Structural alterations in functional neurological disorder and related conditions: a software and hardware problem?

Neuroscience in pictures: Functional neurological disorder

Functional neurological disorder (FND) is a biopsychosocially-complex, prevalent, and potentially disabling neuropsychiatric condition. In this pictorial review, we explore the complexity of FND, from its diagnosis and conceptualization to current mechanistic understandings. We highlight advances in neuroimaging research that have revealed structural and functional brain alterations in FND and discuss a variety of factors that may serve as predisposing vulnerabilities for the development of this condition and/or perpetuate symptoms. This overview is designed as an initial teaching resource to educate trainees, clinicians, and researchers, highlighting core concepts in the literature on FND. Given that mechanistic research in FND is at a relatively early stage and is rapidly evolving, the interested reader should aim to continue updating their mechanistic understanding of FND as research further advances in this area.

Locus coeruleus co-activation patterns at rest show higher state persistence in patients with dissociative seizures: A Pilot Study

OBJECTIVE

Dissociative seizures are paroxysmal disruptions of awareness and behavioral control in the context of affective arousal. Alterations in stress-related endocrine function have been demonstrated, but the timescale of dissociation suggests that the central locus coeruleus (LC) noradrenergic system is likely pivotal. Here, we investigate whether LC activation at rest is associated with altered brain network dynamics.

METHODS

A preliminary co-activation pattern (CAP) analysis of resting-state functional magnetic resonance imaging (fMRI) in 14 patients with dissociative seizures and 14 healthy controls was performed by using the LC as a seeding region. The red nucleus served as a control condition. Entry rates, durations, and state transition probabilities of identified CAPs were calculated. Analyses were corrected for demographic, technical, and clinical confounders including depression and anxiety.

RESULTS

Three LC-related CAPs were identified, with the dominant two showing inverse activations and deactivations of the default mode network and the attention networks, respectively. Analysis of transition probabilities between and within the three CAPs revealed higher state persistence in patients compared to healthy controls for both CAP2LC (Cohen's d = -0.55; p = 0.01) and CAP3LC (Cohen's d = -0.57; p = 0.01). The control analysis using the red nucleus as a seed yielded similar CAPs, but no significant between-group differences in transition probabilities.

SIGNIFICANCE

Higher state persistence of LC-CAPs in patients with dissociative seizures generates the novel hypothesis that arousal-related impairments of network switching might be a candidate neural mechanism of dissociation.

PLAIN LANGUAGE SUMMARY

Dissociative seizures often arise during high affective arousal. The locus coeruleus is a brain structure involved in managing such acute arousal states. We investigated whether the activity of the locus coeruleus correlates with activity in other regions of the brain (which we refer to as "brain states"), and whether those brain states were different between patients with dissociative seizures and healthy controls. We found that patients tended to stay in certain locus coeruleus-dependent brain states instead of switching between them. This might be related to the loss of awareness and disruptions of brain functions ("dissociation") that patients experience during seizures.

Functional Neurological Disorder and Autism Spectrum Disorder: A Complex and Potentially Significant Relationship

INTRODUCTION

Functional neurological disorder (FND) and autism spectrum disorder (ASD) are two complex neuropsychiatric conditions that have been historically classified within psychiatric domains, resulting in a lack of extensive research, insufficient clinical recognition, and persistent societal stigma. In recent years, there has been an increasing recognition among professionals and affected individuals of their possible overlap. This review explores the potential clinical and mechanistic overlap between FND and ASD, with particular attention to shared symptoms across sensory, motor, and psychiatric domains.

METHODS

We conducted a narrative analysis utilizing the PubMed, CINAHL, MEDLINE, and ScienceDirect databases from inception to June 2024. The search employed specific MeSH terms related to ASD and FND. Given the limited data availability, we included all relevant articles that explored the potential connections between FND and ASD, focusing on established findings and theoretical hypotheses areas.

RESULTS

Scientific evidence indicates that FND and ASD may co-occur more frequently than previously acknowledged and with notable overlaps in their clinical presentations and pathophysiology. Theoretical models that have been applied to FND and ASD, such as the Bayesian brain theory and the tripartite model of autism, may provide valuable insights into the intersection of these conditions. Although much of the current evidence remains speculative, it underscores the need for hypothesis-driven research to investigate these potential connections further.

CONCLUSION

ASD and FND are heterogeneous conditions that appear to co-occur in a subset of individuals, with overlapping symptomatology and possibly shared underlying mechanisms. This hypothesis-generating review emphasizes the need for further research to better understand these links, ultimately aiming to improve clinical recognition and develop targeted interventions that enhance the quality of life for affected individuals.

Functional Movement Disorder as a Prodromal Symptom of Parkinson's Disease-Clinical and Pathophysiological Insights

Functional movement disorder (FMD) is a common manifestation of functional neurological disorder. FMD can occur alongside other neurological conditions, but especially in patients with established Parkinson's disease (PD). An interesting observation emerging across cohort studies and case series is that FMD can precede the diagnosis of PD, suggesting that FMD may itself be a prodromal symptom of neurodegeneration. Such a notion would have significant clinical implications for the assessment and management of people with FMD, particularly with respect to decisions around the use of auxiliary investigations, counselling, and follow-up. In this Viewpoint we review the evidence concerning the temporal relationship between FMD and PD. We discuss the potential explanations and mechanisms for FMD as a prodromal symptom of PD, and highlight clinical considerations and important outstanding questions in the field. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Living with functional movement disorders: a tale of three battles. An interpretative phenomenological analysis

OBJECTIVES

Functional movement disorders (FMD) have poor prognosis and high physical and psychological co-morbidity. Their pathogenesis remains unclear, clinicians often find them difficult to treat, and lack of agreement between healthcare providers and patients is common. This study aimed to explore the experiences of living with FMD to improve understanding of its impact and patients' needs.

METHODS

Ten participants across the UK were recruited online through a charity's social media platforms. Semi structured interviews were conducted via video calls and were audio recorded and verbatim transcripts were analysed using interpretative phenomenological analysis.

RESULTS

Three superordinate themes were generated from the data, representing the three battles fought by the participants: (1) intrapersonal: the tug of war with the secret agent within- the power struggle with symptoms; (2) interpersonal: navigating stigma and self-preservation; (3) systemic: pursuing hope and treatments against helplessness and passivity.

CONCLUSIONS

Loss of control, feelings of powerlessness and oppression by symptoms is often mirrored in participants' experiences of seeking healthcare and navigating societal stigma. Active efforts to regain influence, improve quality of life and maintain hope can be jeopardised by others' dismissive attitudes and lack of knowledge. Antonovsky's model of salutogenesis is proposed as a useful framework for facilitating empowerment in FMD service provision.

