Psychopathology and psychogenic movement disorders

Social cognition in Parkinson's disease and functional movement disorders

INTRODUCTION

Functional movement disorders (FMD) can overlap with Parkinson's disease (PD), and distinguishing between the two clinical conditions can be complex. Framing social cognition (theory of mind) (TOM) disorder, attention deficit, and psychodynamic features of FMD and PD may improve diagnosis.

METHODS

Subjects with FMD and PD and healthy controls (HC) were administered tasks assessing TOM abilities and attention. The psychodynamic hypothesis of conversion disorder was explored by a questionnaire assessing dissociative symptoms. A comprehensive battery of neuropsychological tasks was also administered to FMD and PD.

RESULTS

Although both FMD and PD scored lower than HC on all TOM tests, significant correlations between TOM and neuropsychological tasks were found only in PD but not in FMD. Only PD showed a reduction in attentional control. Dissociative symptoms occurred only in FMD.

DISCUSSION

Cognitive-affective disturbances are real in FMD, whereas they are largely dependent on cognitive impairment in PD. Attentional control is preserved in FMD compared to PD, consistent with the hypothesis that overload of voluntary attentional orientation may be at the basis of the onset of functional motor symptoms. On a psychodynamic level, the confirmation of dissociative symptoms in FMD supports the conversion disorder hypothesis.

CONCLUSION

FMD and PD can be distinguished on an affective and cognitive level. At the same time, however, the objective difficulty often encountered in distinguishing between the two pathologies draws attention to how blurred the boundary between 'organic' and 'functional' can be.

Functional Movement Disorders: Updates and Clinical Overview

Functional movement disorder (FMD) is a type of functional neurological disorder that is common but often difficult to diagnose or manage. FMD can present as various phenotypes, including tremor, dystonia, myoclonus, gait disorders, and parkinsonism. Conducting a clinical examination appropriate for assessing a patient with suspected FMD is important, and various diagnostic testing maneuvers may also be helpful. Treatment involving a multidisciplinary team, either outpatient or inpatient, has been found to be most effective. Examples of such treatment protocols are also discussed in this review. While recognition and understanding of the disorder has improved over the past few decades, as well as the development of treatments, it is not uncommon for patients and physicians to continue to experience various difficulties when dealing with this disorder. In this review, I provide a practical overview of FMD and discuss how the clinical encounter itself can play a role in patients' acceptance of the diagnosis. Recent neuroimaging studies that aid in understanding the pathophysiology are also discussed.

[Interpretation of a concept for functional movement disorders from the perspective of older patients]

A recently published concept considers a significant proportion of the occurrence and persistence of functional movement disorders (FMD) to be explained by increased/incorrect weighting of the expected movement (feedforward signal) in the presence of decreased/altered actual feedback of the movement. In the context of aging and age-associated diseases, there is an increased likelihood that these prerequisites will occur, also in combination. For example, the feedforward signal can be enhanced by accumulation of a wealth of experience but can for example become prone to error due to changes in attention and (fear of) falling. Conversely, the actual feedback is subject to age-related changes, such as reduction of sensory functions. This could explain why FMDs also occur in old age and offer treatment approaches for this so far poorly studied disorder. It follows that a specific focus on (the correction of) feedforward signals and strengthening as well as training of the actual feedback are potentially promising therapeutic approaches for older people with FMD.

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.

Similarities and Differences in Functional Movement Disorders and Functional Seizures at a Tertiary Care Center: A Prospective Study

Background

Functional movement disorders (FMDs) and functional seizure (FS) are the two most important subcategories of functional neurologic disorders (FNDs).

Objectives

This study aimed to discern similarities and differences between patients with FMD and FS.

Methods

A prospective comparative study of 94 patients with FNDs (FMD = 47, FS = 47) was conducted.

Results

Tremor and pauci-kinetic attack with preserved responsiveness were the most common subtypes observed in patients with FMD and FS, respectively. A significantly higher number of patients with FMD had more than one precipitating factor (P = 0.03). Headache was significantly more common in patients with FS (P = 0.03). More patients came for follow-up in the FMD group (P = 0.01). More patients in the FS group reported "very much improvement" (P = 0.04), and "no change" was more commonly reported by the FMD group patients (P = 0.009).

Conclusion

Emotional stress was the most common precipitating factor in patients with FMD and FS. The prognosis was better in patients with FS.

The Role of a Dopamine-Dependent Limbic-Motor Network in Sensory Motor Processing in Parkinson Disease

Limbic and motor integration is enabled by a mesial temporal to motor cortex network. Parkinson disease (PD) is characterized by a loss of dorsal striatal dopamine but relative preservation of mesolimbic dopamine early in disease, along with changes to motor action control. Here, we studied 47 patients with PD using the Simon conflict task and [18F]fallypride PET imaging. Additionally, a cohort of 16 patients participated in a single-blinded dextroamphetamine (dAMPH) study. Task performance was evaluated using the diffusion model for conflict tasks, which allows for an assessment of interpretable action control processes. First, a voxel-wise examination disclosed a negative relationship, such that longer non-decision time is associated with reduced D2-like binding potential (BPND) in the bilateral putamen, left globus pallidus, and right insula. Second, an ROI analysis revealed a positive relationship, such that shorter non-decision time is associated with reduced D2-like BPND in the amygdala and ventromedial OFC. The difference in non-decision time between off-dAMPH and on-dAMPH trials was positively associated with D2-like BPND in the globus pallidus. These findings support the idea that dysfunction of the traditional striatal-motor loop underlies action control deficits but also suggest that a compensatory parallel limbic-motor loop regulates motor output.

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.

Panic Attack, Severe Hypophosphatemia and Rhabdomyolysis in the Setting of a Motor Functional Neurological Disorder

(1) Background: panic attack is often regarded as a benign disorder with variable physical and psychological symptoms. (2) Case Presentation: We here report the case of a 22-year-old patient known for an episode of motor functional neurological disorder a year earlier who presented a panic attack with hyperventilation causing severe hypophosphatemia and rhabdomyolysis, as well as mild tetraparesis. Electrolyte disturbances quickly resolved after phosphate substitution and rehydration. However, clinical signs suggesting a relapse of a motor functional neurological disorder appeared (improved walking with dual tasks). Diagnostic workup, including brain and spinal magnetic resonance imaging, as well as electroneuromyography and genetic testing for hypokalemic periodic paralysis, was unremarkable. Tetraparesis, lack of endurance, and fatigue eventually improved after several months. (3) Conclusions: the present case report highlights the intertwined relationship between a psychiatric disorder, leading to hyperventilation and acute metabolic disturbances, and functional neurological manifestations.

