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

Functional neurological disorder: Practical management

Functional Neurological Disorder (FND) is a common and disabling condition seen by nearly every clinician in nearly every clinical setting. There are multiple subtypes with seizure and motor/movement being the most common. There is high health care utilization and costs, and many patients have a chronic course and remain disabled. It is clear from research over the past two decades that abnormalities in brain network activity are implicated in the pathophysiology of FND. Diagnosis requires positive criteria and knowing how to obtain a good history and avoid common pitfalls. There are evidence-based treatments and expert consensus recommendations. A multidisciplinary team knowledgeable about the disorder is important for the best outcomes but there is much more work to be done. This review will focus on the practical aspects of diagnosing and managing FND.

Neuroplastic changes in patients with functional seizures following neurobehavioral therapy

Given the high prevalence of functional neurological symptom disorder and its negative effects on the individual, family, and society, the development of interventions to treat it-including the subtype of functional seizures (FS)-is critical.Although we have limited understanding of the neurobiological effects of neurobehavioral therapy (NBT), studies indicate that NBT reduces seizures and improves psychological comorbidities in FS. In this study, healthy adults (N = 33) and patients with a history of TBI with (TBI-FS; N = 50) and without FS (TBI-only; N = 50) underwent magnetic resonance imaging (MRI) at 3 T approximately 12 weeks apart. TBI-FS participants underwent up to 12 sessions of NBT between scans. Structural MRI data were analyzed using voxel-based morphometry. A voxelwise repeated measures ANOVA tested changes in grey matter volume (GMV) between groups over time. Following treatment with NBT, TBI-FS participants showed a 1.23 % GMV increase in the left inferior and middle temporal gyri (pFWE < 0.05) along with a 35.78 % reduction in seizure events and decrease in depressive (p < 0.001) and anxiety (p = 0.01) symptoms. Left temporal GMV increases were directly associated (p = 0.04, r = 0.26) with improvements in overall psychological, social, and occupational functioning (p < 0.001). We observed structural brain changes within the left inferior temporal gyrus following NBT that correspond to functional and psychological improvements in patients with TBI-FS. This work highlights the need for further research into the neurobiological effects of NBT, building on the relationship between NBT and brain plasticity and demonstrating putative targets for interventions.

The impact of motor and non-motor symptoms fluctuations on health-related quality of life in people with functional motor disorder

OBJECTIVE

To assess the effect of overall, between- and within-day subjectively rated fluctuations in motor and non-motor symptoms in people with functional motor disorder (FMD) on the health-related quality of life (HRQoL).

BACKGROUND

FMD is a complex condition characterized by fluctuating motor and non-motor symptoms that may negatively impact HRQoL.

METHODS

Seventy-seven patients (54 females, mean age 45.4 ± 10.4 years) with a clinically established diagnosis of FMD, including weakness, completed symptom diaries, rating the severity of motor and non-motor symptoms (i.e., pain, fatigue, mood, cognitive difficulties) on a 10-point numerical scale three times daily for seven consecutive days. HRQoL was assessed using the SF-36 questionnaire. For the analysis, fluctuation magnitude was defined in terms of the variability in self-reported symptom scores.

RESULTS

The mental component of SF-36 was jointly predicted by the overall severity scores (t(74) = -3.61, P < 0.001) and overall general fluctuations (t(74) = -2.98, P = 0.004). The physical SF-36 was found to be related only to the overall symptom severity scores (t(74) = -7.09, P < 0.001), but not to the overall fluctuations. The assessment of the impact of different components showed that the mental component of SF-36 was significantly influenced by the combined effect of average fatigue (t(73) = -3.86, P < 0.001), between-day cognitive symptoms fluctuations (t(73) = -3.22, P = 0.002), and within-day mood fluctuations (t(73) = -2.48, P = 0.015).

CONCLUSIONS

This study demonstrated the impact of self-reported symptom fluctuations across multiple motor and non-motor domains on mental but not physical HRQoL in FMD and highlighted the importance of assessing and managing fluctuations in clinical practice.

Sex Differences in Parkinson's Disease: A Narrative Review

Sex differences in epidemiology, clinical features, and therapeutical responses are emerging in several movement disorders, even though they are still not widely recognized. Parkinson's disease (PD) is not an exception: men and women suffering from PD have different levels of disability. Research has been performed using multiple databases and scientific journals; this review summarizes the available evidence on sex differences in PD regarding epidemiology, risk factors, genetics, clinical phenotype, social impact, and therapeutic management. The role of hormones in determining such differences is also briefly discussed. The results confirm the existence of differences between men and women in PD; women have a higher risk of developing disabling motor complications and non-motor fluctuations compared to men, while men have a higher risk of developing cognitive impairment, postural instability, and gait disorders. Improving our knowledge in these differences may result in the implementation of strategies for disease-tailored treatment and management.

Qualitative systematic review on the lived experience of functional neurological disorder

Objectives

Functional neurological disorder (FND) is a complex disorder, recently attracting much research into aetiology and treatment. However, there is limited research on the patient's lived experience. This paper addresses this gap to ask: 'What is the subjective life experience of adult patients living with FND?'