Long COVID Is Not a Functional Neurologic Disorder

Long COVID is a common sequela of SARS-CoV-2 infection. Data from numerous scientific studies indicate that long COVID involves a complex interaction between pathophysiological processes. Long COVID may involve the development of new diagnosable health conditions and exacerbation of pre-existing health conditions. However, despite this rapidly accumulating body of evidence regarding the pathobiology of long COVID, psychogenic and functional interpretations of the illness presentation continue to be endorsed by some healthcare professionals, creating confusion and inappropriate diagnostic and therapeutic pathways for people living with long COVID. The purpose of this perspective is to present a clinical and scientific rationale for why long COVID should not be considered as a functional neurologic disorder. It will begin by discussing the parallel historical development of pathobiological and psychosomatic/sociogenic diagnostic constructs arising from a common root in neurasthenia, which has resulted in the collective understandings of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and functional neurologic disorder (FND), respectively. We will also review the case definition criteria for FND and the distinguishing clinical and neuroimaging findings in FND vs. long COVID. We conclude that considering long COVID as FND is inappropriate based on differentiating pathophysiologic mechanisms and distinguishing clinical findings.

Machine learning classification of functional neurological disorder using structural brain MRI features

BACKGROUND

Brain imaging studies investigating grey matter in functional neurological disorder (FND) have used univariate approaches to report group-level differences compared with healthy controls (HCs). However, these findings have limited translatability because they do not differentiate patients from controls at the individual-level.

METHODS

183 participants were prospectively recruited across three groups: 61 patients with mixed FND (FND-mixed), 61 age-matched and sex-matched HCs and 61 age, sex, depression and anxiety-matched psychiatric controls (PCs). Radial basis function support vector machine classifiers with cross-validation were used to distinguish individuals with FND from HCs and PCs using 134 FreeSurfer-derived grey matter MRI features.

RESULTS

Patients with FND-mixed were differentiated from HCs with an accuracy of 0.66 (p=0.005; area under the receiving operating characteristic (AUROC)=0.74); this sample was also distinguished from PCs with an accuracy of 0.60 (p=0.038; AUROC=0.56). When focusing on the functional motor disorder subtype (FND-motor, n=46), a classifier robustly differentiated these patients from HCs (accuracy=0.72; p=0.002; AUROC=0.80). FND-motor could not be distinguished from PCs, and the functional seizures subtype (n=23) could not be classified against either control group. Important regions contributing to statistically significant multivariate classifications included the cingulate gyrus, hippocampal subfields and amygdalar nuclei. Correctly versus incorrectly classified participants did not differ across a range of tested psychometric variables.

CONCLUSIONS

These findings underscore the interconnection of brain structure and function in the pathophysiology of FND and demonstrate the feasibility of using structural MRI to classify the disorder. Out-of-sample replication and larger-scale classifier efforts incorporating psychiatric and neurological controls are needed.

Predictive Processing and the Pathophysiology of Functional Neurological Disorder

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

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.

Understanding Functional Neurological Disorder: Recent Insights and Diagnostic Challenges

Functional neurological disorder (FND), formerly called conversion disorder, is a condition characterized by neurological symptoms that lack an identifiable organic purpose. These signs, which can consist of motor, sensory, or cognitive disturbances, are not deliberately produced and often vary in severity. Its diagnosis is predicated on clinical evaluation and the exclusion of other medical or psychiatric situations. Its treatment typically involves a multidisciplinary technique addressing each of the neurological symptoms and underlying psychological factors via a mixture of medical management, psychotherapy, and supportive interventions. Recent advances in neuroimaging and a deeper exploration of its epidemiology, pathophysiology, and clinical presentation have shed new light on this disorder. This paper synthesizes the current knowledge on FND, focusing on its epidemiology and underlying mechanisms, neuroimaging insights, and the differentiation of FND from feigning or malingering. This review highlights the phenotypic heterogeneity of FND and the diagnostic challenges it presents. It also discusses the significant role of neuroimaging in unraveling the complex neural underpinnings of FND and its potential in predicting treatment response. This paper underscores the importance of a nuanced understanding of FND in informing clinical practice and guiding future research. With advancements in neuroimaging techniques and growing recognition of the disorder's multifaceted nature, the paper suggests a promising trajectory toward more effective, personalized treatment strategies and a better overall understanding of the disorder.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

From Software to Hardware: A Case Series of Functional Neurological Symptoms and Cerebrovascular Disease

OBJECTIVE

Neuroimaging studies have identified alterations in both brain structure and functional connectivity in patients with functional neurological disorder (FND). For many patients, FND emerges from physical precipitating events. Nevertheless, there are a limited number of case series in the literature that describe the clinical presentation and neuroimaging correlates of FND following cerebrovascular disease.

METHODS

The authors collected data from two clinics in the United Kingdom on 14 cases of acute, improving, or delayed functional neurological symptoms following cerebrovascular events.

RESULTS

Most patients had functional neurological symptoms that were localized to cerebrovascular lesions, and the lesions mapped onto regions known to be part of functional networks disrupted in FND, including the thalamus, anterior cingulate gyrus, insula, and temporoparietal junction.

CONCLUSIONS

The findings demonstrate that structural lesions can lead to FND symptoms, possibly explained through changes in relevant mechanistic functional networks.

A Web-Based Educational Module Using Clinical Neuroscience to Deliver the Diagnosis of Functional Neurological Disorder

Neuroscience-based patient education has become an evidence-based strategy for enhancing chronic pain treatment. Advances in understanding the neuroscience of functional neurological disorder (FND) may allow similar approaches to be developed and disseminated to clinicians, given the public health need for greater provider awareness and expertise around the condition. Accordingly, the authors developed an online video module for clinicians that delivers neuroscience-based psychoeducation for FND and assessed whether the intervention would be associated with changes in clinicians' perception of FND patients and knowledge about the condition. The online intervention consisted of a 20-minute video module, including an 8-minute scripted role-play that modeled neuroscience-informed diagnosis delivery. Pre- and postintervention questionnaires were embedded into the online module and included a self-assessment of FND-related perceptions and knowledge and a multiple-choice assessment of retention of the neuroscience-based content. Wilcoxon signed-rank tests and McNemar's tests were used for statistical analyses. Of the 103 individuals who submitted surveys, 40 participants provided a complete data set from before and after the intervention. Following the intervention, self-assessment items showed respondents had significantly greater comfort with diagnosis delivery and treatment options and decreased negative perception of FND patients. The percentage of correct responses on a multiple-choice assessment regarding the functional neuroanatomy of FND was significantly increased. In summary, the online neuroscience-based educational intervention was effective for increasing clinician knowledge about FND and comfort with diagnosis delivery and treatment options. Implementing web-based formats may be a viable and cost-effective approach to disseminating knowledge and basic clinical skills in the care of patients with FND.

