Life events and escape in conversion disorder

Forensic assessment of somatoform and functional neurological disorders

Functional neurological disorders (FND) and somatization are common in clinical practice and medicolegal settings. These conditions are frequently disabling and, if arising following an accident, may lead to claims for legal compensation or occupational disability (such as social security disability insurance). However, distinguishing FND and somatization from symptoms that are intentionally produced (i.e., malingered or factitious) may pose a major forensic psychiatric challenge. In this article, we describe how somatoform disorders and FND lie along a spectrum of abnormal illness-related behaviors, including factitious disorder, compensation neurosis, and malingering. We provide a systematic approach to the forensic assessment of FND and conclude by describing common litigation scenarios in which FND may be at issue. Forensic testimony may play an important role in the resolution of such cases.

Myths and facts about functional neurological disorders: a cross-sectional study of knowledge and awareness among medical students and healthcare professionals in Iraq

Background

Functional neurological disorder (FND) is a complex condition with neurological symptoms but no clear structural or biochemical explanation. Myths and misconceptions about FND can lead to misdiagnosis and inappropriate treatment. This study aimed to assess knowledge and common myths about FND among medical students and practitioners.

Methods

Data were collected from 324 participants using a structured questionnaire. The questionnaire included demographics, general information about FND and myths about FND. Data were analysed using non-parametric tests and Spearman's r for correlations.

Results

The majority of participants were clinical-years medical students (65.1%) and female (59.6%). Overall, knowledge about FND was limited, with a mean score of 42.3% of correct answers. Common myths included the belief that FND is a psychological disorder and that patients feign symptoms. Knowledge scores differed significantly among different grades/experience levels, with postgraduate practitioners having the highest scores. There was a positive correlation between knowledge scores and confidence in managing FND.

Conclusion

This study highlights the prevalence of myths and misconceptions about FND among medical students and practitioners, emphasising the need for accurate education to improve diagnosis and management. Healthcare professionals should take a biopsychosocial approach to FND, considering the complex interplay between biological, psychological and social factors. Efforts to increase awareness and reduce stigma associated with FND are crucial for promoting better care. Targeted educational interventions may be beneficial to improve the understanding and management of FND among medical professionals.

Functional Seizure Clinics: A Proposed Financially Viable Solution to the Neurologist Supply and Demand Mismatch

Background and Objectives

Projections from recent studies suggest that by 2025, there will not be enough neurologists to meet the demand in 41 states. In this study, we investigate the financial impact and improved access to care for persons with epilepsy that is possible by implementing a multidisciplinary treatment clinic for persons with functional seizures (FS), previously referred to as psychogenic nonepileptic seizures, thus separating those patients out of an epilepsy clinic.

Methods

This observational retrospective study used real-time data of 156 patients referred to an FS clinic integrated into a tertiary care epilepsy center to simulate its effect on epilepsy division access and finances. Access was measured using simulations of the number of return patient visits (RPVs) and new patient visits (NPVs) of patients with FS to a dedicated epilepsy clinic, based on survey results inquiring about the standard of care without the FS clinic. Finances were simulated using the resultant access multiplied by respective wRVU and reimbursement per CPT code.

Results

Treatment of 156 patients with FS in a multidisciplinary FS clinic resulted in 343 newly opened NPVs, reimbursement of $102,000, and 1,200 wRVUs in our dedicated epilepsy clinic. There were 686 RPVs, $103,000 in reimbursement, and 1,320 wRVUs. Relative to the total number of NPVs with epilepsy clinic epileptologists, 343 NPVs represent a biennial 15.5% increase in available new patient visit slots.

Discussion

Our findings describe the financial viability of integrating a treatment clinic for persons with FS by directing them to FS-specialized treatment and thereby increasing access for patients with probable epilepsy to the dedicated epilepsy clinic. This study provides a potential solution to the national mismatch in the supply and demand of neurologists and an initial framework to use for those who wish to establish or integrate FS services in their institution.

Methylome changes associated with functional movement/conversion disorder: Influence of biological sex and childhood abuse exposure

Epigenetic changes, such as DNA methylation (DNAm), may represent an important mechanism implicated in the etiopathogenesis of functional movement/conversion disorder (FMD). Here, we aimed to identify methylomic variations in a case-control cohort of FMD and to uncover specific epigenetic signatures associated with female sex and childhood abuse, two key risk factors for FMD and other functional neurological disorders. Genome-wide DNAm analysis was performed from peripheral blood in 57 patients with FMD and 47 healthy controls with and without childhood abuse. Using principal component analysis, we examined the association of principal components with FMD status in abused and non-abused individuals, in the entire study sample and in female subjects only. Next, we used enrichment pathway analysis to investigate the biological significance of DNAm changes and explored differences in methylation levels of genes annotated to the top enriched biological pathways shared across comparisons. We found that FMD was associated with DNAm variation across the genome and identified a common epigenetic 'signature' enriched for biological pathways implicated in chronic stress and chronic pain. However, methylation levels of genes included in the top two shared pathways hardly overlapped, suggesting that transcriptional profiles may differ as a function of childhood abuse exposure and sex among subjects with FMD. This study is unique in providing genome-wide evidence of DNAm changes in FMD and in indicating a potential mechanism linking childhood abuse exposure and female sex to differences in FMD pathophysiology. Future studies are needed to replicate our findings in independent cohorts.

MODIFI: protocol for randomised feasibility study of eye-movement desensitisation and reprocessing therapy (EMDR) for functional neurological disorder (FND)

INTRODUCTION

Functional neurological disorder (FND) refers to an involuntary loss of control over and/or aberrant perception of the body. Common presenting symptoms are functional (non-epileptic) seizures, and functional motor disorder, for example, walking difficulties, weakness or tremor. Greater access to effective treatments would lead to reduced distress and disability; and reduce unnecessary healthcare costs.This study will examine eye-movement desensitisation and reprocessing therapy (EMDR) as a treatment for FND. EMDR is an evidence-based treatment for post-traumatic stress disorder (PTSD), but its use for other conditions is growing. An FND-specific EMDR protocol will be tested, and if the intervention proves feasible with promising clinical outcomes, progression to a substantive study could take place.