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.

Moving Beyond Movement: Diagnosing Functional Movement Disorder

Functional movement disorder (FMD) is a complex neuropsychiatric syndrome, encompassing abnormal movements and weakness, and is a common cause of potentially disabling neurological symptoms. It is vital to recognize that FMD is a syndrome, with nonmotor manifestations negatively affecting a patient's quality of life. This review highlights a diagnostic algorithm, where a history suggestive of FMD is combined with the presence of positive signs on examination and appropriate investigations to make the diagnosis. Positive signs indicate internal inconsistency such as variability and distractibility, and clinical findings that are incongruent with other known neurological disease. Importantly, the clinical assessment acts as the first opportunity to allow patients to understand FMD as the cause for their symptoms. Accurate and early diagnosis of FMD is necessary given that it is a treatable and potentially reversible cause of disability, with significant risk of iatrogenic harm associated with misdiagnosis.

Functional Movement Disorders during COVID-19: Psychological Distress, Affective Temperament and Emotional Dysregulation

Background and objective: Functional movement disorders (FMD) represent a spectrum of psychosomatic symptoms particularly sensitive to stress. The COVID-19 pandemic has increased psychological distress worldwide and may have worsened FMD. The study aimed to confirm this hypothesis and to test whether in FMD there is a relationship between affective temperament, emotional dysregulation and psychological distress due to the pandemic. Methods: We recruited individuals with FMD, diagnosed them according to validated criteria and matched them with healthy controls (HC). Psychological distress and temperament were obtained using the Kessler-10 and the Temperament Evaluation of Memphis, Pisa and San Diego Autoquestionnaire, respectively. We used bootstrapped mediation analysis to test the mediator role of emotional dysregulation on the effect of temperament on psychological distress. Results: The sample consisted of 96 individuals. During the pandemic, 31.3% of the patients reported the need for urgent neurological care, and 40.6% reported a subjective worsening neurological condition. Patients with FMD presented with more psychological distress during the COVID-19 pandemic (F = 30.15, df = 1, p ≤ 0.001) than HC. They also reported more emotional dysregulation (F = 15.80, df = 1, p ≤ 0.001) and more cyclothymic traits (F = 14.84, df = 1, p ≤ 0.001). Cyclothymic temperament showed an indirect effect on COVID-19-related psychological distress, mediated by deficits in emotion regulation mechanisms (Bootstrapped LLCI = 0.41, ULCI = 2.41). Conclusion: Our results suggest that emotional dysregulation may represent a dimension mediating cyclotimic temperament response to the stressful effect of the pandemic and provide insight for developing intervention policies.

Dissociation and its biological and clinical associations in functional neurological disorder: systematic review and meta-analysis

BACKGROUND

Studies have reported elevated rates of dissociative symptoms and comorbid dissociative disorders in functional neurological disorder (FND); however, a comprehensive review is lacking.

AIMS

To systematically review the severity of dissociative symptoms and prevalence of comorbid dissociative disorders in FND and summarise their biological and clinical associations.

METHOD

We searched Embase, PsycInfo and MEDLINE up to June 2021, combining terms for FND and dissociation. Studies were eligible if reporting dissociative symptom scores or rates of comorbid dissociative disorder in FND samples. Risk of bias was appraised using modified Newcastle-Ottawa criteria. The findings were synthesised qualitatively and dissociative symptom scores were included in a meta-analysis (PROSPERO CRD42020173263).

RESULTS

Seventy-five studies were eligible (FND n = 3940; control n = 3073), most commonly prospective case-control studies (k = 54). Dissociative disorders were frequently comorbid in FND. Psychoform dissociation was elevated in FND compared with healthy (g = 0.90, 95% CI 0.66-1.14, I² = 70%) and neurological controls (g = 0.56, 95% CI 0.19-0.92, I² = 67%). Greater psychoform dissociation was observed in FND samples with seizure symptoms versus healthy controls (g = 0.94, 95% CI 0.65-1.22, I² = 42%) and FND samples with motor symptoms (g = 0.40, 95% CI -0.18 to 1.00, I² = 54%). Somatoform dissociation was elevated in FND versus healthy controls (g = 1.80, 95% CI 1.25-2.34, I² = 75%). Dissociation in FND was associated with more severe functional symptoms, worse quality of life and brain alterations.

CONCLUSIONS

Our findings highlight the potential clinical utility of assessing patients with FND for dissociative symptomatology. However, fewer studies investigated FND samples with motor symptoms and heterogeneity between studies and risk of bias were high. Rigorous investigation of the prevalence, features and mechanistic relevance of dissociation in FND is needed.

Functional neurological disorder and placebo and nocebo effects: shared mechanisms

Functional neurological disorder (FND) is characterized by neurological symptoms that cannot be explained by a structural neurological cause. Among the different aetiological models that have been proposed for FND, of note is the Bayesian predictive coding model, which posits that perception relies on top-down cortical predictions (priors) to infer the source of incoming sensory information. This model can also apply to non-pathological experiences, such as placebo and nocebo effects, wherein sensory information is shaped by prior expectations and learning. To date, most studies of the relationship between placebo and nocebo effects and FND have focused on the use of placebos for diagnosis and treatment of FND. Here, we propose that this relationship might go beyond diagnosis and therapy. We develop a framework in which shared cognitive, personality and neuroanatomical factors justify the consideration of a deeper link between FND and placebo and nocebo effects. This new perspective might offer guidance for clarification of the pathogenesis of FND and for the identification of potential biomarkers and therapeutic targets.

Functional Neurological Disorders: Clinical Spectrum, Diagnosis, and Treatment

BACKGROUND

Functional neurological disorders (FNDs) are common but often misdiagnosed.

REVIEW SUMMARY

The incidence of FNDs is between 4 and 12 per 100,000, comparable to multiple sclerosis and amyotrophic lateral sclerosis, and it is the second most common diagnosis in neurology clinics. Some clues in the history are sudden onset, intermittent time course, variability of manifestation over time, childhood trauma, and history of other somatic symptoms. Anxiety and depression are common, but not necessarily more than in the general population. Although there are no tests currently capable of demonstrating whether symptoms are willfully produced, there may not be a clear categorical difference between voluntary and involuntary symptoms. The prognosis of an FND is linked to early diagnosis and symptom duration, but unfortunately, the majority of the patients are diagnosed after considerable delays.