Not a general, symptom-unspecific, transdiagnostic marker for functional symptoms: sensorimotor processing of head control is intact in chronic pain

Introduction

Functional disorders are prevalent in all medical fields and pose a tremendous public health problem, with pain being one of the most common functional symptoms. Understanding the underlying, potentially unifying mechanism in functional (pain) disorders is instrumental in facilitating timely diagnosis, stigma reduction, and adequate treatment options. Neuroscientific models of perception suggest that functional symptoms arise due to dysregulated sensorimotor processing in the central nervous system, with brain-based predictions dominating the eventual percept. Experimental evidence for this transdiagnostic mechanism has been established in various functional symptoms. The goal of the current study was to investigate whether erroneous sensorimotor processing is an underlying transdiagnostic mechanism in chronic (functional) pain.

Method

A total of 13 patients with chronic (functional) pain [three patients with chronic (functional) pain disorder, F45.40, ICD-10; 10 patients with chronic pain disorder with somatic and psychological factors, F45.41, ICD-10]; and 15 healthy controls performed large combined eye-head gaze shifts toward visual targets, naturally and with increased head moment of inertia. We simultaneously measured participants' eye and head movements to assess head oscillations at the end of the gaze shift, which are an established indicator of (transdiagnostic) sensorimotor processing deficits of head control.

Results

Using a Bayesian analysis protocol, we found that patients with chronic (functional) pain and control participants stabilized their heads equally well (Bayes Factor 01 = 3.7, Bayes Factor exclusion = 5.23; corresponding to substantial evidence) during all sessions of the experiment.

Conclusion

Our results suggest that patients with chronic (functional) pain do not show measurable symptom-unspecific sensorimotor processing deficits. We discuss outcome parameter choice, organ system specificity, and selection of patient diagnoses as possible reasons for this result and recommend future avenues for research.

Functional neurological disorder and functional somatic syndromes among sexual and gender minority people: A scoping review

OBJECTIVE

To describe the current literature on functional neurological disorder and functional somatic syndromes among sexual and gender minority people (SGM).

METHODS

A search string with descriptors of SGM identity and functional disorders was entered into PubMed, Embase, Web of Science, PsycInfo, and CINAHL for articles published before May 24, 2022, yielding 3121 items entered into Covidence, where 835 duplicates were removed. A neurologist and neuropsychiatrist screened titles and abstracts based on predefined criteria, followed by full-text review. A third neurologist adjudicated discrepancies. Eligible publications underwent systematic data extraction and statistical description.

RESULTS

Our search identified 26 articles on functional disorders among SGM people. Most articles were case (13/26, 46%) or cross-sectional (4/26, 15%) studies. Gender minority people were represented in 50% of studies. Reported diagnoses included fibromyalgia (n = 8), functional neurological disorder (n = 8), somatic symptom disorder (n = 5), chronic fatigue syndrome (n = 3), irritable bowel syndrome (n = 2), and other functional conditions (n = 3). Three cohort studies of fibromyalgia or somatic symptom disorder reported an overrepresentation of gender minority people compared to cisgender cohorts or general population measures. Approximately half of case studies reported pediatric or adolescent onset (7/13, 54%), functional neurological disorder diagnosis (7/13, 54%), and symptom improvement coinciding with identity-affirming therapeutic interventions (7/13, 58%).

CONCLUSION

Despite a methodologically rigorous literature search, there are limited data on functional neurological disorder and functional somatic syndromes among SGM people. Several studies reported increased prevalence of select conditions among transgender people. More observational studies are needed regarding the epidemiology and clinical course of functional disorders among SGM people.

Functional neurological disorder is a feminist issue

Functional neurological disorder (FND) is a common and disabling disorder, often misunderstood by clinicians. Although viewed sceptically by some, FND is a diagnosis that can be made accurately, based on positive clinical signs, with clinical features that have remained stable for over 100 years. Despite some progress in the last decade, people with FND continue to suffer subtle and overt forms of discrimination by clinicians, researchers and the public. There is abundant evidence that disorders perceived as primarily affecting women are neglected in healthcare and medical research, and the course of FND mirrors this neglect. We outline the reasons why FND is a feminist issue, incorporating historical and contemporary clinical, research and social perspectives. We call for parity for FND in medical education, research and clinical service development so that people affected by FND can receive the care they need.

A Case Series of Transgender and Gender-Nonconforming Patients in a Pediatric Functional Neurologic Disorder Clinic

Youth who identify as transgender and gender nonconforming (TGNC) are at increased risk of anxiety, depression, bullying, and loss of social and family support. These factors may increase the risk of developing functional neurologic disorder (FND). If the risk of FND is increased in TGNC youth, then identifying which youth are at increased risk, and the particular times when risk is increased, may allow for earlier diagnosis and treatment of FND. Better awareness of functional symptoms among clinicians who care for TGNC youth may prevent disruption of gender-affirming care if FND symptoms emerge. Patients diagnosed with FND who are TGNC may require different forms of intervention than other youth with FND. We present 4 cases from our multidisciplinary pediatric FND program of TGNC youth who developed FND. In all individuals for whom follow-up information was available, access to gender-affirming health care was associated with marked improvement or resolution of FND symptoms.

Microstructural Differences of the Cerebellum-Thalamus-Basal Ganglia-Limbic Cortex in Patients with Somatic Symptom Disorders: a Diffusion Kurtosis Imaging Study

Somatic symp tom disorders (SSDs) are a group of psychiatric disorders characterized by persistent disproportionate concern and obsessive behaviors regarding physical conditions. Currently, SSDs lack effective treatments and their pathophysiology is unclear. In this paper, we aimed to examine microstructural abnormalities in the brains of patients with SSD using diffusion kurtosis imaging (DKI) and to investigate the correlation between these abnormalities and clinical indicators. Diffusion kurtosis images were acquired from 30 patients with SSD and 30 healthy controls (HCs). Whole-brain maps of multiple diffusion measures, including fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD), mean kurtosis (MK), radial kurtosis (RK), and axial kurtosis (AK), were calculated. To analyze differences between the two groups, nonparametric permutation testing with 10,000 randomized permutations and threshold-free cluster enhancement was used with family-wise error-corrected p values < 0.05 as the threshold for statistical significance. Then, the correlations between significant changes in these diffusion measures and clinical factors were examined. Compared to HCs, patients with SSD had significantly higher FA, MK, and RK and significantly lower MD and RD in the cerebellum, thalamus, basal ganglia, and limbic cortex. The FA in the left caudate and the pontine crossing tract were negatively correlated with disease duration; the MD and the RD in the genu of the corpus callosum were positively correlated with disease duration. Our findings highlight the role of the cerebellum-thalamus-basal ganglia-limbic cortex pathway, especially the cerebellum, in SSDs and enhance our understanding of the pathogenesis of SSDs.