METHODS AND ANALYSIS

Fifty adult patients diagnosed with FND will be recruited. It will be a single-blind randomised controlled trial with two arms: EMDR (plus standard neuropsychiatric care; NPC) and standard NPC. The two groups will be compared at baseline (T0), 3 months (T1), 6 months (T2) and 9 months (T3). Measures of feasibility include safety, recruitment, retention, treatment adherence and acceptability. Clinical outcome measures will assess health-related functioning/quality of life, ratings of FND symptoms and severity, depression, anxiety, PTSD, dissociation, service utilisation and other costs. Improvement and satisfaction ratings will also be assessed. Feasibility outcomes will be summarised using descriptive statistics. Exploratory analyses using (linear/logistic) mixed-effect models will examine the rate of change in the groups' clinical outcome measures across the four time-points.After the intervention period, a sample of participants, and clinicians, will be invited to attend semistructured interviews. The interviews will be analysed using reflexive thematic analysis.

ETHICS AND DISSEMINATION

This study has been approved by the NHS West Midlands-Edgbaston Research Ethics Committee. Study findings will be published in open access peer-reviewed journals, presented at conferences, and communicated to participants and other relevant stakeholders.

TRIAL REGISTRATION

NCT05455450 (www.

CLINICALTRIALS

gov).

Longitudinal outcome of Functional Neurological Disorder in Children and Adolescents in a Tertiary Care centre from Northern India

FND is common in Indian children and adolescents. Outcome related factors are not well known. With objective to study short-term outcome of FND, prospective, longitudinal, nine months follow-up study of 6-16 years was planned. Socioeconomic, clinical variables, I.Q. and personality traits at baseline and new psychiatric/physical illness, psychosocial factors and comorbidities during follow-up were assessed. Out of 68 children, scholastic (64.7%) and family problems (23.5%) were common psychosocial factors. After nine months,73% achieved remission. Reasons for non-remission were persistence of psychosocial factors and psychiatric comorbidities. A need arises for increasing awareness among general practitioners for early identification and management.

Heterogeneity of patients with functional/dissociative seizures: Three multidimensional profiles

OBJECTIVE

Current concepts highlight the neurological and psychological heterogeneity of functional/dissociative seizures (FDS). However, it remains uncertain whether it is possible to distinguish between a limited number of subtypes of FDS disorders. We aimed to identify profiles of distinct FDS subtypes by cluster analysis of a multidimensional dataset without any a priori hypothesis.

METHODS

We conducted an exploratory, prospective multicenter study of 169 patients with FDS. We collected biographical, trauma (childhood and adulthood traumatic experiences), semiological (seizure characteristics), and psychopathological data (psychiatric comorbidities, dissociation, and alexithymia) through psychiatric interviews and standardized scales. Clusters were identified by the Partitioning Around Medoids method. The similarity of patients was computed using Gower distance. The clusters were compared using analysis of variance, chi-squared, or Fisher exact tests.

RESULTS

Three patient clusters were identified in this exploratory, hypothesis-generating study and named on the basis of their most prominent characteristics: A "No/Single Trauma" group (31.4%), with more male patients, intellectual disabilities, and nonhyperkinetic seizures, and a low level of psychopathology; A "Cumulative Lifetime Traumas" group (42.6%), with clear female predominance, hyperkinetic seizures, relatively common comorbid epilepsy, and a high level of psychopathology; and A "Childhood Traumas" group (26%), commonly with comorbid epilepsy, history of childhood sexual abuse (75%), and posttraumatic stress disorder, but also with a high level of anxiety and dissociation.

SIGNIFICANCE

Although our cluster analysis was undertaken without any a priori hypothesis, the nature of the trauma history emerged as the most important differentiator between three common FDS disorder subtypes. This subdifferentiation of FDS disorders may facilitate the development of more specific therapeutic programs for each patient profile.

ASTASIA-ABASIA, PSYCHOGENIC OR ORGANIC? IT ́S NOT EASY

Astasia-abasia was described by Paul Blocq as a psychogenic condition; later, several brain injuries have been described for its explanation too.

A review of the treatment of functional neurological disorder with intensive short-term dynamic psychotherapy

The purpose of this article was to raise awareness of an under-recognized but well-supported treatment for Functional Neurological Disorders (FND) termed Intensive Short-term Dynamic Psychotherapy (ISTDP). There has been significant interest in the role of psychological mechanisms in FND onset and maintenance with specific evidence for maladaptive emotional processing. We outline how this supports the theoretical basis for ISTDP as an option in FND treatment and undertake a literature review of the current evidence base. We describe the application of ISTDP to FND illustrated through direct therapy transcripts. We conclude with reflections on the strengths and limitations of ISTDP as well as recommendations regarding future research.

The relationship between types of life events and the onset of functional neurological (conversion) disorder in adults: a systematic review and meta-analysis

Adverse life events precede the onset of functional neurological disorder (FND, also known as conversion disorder) more commonly than other neuropsychiatric conditions, but their aetiological role is unclear. We conducted a systematic review and quantitative analysis of the type, timing and number of life events preceding the onset of FND in adults, and a meta-analysis of the proportions of types of events in controlled studies. Fifty-one studies of different designs, covering 4247 patients, were eligible for inclusion. There was no clear majority of any type of preceding event. Family problems were the most common category of events, followed by relationship problems. Females were more likely to experience preceding family/relationship problems than males, who reported more work problems. Family problems were the commonest type of preceding event in studies in developing countries, whereas family and health problems were equally common in developed countries. Abuse was associated with early symptom onset, while patients with later onset were more likely to report family problems. The median number of events was one, and the events occurred closer to onset than in controls. Meta-analysis found that family, relationship and work events were all relatively more common in patients than pathological controls, as were events where symptoms might provide a solution to the stressor. In conclusion, although a range of events precede the onset of FND, they do not appear to do so uniformly. This may support a different aetiological role for stressors than in other disorders, although the support is indirect and the quality generally low.

Toward a possible trauma subtype of functional neurological disorder: Impact on symptom severity and physical health

BACKGROUND

As a group, individuals with functional neurological disorder (FND) report an approximately 3-fold increase in adverse life experiences (ALEs) compared to healthy controls. In patients with FND, studies have identified a positive correlation between symptom severity and the magnitude of ALEs. While not all individuals with FND report ALEs, such findings raise the possibility of a trauma-subtype of FND.