CONCLUSIONS

A positive diagnosis of FNDs can be made on the basis of history and neurological signs without reliance on psychological stressors. Past sensitizing events and neurobiological abnormalities contribute to the pathogenesis of FNDs. Physical rehabilitation and psychological interventions alone or in combination are helpful in the treatment.

Sex and gender differences in movement disorders: Parkinson's disease, essential tremor, dystonia and chorea

Sex and gender-based differences in epidemiology, clinical features and therapeutical responses are emerging in several movement disorders, even though they are still not widely recognized. In this chapter, we summarize the most relevant evidence concerning these differences in Parkinson's disease, essential tremor, dystonia and chorea. Indeed, both sex-related biological (hormonal levels fluctuations) and gender-related variables (socio-cultural and environmental factors) may differently impact symptoms manifestation and severity, phenotype and disease progression of movement disorders on men and women. Moreover, sex differences in treatment responses should be taken into account in any therapeutical planning. Physicians need to be aware of these major differences between men and women that will eventually have a major impact on better tailoring prevention, treatment, or even delaying progression of the most common movement disorders.

The recent surge of functional movement disorders: social distress or greater awareness?

PURPOSE OF REVIEW

To analyze the interrelated factors that have led to the striking increase in functional movement disorders in recent years, with a focus on functional tic-like behaviours (FTLB).

RECENT FINDINGS

The sudden onset of FTLB has been widely observed in several countries since the beginning of the SARS-CoV-2 pandemic, whereas it was previously very rarely reported. Pandemic-related FTLB typically occur in young females, share complex, disabling and tic-lookalike patterns, and are usually triggered by the exposure to videos portraying tic-like behaviours on social media. Both pandemic-related FTLB and prepandemic FTLB are associated with high levels of depression and anxiety. FTLB related to the pandemic highlight the role of social media in the psychopathological behaviours of our time.

SUMMARY

We suggest FTLB are due to a combination of predisposing factors (high genetic and epigenetic risk for anxiety and depression, negative past experiences) and precipitating factors (pandemic and its impact on mental health, exposure to certain social media content). These factors of vulnerability may increase the risk of developing behavioural and emotional problems in youth, such as FTLB. Early diagnosis and appropriate treatment of psychiatric comorbidities seem to be predictors of positive prognosis.

Gender disparity and abuse in functional movement disorders: a multi-center case-control study

BACKGROUND

To determine gender differences in rates of sexual and physical abuse in functional movement disorders compared to controls and evaluate if the gender disparity of functional movement disorders is associated with abuse history.

METHODS

We performed a retrospective case-control study of self-reported trauma data from 696 patients (512 women) with functional movement disorders from six clinical sites compared to 141 controls (98 women) and population data. Chi-square was used to assess gender and disorder associations; logistic regression was used to model additive effects of abuse and calculate the attributable fraction of abuse to disorder prevalence.

RESULTS

Higher rates of sexual abuse were reported by women (35.3%) and men (11.5%) with functional movement disorders compared to controls (10.6% of women; 5.6% of men). History of sexual abuse increased the likelihood of functional movement disorders among women by an odds ratio of 4.57 (95% confidence interval 2.31-9.07; p < 0.0001) and physical abuse by an odds ratio of 2.80 (95% confidence interval 1.53-5.12; p = 0.0007). Population attributable fraction of childhood sexual abuse to functional movement disorders in women was 0.12 (0.05-0.19). No statistically significant associations were found in men, but our cohort of men was underpowered despite including multiple sites.

CONCLUSIONS

Our study suggests that violence against women may account for some of the gender disparity in rates of functional movement disorders. Most people with functional movement disorders do not report a history of abuse, so it remains just one among many relevant risk factors to consider.

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.

Diagnosis and Initial Treatment of Functional Movement Disorders in Children

Functional movement disorders (FMD) are complex neurobehavioral disorders that can be a significant source of disability for both children and their caregivers. While FMD in the adult population is better characterized, the aim of this paper is to review the pertinent clinical and historical features, diagnostic criteria, and multi-disciplinary management of FMD in the pediatric population. We highlight recent trends in pediatric FMD, including the increase in functional tic-like behaviors that has been observed during the COVID-19 pandemic.

Influence of Adverse Childhood Experiences and Perfectionism on Musician's Dystonia: a Case Control Study

Background

Musician's dystonia (MD) is a task-specific movement disorder characterized by muscle cramps and impaired voluntary motor-control whilst playing a musical instrument. Recent studies suggest an involvement of adverse childhood experiences (ACEs) in the development of MD.

Objectives

By investigating the prevalence of ACEs in MD patients with perfectionism as possible mediating factor this study aims to gain further insights into the etiology of MD.

Methods

The Adverse Childhood Experiences Scale (ACE-S), the Childhood Trauma Questionnaire (CTQ) and Frost's Multidimensional Perfectionism Scale (FMPS) were answered by 128 MD patients and 136 healthy musicians. Regression and mediator analyses were conducted to identify relevant predictors of MD and to investigate the role of perfectionism.

Results

The CTQ total score (OR: 1.04; 95% CI [1.01, 1.08]) and the sub-score "emotional neglect" (OR: 1.13; 95% CI [1.02, 1.25]) were identified as two predictors of MD. Patients scored significantly higher on the sub-score emotional neglect, but no significant differences were observed for other forms of ACEs. Perfectionism had no mediating function on the association between ACEs and MD.

Discussion

Though only slight differences between both groups were found, there is a trend towards higher rates of emotional neglect among dystonic musicians. A possible explanation for the association between musician's dystonia and emotional neglect could be a lower stress resilience in musicians with a history of ACEs, which increases vulnerability to acquire dysfunctional movement patterns.These tendencies should be further investigated in future studies in which the MD and HM groups are more evenly matched in sex and age.

Highlights

We investigated the role of Adverse Childhood Experiences in the development of musician's dystonia, comparing a large sample of healthy musicians and dystonia patients. Our findings suggest that experiencing emotional neglect might increase the probability to acquire musician's dystonia. The findings offer new implications for etiology and treatment of dystonia.

