, and Stress Scales (DASS) with her mother - and scored 48 of the possible score of 63 (very high) - her mother understood that MT perceived the cumulative stressors that she had experienced as very substantial.[2] (3) MT's parents - and the team - realized that MT's recovery process would take longer than was typical for young children and that they needed to prepare for the long haul. Stephen Porges, PhD As a consultant in this Clinical Challenge, I see my role as twofold: (1) to explain the core mechanisms that would manifest in a subset of symptoms experienced by MT, and (2) to explain how modulated vocalizations/music would function as a neuromodulator to optimize neurophysiological regulation and reduce MT's symptoms. It is important to note, however, that analgesia is achieved at lower doses than those needed to address depression[83] and that tricyclics are ineffective for depression in youth.[84] As was evident in MT's case, patients with functional seizures often present in a high state of physiological arousal.[85] Given that alpha agonist medications, such as the guanfacine used with MT, often decrease sympathetic arousal, they may be helpful with FND symptoms.[[86]] Anticonvulsants are also often prescribed for patients with FND. As expected, MT's symptoms improved when parents and teachers minimized attention to her symptoms The multidisciplinary approach involves intervening in patients' illness beliefs, reducing maladaptive behaviors,[78] minimizing and normalizing functional symptoms, addressing problematic family dynamics, and emphasizing the importance of restoring functioning, along with psychoeducation.[79] This approach was paramount in achieving a positive outcome in MT's case. [Extracted from the article]

• Mental health and neurodevelopmental disorders are common in childhood epilepsy. • Timely detection and intervention for these comorbidities is critical. • We reviewed and evaluated mental health PROMs designed for paediatric epilepsy. • There were few validated PROMs for mental health outcomes in this population. • Development and validation of childhood epilepsy mental health PROMs is needed. Children and young people with epilepsy are at higher risk of mental health disorders and atypical neurodevelopmental outcomes compared to the general population. It is essential to detect such comorbidities early in children with epilepsy and provide appropriate interventions, to improve clinical outcomes. We aimed to identify and evaluate the measurement properties of Patient-Reported Outcome Measures (PROMs) that have been validated specifically to measure mental health and neurodevelopmental outcomes in children and/or young people with epilepsy. We searched Embase, Medline, and PsycINFO in May 2023 for relevant studies. Mental health was defined as psychological symptoms (e.g., anxiety, depression, psychosis) and/or behavioural difficulties (e.g., conduct disorders). Neurodevelopmental outcomes included neurodevelopmental disorder traits such as attention-deficit hyperactivity disorder (ADHD) and autistic spectrum disorders. We assessed methodological quality using Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) guidance. Twelve papers were identified that psychometrically evaluated 13 relevant PROMs (two epilepsy-specific, eleven generic). The appraisal of the PROMs was limited by the availability of only one or two published articles for each, and incomplete psychometric evaluations in some cases. The tool demonstrating the strongest evidence was The Neurological Disorders Depression Inventory-Epilepsy for Youth. The ADHD Rating Scale-IV and The Paediatric Symptom Checklist -17 demonstrated good evidence in favour of at least two measurement properties. This review identified only a small number of mental health and neurodevelopmental PROMs evaluated specifically in paediatric epilepsy. There is a need for further validation of mental health and neurodevelopmental PROMs in children with epilepsy. [ABSTRACT FROM AUTHOR]

Background and purpose: Functional neurological disorder (FND) is common, and symptoms can be severe. There have been no international large‐scale studies of patient experiences of FND. Methods: A patient questionnaire was created to assess FND patient characteristics, symptom comorbidities and illness perceptions. Respondents were recruited internationally through an open access questionnaire via social media and patient groups over a month‐long period. Results: In total, 1048 respondents from 16 countries participated. Mean age was 42 years (86% female). Median FND symptom duration was 5 years, and median time from first symptom to diagnosis was 2 years. Mean number of current symptoms (core FND and associated) was 9.9. Many respondents had associated symptoms, for example fatigue (93%), memory difficulties (80%) and headache (70%). Self‐reported psychiatric comorbidities were relatively common (depression, 43%; anxiety, 51%; panic, 20%; and post‐traumatic stress disorder, 22%). Most respondents reported that FND had multiple causes, including physical and psychological. Conclusions: This large survey adds further evidence that people with FND typically have high levels of multiple symptom comorbidity with resultant distress. It also supports the notion that associated physical symptoms are of particular clinical significance in FND patients. Dualistic ideas of FND were not supported by respondents, who generally preferred to conceptualize the disorder as one at the interface of mind and brain. The need for a broad approach to this poorly served patient group is highlighted. Potential selection and response biases due to distribution of the survey online, mostly via FND patient groups, are a key limitation. [ABSTRACT FROM AUTHOR]

The aim of the study was to examine the effects of acute dissociation on emotional responsivity in healthy individuals. We used a previously validated technique (mirror-gazing, Caputo, 2010) to experimentally induce acute dissociation in non-clinical participants and assessed post-induction subjective responsivity (ratings of valence and arousal) to standardized emotional images. Fifty non-clinical participants were randomised to either the dissociation induction (n = 25) or control conditions (n = 25). The dissociation manipulation effect was corroborated by a significant post-induction elevation in state dissociation in the dissociation-induction group relative to controls (p =.004). The dissociation-induction group rated negative (p =.028) and neutral (p =.025) stimuli as significantly less unpleasant than controls. There was also a non-significant trend for positive stimuli to be rated as less pleasant by the dissociation-induction group compared to controls (p =.060). These findings provide experimental evidence for the short-term alleviation (i.e., emotional numbing) of negative affect during dissociative states, which may serve as a coping mechanism for some individuals. However, this tendency of emotional numbing also reduced positive affective responses to pleasant stimuli to some extent. Further investigation of dissociative phenomena and their impact on emotional processing appears warranted. • The dissociation induction procedure successfully elicited acute state dissociation. • The dissociation-induction group displayed post-induction emotional numbing. • They rated negative and neutral images as less unpleasant than controls. [ABSTRACT FROM AUTHOR]