OBJECTIVE

This study investigated if patients with FND, with or without probable post-traumatic stress disorder (PTSD) and/or significant childhood maltreatment, differed in their symptom severity and physical health.

MATERIALS AND METHODS

Seventy-eight patients with FND were recruited (functional seizures, n = 34; functional movement disorder, n = 56). Participants completed self-report measures of symptom severity [Somatoform Dissociation Questionniare-20 (SDQ-20), Screening for Somatoform Disorders: Conversion Disorder subscale (SOMS:CD), Patient Health Questionniare-15 (PHQ-15)], physical health [Short Form Health Survey-36 (SF36-physical health)], childhood maltreatment [Childhood Trauma Questionnaire (CTQ)], and PTSD [PTSD Checklist-5 (PCL-5)]; a psychometric battery of other common predisposing vulnerabilities was also completed. To adjust for multiple comparisons, a Bonferroni correction was applied to all univariate analyses.

RESULTS

Patients with FND and probable PTSD (n = 33) vs. those without probable PTSD (n = 43) had statistically significant increased scores on all symptom severity measures - as well as decreased physical health scores. In secondary post-hoc regression analyses, these findings remained significant adjusting for age, sex, race, college education, and: pathological dissociation; alexithymia; attachment styles; personality characteristics; resilience scores; functional seizures subtype; or moderate-to-severe childhood abuse and neglect scores; SOMS:CD and SDQ-20 findings also held adjusting for depression and anxiety scores. In a separate set of analyses, patients with FND and moderate-to-severe childhood abuse (n = 46) vs. those without moderate-to-severe childhood abuse (n = 32) showed statistically significant increased SDQ-20 and PHQ-15 scores; in post-hoc regressions, these findings held adjusting for demographic and other variables. Stratification by childhood neglect did not relate to symptom severity or physical health scores.

CONCLUSION

This study provides support for a possible trauma-subtype of FND. Future research should investigate the neurobiological and treatment relevance of a FND trauma-subtype, as well as continuing to delineate clinical characteristics and mechanisms in individuals with FND that lack a history of ALEs.

Combined Fainting and Psychogenic Non-epileptic Seizures as Significant Therapy Hurdles in Blood-Injury-Injection Phobia: A Mini-Review and Case Report

BACKGROUND

Anxiety disorders are the most frequent mental disorders. Among the different subtypes, specific phobias are the commonest. Due to the ongoing SARS-CoV-19 pandemic, blood-injury-injection phobia (BII) has gained wider attention in the context of large-scale vaccination campaigns and public health. In this BII phobia mini-review and case report, we describe the successful treatment of a severe BII phobia case with combined fainting and psychogenic non-epileptic seizures (PNES) and demonstrate the role of specialized outpatient care.

CASE REPORT

The patient was a 28-year-old woman. She suffered from intense fear and recurrent fainting with regard to needles, injections, injuries, and at the sight of blood since early childhood. Medical history revealed infrequent events suggestive of PNES following panic attacks after sustained exposure to phobic stimuli. Family history was positive for circulation problems and BII fears. Psychopathological evaluation confirmed BII phobia symptoms and diagnosis was made according to the DSM-5. The Multidimensional Blood/Injury Phobia Inventory short version (MBPI-K) revealed severe manifestation of the disease. Neurological examination was ordinary. Repeated electroencephalography detected no epileptic pattern. Cranial magnetic resonance imaging showed normal morphology. Treatment was carried out by a seasoned, multidisciplinary team. Cognitive behavior therapy and exposure were performed. Modification of standard treatment protocol was necessary due to hurdles posed by recurrent fainting and a severe panic-triggered dissociative PNES during in vivo exposure. Modification was implemented by limiting in vivo exposure intensity to moderate anxiety levels. In addition to applied muscle tension and ventilation techniques, increased psychoeducation, cognitive restructuring, and distress tolerance skills (e.g., ice pack, verbal self-instructions) were used to strengthen the patient's situational control during in vivo exposure. A total of 15 sessions were performed. Therapy success was proven by 83% reduction in MBPI-K rating, SARS-CoV-19 vaccination, and a blood draw without psychological assistance, fainting, or seizure.

CONCLUSION

Taken together, this case demonstrates the potential of and need for specialized outpatient care and individualized treatment for severe BII phobia patients in order to provide them the perspective to have necessary medical procedures done and get vaccinated.

A historical review of functional neurological disorder and comparison to contemporary models

Over the centuries, various etiologies have been proposed to explain functional neurological disorders (FND), including functional seizures. These have included models relying on supernatural influences upon the body, emphasis on consequences of malfunctioning reproductive organs, the bodily expression of painful emotions involving traumatic memories, or cognitive distortions through attention and predictive biases. Many theorists, especially since the 19th century, have had overlapping themes that continue to be relevant in modern clinical use. Treatments developed in accordance with different conceptual mechanisms. Given the heterogeneity of the disorder and the variable response to individual treatments obtained through history, physicians must consider symptom expression of an FND as an overestimation. An appreciation of multiple theories allows flexible development of unique treatment plans for individual patients.

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.

A Review and Expert Opinion on the Neuropsychiatric Assessment of Motor Functional Neurological Disorders

Functional neurological (conversion) disorder (FND) is a prevalent and disabling condition at the intersection of neurology and psychiatry. Advances have been made in elucidating an emerging pathophysiology for motor FND, as well as in identifying evidenced-based physiotherapy and psychotherapy treatments. Despite these gains, important elements of the initial neuropsychiatric assessment of functional movement disorders (FND-movt) and functional limb weakness/paresis (FND-par) have yet to be established. This is an important gap from both diagnostic and treatment planning perspectives. In this article, the authors performed a narrative review to characterize clinically relevant variables across FND-movt and FND-par cohorts, including time course and symptom evolution, precipitating factors, medical and family histories, psychiatric comorbidities, psychosocial factors, physical examination signs, and adjunctive diagnostic tests. Thereafter, the authors propose a preliminary set of clinical content that should be assessed during early-phase patient encounters, in addition to identifying physical signs informing diagnosis and potential use of adjunctive tests for challenging cases. Although clinical history should not be used to make a FND diagnosis, characteristics such as acute onset, precipitating events (e.g., injury and surgery), and a waxing and waning course (including spontaneous remissions) are commonly reported. Active psychiatric symptoms (e.g., depression and anxiety) and ongoing psychosocial stressors also warrant evaluation. Positive physical examination signs (e.g., Hoover's sign and tremor entrainment) are key findings, as one of the DSM-5 diagnostic criteria. The neuropsychiatric assessment proposed emphasizes diagnosing FND by using "rule-in" physical signs while also considering psychiatric and psychosocial factors to aid in the development of a patient-centered treatment plan.