We Move or Are We Moved? Unpicking the Origins of Voluntary Movements to Better Understand Semivoluntary Movements

The capacity for voluntary control is seen as essential to human movements; the sense that one intended to move (willing) and those actions were self-generated (self-agency) gives the sense of voluntariness and of being in control. While the mechanisms underlying voluntary movement have long been unclear, recent neuroscientific tools have identified networks of different brain areas, namely, the prefrontal cortex, supplementary motor area, and parietal cortex, that underlie voluntary action. Dysfunction in these brain areas can result in different forms of semivoluntary movement as the borderland of voluntary and involuntary movement where a person may experience a disordered sense of will or agency, and thus the movement is experienced as unexpected and involuntary, for an otherwise voluntary-appearing movement. Tics, functional movement disorders, stereotypies, perseveration, compulsions, utilization behaviors, and motor mannerism have been described elsewhere in the context of psychoses, and are often mistaken for each other. Yet, they reflect an impairment of prefrontal cortices and related circuits rather than simple motor systems, which results in the absence of subjective recognition of the movements, in contrast to other neurological movement disorders where principal abnormalities are located within the basal ganglia and its connections. Therefore, their recognition is clinically important since they are usually associated with neurodevelopmental and neurodegenerative disorders. In this review, we first defined a conceptual framework, from both a neuroanatomical and a neurophysiological point of view, for the generation of voluntary movement. We then examined the evidence linking dysfunctions in different motor pathways to each type of movement disorder. We looked at common semivoluntary movement disorders providing an overview, where possible, of their phenomenology and brain network abnormalities for each condition. We also emphasized important clinical feature similarities and differences to increase recognition of each condition in practice.

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.

In Patients With Functional Movement Disorders, Is Specialized Physical Therapy Effective in Improving Motor Symptoms?: A Critically Appraised Topic

BACKGROUND

Functional movement disorders (FMD, aka psychogenic movement disorders) are very common and frequently chronic and disabling. Despite this, there is a paucity of evidence-based treatment to manage and alleviate these conditions. Specialized physical therapy (PT), involving sequential motor relearning and redirecting attention, has shown promise as a therapeutic intervention for motor symptoms.

METHODS

The objective of this study was to critically assess current evidence regarding specialized PT compared with usual care in improving motor symptoms among patients with FMD. This was addressed through the development of a structured critically appraised topic. This included a clinical scenario with a clinical question, literature search strategy, critical appraisal, results, evidence summary, commentary, and bottom-line conclusions. Participants included consultant and resident neurologists, a medical librarian, and content experts in the fields of physical medicine and rehabilitation, physical and occupational therapy, psychiatry, and psychology.

RESULTS

A randomized controlled feasibility trial was identified and selected for critical appraisal. This study randomized 60 patients with FMD to a 5-day specialized outpatient PT program or to general outpatient PT referral, and measured patient-reported and clinician-measured outcomes. At 6 months, 72% of patients in the intervention group had a good outcome compared with 18% of control group patients. Patients in the specialized outpatient PT program had significantly better outcomes in 3 Short-Form 36 (SF36) domains (d=0.46 to 0.79) and multiple other scales of physical and social function as well as clinician-measured outcomes. The intervention resulted in 0.08 additional quality-adjusted life years in a cost-effective manner.

CONCLUSIONS

Current evidence suggests that in patients with FMD, specialized PT improves motor symptoms in a clinically significant, sustained, and cost-effective manner. This promising intervention warrants further investigation and replication.

Management of Functional Neurological Disorders (FND): Experience from a Swiss FND Clinic

Functional neurological disorder (FND) represent a common disorder with significant socio-economic impact. In this context and alongside recent new neuroscientific insights, FND attracts a growing interest both in clinical practice and academic activities. New international recommendation and expert opinions suggest that therapy of FND should be a tailored multidisciplinary management involving the neurologist, the physiotherapist, and in most cases the psychotherapist/psychiatrist. A first decisive step is the establishment of a definitive diagnosis, based on the presence of clinical positive signs during neurological assessment together with a clear communication and explanation of the diagnosis by the neurologist. A second important step is based on individual therapeutic sessions, involving different disciplines (neurology and psychotherapy or neurology and physiotherapy). Comorbidities, such as pain or fatigue and psychiatric comorbidities (anxiety, depression, dissociation etc.) should be carefully evaluated, as they need an individualized treatment path. New FND clinics have been created worldwide over the last decades to offer such multidisciplinary settings and this article will present the experience of a first Swiss FND clinic created in 2016. The aim is to highlight in the form of a narrative review the current literature supporting the usefulness and importance of FND clinics, by reviewing the latest evidence on multidisciplinary interventions in FND.

Remission of functional motor symptoms following esketamine administration in a patient with treatment-resistant depression: a single-case report

Functional movement disorders (FMD) involve a broad range of abnormal involuntary movements not consistent with neurological diseases. These conditions often occur in combination with mood and anxiety disorders and are associated with poor clinical outcomes. We report the case of a 57-year-old woman diagnosed with treatment-resistant depression (TRD) and comorbid FMD treated with weekly intranasal administrations of esketamine over a six-month follow-up period. A comprehensive clinical and psychometric assessment was carried out at different time points. After 2 months of treatment, a complete remission of motor and axial functional disturbances (athetosis, trunk torsion and genuflections) was detectable, along with a progressive improvement in depressive symptoms during follow-up until full remission. According to novel lines of evidence, glutamatergic transmission might play a role in the pathophysiology of FMD through aberrant limbic-motor interactions. We report that treatment with esketamine, a noncompetitive N-methyl-d-aspartate glutamatergic receptor antagonist, was associated with remission of FMD symptoms in a patient with TRD. Pharmacological compounds modulating brain glutamatergic activity may be of potential benefit in the clinical management of FMD.

Economic Costs of Delayed Diagnosis of Functional Motor Disorders: Preliminary Results From a Cohort of Patients of a Specialized Clinic

Background: Functional motor disorders (FMDs) are prevalent and highly disabling conditions in young adults that can result in reduced independence. Despite advances in diagnosis and treatment, the economic burden of FMDs is largely unknown.

Objective: This pilot retrospective study provides a real-world overview of the economic costs related to delayed diagnosis of FMDs from a cohort of patients of a specialized clinic in Italy, based on Italian healthcare costs.

Methods: Sociodemographic data, clinical history, healthcare service utilization, and associated direct costs were collected for a period of up to 5 years before a definite diagnosis of FMDs in 40 patients.