Methods

From 1980 to 2020, Medline, PsycInfo, Scopus, Science Direct, PubMed, CINAHL and Embase were searched for English language qualitative adult research. The disciplines used general medicine, psychiatry, physiotherapy, nursing, neurology, psychosomatic medicine and occupational therapy. The qualitative literature search included book chapters, theses, fellowship reports and conference articles as well as peer-reviewed scientific journals.The Critical Appraisal Skills Programme tool was used to assess 33 papers, with eight papers included in the final synthesis. Nine additional papers, suggested during review, were evaluated but excluded from synthesis, though incorporated elsewhere in the paper. Two authors used an integrative immersion approach to identify the literature's main themes using line-by-line and top-down methods.

Results

Eight main themes were identified: lost, body-mind dualism, preceding stressful events, relatedness, stigma, the battle or fight, the burden and losses of the illness and trust versus mistrust. From these emerged a central overarching theme of relationally regulated selves, which posits the essence of the lived experience of FND as responding to stressful experiences within a relational, regulatory context.

Conclusions

The prevalent themes give valuable insight into the lived experience of FND and the impact of stressors, past and present, and the relational environment in the development of and recovery from the disorder. Further research is needed to support the formulation of the patient experience and cocreated recovery pathways.

Functional Neurological Disorder: A Case of Psychosomatic Paralysis Following Bereavement

Functional neurologic disorder (FND), alternatively known as conversion disorder, presents a unique diagnostic challenge due to its complex interplay of psychological, neurobiological, and social factors. This complexity is particularly evident in patients who experience significant psychological stressors, which may trigger or exacerbate symptoms. The following case report describes a 36-year-old woman who developed FND following the death of her father. This case highlights the diagnostic complexities of FND, particularly in patients with a prior psychiatric diagnosis. It underscores the importance of addressing the psychological factors underlying physical symptoms in such presentations.

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.

Are there predictable neuropsychological impairments in persons with functional movement disorder?

This study attempted to partially test the hypotheses recently proposed by Spagnolo, Garvey, and Hallett that patients with functional movement disorders (FMDs) should demonstrate impaired performance when presented with tasks that sample affect expression/perception, working memory, and cognitive/motor control. A retrospective chart review of the neuropsychological test performance of 17 adult FMD patients was performed to test these hypotheses. Performance on the Barrow Neurological Institute Screen for Higher Cerebral Functions, the Wechsler Adult Intelligence Scale-Fourth Edition, and the modified version of the Halstead Finger Tapping Test were used to measure these behaviors. Patients with FMD had difficulty performing tasks involving affect expression/perception and working memory relative to other cognitive functions. However, only one-third of the sample demonstrated clinically relevant slow finger tapping speeds. Our findings are consistent with the predictions proposed by Spagnolo et al. that disturbance of affect expression/perception and working memory are common in patients with FMD. However, there was less evidence for consistent disturbances in cognitive/motor control. Exploring what FMD patients experience when performing these tasks may facilitate their awareness of how non-neurological factors may contribute to their symptoms.

Phenomenology and psychiatric correlates of pseudocataplexy

STUDY OBJECTIVES

Pseudocataplexy is a rare functional neurological disorder that mimics cataplexy, pathognomonic for narcolepsy type 1 (NT1). We describe the psychiatric comorbidity and personality traits of patients with pseudocataplexy versus NT1 cases.

METHODS

The case-control observational study enrolled consecutive patients with pseudocataplexy and a control group of age-matched consecutive NT1 patients. The diagnostic work-up included a structured interview, 48-hour polysomnography, multiple sleep latency test, cataplexy provoking test, and hypocretin-1 measurement in cerebrospinal fluid. All participants were administered Beck Depression Inventory, State-Trait Anxiety Inventory, Patient Health Questionnaire-15 (PHQ-15), Personality Inventory for DSM-5 brief form, and quality-of-life (QoL) measurement by 36-item Short Form health survey (SF-36).

RESULTS

Fifteen patients with pseudocataplexy and 30 with NT1 were included. Despite the suspicion of possible cataplexy, none of the pseudocataplexy participants fulfilled international diagnostic criteria for NT1. Pseudocataplexy patients presented higher rates of moderate state anxiety (40% vs. 10%, p = 0.018), medium level of somatic symptoms, defined by PHQ-15 score > 10 (66.7% vs. 16.7%, p = 0.003), and a trend towards moderate-to-severe depressive symptoms (33.3% vs. 10%, p = 0.054) compared to NT1. No significant differences in personality traits emerged. Pseudocataplexy patients had worse QoL profiles in almost all SF-36 domains including physical (mean ± SD: 37.7 ± 9.88 vs. 51.13 ± 7.81, p < 0.001) and mental (mean ± SD: 33.36 ± 12.69 vs.42.76 ± 11.34, p = 0.02) summary scores.

CONCLUSIONS

Patients with pseudocataplexy present more severe psychiatric symptoms and a lower QoL profile in comparison with patients with NT1. The severe somatoform and affection impairment in pseudocataplexy may explain the poorer QoL and should require a tailored therapeutic approach.