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.

A dimensional approach to functional movement disorders: Heresy or opportunity

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

Emotion Induced Monoamine Neuromodulator Release Affects Functional Neurological Disorders

Functional neurologic disorders (FNDs), also called conversion disorder (previously called hysteria), can show almost all the symptoms of other neurological diseases, including both physical (for example, seizure, weakness, fatigue) and psychological (for instance, depression, anxiety) symptoms. In spite of our general knowledge about emotional processes and developmental defects in the formation of these somatic symptoms, there is still no systemic and comprehensive research on the effects of emotional developmental variables in FND. Recently, both experimental and theoretical emotion studies have been greatly increased, such as prediction error, conceptual act model, basic emotional theory, and monoamine neuromodulator based three primary emotions. In addition, a large amount of evidence has confirmed the role of psychosocial adversity (such as stressful life events, interpersonal difficulties) as an important risk factor for FND. Here, we review recent advances about emotional stress on FND, and pay special attention to the effects of monoamine neuromodulators, such as how norepinephrine and serotonin affect behaviors. Then, we discuss the significance of these changes for FND, which may contribute to clarifying the pathogenesis of FND, and thus provide potential therapeutic drug targets or psychological intervention methods in the future.

Functional Seizures

Functional or psychogenic seizures have proved a diagnostic and therapeutic challenge for centuries. Functional seizures can look and feel similar to epileptic seizures but are instead a common and highly disabling form of functional neurologic disorder, or conversion disorder. Consistent with the biopsychosocial model of mental illness, functional seizures are caused by biological, psychological, and social factors unrelated to epileptic discharges. People with functional seizures do not consciously fake their symptoms. Functional seizures can be differentiated from epileptic seizures through the clinical history, features of the seizures themselves, and electroencephalography findings. Psychotherapy is effective in treating functional seizures.

Psychological Profiles and Clinical Clusters of Patients Diagnosed With Functional Neurological Disorder

Our understanding about underlying mechanisms leading to Functional Neurological Disorders (FND) has changed in recent years. While in the past these disorders were presumed to be solely due to psychological issues we know now that their development is dependent on complex interactions between biological, psychological and social factors. We present an analysis of clinical presentations and psychological profiles of patients who were seen in our FND outpatient clinic over 3 years. We aim to review the prevalence of common symptoms in the patients seen within our clinic, and to identify any common psychological or psychiatric profiles that differentiated these symptom groups. This may help to elucidate underlying mechanisms leading to the development of functional symptoms and identify the predisposing, triggering and perpetuation factors.

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

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

Functional Stroke Symptoms: A Narrative Review and Conceptual Model

Stroke services have been reconfigured in recent years to facilitate early intervention. Throughout stroke settings, some patients present with functional symptoms that cannot be attributed to a structural cause. Emphasis on fast diagnosis and treatment means that a proportion of patients entering the care pathway present with functional symptoms that mimic stroke or have functional symptoms in addition to vascular stroke. There is limited understanding of mechanisms underlying functional stroke symptoms, how the treatment of such patients should be managed, and no referral pathway or treatment. Predisposing factors vary between individuals, and symptoms are heterogeneous: onset can be acute or insidious, and duration can be short-lived or chronic in the context of new or recurrent illness cognitions and behaviors. This article proposes a conceptual model of functional symptoms identified in stroke services and some hypotheses based on a narrative review of the functional neurological disorder literature. Predisposing factors may include illness experiences, stressors, and chronic autonomic nervous system arousal. Following the onset of distressing symptoms, perpetuating factors may include implicit cognitive processes, classical and operant conditioning, illness beliefs, and behavioral responses, which could form the basis of treatment targets. The proposed model will inform the development of theory-based interventions as well as a functional stroke care pathway.

Evaluation of LiNES: A New Measure of Trauma, Negative Affect, and Relationship Insecurity Over the Life Span in Persons With FND

OBJECTIVE

The authors evaluated potential predisposing vulnerabilities and perpetuating factors among individuals with functional neurological disorder (FND) by using the novel Lifespan Negative Experiences Scale (LiNES), which assesses retrospective self-report of interpersonal trauma, negative affect, and relationship insecurity at three developmental stages: childhood, adolescence, and adulthood.

METHODS

The LiNES, Childhood Abuse and Trauma Scale (CATS), Relationship Scales Questionnaire (RSQ), and Positive and Negative Affect Schedule (PANAS) were administered to 71 individuals with FND. The reliability and validity of LiNES were examined by correlation with the other measures. FND patients' responses on LiNES were compared with those of 170 healthy control subjects.

RESULTS

LiNES scores in the FND group were internally consistent and correlated highly with CATS, RSQ, and PANAS scores. At each developmental stage, LiNES trauma scores were higher among patients with FND, compared with control subjects. The FND subgroup, which comprised patients who also had nonepileptic attack disorder, had higher trauma scores, compared with the FND-only subgroup. Compared with control subjects, patients with FND reported greater negative affect and relationship insecurity in adulthood. Lifetime LiNES scores for interpersonal trauma and relationship insecurity predicted FND group classification with >80% accuracy.

CONCLUSIONS

This study provides further support for the links between FND and trauma, negative affect, and insecure attachment. Recognition of these factors is likely to be important for treatment and stratification of important subpopulations in research. These findings provide new insights into the association between the timing of negative experiences and their effect, with LiNES emerging as a potentially useful measure for patients presenting with FND.