Results: The mean time lag between the onset of FMDs symptoms and diagnosis was 6.63 years (±8.57). The mean annual use of recourses per patient was three specialist visits (95% CI 2.4–3.4) and three diagnostic examinations (95% CI 2.2–3.6) that made up a total of six investigations and over seven (95% CI 5.5–9.7) rehabilitation contacts per year per patient were used before a diagnosis of FMDs was established. In more than 50% of the cases, patients had been hospitalized or made an ER visit at least once before receiving the correct diagnosis. The average annual costs for delayed diagnosis, taking into account only direct healthcare costs (without medications), was about €2,302 (CI 95% €1,570–2,830) per patient [€1,524 covered by the NHS (CI 95% €1,214–1,834) and € 778 by the patient (CI 95% €606–960)]. Hospitalization accounted for €916 (CI 95% €670–1,160) per patient per year, followed by rehabilitation €493 (CI 95% €345–641) and diagnostic tests € 387 (CI 95% €314–460).

Conclusion: These preliminary results shed some light on the high healthcare services volume and direct healthcare costs from clinic to clinic for visits, unnecessary tests, and prescribed treatments in a real-world overview from a cohort of patients of a specialized clinic in Italy. It may represent a starting point for future studies to statistically test and quantify cost reduction after implementing appropriate healthcare pathways.

Functional Movement Disorder and Functional Seizures: What have we learned from different subtypes of functional neurological disorders?

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Functional seizures (FS) and functional movement disorders (FMD) are the most common manifestations of functional neurological disorders.

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FMD and FS may have similarities in etiology and pathophysiology.

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FMD and FS share disabling comorbidities of chronic pain, fatigue, and cognitive symptoms.

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Neuroimaging has demonstrated structural and functional changes in emotional and motor planning pathways in FND.

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A multidisciplinary approach and psychotherapy are the treatments for FMD and FS, respectively.

The objective of this paper is to compare and contrast FMD and FS, and highlight important differences in etiology and the clinical approach towards these two entities. While patients with FMD often experience abnormal movements on a daily basis, FS is characterized by paroxysmal events. Both patient populations share psychiatric and environmental comorbidities, but patients with FS may have increased anxiety and neuroticism and a higher percentage of childhood trauma. Functional MRI scans have demonstrated impaired executive control over motor behavior in both groups. FMD responds well to multidisciplinary rehabilitation-oriented treatment, while psychotherapy remains the mainstay of treatment for FS. For practicing clinicians, recognizing commonalities and differences in patients with FMD and FS is important to develop the most appropriate treatment plan.

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.

A single-center series of 482 patients with functional motor disorders

Functional motor disorders (FMD) are common and disabling. They are known to predominantly affect women and young to middle-aged patients, although they also occur during childhood or in the elderly. Demographic and clinical characteristics of patients with FMD are poorly known, since large series of consecutive patients are scarce.

METHODS

In a chart review study, we retrospectively abstracted data from consecutive FMD patients who were referred to the Neurophysiology Department of the Salpêtrière University Hospital between 2008 and 2016 for treatment with repeated transcranial magnetic stimulation.

RESULTS

482 patients were included. Most patients were women (73.7%). Median age at symptoms onset was 35.5 years and symptoms were mostly characterized by acute (47.3%) or subacute (46%) onset. Only 23% of patients were active workers, while 58.3% were unemployed because of FMD. Half of the patients had functional motor weakness (n = 241) whereas the other half had movement disorders (n = 241), mainly with tremor (21.1%) or dystonia (20.5%). Among all patients, 66.4% had psychiatric comorbidity and 82.6% reported a history of trauma in the 6 months before symptoms onset. No difference was found in age or gender according to clinical phenotypes.

CONCLUSION

This large series will contribute to better characterize FMDs.

Evaluation of Individualized Multi-Disciplinary Inpatient Treatment for Functional Movement Disorders

BACKGROUND

Functional movement disorders (FMD) are associated with considerable morbidity and impairment of quality of life. Specialized treatment is scarce and data on efficacy of different therapies are limited.

OBJECTIVE

To evaluate a multi-modal inpatient treatment program for patients with FMD.

METHODS

Thirty-one patients with FMD were analyzed before (t1) and after multi-modal inpatient treatment (t2) by a blinded video rating using the Psychogenic Movement Disorder Rating Scale (PMDRS), the simplified Functional Movement Disorder Rating Scale (S-FMDRS), and the Clinical Global Impression Scale of Severity (CGI-S), as well as patients' self-rating. In 23 out of 31 patients a 5 months follow-up investigation was performed (t3). Wilcoxon signed-rank test and Friedman test were used for rating scale and self-rating comparisons over time. Spearman correlation was used for correlation of symptom improvement and clinical characteristics.

RESULTS

Video rating revealed significant reduction of scores after therapy (median PMDRS t1 = 24, t2 = 8, P = 0.0006; S-FMDRS t1 = 11, t2 = 4, P = 0.008; CGI-S t1 = 4, t2 = 3, P = 0.000136) with sustained score decrease in follow-up evaluations (PMDRS t1 = 31, t2 = 8, t3 = 7, P = 0.000032; S-FMDRS t1 = 12, t2 = 4, t3 = 3, P = 0.000888; CGI-S t1 = 4, t2 = 3, t3 = 3, P = 0.000032). Patients reported a stable reduction of symptoms in the self-rating (CGI-S t1 = 5, t2 = 4, t3 = 4, P = 0.016). Age correlated with treatment response with older patients showing better improvement, but disease duration did not correlate with outcome. Patients who suffered from physical trauma, sexual or physical abuse had smaller score reductions.

CONCLUSION

Blinded video and self-rating assessment showed significant score reduction in patients with FMD after an individualized interdisciplinary inpatient intervention.

International online survey of 1048 individuals with functional neurological disorder

BACKGROUND AND PURPOSE

Functional neurological disorder (FND) is common, and symptoms can be severe. There have been no international large-scale studies of patient experiences of FND.

METHODS

A patient questionnaire was created to assess FND patient characteristics, symptom comorbidities and illness perceptions. Respondents were recruited internationally through an open access questionnaire via social media and patient groups over a month-long period.

RESULTS

In total, 1048 respondents from 16 countries participated. Mean age was 42 years (86% female). Median FND symptom duration was 5 years, and median time from first symptom to diagnosis was 2 years. Mean number of current symptoms (core FND and associated) was 9.9. Many respondents had associated symptoms, for example fatigue (93%), memory difficulties (80%) and headache (70%). Self-reported psychiatric comorbidities were relatively common (depression, 43%; anxiety, 51%; panic, 20%; and post-traumatic stress disorder, 22%). Most respondents reported that FND had multiple causes, including physical and psychological.