The Neuroconnective Endophenotype, a New Approach Toward Typing Functional Neurological Disorder: A Case-Control Study

OBJECTIVE

Functional neurological disorder (FND) is a core neuropsychiatric condition that includes both physical and mental symptoms. Recently, a validated clinical phenotype termed neuroconnective endophenotype (NEP), which includes several physical and psychological characteristics together with joint hypermobility (hypermobility spectrum disorders), was found at a significantly higher frequency among patients with anxiety. The purpose of the present study was to examine the presence of the NEP among patients with FND.

METHODS

The authors conducted a multicenter case-control study comprising 27 FND patients and 27 healthy control participants (matched by sex and age) ages 13 to 58 years. Eight questionnaires were administered. Proportional differences were examined with Student's t tests, one-way analyses of variance, and chi-square tests.

RESULTS

Differences between FND patients and control participants were observed. FND patients had higher sensory sensitivity, increased prevalence of hypermobility features (including relevant physical signs and symptoms), greater frequency of polarized behaviors, a greater number of both psychiatric and physical comorbidities, and an increase in the characteristics and sensations typical of anxiety. Particularly striking was the presence of the hypermobility spectrum in more than 75% of FND patients compared with 15% among control participants.

CONCLUSIONS

FND patients presented higher scores in all five dimensions included in the NEP. Thus, this phenotype, solidifying the original association between anxiety and the hypermobility spectrum, could help to identify an FND subtype when evaluating and managing FND patients, because it provides a new global view of patients' physical and mental symptoms.

The role of neuropsychology in the care of patients with functional neurological symptom disorder

OBJECTIVE

Functional neurological symptom disorder (FNSD) is a neuropsychiatric condition characterized by signs/symptoms associated with brain network dysfunction. FNSDs are common and are associated with high healthcare costs. FNSDs are relevant to neuropsychologists, as they frequently present with chronic neuropsychiatric symptoms, subjective cognitive concerns, and/or low neuropsychological test scores, with associated disability and reduced quality of life. However, neuropsychologists in some settings are not involved in care of patients with FNSDs. This review summarizes relevant FNSD literature with a focus on the role of neuropsychologists.

METHODS

A brief review of the literature is provided with respect to epidemiology, public health impact, symptomatology, pathophysiology, and treatment.

RESULTS

Two primary areas of focus for this review are the following: (1) increasing neuropsychologists' training in FNSDs, and (2) increasing neuropsychologists' role in assessment and treatment of FNSD patients.

CONCLUSIONS

Patients with FNSD would benefit from increased involvement of neuropsychologists in their care.

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.

[Understanding and explaining functional movement disorders]

Functional movement disorders are not uncommon in neurological consultations, hospitals and emergency departments. Although the disorder can usually be recognized clinically, the communication of the diagnosis is often unsatisfactory. Those affected are indirectly accused of a lack of insight or openness but it is often the doctors who fail to formulate a coherent and comprehensible explanation of the underlying disorder. In this review an integrative model for the development of functional movement disorders is presented, which places the motor (and nonmotor) symptoms in a neuroscientific light. In addition, explanations and metaphors are presented that have proven helpful in conveying an understanding of the disorder.

Symptom Severity and Health Impacts of Functional Tic-Like Behaviors in Youth

BACKGROUND

We performed this study to improve understanding of the relationship between functional tic-like behaviors (FTLBs) and quality of life, loneliness, family functioning, anxiety, depression, and suicidality.

METHOD

This cross-sectional study assessed self-reported quality of life, disability, loneliness, depression, anxiety, family functioning, tic severity, and suicide risk in age- and birth-sex matched youth with FTLBs, Tourette syndrome (TS), and neurotypical controls. We performed specific subanalyses comparing individuals with FTLBs who identified as transgender/gender diverse (TGD) with cisgender individuals.

RESULTS

Eighty-two youth participated (age range 11 to 25, 90% female at birth), including 35 with FTLBs, 22 with TS, and 25 neurotypical controls. A significantly higher proportion of participants with FTLB identified as TGD (15 of 35) than TS (two of 22) and neurotypical control (three of 25) participants. Compared with neurotypical controls, individuals with FTLBs had significantly lower quality of life, greater disability, loneliness, social phobia, anxiety symptoms, depressive symptoms, and suicidality. Compared with individuals with TS, individuals with FTLBs had more school/work absences due to tics, had more depressive symptoms, were more likely to be at high risk for suicidality, and had disability in self-care and life activity domains. There were no significant differences between cisgender and TGD participants with FTLB in any of the domains assessed.

CONCLUSIONS

Youth with FTLB have unique health care needs and associations with anxiety, depression, sex, and gender.

Recent advances in understanding the neurobiology of pediatric functional neurological disorder

INTRODUCTION

Functional neurological disorder (FND) is a neuropsychiatric disorder that manifests in a broad array of functional motor, sensory, or cognitive symptoms, which arise from complex interactions between brain, mind, body, and context. Children with FND make up 10%-20% of presentations to neurology services in children's hospitals and up to 20% of adolescents admitted to hospital for the management of intractable seizures.

AREAS COVERED

The current review focuses on the neurobiology of pediatric FND. The authors present an overview of the small but growing body of research pertaining to the biological, emotion-processing, cognitive, mental health, physical health, and social system levels.