Clinical Correlates of Functional Motor Disorders: An Italian Multicenter Study

Background

Functional motor disorders (FMDs) are abnormal movements that are significantly altered by distractive maneuvers and are incongruent with movement disorders seen in typical neurological diseases.

Objective

The objectives of this article are to (1) describe the clinical manifestations of FMDs, including nonmotor symptoms and occurrence of other functional neurological disorders (FND); and (2) to report the frequency of isolated and combined FMDs and their relationship with demographic and clinical variables.

Methods

For this multicenter, observational study, we enrolled consecutive outpatients with a definite diagnosis of FMDs attending 25 tertiary movement disorders centers in Italy. Each patient underwent a detailed clinical evaluation with a definition of the phenotype and number of FMDs (isolated, combined) and an assessment of associated neurological and psychiatric symptoms.

Results

Of 410 FMDs (71% females; mean age, 47 ± 16.1 years) the most common phenotypes were weakness and tremor. People with FMDs had higher educational levels than the general population and frequent nonmotor symptoms, especially anxiety, fatigue, and pain. Almost half of the patients with FMDs had other FNDs, such as sensory symptoms, nonepileptic seizures, and visual symptoms. Patients with combined FMDs showed a higher burden of nonmotor symptoms and more frequent FNDs. Multivariate regression analysis showed that a diagnosis of combined FMDs was more likely to be delivered by a movement disorders neurologist. Also, FMD duration, pain, insomnia, diagnosis of somatoform disease, and treatment with antipsychotics were all significantly associated with combined FMDs.

Conclusions

Our findings highlight the need for multidimensional assessments in patients with FMDs given the high frequency of nonmotor symptoms and other FNDs, especially in patients with combined FMDs.

Chronic Functional Tremor: Positive Signs in the Management, Including Mirror Therapy

Functional tremor (FT) is a common functional neurological symptom disorder (FNSD) and difficult to treat. Diagnosis is often delayed in FNSD, which reinforces maladaptation and chronicity. The presented case, who had suffered from FT for 2 years, demonstrates the value of positive neurological symptoms in the diagnosis and treatment of FNSD, even in a chronic case. The patient improved well during integrated inpatient rehabilitation, which included mirror therapy (MT). He had complete suppressibility of the tremor during distraction, which was shown to him, and reversibility of the FT was emphasized. Due do the suppressibility when focusing on the contralateral arm, we installed MT as part of a combined inpatient neurological-psychotherapeutic rehabilitation treatment lasting 8 weeks. During treatment, some strong emotional themes came up. At the end of rehabilitation, the tremor almost completely subsided. Possible pathomechanisms are discussed. Future studies are recommended for determining the effectiveness of MT in FNSD with one-sided symptoms.

Neuropsychiatric Aspects of Epilepsy

This article reviews common and clinically important neuropsychiatric aspects of epilepsy. Comorbidities are common, underdiagnosed, and powerfully impact clinical outcomes. Biological, psychological, and social factors contribute to the associations between epilepsy and neuropsychiatric disorders. Epidemiologic studies point to a bidirectional relationships between epilepsy and neuropsychiatric disorders. People with epilepsy are more likely to develop certain neuropsychiatric disorders, and those with these disorders are more likely to develop epilepsy. This relationship suggests the possibility of shared underlying pathophysiologies. We review the neuropsychiatric impact of antiseizure medications and therapeutic options for treatment. Diagnosis and treatment involve close collaboration among a multidisciplinary team.

Attentional avoidance of emotions in functional movement disorders

OBJECTIVE

Emotional difficulties are common in functional movement disorders (FMD), yet their contribution to the disease remains unclear. We explored the potential role of emotional difficulties as risk and maintaining factors of FMD by looking at the effect of emotions on attention.

METHOD

The dot-probe task was used to investigate attentional biases induced by emotional faces in 25 patients with FMD and 25 healthy controls (HC). A pair of faces, one emotional (happy, angry, sad) and the other neutral, was displayed on a monitor to either the left or the right side of a central fixation cross. The face disappeared and a dot was flashed in place of one of the faces. Participants had to indicate the location of the dot. All participants completed the Toronto Alexithymia Scale. Psychological assessment of 23 patients also involved the Short Form Health Survey, the Hamilton Anxiety and the Hamilton Depression Rating Scales.

RESULTS

A general attentional bias away from emotional faces was noted for the FMD group compared to the HC. A more fine-tuned analysis revealed an attentional bias specifically away from sad faces for the FMD.

CONCLUSION

Our findings suggest a specific effect of emotions on attention in FMD that likely involves avoidance of sadness. Since this was not related to alexithymia or mood, we excluded these factors in explaining the results. Attentional bias away from sad faces correlated with general health, suggesting that avoidance of sadness might contribute to the perception of a better general health status in FMD.

Functional gait disorders: A sign-based approach

Functional gait disorders are common in clinical practice. They are also usually disabling for affected individuals. The diagnosis is challenging because no single walking pattern is pathognomonic for a functional gait disorder. Establishing a diagnosis is based not primarily on excluding organic gait disorders but instead predominantly on recognizing positive clinical features of functional gait disorders, such as an antalgic, a buckling, or a waddling gait. However, these features can resemble and overlap with organic gait disorders. It is therefore necessary to also look for inconsistency (variations in clinical presentation that cannot be reconciled with an organic lesion) and incongruity (combination of symptoms and signs that is not seen with organic lesions). Yet, these features also have potential pitfalls as inconsistency can occur in patients with dystonic gait or those with freezing of gait. Similarly, patients with dystonia or chorea can present with bizarre gait patterns that may falsely be interpreted as incongruity. A further complicating factor is that functional and organic gait disorders may coexist within the same patient. To improve the diagnostic process, we present a sign-based approach-supported by videos-that incorporates the diverse clinical spectrum of functional gait disorders. We identify 7 groups of supportive gait signs that can signal the presence of functional gait disorders. For each group of signs, we highlight how specific clinical tests can bring out the inconsistencies and incongruencies that further point to a functional gait disorder.