Overall comorbidities in functional neurological disorder: A narrative review

INTRODUCTION

The importance to assess and include the frequent comorbidities in the personalised care management plan of patients with functional neurological disorders (FND) has arisen through the years. FND patients are not only complaining from motor and/or sensory symptoms. They also report some non-specific symptoms that participate to the burden of FND. In this narrative review, we aim to better describe these comorbidities in terms of prevalence, clinical characteristics and their variability depending on the subtype of FND.

METHODS

The literature was searched for on Medline and PubMed. The search was narrowed to articles between 2000 and 2022.

RESULTS

Fatigue is the most common symptom reported in relation to FND (from 47 to 93%), followed by cognitive symptoms (from 80 to 85%). Psychiatric disorders are reported in 40 to 100% FND patients, depending on the FND subtype (functional motor disorder [FMD], functional dissociative seizures [FDS]…) but also on the type of psychiatric disorder (anxiety disorders being the most frequent, followed by mood disorders and neurodevelopmental disorders). Stress factors such as childhood trauma exposure (emotional neglect and physical abuse predominantly) have also been identified in up to 75% of FND patients, along with maladaptive coping strategies. Organic disorders are commonly reported in FND, such as neurological disorders (including epilepsy in FDS [20%] and FMD in Parkinson's Disease [7%]). Somatic symptom disorders including chronic pain syndromes are frequently associated to FND (about 50%). To be noted, recent data also suggest a high comorbidity between FND and hypermobile Ehlers Danlos Syndrome (about 55%).

CONCLUSION

Put together, this narrative review highlights the high burden of FND patients, not only due to somatosensory alterations but also by considering the frequent comorbidities reported. Thus, such comorbidities must be taken into consideration when defining the FND personalised care management strategy for the patients.

Glutamatergic dysfunction, neuroplasticity, and redox status in the peripheral blood of patients with motor conversion disorders (functional movement disorders): a first step towards potential biomarkers discovery

Functional movement disorders (FMD) are characterized by the presence of neurological symptoms that cannot be explained by typical neurological diseases or other medical conditions. First evidence showed that, compared to healthy controls (CTR), FMD patients presented increased levels of glutamate+glutamine in the anterior cingulate cortex/medial prefrontal cortex, and decreased levels of glutamate in the cerebrospinal fluid, suggesting that a glutamatergic dysfunction might play a role in FMD pathophysiology. In this study, 12 FMD patients and 20 CTR were recruited and underwent venous blood sampling and urine collection: levels of glutamate, BDNF, dopamine, oxidative stress, creatinine, neopterin, and uric acid were analyzed. Participants also underwent a psychometric assessment investigating depression, anxiety, and alexithymia. We found that levels of glutamate, BDNF, and dopamine were significantly lower in the blood of FMD patients than CTR. Glutamate and dopamine levels were positively associated with levels of alexithymia. Our findings give further evidence that glutamatergic dysfunction might be involved in the pathophysiology of FMD, possibly representing a biomarker of disease; moreover, since glutamatergic and dopaminergic systems are closely interconnected, our results might have a relevance in terms of treatment options for FMD patients.

Neurological Dysfunction in Long COVID Should Not Be Labelled as Functional Neurological Disorder

There have been suggestions that Long COVID might be purely functional (meaning psychological) in origin. Labelling patients with neurological dysfunction in Long COVID as having functional neurological disorder (FND) in the absence of proper testing may be symptomatic of that line of thought. This practice is problematic for Long COVID patients, as motor and balance symptoms have been reported to occur in Long COVID frequently. FND is characterized by the presentation of symptoms that seem neurological but lack compatibility of the symptom with a neurological substrate. Although diagnostic classification according to the ICD-11 and DSM-5-TR is dependent predominantly on the exclusion of any other medical condition that could account for the symptoms, current neurological practice of FND classification allows for such comorbidity. As a consequence, Long COVID patients with motor and balance symptoms mislabeled as FND have no longer access to Long COVID care, whereas treatment for FND is seldom provided and is ineffective. Research into underlying mechanisms and diagnostic methods should explore how to determine whether motor and balance symptoms currently diagnosed as FND should be considered one part of Long COVID symptoms, in other words, one component of symptomatology, and in which cases they correctly represent FND. Research into rehabilitation models, treatment and integrated care are needed, which should take into account biological underpinnings as well as possible psychological mechanisms and the patient perspective.

Functional Neurologic Disorders, disorders to be managed by neurologists, or are neurologists wandering in a dangerous field with inadequate resources?

In recent years, some neurologists reconsidered their approach to Medically Unexplained Symptoms and proposed Functional Neurologic Disorders (FND) as a new entity, claiming that neurology could offer alternative treatment options to the psychotherapies provided in psychiatry settings. FNDs, for this purpose, should include only the disorders listed as Conversion from the Somatic Symptom and Related Disorders (SSRD) group. The present review analyzes the rationale of this position and challenges the arguments provided for its support. The review also discusses the systematization of these disorders as provided by public health systems. It outlines risks stemming from economic support and public funding uncertainty, given their negligible epidemiological dimensions resulting from the parcellation of SSRD. The review underlines the unresolved issue of Factitious Disorders, which are in the same SSRD category of the international classification but are, nonetheless, overlooked by the theoretical proponents of the FND entity. Comorbidity with other psychiatric disorders is also analyzed. We propose a model that supports the continuum between different SSRD conditions, including Factitious Disorders. The model is based on the emergence of feigned death reflex and deception from frontal lobe dysfunction. Finally, the paper summarizes the wealth of historical psychiatric and psychodynamic approaches and critical reviews. The study also puts in context the categorization and interpretation efforts provided by the most eminent researchers of the past century.