EXPERT OPINION

Emerging research suggests that pediatric FND is underpinned by aberrant changes within and between neuron-glial (brain) networks, with a variety of factors - on multiple system levels - contributing to brain network changes. In pediatric practice, adverse childhood experiences (ACEs) are commonly reported, and activation or dysregulation of stress-system components is a frequent finding. Our growing understanding of the neurobiology of pediatric FND has yielded important flow-on effects for assessing and diagnosing FND, for developing targeted treatment interventions, and for improving the treatment outcomes of children and adolescents with FND.

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.

Personality traits related to cognitive functioning in patients with functional neurological disorder

Cognitive symptoms are prevalent in patients with functional neurological disorder (FND). Several studies have suggested that personality traits such as neuroticism may play a pivotal role in the development of FND. FND has also been associated with alexithymia: patients with FND report difficulties in identifying, analyzing, and verbalizing emotions. Whether or not alexithymia and other personality traits are associated with cognitive symptomatology in patients with FND is unknown. In the current study, we explored whether the Big Five personality model factors (neuroticism, extraversion, openness, agreeableness, and conscientiousness) and alexithymia were associated with cognitive functioning in FND. Twenty-three patients with FND were assessed using a neuropsychological assessment and questionnaire assessment to explore personality traits (Neuroticism-Extraversion-Openness Five-Factor Inventory) and alexithymia (Bermond-Vorst Alexithymia Questionnaire). The results indicated that high conscientiousness was associated with lower planning scores (ρ = -0.52, p = .012) and high scores on alexithymia were associated with lower scores on verbal memory scores (ρ = -0.46, p = .032) and lower sustained attention scores (ρ = -0.45, p = .046). The results did not remain significant after controlling for multiple testing. The preliminary results of our study suggest that personality and cognitive symptomatology in patients with FND are topics that should be further explored in future studies, as cognitive symptomology can affect treatment results.

Neuropsychiatric phenotypes in functional movement disorder

OBJECTIVE

Functional movement disorder (FMD), the motor-dominant subtype of functional neurological disorder, is a complex neuropsychiatric condition. Patients with FMD also manifest non-motor symptoms. Given that patients with FMD are diagnosed based on motor phenotype, the contribution of non-motor features to the neuropsychiatric syndrome is not well characterized. The objective of this hypothesis-generating study was to explore potential novel, neuropsychiatric FMD phenotypes by combining movement disorder presentations with non-motor comorbidities including somatic symptoms, psychiatric diagnoses, and psychological traits.

METHODS

This retrospective chart review evaluated 158 consecutive patients with a diagnosis of FMD who underwent deep phenotyping across neurological and psychiatric domains. Demographic, clinical, and self-report features were analyzed. A data-driven approach using cluster analysis was performed to detect patterns when combining the movement disorder presentation with somatic symptoms, psychiatric diagnoses, and psychological factors. These new neuropsychiatric FMD phenotypes were then tested using logistic regression models.

RESULTS

Distinct neuropsychiatric FMD phenotypes emerged when stratifying by episodic vs. constant motor symptoms. Episodic FMD was associated with hyperkinetic movements, hyperarousal, anxiety, and history of trauma. In contrast, constant FMD was associated with weakness, gait disorders, fixed dystonia, activity avoidance, and low self-agency. Pain, fatigue, somatic preoccupation, and health anxiety were common across all phenotypes.

CONCLUSION

This study found patterns spanning the neurological-psychiatric interface that indicate that FMD is part of a broader neuropsychiatric syndrome. Adopting a transdisciplinary view of illness reveals readily identifiable clinical factors that are relevant for the development and maintenance of FMD.

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: Diagnostic Pitfalls and Differential Diagnostic Considerations

Functional neurologic disorder (FND) is a "rule-in" diagnosis, characterized by positive examination signs or semiological features. Similar to other clinical diagnoses, providers should ideally see robustly present features, including if possible the identification of multiple features consistent with FND for the diagnosis to be made with a high degree of certainty. Diagnostic pitfalls need to be guarded against and vary depending on FND symptom subtype and the specific patient presentation. This perspective article aims to review pitfalls based on an FND symptom subtype, as well as discuss differential diagnostic considerations with respect to both neurologic and psychiatric entities.

Functional Movement Disorder: Assessment and Treatment

Functional movement disorder (FMD) is a common, potentially reversible source of disability in neurology. Over the last two decades, there have been major advances in our understanding of the clinical picture, diagnosis, and management of this condition. Motor presentation is heterogeneous and several non-motor symptoms (e.g., pain, fatigue) are part of the clinical spectrum. The diagnosis should be made by neurologists or neuropsychiatrists based on the presence of positive signs of inconsistency and incongruence with neurological diseases. Promising evidence has accumulated for the efficacy of physiotherapy, psychotherapy, or both in the management of FMD, for a majority of patients.

Functional Speech and Voice Disorders: Approaches to Diagnosis and Treatment

Historically, formal training for speech-language therapists (SLTs) in the area of functional speech and voice disorders (FSVD) has been limited, as has the body of empirical research in this content area. Recent efforts in the field have codified expert opinions on best practices for diagnosing and treating FSVD and have begun to demonstrate positive treatment outcomes. To provide comprehensive interventions for these complex conditions at the intersection of neurology, psychiatry, and other medical specialties, the SLT must not only build knowledge of diagnostic strategies and components of symptomatic treatment in FSVD but also embrace behavior change techniques and counseling strategies.