Neuropsychiatry: Definitions, Concepts, and Patient Types

Neuropsychiatry is an integrative discipline defined by its history, its preferred patients, and its theoretic framework. Dealing with human behavior needs to consider the brain, but such consideration should avoid oversimplification: neurologic understanding is not essential, necessary, or desirable in all conditions encountered in clinical psychiatry. Neuropsychiatric theory is founded on discoveries in the areas of synaptic plasticity and cortical/limbic anatomy (bottom-up), but also evolutionary biology and anthropology (top-down). Going forward, we need to synthesize vital information, distinguish the essential from the trivial or tenuous, and remain open to dialogue with allied disciplines, our patients, and our students.

Functional stroke symptoms: A prospective observational case series

OBJECTIVE

Functional symptoms are a common mimic of stroke in acute stroke settings, but there are no guidelines on how to manage such patients and scant research on their clinical profile. We explore the presentation of patients with functional stroke symptoms at admission and 2-month follow-up.

METHODS

We conducted a prospective observational study across four SE London acute stroke units, with two-month follow-up. Demographic information, clinical data and GP attendances were recorded. Patients completed self-report measures: Cognitive Behavioural Responses Questionnaire short version, Brief Illness Perception Questionnaire, Hospital Anxiety and Depression Scale, Work and Social Adjustment Scale and Short Form Health Survey.

RESULTS

Fifty-six patients (mean age: 50.9 years) were recruited at baseline; 40 with isolated functional symptoms, the remaining functional symptoms in addition to stroke. Thirty-one completed self-report follow-up measures. Of 56 participants, 63% were female. Patients presented symptoms across modalities, with unilateral and limb weakness the most frequent. There was inconsistent and ambiguous recording of symptoms on medical records. Approximately 40% of patients reported levels of anxiety and depression above the threshold indicating a probable diagnosis. Higher anxiety was associated with greater resting or all-or-nothing behaviours, embarrassment avoidance and symptom focussing on the CBRQ. Only SF-36 physical functioning improved at follow-up. Less than 50% who responded at follow-up were accessing a treatment, though 82% had ongoing symptoms.

CONCLUSION

Patients with functional symptoms in stroke settings report substantial distress, associated with cognitive-behavioural responses to symptoms. Follow-up data suggest recovery can be slow, indicating access to supportive interventions should be improved.

Neurocognitive functioning in patients with conversion disorder/functional neurological disorder

Neurocognitive symptoms are common in individuals with somatic symptom and related disorders (SSRD), but little is known about the specific impairments in neurocognitive domains in patients with conversion disorder (CD)/functional neurological disorder (FND). This study examines neurocognitive functioning in patients with CD/FND compared to patients with other SSRD. The sample consisted of 318 patients. Twenty‐nine patients were diagnosed with CD/FND, mean age 42.4, standard deviation (SD) = 13.8 years, 79.3% women, and 289 patients had other SSRD (mean age 42.1, SD = 13.3, 60.2% women). Patients completed a neuropsychological test battery that addressed a broad range of neurocognitive domains, including information processing speed, attention and executive functioning. Patients with CD/FND had clinically significant neurocognitive deficits in all neurocognitive domains based on normative data comparison. Patients with CD/FND also performed significantly worse than patients with other SSRD on information processing speed (Digit Symbol Substitution Test (V = .115, p = .035), Stroop Color–Word Test (SCWT) card 1 (V = .190, p = .006), and SCWT card 2 (V = .244, p < .001). No CD/FND vs. other SSRD differences were observed in other neurocognitive domains. These findings indicate the patients with CD/FND perform worse on information processing speed tests compared to patients with other SSRD.

Shame, dissociative seizures and their correlation among traumatised female Yazidi with experience of sexual violence

BACKGROUND

Survivors of Islamic State of Iraq and Syria (ISIS) captivity are at high risk of developing mental disorders such as post-traumatic stress disorder (PTSD).

AIMS

This study looks at the correlation between sexual abuse, shame, somatoform or bodily distress disorders, and dissociative seizures (psychogenic non-epileptic seizures).

METHOD

The psychological effects of traumatic events and dissociative seizure were assessed in Yazidi women who were held captive by ISIS in Northern Iraq between 2014 and 2018. These effects were examined comparing 64 women who were held captive and sexually abused by ISIS with 60 women suffering from PTSD who were not held captive and sexually abused by ISIS. Structured clinical-psychological interviews and established psychometric questionnaires were used to assess mental disorders especially dissociative seizures and somatoform disorders, and shame related to trauma.

RESULTS

Women who were held captive by ISIS showed a significantly higher prevalence of dissociative seizures (43.7%; P = 0.02) and somatisation disorder (38.7%; P = 0.02), as well as depressive (75.0%; P = 0.42) and anxiety disorders (62.5%; P = 0.44), than women who were not held captive and sexually abused by ISIS. Dissociative disorders were identified in 40.6% (P = 0.36) of those female Yazidi who experienced sexual violence while being held captive.

CONCLUSIONS

Shame in connection with sexual violence seems to play an important role in negative self-perception after rape. Dissociation not only plays an important role in unprocessed childhood trauma with feelings of shame, but also in more recent trauma experiences with shame.

Characteristics of patients with motor functional neurological disorder in a large UK mental health service: a case-control study

BACKGROUND

Functional neurological disorder (FND), previously known as conversion disorder, is common and often results in substantial distress and disability. Previous research lacks large sample sizes and clinical surveys are most commonly derived from neurological settings, limiting our understanding of the disorder and its associations in other contexts. We sought to address this by analysing a large anonymised electronic psychiatric health record dataset.

METHODS

Data were obtained from 322 patients in the South London and Maudsley NHS Foundation Trust (SLaM) who had an ICD-10 diagnosis of motor FND (mFND) (limb weakness or disorders of movement or gait) between 1 January 2006 and 31 December 2016. Data were collected on a range of socio-demographic and clinical factors and compared to 644 psychiatric control patients from the same register.

RESULTS

Weakness was the most commonly occurring functional symptom. mFND patients were more likely to be female, British, married, employed pre-morbidly, to have a carer and a physical health condition, but less likely to have had an inpatient psychiatric admission or to receive benefits. No differences in self-reported sexual or physical abuse rates were observed between groups, although mFND patients were more likely to experience life events linked to inter-personal difficulties.