CONCLUSIONS

This large survey adds further evidence that people with FND typically have high levels of multiple symptom comorbidity with resultant distress. It also supports the notion that associated physical symptoms are of particular clinical significance in FND patients. Dualistic ideas of FND were not supported by respondents, who generally preferred to conceptualize the disorder as one at the interface of mind and brain. The need for a broad approach to this poorly served patient group is highlighted. Potential selection and response biases due to distribution of the survey online, mostly via FND patient groups, are a key limitation.

Are functional movement disorder phenotypes or age at onset correlated with perfectionism or history of abuse?

Objective

To assess if the phenotype or age at onset of Functional Movement Disorders (FMD) vary as a function of presence of a perfectionism or history of abuse. Detecting such a potential association might help guide future research into the pathophysiology of FMD.

Methods

Charts of all patients diagnosed with FMD by a movement disorder specialist using the commonly accepted clinical diagnostic criteria for FMD seen at a tertiary center over 8 years were reviewed. Data collected were sex, age at the onset of the first FMD, phenotype of the first predominant FMD, history of perfectionism and history of childhood abuse (physical, sexual, emotional, or neglect). Statistical analyses were performed as appropriate.

Results

68 patients with FMD were identified from which 12 were excluded for incomplete documentation. 56 patients were included in the analysis, 43 (76.8%) were women, with average age at onset 41.5y (range 13-74.4). The most frequent predominant initial FMD phenotypes were tremor (39%), dystonia (20.3%) and gait disorders (20.3%).Perfectionism was reported in 30 (53.6%) patients and history of abuse in 27 (48.2%).There was no significant correlation between each of the FMD phenotypes and perfectionism or history of childhood abuse. There was also no correlation between the age at symptoms onset and perfectionism or history of abuse.

Conclusion

We could not demonstrate a significant correlation between FMD phenotype or age at onset and perfectionist personality trait or history of abuse. Factors leading to the development of one specific FMD phenotype rather than another are still to be elucidated.

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.

Psychiatric Comorbidities in Functional Movement Disorders: A Retrospective Cohort Study

Background

Functional movement disorders (FMD) are characterized by abnormal movements and motor symptoms incongruent with a known structural neurologic cause. While psychological stressors have long been considered an important risk factor for developing FMD, little is known about the impact of psychiatric comorbidities on disease manifestations or complexity.

Objectives

To compare characteristics of FMD patients with co-occurring mood and trauma-related psychiatric conditions to FMD patients without psychiatric conditions.

Methods

We performed a retrospective cohort study of patients seen in the University of Colorado Health system between January 1, 2015 and December 31, 2019. Patients were included if they had a diagnosis of FMD, determined by ICD-10 coding and ≥1 phenomenology-related diagnostic code (tremor, gait disturbances, ataxia, spasms, and weakness), and at least one encounter with a neurology specialist. Fisher's exact and unpaired t-tests were used to compare demographics, healthcare utilization, and phenomenologies of patients with psychiatric conditions to those with none.

Results

Our review identified 551 patients with a diagnosis of FMD who met inclusion criteria. Patients with psychiatric conditions (N = 417, 75.7%) had increased five-year healthcare utilization (mean emergency room encounters 9.9 vs. 3.5, P = 0.0001) and more prevalent non-epileptic seizures (18.2% vs. 7.5%, P = 0.001). Suicidal ideation (8.4%) and self-harm (4.1%) were only observed amongst patients with comorbid psychiatric conditions.

Conclusions

Patients with FMD and comorbid psychiatric conditions require more healthcare resources and have greater disease complexity than patients without psychiatric illness. This may have implications for treatment of patients without comorbid psychiatric conditions who may benefit from targeted physiotherapy alone.

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.

Neuroimaging in Functional Neurological Disorder: State of the Field and Research Agenda

Functional neurological disorder (FND) was of great interest to early clinical neuroscience leaders. During the 20th century, neurology and psychiatry grew apart - leaving FND a borderland condition. Fortunately, a renaissance has occurred in the last two decades, fostered by increased recognition that FND is prevalent and diagnosed using "rule-in" examination signs. The parallel use of scientific tools to bridge brain structure - function relationships has helped refine an integrated biopsychosocial framework through which to conceptualize FND. In particular, a growing number of quality neuroimaging studies using a variety of methodologies have shed light on the emerging pathophysiology of FND. This renewed scientific interest has occurred in parallel with enhanced interdisciplinary collaborations, as illustrated by new care models combining psychological and physical therapies and the creation of a new multidisciplinary FND society supporting knowledge dissemination in the field. Within this context, this article summarizes the output of the first International FND Neuroimaging Workgroup meeting, held virtually, on June 17th, 2020 to appraise the state of neuroimaging research in the field and to catalyze large-scale collaborations. We first briefly summarize neural circuit models of FND, and then detail the research approaches used to date in FND within core content areas: cohort characterization; control group considerations; task-based functional neuroimaging; resting-state networks; structural neuroimaging; biomarkers of symptom severity and risk of illness; and predictors of treatment response and prognosis. Lastly, we outline a neuroimaging-focused research agenda to elucidate the pathophysiology of FND and aid the development of novel biologically and psychologically-informed treatments.

Multidisciplinary inpatient rehabilitation for Functional Movement Disorders: A prospective study with long term follow up

INTRODUCTION

Functional Movement Disorders (FMDs) are challenging to treat. We assessed the effect of multidisciplinary inpatient rehabilitation, involving motor retraining, psychotherapy and psychotropic medication on FMD patient function and maintenance of improvement after one year.

METHODS

FMD patients in a movement disorders clinic were referred for inpatient rehabilitation. Baseline, discharge and one year follow-up measures included: Clinical Global Impression (CGI-severity, CGI-change); Depression and Somatic Symptom Scale (DSSS); Generalized Anxiety Disorder-7 (GAD-7); Patient Health Questionnaire-9 (PHQ-9); Post-traumatic stress disorder check-list for DSM-5 (PCL-5). Outcomes were analyzed with non-parametric models.