Increased Frequency of Self-Reported Obsessive-Compulsive Symptoms in Patients with Functional Movement Disorders

Background

Functional movement disorders (FMD) are associated with a high prevalence of psychiatric comorbidities.

Objective

To assess the frequency of obsessive-compulsive symptoms (OCS) in FMD.

Methods

A total of 167 consecutive patients with clinically definite FMD (mean age = 44.4 years, standard deviation [SD] = 12.0, 119 females) and 145 healthy controls (mean age = 43.2 years, SD = 11.8, 103 females) completed the Obsessive-Compulsive Inventory-Revised (OCI-R), which is a widely used tool for assessing OCS. The cutoff score ≥21 is indicative of clinically significant obsessive-compulsive disorder (OCD). Motor symptom severity was assessed using the Simplified FMD Rating Scale (S-FMDRS). All subjects completed questionnaires for depression, anxiety, pain, fatigue, cognitive complaints, health-related quality of life, and childhood trauma. Personality traits were assessed using the Big Five questionnaire.

Results

FMD patients had higher mean OCI-R score and higher proportion of individuals with OCI-R ≥ 21 42%, 95% confidence interval (CI) = (30.2, 54.6) versus 16%, 95% CI = (8.2, 28.2) in controls, P < 0.001. Patients had higher scores in three domains: checking, ordering, and obsessing (P < 0.001). FMD patients with OCI-R score ≥21 had higher depression, anxiety, cognitive complaints, and lower quality of life compared to those with score <21 (P < 0.001). No correlation between OCI-R and S-FMDRS scores was found.

Conclusions

FMD patients reported higher rates of OCS compared to controls, along with higher rates of non-motor symptoms and lower quality of life. This finding may have clinical implications and raises the possibility of shared risk factors and common pathophysiological mechanisms in FMD and OCD.

[Diagnostic criteria, epidemiology and assessment of patients with functional neurological disorders]

Functional neurological disorders (FND) are symptoms that can affect a variety of functions including motor, sensory and cognitive. These symptoms are genuinely experienced by the patient and are related to a functional disorder rather than a structural one. There is little epidemiological data on these disorders, but their frequency is well established in clinical practice, it is the second most frequent reason for consultation in Neurology. Despite of the frequency of the disorder, general practitioners and specialists are insufficiently trained in the disease, and patients often suffer from stigmatization and/or unnecessary investigations. It is therefore important to be aware of the diagnostic approach to FND, which mostly relies on positive clinical signs. Psychiatric evaluation can help with the characterization of predisposing, precipitating and perpetuating factors of the symptoms (according to the 3P biopsychosocial model related to FND), and guide their management. Finally, diagnosis explanation is a crucial step in the management of the disease, which can in itself have a therapeutic effect, and allow the patient to adhere to the treatments.

Functional Neurological Symptom Disorder: A Continuing Conundrum for the Perioperative Physician

Functional neurological symptom disorder (FNSD) or functional neurological disorder (FND) or conversion disorder, is a syndrome of neurological complications unexplained by neuropathology. The term FNSD or FND is now preferred, as conversion disorder is not an etiologically neutral term and is thus falling from use by researchers and clinicians in the field. We report a case of new-onset postoperative neurological deficit in a patient who had undergone uneventful general anesthesia for a urology procedure. Postoperatively, in the post-anesthesia care unit, the patient was found to be unable to move her upper and lower limbs. Organic pathology was excluded and a diagnosis of FNSD was made. Four weeks after the surgery, the patient was only able to ambulate with the help of a mechanical walker device. It is now suggested that procedures involving anesthesia are relatively common triggers for the development of FNSD. The occurrence of FNSD in the postoperative period is increasingly being attributed to the effects of anesthesia, the hypothesis being that it arises from the abreactive or dissociative effects of anesthetic agents. Another theory is the vulnerability of the anesthetized state which may evoke previous traumatic experiences. Psychiatric co-morbidities such as anxiety and depression may be seen in these patients. Preoperative psychological assessment may help identify patients at risk for FNSD. If postoperative neurological deficit occurs, detailed neurological, metabolic, and psychiatric assessments should be done with FNSD being a diagnosis of exclusion. We present this case to increase awareness regarding this uncommon condition which can cause significant distress to the patient and healthcare team. Management should comprise honest disclosure, reassurance of recovery, and reinforcement of alternative coping strategies. The development of preoperative screening tools may help identify patients at risk for this disorder.