Linking gene expression patterns and brain morphometry to trauma and symptom severity in patients with functional seizures

Within stress-diathesis models, adverse life experiences (ALEs) increase the susceptibility to functional neurological symptoms through neuroplasticity effects. We aimed to characterize potential genetic influences on this relationship in 20 patients with functional seizures. Questionnaires, structural MRIs and Allen Human Brain Atlas gene expression information were used to probe the intersection of symptom severity (Somatoform Dissociation Questionnaire, SDQ-20), ALE burden, and gray matter volumes. SDQ-20 scores positively correlated with sexual trauma, emotional neglect, and threat to life experiences. Higher SDQ-20 scores related to lower bilateral insula, left orbitofrontal, right amygdala, and perigenual/posterior cingulate volumes. Higher sexual trauma burden correlated with lower right posterior insula and putamen volumes; higher emotional neglect related to lower bilateral insula/right amygdala volumes. Findings in left insula/ventral precentral gyrus (SDQ-20), right insula/putamen (sexual trauma), and right amygdala (emotional neglect) held when controlling for comorbid psychopathology. At the intersection of symptom severity and sexual trauma volumetric findings, genes overrepresented in adrenergic, serotonergic, and oxytocin receptor signaling as well as in cortical and amygdala development were spatially correlated. In conclusion, ALEs and symptom severity were associated with gray matter volumes in cingulo-insular and amygdala areas, spatially overlapping with expression patterns of genes involved in stress-related signaling and neurodevelopment.

Clinical MRI morphological analysis of functional seizures compared to seizure-naïve and psychiatric controls

PURPOSE

Functional seizures (FS), also known as psychogenic nonepileptic seizures (PNES), are physical manifestations of acute or chronic psychological distress. Functional and structural neuroimaging have identified objective signs of this disorder. We evaluated whether magnetic resonance imaging (MRI) morphometry differed between patients with FS and clinically relevant comparison populations.

METHODS

Quality-screened clinical-grade MRIs were acquired from 666 patients from 2006 to 2020. Morphometric features were quantified with FreeSurfer v6. Mixed-effects linear regression compared the volume, thickness, and surface area within 201 regions-of-interest for 90 patients with FS, compared to seizure-naïve patients with depression (n = 243), anxiety (n = 68), and obsessive-compulsive disorder (OCD, n = 41), respectively, and to other seizure-naïve controls with similar quality MRIs, accounting for the influence of multiple confounds including depression and anxiety based on chart review. These comparison populations were obtained through review of clinical records plus research studies obtained on similar scanners.

RESULTS

After Bonferroni-Holm correction, patients with FS compared with seizure-naïve controls exhibited thinner bilateral superior temporal cortex (left 0.053 mm, p = 0.014; right 0.071 mm, p = 0.00006), thicker left lateral occipital cortex (0.052 mm, p = 0.0035), and greater left cerebellar white-matter volume (1085 mm³, p = 0.0065). These findings were not accounted for by lower MRI quality in patients with FS.

CONCLUSIONS

These results reinforce prior indications of structural neuroimaging correlates of FS and, in particular, distinguish brain morphology in FS from that in depression, anxiety, and OCD. Future work may entail comparisons with other psychiatric disorders including bipolar and schizophrenia, as well as exploration of brain structural heterogeneity within FS.

A new science of emotion: implications for functional neurological disorder

Functional neurological disorder reflects impairments in brain networks leading to distressing motor, sensory and/or cognitive symptoms that demonstrate positive clinical signs on examination incongruent with other conditions. A central issue in historical and contemporary formulations of functional neurological disorder has been the mechanistic and aetiological role of emotions. However, the debate has mostly omitted fundamental questions about the nature of emotions in the first place. In this perspective article, we first outline a set of relevant working principles of the brain (e.g. allostasis, predictive processing, interoception and affect), followed by a focused review of the theory of constructed emotion to introduce a new understanding of what emotions are. Building on this theoretical framework, we formulate how altered emotion category construction can be an integral component of the pathophysiology of functional neurological disorder and related functional somatic symptoms. In doing so, we address several themes for the functional neurological disorder field including: (i) how energy regulation and the process of emotion category construction relate to symptom generation, including revisiting alexithymia, 'panic attack without panic', dissociation, insecure attachment and the influential role of life experiences; (ii) re-interpret select neurobiological research findings in functional neurological disorder cohorts through the lens of the theory of constructed emotion to illustrate its potential mechanistic relevance; and (iii) discuss therapeutic implications. While we continue to support that functional neurological disorder is mechanistically and aetiologically heterogenous, consideration of how the theory of constructed emotion relates to the generation and maintenance of functional neurological and functional somatic symptoms offers an integrated viewpoint that cuts across neurology, psychiatry, psychology and cognitive-affective neuroscience.

Functional neurological disorder: new subtypes and shared mechanisms

Functional neurological disorder is common in neurological practice. A new approach to the positive diagnosis of this disorder focuses on recognisable patterns of genuinely experienced symptoms and signs that show variability within the same task and between different tasks over time. Psychological stressors are common risk factors for functional neurological disorder, but are often absent. Four entities-functional seizures, functional movement disorders, persistent perceptual postural dizziness, and functional cognitive disorder-show similarities in aetiology and pathophysiology and are variants of a disorder at the interface between neurology and psychiatry. All four entities have distinctive features and can be diagnosed with the support of clinical neurophysiological studies and other biomarkers. The pathophysiology of functional neurological disorder includes overactivity of the limbic system, the development of an internal symptom model as part of a predictive coding framework, and dysfunction of brain networks that gives movement the sense of voluntariness. Evidence supports tailored multidisciplinary treatment that can involve physical and psychological therapy approaches.

Socio-demographic characteristics and psychopathological assessment in a sample of 13 paediatric patients with functional neurological disorders: A preliminary report

This observational study aims to characterize, from a socio-demographic and psychopathological perspective, a sample of children with Functional Neurological Disorders (FND). Thirteen paediatric patients (below 18 years old) with FND and their parents completed a battery of anamnestic and neuropsychological tests, assessing socio-demographic status, cognitive level, behavioural and emotional issues, depression, anxiety, alexithymic traits and dissociative symptoms. Five patients presented movement disorders (tremor, myoclonus and gait disorder), three patients psychogenic non-epileptic seizures and five patients sensitivity disturbances (pain, anaesthesia and paraesthesia). Cognitive profile was normal in 11 patients; academic performance was good in nine patients, but three had a diagnosis of Specific Learning Difficulty or Attention Deficit Hyperactivity Disorder. Precipitating events occurred in 11 patients. At the self-report questionnaires, mean scores close to the clinical cut off were documented with respect to affective and somatic problems. At the parent-report questionnaires, clinically significant mean scores were observed in the subscales assessing anxious-depressive symptoms and somatic complaints. We speculate that paediatric FND patients, although acknowledging the relevance of somatic symptoms, have difficulties in recognizing internal emotional states (that, instead, are easily recognized by their parents). The case of one FND patient was described. These preliminary data might help identifying different clinical phenotypes of paediatric FND.