RESULTS

Seventeen patients completed rehabilitation. Thirteen completed one-year follow-up. Median CGI-severity was "markedly ill." At discharge, movement disorder improved in 93% (median CGI-change = 2, "much improved") as assessed by neurologist and patient. Psychiatrist ratings showed improvement among 86.7%; physiatrist and psychologist ratings were 66.7% and 53.3%, respectively. Symptoms improved on DSSS (Wilcoxon Z = -2.914, p ≤ 0.004); GAD-7 (Z = -3.045, p ≤ 0.002); PHQ-9 (Z = -3.415, p ≤ 0.01) but not PCL-5 (Z = -1.506, p = 0.132). At 1 year, 54% maintained at least minimal improvement by neurologist rating and 77% by patient rating (median CGI-change = 3, "minimally improved"). Improvement was not maintained for DSSS (Wilcoxon Z = -0.385. p = 0.701), GAD-7 (Z = -0.943, p = 0.357) or PHQ-9 (Z = -0.55, p = 0.582).

CONCLUSIONS

Multidisciplinary inpatient rehabilitation improved FMD patient function, depression, anxiety and somatic symptoms. One-year follow-up demonstrated minimal sustained improvement and worsening psychopathology, reflecting chronic debility despite initial rehabilitative success.

Diagnosing functional neurological disorder: seeing the whole picture

Functional neurological disorder (FND) is a complex neuropsychiatric syndrome with many phenotypes that are commonly encountered in clinical practice. Despite the heterogeneity of FND, the rate of misidentification is consistently low. For the more common motor subtypes, there are clear positive clinical, electrophysiological, and rarely imaging criteria that can establish the diagnosis in the traditional sense. For nonmotor subtypes, the characterization may be less clear. Here, we argue that the current diagnostic criteria are not reflective of the current shared neuropsychiatric understanding of FND, and, as a result, provide an incomplete picture of the diagnosis. We propose a three-step diagnostic triad for FND, in which the traditional neurological diagnosis is only the first element. Other steps include psychiatric/psychological formulation, integration, and follow-up. We advocate that this diagnostic approach should be the shared responsibility of neurology and mental health professionals. Finally, a research agenda is proposed to address the missing factors in the field.

Changes of Phenotypic Pattern in Functional Movement Disorders: A Prospective Cohort Study

Introduction: Functional movement disorders (FMD) refer to a group of movement disorders that present with clinical characteristics incongruent to those due to established pathophysiologic processes, as for example in the case of neurodegeneration or lesions. The aim of this study was to assess clinical features that contribute to the specific phenotypic presentations and disease course of FMD. Methods: The study consisted of 100 patients with FMD treated at Clinic for Neurology, Clinical Center of Serbia, who were longitudinally observed. Comprehensive clinical and psychiatric assessment was performed at the baseline, when initial FMD phenotype was defined. Follow-up assessment of phenotypic pattern over the time and clinical course was done after 3.2 ± 2.5 years at average. Results: We showed that 48% of FMD patients were prone to changes of phenotypic pattern during the disease course. Dystonia had tendency to remains as single and unchanged phenotype over the time (68.2%), while patients initially presented with Tremor, Gait disorder, Parkinsonism and Mixed phenotype were more susceptible to developing additional symptoms (62.5, 50, and 100%, respectively). Higher levels of somatoform experiences (p = 0.033, Exp(B) = 1.082) and higher motor severity (p = 0.040, Exp(B) = 1.082) at baseline assessment were associated with an increased likelihood of further enriching of FMD phenotype with additional functional symptoms. Also, these patients more frequently reported pain, and had higher scores on majority of applied psychiatric scales, together with more frequent presence of major depressive disorder. Conclusion: Results from this prospective study suggested tendency for progression and enrichment of functional symptoms in FMD patients over time. Besides functional core symptoms, other key psychological and physical features (like pain or multiple somatisations) were quite relevant for chronicity and significant dysability of FMD patients.

Functional movement disorder comorbidity in Parkinson's disease: Unraveling the web

Functional movement disorders are commonly seen in neurology services and may coexist with other neurological diseases. This combination is known as "functional overlay" and an increasing interest on this topic has emerged in the past decade as the field of functional neurological disorders has moved forward. Some neurological diseases may be more prone to develop "functional overlay" than others, and within the field of movement disorders, most studies have focused on patients with Parkinson's disease. This review comprehensively summarizes the current body of knowledge on this topic and provides an expert opinion to equip clinicians with a pragmatic approach to recognize functional movement disorders in patients with Parkinson's disease, to communicate the diagnosis and to become familiar with potential therapies in this complex clinical scenario. Potential underlying mechanisms and risk factors that may play a role in increasing the vulnerability of Parkinson's disease patients to develop functional movement disorder comorbidity are also discussed within the framework of modern neurobiological theories of brain functioning.

Predisposing Risk Factors for Functional Limb Weakness: A Case-Control Study

OBJECTIVE

Functional limb weakness is a common symptom of functional neurological disorder. Few controlled studies have examined possible predisposing factors to determine their specificity for this symptom.

METHODS

In this prospective case-control study, patients with functional limb weakness (<2 years duration, N=107) were compared with a control group (comprising patients with weakness attributable to neurological disease, N=46, and healthy individuals, N=39). A structured clinical interview and questionnaires assessed potential predisposing factors, including family structure and childhood abuse and neglect (Childhood Trauma Questionnaire [CTQ]), personality traits (NEO Five-Factor Inventory), medical and surgical comorbidity, and exposure to a symptom model.

RESULTS

The patients with functional limb weakness and the control subjects were similar in gender and age. Self-reported childhood sexual abuse (15% versus 5%, p<0.01), and physical abuse (18% versus 7%, p<0.01; CTQ "moderate or above") were more common in the functional limb weakness group, although the absolute frequency was lower than anticipated. In the functional limb weakness group, there were modest differences in two personality traits, compared with the control group: higher neuroticism (p=0.02) and lower openness (p=0.01). Medical comorbidity, including appendectomy (33% versus 5%), irritable bowel syndrome (36% versus 18%), and chronic back pain (40% versus 16%), was more frequent in the functional limb weakness group. There were no differences in birth order or exposure to a symptom model.

CONCLUSIONS

Medical and surgical comorbidity and adverse childhood experience are risk factors, but not essential, for the development of functional limb weakness. However, evidence for personality traits or exposure to a symptom model is less robust.