The Classification of Movement in Infants for the Autonomous Monitoring of Neurological Development

Neurodevelopmental delay following extremely preterm birth or birth asphyxia is common but diagnosis is often delayed as early milder signs are not recognised by parents or clinicians. Early interventions have been shown to improve outcomes. Automation of diagnosis and monitoring of neurological disorders using non-invasive, cost effective methods within a patient's home could improve accessibility to testing. Furthermore, said testing could be conducted over a longer period, enabling greater confidence in diagnoses, due to increased data availability. This work proposes a new method to assess the movements in children. Twelve parent and infant participants were recruited (children aged between 3 and 12 months). Approximately 25 min 2D video recordings of the infants organically playing with toys were captured. A combination of deep learning and 2D pose estimation algorithms were used to classify the movements in relation to the children's dexterity and position when interacting with a toy. The results demonstrate the possibility of capturing and classifying children's complexity of movements when interacting with toys as well as their posture. Such classifications and the movement features could assist practitioners to accurately diagnose impaired or delayed movement development in a timely fashion as well as facilitating treatment monitoring.

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.

Classification of Functional Movement Disorders with Resting-State Functional Magnetic Resonance Imaging

Introduction: Functional movement disorder (FMD) is a type of functional neurological disorder characterized by abnormal movements that patients do not perceive as self-generated. Prior imaging studies show a complex pattern of altered activity, linking regions of the brain involved in emotional responses, motor control, and agency. This study aimed to better characterize these relationships by building a classifier using a support vector machine to accurately distinguish between 61 FMD patients and 59 healthy controls using features derived from resting-state functional magnetic resonance imaging. Materials and Methods: First, we selected 66 seed regions based on prior related studies, then we calculated the full correlation matrix between them before performing recursive feature elimination to winnow the feature set to the most predictive features and building the classifier. Results: We identified 29 features of interest that were highly predictive of the FMD condition, classifying patients and controls with 80% accuracy. Several key features included regions in the right sensorimotor cortex, left dorsolateral prefrontal cortex, left cerebellum, and left posterior insula. Conclusions: The features selected by the model highlight the importance of the interconnected relationship between areas associated with emotion, reward, and sensorimotor integration, potentially mediating communication between regions associated with motor function, attention, and executive function. Exploratory machine learning was able to identify this distinctive abnormal pattern, suggesting that alterations in functional linkages between these regions may be a consistent feature of the condition in many FMD patients. Clinical-Trials.gov ID: NCT00500994 Impact statement Our research presents novel results that further elucidate the pathophysiology of functional movement disorder (FMD) with a machine learning model that classifies FMD and healthy controls correctly 80% of the time. Herein, we demonstrate how known differences in resting-state functional magnetic resonance imaging connectivity in FMD patients can be leveraged to better understand the complex pattern of neural changes in these patients. Knowing that there are measurable predictable differences in brain activity in patients with FMD may help both clinicians and patients conceptualize and better understand the illness at the point of diagnosis and during treatment. Our methods demonstrate how an effective combination of machine learning and qualitative approaches to analyzing functional brain connectivity can enhance our understanding of abnormal patterns of brain activity in FMD patients.

Cushing's Disease Presenting with Functional Neurological (Conversion) Disorder

While psychiatric manifestations are common in patients with Cushing's syndrome (CS), to our knowledge, there are no reported cases of CS presenting with functional neurological disorder (FND), a neuropsychiatric condition in which patients experience neurological symptoms, such as motor dysfunctions, sensory symptoms, speech disorders, or nonepileptic seizures, in the absence of neurological disease. Here, we report a case of a complex patient with Cushing's disease who presented with multiple FND symptoms including nonepileptic seizures, bilateral lower extremity paralysis, decreased finger flexion resulting in limited hand function, and stuttering. This case illustrates a rare psychiatric manifestation of CS presenting as multiple neurological complaints. Furthermore, we elucidate how a multidisciplinary treatment approach improved our patient's FND symptoms.

Functional neurological symptoms are a frequent and relevant comorbidity in patients with multiple sclerosis

Introduction

Functional neurological symptoms (FNS) in multiple sclerosis (MS) have shown to be underinvestigated even though neurological diseases such as MS represent a risk factor for developing FNS. Comorbidity of FNS and MS can produce high personal and social costs since FNS patients have high healthcare utilization costs and a quality of life at least as impaired as in patients with disorders with underlying structural pathology. This study aims to assess comorbid FNS in patients with MS (pwMS) and investigate whether FNS in pwMS are associated with poorer health-related quality of life and work ability.

Methods

Newly admitted patients (234) with MS were studied during their stay at Kliniken Schmieder, a neurological rehabilitation clinic in Konstanz, Germany. The degree to which the overall clinical picture was explained by MS pathology was rated by neurologists and allied health practitioners on a five-point Likert scale. Additionally, neurologists rated each symptom reported by the patients. Health-related quality of life was assessed using a self-report questionnaire and work ability was assessed using the mean number of hours worked per day and information regarding disability pension as reported by patients.

Results

In 55.1% of cases, the clinical picture was completely explained by structural pathology due to MS. 17.1% of pwMS presented an overall clinical picture half or less of which could be explained by underlying structural pathology. PwMS with a higher comorbid FNS burden had a lower health-related quality of life and reported fewer working hours per day than pwMS with symptoms explained by structural pathology. Furthermore, pwMS with a full disability pension had a higher comorbid FNS burden than pwMS with no or partial disability pension.

Discussion

These results show that FNS should be addressed diagnostically and therapeutically since such symptoms are an important comorbidity in MS that is related to poorer health-related quality of life and lower work ability.