Development of an inpatient rehabilitation pathway for motor functional neurological disorders: Initial reflections

BACKGROUND: Emerging research supports a primary role for rehabilitation therapy alongside psychoeducation and psychotherapy in the treatment of functional neurological disorder (FND). OBJECTIVE: While consensus recommendations for physical therapists, occupational therapists, and speech and language pathologists treating FND have been published, specific recommendations for multidisciplinary FND care delivered on an inpatient rehabilitation unit are yet to be established. METHODS: This report describes one inpatient rehabilitation facility’s efforts to design and implement a clinical pathway for patients with acute-onset motor FND—patients recently hospitalized for work-up of new neurological symptoms subsequently deemed functional. RESULTS: Detailed descriptions on defining admission criteria and delivering consensus- and evidence-based multidisciplinary inpatient rehabilitation are provided. CONCLUSIONS: In the context of prospective research studies, considerably more work is needed to delineate the optimal duration and intensity of inpatient rehabilitation treatment for the management of patients with motor FND.

Functional neurological disorder: Extending the diagnosis to other disorders, and proposing an alternate disease term—Attentionally-modifiable disorder

BACKGROUND: The term “functional neurological disorder,” or “FND,” applies to disorders whose occurrence of neurological symptoms fluctuate with the patient’s attention to them. However, many other disorders that are not called “FND” nonetheless can also follow this pattern. Consequently, guidelines are unclear for diagnosing “FND.” OBJECTIVE: To review the neurological conditions that follow this pattern, but which have not so far been termed “FND,” to understand their overlap with conditions that have been termed “FND,” and to discuss the rationale for why FND has not been diagnosed for them. METHOD: A systematic review of the PubMed literature registry using the terms “fluctuation,” “inconsistency,” or “attention” did not yield much in the way of these candidate disorders. Consequently, this review instead relied on the author’s personal library of peer-reviewed studies of disorders that have resembled FND but which were not termed this way, due to his longstanding interest in this problem. Consequently, this approach was not systematic and was subjective regarding disease inclusion. RESULTS: This review identified numerous, diverse conditions that generally involve fluctuating neurological symptoms that can vary with the person’s attention to them, but which have not been called “FND.” The literature was unclear for reasons for not referring to “FND” in these instances. CONCLUSION: Most likely because of historical biases, the use of the term “FND” has been unnecessarily restricted. Because at its core FND is an attentionally-influenced disorder that can respond well to behavioral treatments, the field of neurological rehabilitation could benefit by extending the range of conditions that could be considered as “FND” and referred for similar behavioral treatments. Because the term “FND” has been viewed unfavorably by some patients and clinical practitioners and whose treatment is not implied, the alternative term attentionally-modifiable disorder is proposed.

Physical therapy interventions in an inpatient rehabilitation setting for functional neurological disorder: A case series

BACKGROUND: Patients with functional neurological disorder (FND) experience a variety of symptoms that affect their functional mobility and quality of life. Physical therapy can help promote normal movement patterns and restore independence. Although consensus recommendations have been published, choosing specific interventions can be a challenge due to the heterogeneity of symptom presentation. OBJECTIVE: This case series aims to detail specific interventions for three patients with FND who were admitted to an inpatient rehabilitation facility in Boston, MA, USA. CASE REPORT: Each presented with gait disturbances as his or her primary symptom and received physical therapy at least five times per week during the inpatient stay, as well as treatment from a multidisciplinary team. CONCLUSION: As emerging literature continues and the diagnosis is more widely accepted, specific symptom interventions may become more generalized and lead to better outcomes with this patient population.

Cortical thickness in default mode network hubs correlates with clinical features of dissociative seizures

BACKGROUND

Dissociative seizures (DS) are a common subtype of functional neurological disorder (FND) with an incompletely understood pathophysiology. Here, gray matter variations and their relationship to clinical features were investigated.

METHODS

Forty-eight patients with DS without neurological comorbidities and 43 matched clinical control patients with syncope with structural brain MRIs were identified retrospectively. FreeSurfer-based cortical thickness and FSL FIRST-based subcortical volumes were used for quantitative analyses, and all findings were age and sex adjusted, and corrected for multiple comparisons.

RESULTS

Groups were not statistically different in cortical thickness or subcortical volumes. For patients with DS, illness duration was inversely correlated with cortical thickness of left-sided anterior and posterior cortical midline structures (perigenual/dorsal anterior cingulate cortex, superior parietal cortex, precuneus), and clusters at the left temporoparietal junction (supramarginal gyrus, postcentral gyrus, superior temporal gyrus), left postcentral gyrus, and right pericalcarine cortex. Dissociative seizure duration was inversely correlated with cortical thickness in the left perigenual anterior cingulate cortex, superior/middle frontal gyri, precentral gyrus and lateral occipital cortex, along with the right isthmus-cingulate and posterior-cingulate, middle temporal gyrus, and precuneus. Seizure frequency did not show any significant correlations.

CONCLUSIONS

In patients with DS, illness duration inversely correlated with cortical thickness of left-sided default mode network cortical hubs, while seizure duration correlated with left frontopolar and right posteromedial areas, among others. Etiological factors contributing to neuroanatomical variations in areas related to self-referential processing in patients with DS require more research inquiry.

Functional seizures are associated with cerebrovascular disease and functional stroke is more common in patients with functional seizures than epileptic seizures

PURPOSE

To characterize the relationship between functional seizures (FSe), cerebrovascular disease (CVD), and functional stroke.

METHOD

A retrospective case-control study of 189 patients at a single large tertiary medical center. We performed a manual chart review of medical records of patients with FSe or epileptic seizures (ES), who also had ICD code evidence of CVD. The clinical characteristics of FSe, ES, CVD, and functional stroke were recorded. Logistic regression and Welch's t-tests were used to evaluate the differences between the FSe and ES groups.

RESULTS

Cerebrovascular disease was confirmed in 58.7% and 87.6% of patients with FSe or ES through manual chart review. Stroke was significantly more common in patients with ES (76.29%) than FSe (43.48%) (p = 4.07 × 10^-6). However, compared to nonepileptic controls FSe was associated with both CVD (p < 0.0019) and stroke (p < 6.62 × 10^-10). Functional stroke was significantly more common in patients with FSe (39.13%) than patients with ES (4.12%) (p = 4.47 × 10^-9). Compared to patients with ES, patients with FSe were younger (p = 0.00022), more likely to be female (p = 0.00040), and more likely to have comorbid mental health needs including anxiety (p = 1.06 × 10^-6), PTSD or history of trauma (e.g., sexual abuse) (p = 1.06 × 10^-13), and bipolar disorder (p = 0.0011).