Outcome Measures for Functional Neurological Disorder: A Review of the Theoretical Complexities

The development and selection of optimal outcome measures is increasingly recognized as a key component of evidence-based medicine, particularly the need for the development of a standardized set of measures for use in clinical trials. This process is particularly complex for functional neurological disorder (FND) for several reasons. FND can present with a wide range of symptoms that resemble the full spectrum of other neurological disorders. Additional physical (e.g., pain, fatigue) and psychological (e.g., depression, anxiety) symptoms are commonly associated with FND, which also can be highly disabling with implications for prognosis, and warrant concurrent assessment, despite an unclear etiological relationship with FND. Furthermore, several unique clinical aspects of FND make it likely that the usual prioritization of "objective" (or clinician-rated) over "subjective" (or patient-rated) measures might not be appropriate. Self-report measures may be more clinically meaningful in this patient population. Despite being a common and disabling disorder, there has been little research into outcome measures in FND, and to date trials have largely used measures designed for the assessment of other disorders. An international FND Core Outcome Measure group (FND-COM) has been established to develop a consensus battery of outcomes for FND: a "core outcome set." In this perspective article, the authors reviewed the process of outcome measure development and selection before considering the specific features of FND affecting the development of a core outcome set, as well as a research agenda to optimize outcome measurement in this complex neuropsychiatric disorder.

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.

Towards an Outpatient Model of Care for Motor Functional Neurological Disorders: A Neuropsychiatric Perspective

Functional neurological disorder (FND), a condition at the intersection of neurology and psychiatry, is a common and disabling outpatient referral to neurology and neuropsychiatry clinics. In this perspective article, we focus on the motor spectrum of FND (mFND), including individuals with functional movement disorders (FND-movt), functional limb weakness/paresis (FND-par) and functional [psychogenic non-epileptic/dissociative] seizures (FND-seiz). Over the past several decades, there have been dedicated efforts within the neurologic and psychiatric communities to create "rule-in" diagnostic criteria, as well as thoughtful approaches to the clinical interview, delivery of the diagnosis and the development of a patient-centered treatment plan. These advances allow the promotion of good clinical practices in the outpatient assessment and management of mFND. Informed by the literature and our prior clinical experiences, we provide suggestions on how to evaluate individuals with suspected functional motor symptoms - including conducting sensitive psychiatric and psychosocial screenings. Additional sections discuss common "rule-in" neurological examination and semiologic signs of motor FND, as well as approaches to deliver the diagnosis and formulate a treatment plan based on individual patient needs. To aid the development of shared (partially overlapping) expertise that catalyzes an interdisciplinary approach to mFND, the use of physiotherapy for therapeutic motor retraining and cognitive behavioral therapy to examine relationships between symptoms, thoughts, behaviors and emotions are also discussed. Additional clinical research is needed to further refine and operationalize the assessment and management of mFND, across clinics, healthcare settings and countries.

Cranial Functional Movement Disorders: A Case Series with Literature Review

Background:

Cranial functional movement disorders (CFMDs) affect the face, eyes, jaw, tongue, and palate.

Objectives:

We aimed to examine our large series of functional movement disorders (FMDs) patients where the cranial muscles were involved to determine their phenomenology and other clinical features.

Methods:

This is a chart review of 26 patients who presented with CFMDs.

Results:

There were 16 (61.53%) females and 10 (38.46%) male patients. The mean ± [standard deviation (SD)] age at the presentation was 33.96 ± 16.94 (Range: 11–83) years. The duration of symptoms ranged from one day to 6 years (Mean ±SD: 402.03 ±534.97 days). According to the Fahn-Williams criteria, CFMDs were documented in 24 patients and clinically established in two patients. The facial [38.46% (10/26)] involvement was the most common in our CFMDs patients. Oromandibular [19.23% (5/26)], ocular [15.38% (4/26)], lingual [15.38% (4/26)], speech [15.38% (4/26)] and palatal [(3.85; 1/26)] involvement was also seen. 10 (38.46%) patients also had associated FMD in the extracranial regions. Precipitating factors were present in 84.61% (22/26) of the patients and associated illnesses were present in 42.30% (11/26) of the patients. At 3 months follow-up, 9 (34.61%) patients had improved, 13 (50%) had partial improvement and 4 (15.38%) had no improvement.

Conclusions:

There was a slight female preponderance in our patients. CFMDs are more likely to involve facial muscles. Associated medical conditions like neuropsychiatric disturbances and headaches are frequently present in CFMDs patients. Early clinical diagnosis will avoid unnecessary investigations and allow the patient to seek the right treatment.

Dissociated motor learning and de-adaptation in patients with functional gait disorders

Walking onto a stationary platform that had been previously experienced as moving generates a locomotor after-effect—the so-called ‘broken escalator’ phenomenon. The motor responses that occur during locomotor after-effects have been mapped theoretically using a hierarchal Bayesian model of brain function that takes into account current sensory information that is weighted according to prior contextually-relevant experiences; these in turn inform automatic motor responses. Here, we use the broken escalator phenomenon to explore motor learning in patients with functional gait disorders and probe whether abnormal postural mechanisms override ascending sensory information and conscious intention, leading to maladaptive and disabling gait abnormalities. Fourteen patients with functional gait disorders and 17 healthy control subjects walked onto a stationary sled (‘Before’ condition, five trials), then onto a moving sled (‘Moving’ condition, 10 trials) and then again onto the stationary sled (‘After’ condition, five trials). Subjects were warned of the change in conditions. Kinematic gait measures (trunk displacement, step timing, gait velocity), EMG responses, and subjective measures of state anxiety/instability were recorded per trial. Patients had slower gait velocities in the Before trials (P &lt; 0.05) but were able to increase this to accommodate the moving sled, with similar learning curves to control subjects (P = 0.87). Although trunk and gait velocity locomotor after-effects were present in both groups, there was a persistence of the locomotor after-effect only in patients (P &lt; 0.05). We observed an increase in gait velocity during After trials towards normal values in the patient group. Instability and state anxiety were greater in patients than controls (P &lt; 0.05) only during explicit phases (Before/After) of the task. Mean ‘final’ gait termination EMG activity (right gastrocnemius) was greater in the patient group than controls. Despite a dysfunctional locomotor system, patients show normal adaptive learning. The process of de-adaptation, however, is prolonged in patients indicating a tendency to perpetuate learned motor programmes. The trend to normalization of gait velocity following a period of implicit motor learning has implications for gait rehabilitation potential in patients with functional gait disorders and related disorders (e.g. fear of falling).