The aim of this multicenter international cross-cultural study was to compare clinical variables in a large sample of people with adult-onset psychogenic nonepileptic seizures (PNES). In this retrospective study, we evaluated persons with documented PNES, who were older than 16 years of age at the onset, from four countries (i.e., Iran, Brazil, Venezuela, and Argentina) regarding their age, gender, PNES semiology, and possible predisposing factors. We included 389 patients (244 from Iran, 66 from Brazil, 51 from Venezuela, and 28 from Argentina). Age at diagnosis was 32 ± 9 years (range: 17–64 years), and age at the onset of seizures was 27 ± 8 years (range: 17–49 years). There was a female predominance in all countries. The demographic characteristics and factors associated with PNES were similar among the countries. However, there were significant semiological differences among the countries. This study corroborates the notion that PNES share more similarities than differences cross-culturally and across international borders. However, the background determined by cultural, ethnic, and religious differences may influence the semiology of PNES. Further cross-cultural studies involving more than two continents may advance our understanding of PNES. • We included 389 patients (244 from Iran, 66 from Brazil, 51 from Venezuela, and 28 from Argentina). • There was a female predominance in all countries. • The demographic characteristics and factors associated with PNES were similar among the countries. • However, there were significant semiological differences among the countries. [ABSTRACT FROM AUTHOR]

Sex-related differences have been reported in patients with neurological and psychiatric disorders. It is also plausible to assume that there might be differences between females and males with psychogenic nonepileptic seizures (PNES). In this retrospective study, we investigated patients with PNES, who were admitted to the epilepsy monitoring units at centers in Iran, the USA, Canada, Brazil, Argentina, and Venezuela. Age, sex, age at seizure onset, seizure semiology, factors potentially predisposing to PNES, and video-electroencephalography recording of all patients were registered routinely. Four hundred and fifty-one patients had PNES-only and were eligible for inclusion; 305 patients (67.6%) were females. We executed a logistic regression analysis, evaluating significant variables in univariate analyses (i.e., age, age at onset, aura, presence of historical sexual or physical abuse, and family dysfunction). The only variables retaining significance were historical sexual abuse (p = 0.005) and presence of aura (p = 0.01); physical abuse was borderline significant (p = 0.05) (all three were more prevalent among females). Similarities between females and males outweigh the differences with regard to the demographic and clinical characteristics of PNES. However, notable differences are that females more often report lifetime adverse experiences (sexual and probably physical abuse) and auras. While social, psychological, and genetic factors may interact with lifetime adverse experiences in the inception of PNES, the link is not yet clear. This is an interesting avenue for future studies. • Four hundred and fifty-one patients had PNES-only and were studied. • 305 patients (67.6%) were females. • History of sexual abuse and presence of aura were more prevalent among females. [ABSTRACT FROM AUTHOR]

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. • Intact interoceptive accuracy in functional motor symptoms/seizures (FMS/FS). • Potentially reduced interoceptive insight in FMS/FS versus healthy controls (HC). • Lower levels of "Trusting" and "Not-Distracting" in FMS/FS compared to HC. • Elevated "Self-regulation" positively related to interoceptive confidence in FMS/FS. • Elevated symptom severity/impact negatively related to interoceptive confidence. [ABSTRACT FROM AUTHOR]

Previous studies from a few countries have reported semiological differences in younger children compared with adolescents or adults with psychogenic nonepileptic seizures (PNESs). This study tested the hypothesis that semiological, demographic, and historical risk factors vary with different ages of PNES onset in a large cohort from different countries. In this retrospective study, we investigated patients consecutively referred for PNES, who were admitted to epilepsy monitoring units in Iran, Brazil, Venezuela, Canada, Argentina, and USA. Age, gender, age at seizure onset, seizure semiology, and factors predisposing to PNES (abuse, stressors) were documented according to routine diagnostic practices at each center. Participants were grouped according to their age at onset (i.e., childhood, adolescence, or adulthood). A total of 448 patients were studied. Female predominance was associated with adolescent- (85/122, 70%) and adult-onset (190/270, 70%) but not in childhood-onset PNES (28/56, 50%) (p = 0.011). Event frequency in the month preceding the diagnosis was higher in the childhood- [ x ¯ = 50, standard deviation (sd) = 82, p = 0.025] versus adolescent- (x ¯ = 24, sd = 36) or adult-onset groups (x ¯ = 29, sd = 61). Significant between-group differences were observed for generalized body movements (p = 0.0001) and ictal injury (p = 0.027), suggesting more severe ictal presentations in adult-onset PNES compared with younger ages. Adult-onset patients were also more likely to be taking an unnecessary antiepileptic medication (p = 0.010). While PNES may present at any age, there appear to be notable differences across the lifespan with respect to some of the clinical characteristics. Further international and cross-cultural studies may reveal other interesting characteristics of PNES. • We included 448 patients from 6 countries (Iran = 262, Brazil = 85, Venezuela = 43, Canada = 21, Argentina = 19, and USA = 18). • There was a female predominance in adolescent and adult-onset PNES but not in childhood-onset patients. • Frequency of PNES events was significantly higher in the childhood-onset versus adolescent and adult-onset patients. • Generalized body movements and ictal injury were more common in adult-onset PNES than younger onset age groups. • Unnecessary antiepileptic medication was more likely to be prescribed among adult-onset PNES patients. [ABSTRACT FROM AUTHOR]