Lessons Learned in Outpatient Physical Therapy for Motor Functional Neurological Disorder

BACKGROUND AND PURPOSE

Motor functional neurological disorder is a prevalent and costly condition at the intersection of neurology and psychiatry that is diagnosed using positive "rule-in" signs. Physical therapy is a first-line treatment and consensus recommendations exist to guide clinical care. Nonetheless, optimal outpatient treatment of adults with functional motor symptoms requires an expanded physical therapy tool kit to effectively guide care.

SUMMARY OF KEY POINTS

In this article, lessons learned from a physical therapist practicing in a multidisciplinary and interdisciplinary outpatient functional neurological disorder clinic are highlighted. In doing so, we discuss how use of the biopsychosocial model and neuroscience constructs can inform physical therapy interventions. The importance of team-based care and the delivery of physical therapy through video telehealth services are also outlined.

RECOMMENDATIONS FOR CLINICAL PRACTICE

Use of the biopsychosocial formulation to triage clinical challenges and guide longitudinal care, coupled with application of neuroscience to aid intervention selection, allows for patient-centered physical therapy treatment across the spectrum of functional motor symptoms.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A400 ).

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

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

COVID-19 Vaccination in Young People with Functional Neurological Disorder: A Case-Control Study

BACKGROUND

The emergence of acute-onset functional neurological symptoms, the focus of this study, is one of three stress responses related to immunisation. This case-control study documents the experience of 61 young people with past or current functional neurological disorder (FND) in relation to the COVID-19 vaccination program in Australia.

METHODS

Information about the young person's/parent's choice and response pertaining to COVID-19 vaccination was collected as part of routine clinical care or FND research program follow-up.

RESULTS

61 young people treated for FND (47 females, mean age = 16.22 years) and 46 healthy controls (34 females, mean age = 16.37 years) were included in the study. Vaccination rates were high: 58/61 (95.1%) in the FND group and 45/46 (97.8%) in the control group. In the FND group, 2 young people (2/61, 3.3%) presented with new-onset FND following COVID-19 vaccination; two young people with resolved FND reported an FND relapse (2/36, 5.56%); and two young people with unresolved FND (2/20, 10.0%) reported an FND exacerbation. In the control group no FND symptoms were reported.

CONCLUSIONS

Acute-onset FND symptoms following COVID-19 vaccination are uncommon in the general population. In young people prone to FND, COVID-19 vaccination can sometimes trigger new-onset FND, FND relapse, or FND exacerbation.

Diagnosis and Management of Functional Tic-Like Phenomena

Over the past 3 years, a global phenomenon has emerged characterized by the sudden onset and frequently rapid escalation of tics and tic-like movements and phonations. These symptoms have occurred not only in youth known to have tics or Tourette syndrome (TS), but also, and more notably, in youth with no prior history of tics. The Tourette Association of America (TAA) convened an international, multidisciplinary working group to better understand this apparent presentation of functional neurological disorder (FND) and its relationship to TS. Here, we review and summarize the literature relevant to distinguish the two, with recommendations to clinicians for diagnosis and management. Finally, we highlight areas for future emphasis and research.

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.

Functional Reaction Times of a Simulated Blocking Test among Para Taekwondo Athletes

Para taekwondo is a combat sport martial art that requires fast reaction times for successful defense during fighting. The current classification system is based on the function and the effective length of the upper limbs, which affects the athlete’s ability to block. Therefore, this study aimed to investigate the differences between the different classes in the athlete’s ability to block and move around the ring. A total of 87 Para taekwondo (K42, K43, and K44) athletes’ data were analyzed. Each participant engaged in the blocking reaction time test in a fighting stance with the left leg in front, the right leg in front, and the legs parallel in random order. A foot-stepping reaction test was performed to anlyze how the athletes moved in various directions. The results indicated no significant differences between the classes for the lower body foot stepping reaction times and the upper body blocking performance times. The stimulated blocking time of the Para taekwondo athletes ranged from 0.79 to 0.97 s Furthermore, the neurological group (0.86 ± 0.09 s) was significantly slower than the amputation/dysmelia group (0.81 ± 0.07 s). We thus concluded that the neurologically impaired athletes were disadvantaged and therefore belonged in a separate class.

A Shift in Approach: Assessment and Treatment of Adults With Functional Neurological Disorder

Functional neurological disorder (FND) is a complex condition involving an interaction of psychological, physiological, and social factors. Despite high utilization of medical services, people with FND often suffer from poor long-term health and psychosocial outcomes, and experience stigmatization and marginalization within the medical community. Health service psychologists are well positioned to help patients with FND through the lens of the biopsychosocial model of health. Psychologists can facilitate appropriate assessment and treatment, and advocate for the needs of patients diagnosed with FND within multidisciplinary teams. This article reviews best practices for assessment and treatment of individuals diagnosed with or suspected of having FND and presents some clinical and ethical challenges associated with this complex population.

Updates in Functional Movement Disorders: from Pathophysiology to Treatment Advances

Purpose of Review

This review discusses advances in functional movement disorders (FMD) over the past 3 years, with a focus on risk factors, diagnosis, pathophysiology, neuroimaging studies, and treatment.