CONCLUSIONS

mFND patients have distinct demographic characteristics compared with psychiatric controls. Experiences of abuse appear to be equally prevalent across psychiatric patient groups. This study establishes the socio-demographic and life experience profile of this understudied patient group and may be used to guide future therapeutic interventions designed specifically for mFND.

Psychogenic (Functional) Movement Disorders

PURPOSE OF REVIEW

This article reviews a practical approach to psychogenic movement disorders to help neurologists identify and manage this complex group of disorders.

RECENT FINDINGS

Psychogenic movement disorders, also referred to as functional movement disorders, describe a group of disorders that includes tremor, dystonia, myoclonus, parkinsonism, speech and gait disturbances, and other movement disorders that are incongruent with patterns of pathophysiologic (organic) disease. The diagnosis is based on positive clinical features that include variability, inconsistency, suggestibility, distractibility, suppressibility, and other supporting information. While psychogenic movement disorders are often associated with psychological and physical stressors, the underlying pathophysiology is not fully understood. Although insight-oriented behavioral and pharmacologic therapies are helpful, a multidisciplinary approach led by a neurologist, but also including psychiatrists and physical, occupational, and speech therapists, is needed for optimal outcomes.

SUMMARY

The diagnosis of psychogenic movement disorders is based on clinical features identified on neurologic examination, and neurophysiologic and imaging studies can provide supporting information.

Gender Differences in Functional Movement Disorders

Background

Functional neurological disorders are generally more common in females than males, but the reason for this gender difference is not well understood.

Objectives

In this study, we aim to compare the clinical and demographic features of functional movement disorders (FMDs) between males and females.

Methods

We examined clinical data and video-recordings of patients with FMDs evaluated at the Baylor College of Medicine Movement Disorders Clinic.

Results

Of the 196 patients with FMDs, males represented only 30% (n = 59) of the entire cohort. Men had an older age at onset: 40.5 versus 34.1 years (P = 0.026) and an older age at evaluation: 43.8 versus 38.1 years (P = 0.041) compared to women. Functional dystonia was more frequently observed in women: 47.5 versus 20.3% (P < 0.001), but there was a trend for higher frequency of functional gait disorder in men: 44 versus 30% (P = 0.056). Females were particularly over-represented (73.7%) in children and adolescents; but the genders were equally represented in patients aged ≥50 years.

Conclusions

Female patients are over-represented in FMDs, except in individuals aged ≥50 years. Compared to female patients, males with FMDs present later in life and are less likely to have functional dystonia.

Gender as a Risk Factor for Functional Movement Disorders: The Role of Sexual Abuse

Background

The prevalence of functional movement disorders is 2 to 3 times higher in women than in men. Trauma and adverse life events are important risk factors for developing functional movement disorders. On a population level, rates of sexual abuse against women are higher when compared with the rates against men.

Objectives

To determine gender differences in rates of sexual abuse in functional movement disorders compared with other neurologic disorders and evaluate if the gender prevalence is influenced by higher rates of sexual abuse against women.

Methods

We performed a case-control series including 199 patients with functional movement disorders (149 women) and 95 controls (60 women). We employed chi-squared test to assess gender and sexual abuse associations and Bayes formula to condition on sexual abuse.

Results

Our analysis showed an association between sexual abuse and functional movement disorders in women (odds ratio, 4.821; 95% confidence interval, 2.089-12.070; P < 0.0001), but not men. Bayesian analysis found the functional movement disorder prevalence ratio between women and men conditional on sexual abuse to be 4.87 times the unconditioned ratio.

Conclusions

There is a statistically significant association between sexual abuse and functional movement disorders in women and a greater likelihood that women who are sexually abused will develop functional movement disorders than men who are sexually abused. Our findings suggest that the increased prevalence of functional movement disorders in women is associated, at least in part, with sexual abuse and its sequelae; however, further research is needed to explore the role of other traumatic and nontraumatic factors.

Current Concepts in Diagnosis and Treatment of Functional Neurological Disorders

Importance

Functional neurological disorders (FND) are common sources of disability in medicine. Patients have often been misdiagnosed, correctly diagnosed after lengthy delays, and/or subjected to poorly delivered diagnoses that prevent diagnostic understanding and lead to inappropriate treatments, iatrogenic harm, unnecessary and costly evaluations, and poor outcomes.

Observations

Functional Neurological Symptom Disorder/Conversion Disorder was adopted by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, replacing the term psychogenic with functional and removing the criterion of psychological stress as a prerequisite for FND. A diagnosis can now be made in an inclusionary manner by identifying neurological signs that are specific to FNDs without reliance on presence or absence of psychological stressors or suggestive historical clues. The new model highlights a wider range of past sensitizing events, such as physical trauma, medical illness, or physiological/psychophysiological events. In this model, strong ideas and expectations about these events correlate with abnormal predictions of sensory data and body-focused attention. Neurobiological abnormalities include hypoactivation of the supplementary motor area and relative disconnection with areas that select or inhibit movements and are associated with a sense of agency. Promising evidence has accumulated for the benefit of specific physical rehabilitation and psychological interventions alone or in combination, but clinical trial evidence remains limited.

Conclusions and Relevance

Functional neurological disorders are a neglected but potentially reversible source of disability. Further research is needed to determine the dose and duration of various interventions, the value of combination treatments and multidisciplinary therapy, and the therapeutic modality best suited for each patient.

Memory and motor control in patients with psychogenic nonepileptic seizures

Psychogenic nonepileptic seizures (PNES) are of the most elusive phenomena in epileptology. Patients with PNES present episodes resembling epileptic seizures in their semiology yet lacking the underlying epileptic brain activity. These episodes are assumed to be related to psychological distress from past trauma, yet the underlying mechanism of this manifestation is still unknown. Using resting-state functional magnetic resonance imaging (fMRI), we investigated functional connectivity changes within and between large-scale brain networks in 9 patients with PNES, compared with a group of 13 age- and gender-matched healthy controls. Functional magnetic resonance imaging analyses identified functional connectivity disturbances between the medial temporal lobe (MTL) and the sensorimotor cortex and between the MTL and ventral attention networks in patients with PNES. Within network connectivity reduction was found within the visual network. Our findings suggest that PNES relate to changes in connectivity in between areas that are involved in memory processing and motor activity and attention control. These results may shed new light on the way by which traumatic memories may relate to PNES.