CONCLUSION

Our results confirm the initial observation of increased CVD in patients with FSe and further suggest that patients with FSe may be predisposed to developing another functional neurological disorder (FND) (i.e., functional stroke). We speculate that this may be due to shared risk factors and pathophysiological processes that are common to various manifestations of FND.

Functional (psychogenic non-epileptic/dissociative) seizures: why and how?

Functional seizures (FS) known also as psychogenic non-epileptic seizures or dissociative seizures, present with ictal semiological manifestations, along with various comorbid neurological and psychological disorders. Terminology inconsistencies and discrepancies in nomenclatures of FS may reflect limitations in understanding the neuropsychiatric intricacies of this disorder. Psychological and neurobiological processes of FS are incompletely understood. Nevertheless, important advances have been made on underlying neuropsychopathophysiological mechanisms of FS. These advances provide valuable information about the underlying mechanisms of mind-body interactions. From this perspective, this narrative review summarises recent studies about aetiopathogenesis of FS at two levels: possible risk factors (why) and different aetiopathogenic models of FS (how). We divided possible risk factors for FS into three categories, namely neurobiological, psychological and cognitive risk factors. We also presented different models of FS based on psychological and neuroanatomical understanding, multilevel models and integrative understanding of FS. This work should help professionals to better understand current views on the multifactorial mechanisms involved in the development of FS. Shedding light on the different FS profiles in terms of aetiopathogenesis will help guide how best to direct therapy, based on these different underlying mechanisms.

Repetitive transcranial magnetic stimulation for patients with functional paralysis: a randomized controlled study

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has been proposed to treat functional neurological disorders. Here, we aim to assess the efficacy of rTMS to treat functional paralysis in a controlled randomized trial.

METHODS

Patients received 2 sessions of active or sham 0.25 Hz rTMS (60 stimuli each), with a one-day interval, applied over the motor cortex contralateral to the paralysis. The primary outcome was the number of patients with an increase in motor score between baseline and after the second rTMS session, rated by two investigators blinded to the treatment allocation. Secondary outcomes were changes in global and fine motor scores between groups after rTMS, and occurrence of adverse events.

RESULTS

Sixty-two patients (46 female; mean [SD] age, 35.2 [13.9] years) were enrolled and randomized. Thirteen out of 32 (41%) and 11/30 (37%) patients had increased motor strength after active or sham rTMS, respectively (p=0.80). Changes in both global and fine motor scores after rTMS relative to baseline were also not significantly different between treatment groups (median difference in the global motor score 0.62 [0.83] and 0.37 [0.61], and fine motor scores 0.12 [0.18] and 0.08 [0.11], in active and sham rTMS groups, respectively, p=0.14). We observed six serious adverse events, consisting of 3 cephalalgia in the active group and 2 cephalalgia and 1 asthenia in the sham group.

CONCLUSIONS

Two sessions of sham or active low frequency rTMS were effective to improve functional paralysis, suggesting a placebo effect of this non-invasive brain stimulation technique.

Diagnosis and management of functional neurological disorder

Functional neurological disorder (FND), previously regarded as a diagnosis of exclusion, is now a rule-in diagnosis with available treatments. This represents a major step toward destigmatizing the disorder, which was often doubted and deemed untreatable. FND is prevalent, generally affecting young and middle aged adults, and can cause severe disability in some individuals. An early diagnosis, with subsequent access to evidence based rehabilitative and/or psychological treatments, can promote recovery-albeit not all patients respond to currently available treatments. This review presents the latest advances in the use of validated rule-in examination signs to guide diagnosis, and the range of therapeutic approaches available to care for patients with FND. The article focuses on the two most frequently identified subtypes of FND: motor (weakness and/or movement disorders) and seizure type symptoms. Twenty two studies on motor and 27 studies on seizure type symptoms report high specificities of clinical signs (64-100%), and individual signs are reviewed. Rehabilitative interventions (physical and occupational therapy) are treatments of choice for functional motor symptoms, while psychotherapy is an emerging evidence based treatment across FND subtypes. The literature to date highlights heterogeneity in responses to treatment, underscoring that more research is needed to individualize treatments and develop novel interventions.

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

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

Autonomic, Endocrine, and Inflammation Profiles in Functional Neurological Disorder: A Systematic Review and Meta-Analysis

OBJECTIVE

Functional neurological disorder (FND) is a core neuropsychiatric condition. To date, promising yet inconsistently identified neural circuit profiles have been observed in patients with FND, suggesting that gaps remain in our systems-level neurobiological understanding. As such, other important physiological variables, including autonomic, endocrine, and inflammation findings, need to be contextualized for a more complete mechanistic picture.

METHODS

The investigators conducted a systematic review and meta-analysis of available case-control and cohort studies of FND. PubMed, PsycINFO, and Embase databases were searched for studies from January 1, 1900, to September 1, 2020, that investigated autonomic, endocrine, and inflammation markers in patients with FND. Sixty-six of 2,056 screened records were included in the review, representing 1,699 patients; data from 20 articles were used in the meta-analysis.

RESULTS

Findings revealed that children and adolescents with FND, compared with healthy control subjects (HCs), have increased resting heart rate (HR); there is also a tendency toward reduced resting HR variability in patients with FND across the lifespan compared with HCs. In adults, peri-ictal HR differentiated patients with functional seizures from those with epileptic seizures. Other autonomic and endocrine profiles for patients with FND were heterogeneous, with several studies highlighting the importance of individual differences.

CONCLUSIONS

Inflammation research in FND remains in its early stages. Moving forward, there is a need for the use of larger sample sizes to consider the complex interplay between functional neurological symptoms and behavioral, psychological, autonomic, endocrine, inflammation, neuroimaging, and epigenetic/genetic data. More research is also needed to determine whether FND is mechanistically (and etiologically) similar or distinct across phenotypes.

Prevalence of Alexithymia in Patients with Medically Unexplained Physical Symptoms: A Cross-sectional Study in Egypt

BACKGROUND

There is a high incidence of alexithymia in people who report medically unexplained symptoms. There have been limited studies on the prevalence of alexithymia in patients with medically unexplained physical symptoms (MUPS) in various ethnic and cultural backgrounds.

OBJECTIVE

This study aimed to estimate the prevalence of alexithymia in patients with MUPS and examine their socio-demographic data.