Recent Findings

The past decade has brought a revived interest in functional movement disorders, with a growing number of studies exploring pathophysiological mechanisms. Here, we review recent studies demonstrating changes in attention, emotional and sensorimotor function in FMD. Through international collaborative efforts, progress has been made in defining biomarkers and outcome measures, an important prerequisite towards standardization of diagnosis and reporting of outcomes in clinical trials. Of particular interest are neuroimaging studies demonstrating functional and structural changes in motor and emotional brain circuits, deepening our understanding of FMD as a neurocircuit disorder and potentially paving the way towards new treatments. Currently available treatment modalities have shown successful outcomes via outpatient, inpatient, and virtual delivery.

Summary

The last 3 years have seen tremendous efforts to better understand, diagnose, and treat FMD. The disease model has been broadened to include a biopsychosocial formulation, and insights on the pathophysiology on FMD are informing treatment efforts. Several international multidisciplinary research collaborations are underway to define biomarkers and best outcome measures, highlighting the path towards improved standardization of future treatment trials. Additionally, the rise of telemedicine during the COVID-19 pandemic has reduced geographic barriers and paved the way for virtual therapy sessions and self-guided programs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11910-022-01192-9.

Sensory Processing Difficulties in Patients with Functional Neurological Disorder: Occupational Therapy Management Strategies and Two Cases

Functional neurological disorder (FND) is a condition at the intersection of neurology and psychiatry, with some patients experiencing sensory hypersensitivities and other sensory processing difficulties. It has been postulated that poor integration and modulation of sensory information with cognitive, affective and behavioral processes may play a role in the pathophysiology of FND. In this article, we first succinctly review the role for occupational therapy (OT) in the multidisciplinary therapeutic approach to managing patients with FND. After highlighting previously published data identifying sensory processing difficulties in patients with FND, we subsequently outline the components of the sensory-based outpatient OT program for FND at the Massachusetts General Hospital. Here, we detail how occupational therapists assess and treat sensory modulation difficulties with the aid of resources like the Adolescent/Adult Sensory Profile (AASP), The Canadian Occupational Performance Measure (COPM), and the Sensory-Motor Preference Checklist. We then report on 2 clinical cases representative of the sensory modulation difficulties endorsed by some patients with FND, illustrating how developing an individualized, sensory-based treatment plan can help improve functional neurological symptoms and overall participation in activities of daily living. Prospective, controlled research is needed to further operationalize OT-based sensory modulation interventions, as well as define the tolerability and efficacy of this intervention for pediatric and adult populations with FND.

The Neuropsychiatric Approach to the Assessment of Patients in Neurology

Neuropsychiatry is a clinical neuroscience specialty focused on the evaluation and treatment of patients who present with symptoms at the intersection of neurology and psychiatry. Neuropsychiatrists assess and manage the cognitive, affective, behavioral, and perceptual manifestations of disorders of the central nervous system. Although fellowship training in behavioral neurology-neuropsychiatry exists in the United States and several other countries internationally, the need for neuropsychiatric expertise greatly outweighs the number of specialists in practice or training. This article serves as a primer for both neurologists and psychiatrists seeking to improve or refresh their knowledge of the neuropsychiatric assessment, including detailing aspects of the history-taking, physical exam, psychometric testing, and associated diagnostic work-up. In doing so, we urge the next generation of neurologists and psychiatrists to take on both the opportunity and challenge to work at the intersection of both clinical neuroscience specialties using an integrated neuropsychiatric perspective.

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.

Neuropsychiatric Treatment Approaches for Functional Neurological Disorder: A How to Guide

There is a growing body of knowledge regarding management of functional neurological disorder (FND). The aim of this article is to guide the clinician through FND clinical management, from delivery of the diagnosis, to creation of a biopsychosocially-informed treatment plan, to troubleshooting common issues that arise throughout longitudinal care. We review the evidence and core principles of both rehabilitative therapies (physical therapy, occupational therapy, and speech and language therapy) and psychological therapies for the treatment of FND, and discuss the benefits of engaging a multidisciplinary and interdisciplinary team. The optimal timing of specific therapeutic interventions is also discussed, emphasizing a patient-centered perspective. Resources for further reading, for both patients and clinicians, are provided throughout. Additional research is needed to further optimize the therapeutic approach to patients with FND, including the need to develop novel treatments for those that do not positively respond to currently available interventions.

Using the Biopsychosocial Model to Guide Patient-Centered Neurological Treatments

The biopsychosocial model was defined by George L. Engel to propose a holistic approach to patient care. Through this model, physicians can understand patients in their context to aid the development of tailored, individualized treatment plans that consider relevant biological, psychological, and social-cultural-spiritual factors impacting health and longitudinal care. In this article, we advocate for the use of the biopsychosocial model in neurology practice across outpatient and inpatient clinical settings. To do so, we first present the history of the biopsychosocial model, and its relationships to precision medicine and deep phenotyping. Then, we bring the neurologist up-to-date information on the components of the biopsychosocial clinical formulation, including predisposing, precipitating, perpetuating, and protective factors. We conclude by detailing illustrative neurological case examples using the biopsychosocial model, emphasizing the importance of considering relevant psychological and social factors to aid the delivery of patient-centered clinical care in neurology.