Stress and functional neurological disorders: mechanistic insights

At the interface between mind and body, psychiatry and neurology, functional neurological disorder (FND) remains poorly understood. Formerly dominant stress-related aetiological models have been increasingly challenged, in part due to cases without any history of past or recent trauma. In this perspective article, we review current evidence for such models, and how research into the role of traumatic stress in other disorders and the neurobiology of the stress response can inform our mechanistic understanding of FND. First, we discuss the association between stress and the onset or exacerbation of a variety of physical and mental health problems. Second, we review the role of hypothalamic-pituitary-adrenal axis dysfunction in the neurobiology of ill-health, alongside evidence for similar mechanisms in FND. Third, we advocate a stress-diathesis model, in which biological susceptibility interacts with early life adversity, where FND can be precipitated by traumatic events later in life and maintained by psychological responses. We hypothesise that greater biological susceptibility to FND is associated with less severe remote and recent stress, and that FND precipitated by more severe stress is associated with lower biological vulnerability. This would explain clinical experience of variable exposure to historical and recent traumatic stress among people with FND and requires empirical investigation. A testable, evidence-based stress-diathesis model can inform nuanced understanding of how biological and psychological factors interact at the individual level, with potential to inform personalised treatment pathways. Much-needed research to establish the aetiology of FND will enhance clinical care and communication, facilitate effective treatment and inform prevention strategies.

Abnormal postural behavior in patients with functional movement disorders during exposure to stress

BACKGROUND

Patients affected by functional (psychogenic) movement disorders (FMD) have abnormal processing of stress responses. However, little is known about the influence of this abnormal stress processing on automatic motor defense behavior, such as freeze response. Our aim was thus to investigate stress-induced postural motor responses in FMD.

METHODS

Nine FMD patients and thirteen healthy controls were engaged in the Trier Social Stress Test, while we measured the movement of their body by means of accelerometers and gyroscopes attached to the thorax. Standard deviation of thorax acceleration, reflecting the variability of movement amplitude (body sway), was compared across groups over time in a 2 × 2 ANOVA design. Higuchi's fractal dimension (HFD), reflecting the complexity of movement pattern over time, was also analyzed. Salivary cortisol and α-amylase samples were collected before and after the experiment, as stress biomarkers. Pearson's correlation coefficients were calculated between these biomarkers and movement parameters.

RESULTS

A significant interaction effect was found, showing that healthy controls reduced their thorax sway over time during exposure to stress (from 0.027 ± 0.010 m/s² to 0.023 ± 0.008 m/s², effect size of Cohen's d = 0.95), whereas patients with FMD did not. This change in body sway in controls over time negatively correlated with salivary cortisol values (ρ = -0.67, p = 0.012). A significant group effect revealed that FMD patients had an overall larger body sway (0.038 ± 0.013 m/s²) compared to controls (0.025 ± 0.009 m/s² - effect size of Cohen's d = 1.29) and a lower HFD (1.602 ± 0.071) than controls (1.710 ± 0.078 - Cohen's d = 1.43).

CONCLUSIONS

Patients with FMD failed to show a reduction of body sway over time, i.e., freeze response observed in the controls, thus suggesting an impairment in the automatic defense behavior. Moreover, our analysis found a lower complexity of movement (HFD) in FMD, which deserves future research in order to verify whether this could represent a characteristic trait of the disorder.

Pathogenesis and pathophysiology of functional (psychogenic) movement disorders

Functional movement disorders (FMDs), known over time as "hysteria", "dissociative", "conversion", "somatoform", "non-organic" and "psychogenic" disorders, are characterized by having a voluntary quality, being modifiable by attention and distraction but perceived by the patient as involuntary. Although a high prevalence of depression and anxiety is observed in these patients, a definitive role of psychiatric disorders in FMDs has not been proven, and many patients do not endorse such manifestations. Stressful events, social influences and minor trauma may precede the onset of FMDs, but their pathogenic mechanisms are unclear. Patients with FMDs have several abnormalities in their neurobiology including strengthened connectivity between the limbic and motor networks. Additionally, there is altered top-down regulation of motor activities and increased activation of areas implicated in self-awareness, self-monitoring, and active motor inhibition such as the cingulate and insular cortex. Decreased activation of the supplementary motor area (SMA) and pre-SMA, implicated in motor control and preparation, is another finding. The sense of agency defined as the feeling of controlling external events through one's own action also seems to be impaired in individuals with FMDs. Correlating with this is a loss of intentional binding, a subjective time compression between intentional action and its sensory consequences. Organic and functional dystonia may be difficult to differentiate since they share diverse neurophysiological features including decreased cortical inhibition, and similar local field potentials in the globus pallidus and thalamus; although increased cortical plasticity is observed only in patients with organic dystonia. Advances in the pathogenesis and pathophysiology of FMDs may be helpful to understand the nature of these disorders and plan further treatment strategies.

Malingering and factitious disorder

Although exaggeration or amplification of symptoms is common in all illness, deliberate deception is rare. In settings associated with litigation/disability evaluation, the rate of malingering may be as high as 30%, but its frequency in clinical practice is not known. We describe the main characteristics of deliberate deception (factitious disorders and malingering) and ways that neurologists might detect symptom exaggeration. The key to establishing that the extent or severity of reported symptoms does not truly represent their severity is to elicit inconsistencies in different domains, but it is not possible to determine whether the reports are intentionally inaccurate. Neurological disorders where difficulty in determining the degree of willed exaggeration is most likely include functional weakness and movement disorders, post-concussional syndrome (or mild traumatic brain injury), psychogenic non-epileptic attacks and complex regional pain syndrome type 1 (especially when there is an associated functional movement disorder). Symptom amplification or even fabrication are more likely if the patient might gain benefit of some sort, not necessarily financial. Techniques to detect deception in medicolegal settings include covert surveillance and review of social media accounts. We also briefly describe specialised psychological tests designed to elicit effort from the patient.