METHODS

In this cross-sectional study, 196 patients with MUPS were recruited from tertiary care internal medicine and neuropsychiatry clinics during the first quarter of 2019. Patients completed a structured interview; socio-demographic and medical history data were collected. Somatic symptom severity was assessed using the Arabic version of the Patient Health Questionnaire (PHQ-15). Alexithymia was assessed using the Arabic version of the Toronto Alexithymia Scale.

RESULTS

General fatigue was the most common complaint observed, followed by headache and dyspepsia. In addition, 73.5% of patients had a high Patient Health Questionnaire score, 17.9% had somatic symptoms of medium severity, while 8% and 0.5% had low and marginal somatic symptoms, respectively. Alexithymia was presented in 49.5%, 22.9% had no alexithymia, and 27.6% had borderline/intermediate alexithymia.A weak positive correlation (r<0.4) was found between somatic symptom severity and alexithymic psychopathology (r=0.277;p<0.05). Only the 'difficulty identifying feelings' dimension of alexithymic psychopathology was positively correlated with the severity of somatic symptoms (r=0.271;p<0.05).

CONCLUSION

Alexithymia is associated with the development of MUPS.

Posttraumatic functional movement disorders and litigation

The concept of functional movement disorders has evolved considerably over the past few decades. More specifically, the views on the relation with psychological stressors or personality disorders have substantially changed, emphasizing a shift from the previously dominant dualistic scheme. This evolution is reflected in adaptations to diagnostic criteria and management approaches. Functional movement disorders which arise in a close temporal relationship with a peripheral trauma are specifically challenging with respect to diagnosis and treatment, but similar considerations seem to apply. The relationship of functional disorders with trauma appears to be much closer than is often thought. Clinical and pathophysiological research has identified shared factors underlying functional posttraumatic as well as primary movement disorders. These evolving insights impact on discussions in terms of litigation for compensation after trauma. The literature is reviewed and the consequences for argumentation in litigation are outlined, including ethical and legal considerations. Finally, we formulate a number of recommendations.

Implicit motor imagery using laterality recognition in functional movement disorders

Functional movement disorder (FMD) presents as disabling motor symptoms that cannot be explained by organic processes. Despite the lack of lesion or known central nervous system dysfunction, distortion in sensorimotor processing in movement generation and execution is often observed. A person's capacity to judge laterality of a body part requires processing of sensorimotor information. This prospective observational study compared reaction time (RT) and accuracy (ACC) of hand laterality recognition between 30 people diagnosed with FMD and 30 age-matched healthy control participants. The association of RT and ACC with severity of FMD as measured by the Simplified Functional Movement Disorders Rating Scale (SFMDRS) was also explored. RT was on average 0.6 s slower (95% CI 0.4 - 0.8 s, p < 0.001) in patients with FMD (mean 2.2 s, standard deviation (SD) 0.5) than controls (mean 1.7 s, SD 0.3). ACC was on average 8.9% lower (95% CI -15.7 - -2.2, p = 0.01) in patients with FMD (mean 79.6%, SD 16.6) than controls (mean 88.5%, SD 8.1). When adjusted for SFMDRS using robust regression, RT was 0.3 s slower (95% CI 0.01 - 0.5, p = 0.04) in cases than in controls, but ACC was no longer different between groups. There was a moderate negative correlation between RT and ACC in FMD patients (ρ -0.58, p < 0.001 but not in controls (ρ -0.26, p = 0.17). People with FMD had significantly slower RT and lower ACC compared to the control group. These results provide new insights into underlying sensorimotor processing deficits in those with FMD.

The spectrum of functional neurological disorders: A retrospective analysis at a tertiary hospital in South Africa

BACKGROUND

Functional neurological disorders (FNDs) are commonly encountered in practice; however, there is a paucity of data in Africa.

AIM

To identify and describe the clinical profile of patients presenting with FNDs, underlying medical and psychiatric diagnoses and review the investigation and management of these patients.

SETTING

Inkosi Albert Luthuli Central Hospital (IALCH), a tertiary-level hospital in Durban, South Africa.

METHODS

A retrospective chart review and descriptive analysis were performed over a 14-year period (2003-2017) on cases meeting the study criteria.

RESULTS

Of 158 subjects, the majority were female (72.8%), had a mean age of 32.8 years, were single (63.3%), unemployed (56.3%) and of black African ethnicity (64.6%). The most common clinical presentation was sensory impairment (57%) followed by weakness (53.2%) and seizures (38.6%). Inconsistency was the most frequent examination finding (16.5%). Medical conditions were identified in half of the study population (51.3%), with hypertension (22.2%) and human immunodeficiency virus (HIV) (17.2%) being most common. Of patients with a psychiatric diagnosis (55.1%), 25.3% had depression. Magnetic resonance imaging (MRI) was the most frequently performed investigation (36.1%). The majority of patients received psychotherapy (72%) and most had not shown improvement (55.3%) at a median follow-up of 2 months, whilst 17% had deteriorated.

CONCLUSION

Functional neurological disorders were most frequently diagnosed in young unmarried females, of black African ethnicity. Family history, personal exposure to a neurological illness and certain socioeconomic factors may be potential risk factors. Sensory impairment was the most common clinical phenotype. Further studies are needed to better understand and manage FNDs in the South African context.

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.

Are Functional (Psychogenic Nonepileptic) Seizures the Sole Expression of Psychological Processes?

Functional [psychogenic nonepileptic/dissociative] seizures (FND-seiz) and related functional neurological disorder subtypes were of immense interest to early founders of modern-day neurology and psychiatry. Unfortunately, the divide that occurred between the both specialties throughout the mid-twentieth century placed FND-seiz at the borderland between the two disciplines. In the process, a false Cartesian dualism emerged that labeled psychiatric conditions as impairments of the mind and neurological conditions as disturbances in structural neuroanatomy. Excitingly, modern-day neuropsychiatric perspectives now consider neurologic and psychiatric conditions as disorders of both brain and mind. In this article, we aim to integrate neurologic and psychiatric perspectives in the conceptual framing of FND-seiz. In doing so, we explore emerging relationships between symptoms, neuropsychological constructs, brain networks, and neuroendocrine/autonomic biomarkers of disease. Evidence suggests that the neuropsychological constructs of emotion processing, attention, interoception, and self-agency are important in the pathophysiology of FND-seiz. Furthermore, FND-seiz is a multi-network brain disorder, with evidence supporting roles for disturbances within and across the salience, limbic, attentional, multimodal integration, and sensorimotor networks. Risk factors, including the magnitude of previously experienced adverse life events, relate to individual differences in network architecture and neuroendocrine profiles. The time has come to use an integrated neuropsychiatric approach that embraces the closely intertwined relationship between physical health and mental health to conceptualize FND-seiz and related functional neurological disorder subtypes.