Gender Differences in Functional Movement Disorders

Opinions and experience of neurologists and neurology trainees in Saudi Arabia on functional neurological disorders: a survey based study

BACKGROUND

Functional Neurological Disorder (FND) is commonly encountered in clinical practice, causing functional impairment and poor quality of life. As there is limited data from Saudi Arabia, our study aims to explore the experience and opinions of Saudi neurologists and neurology trainees regarding FND.

METHODS

In our cross-sectional observational study, we included 100 neurology consultants and trainees. Data was collected using an online questionnaire from March to August 2023.

RESULTS

A total of one hundred neurologists participated in the survey. Although 41% of physicians encountered FND patients on a weekly basis or more frequently, only 41.7% of trainees reported receiving dedicated lectures on FND. Furthermore, only 46% of respondents felt comfortable providing a clear explanation of the FND diagnosis to their patients. While the majority (64%) used the term "Functional Neurological Disorder" in medical documentation, only 43% used this term when communicating the diagnosis to patients, with the terminology varying widely. Clinicians emphasized that inconsistent and variable neurological examinations were key indicators raising diagnostic suspicion, which aligns with the recommended reliance on detailed clinical history and neurological examination. Lastly, 61% of physicians stated that their approach to patients with FND lacked a structured management plan.

CONCLUSION

Our study findings emphasize that FND is commonly encountered in clinical practice and reveal a significant lack of targeted education on FND for neurology trainees. Enhancing educational programs for both trainees and practicing neurologists on this prevalent neurological condition is essential for improving patient care and outcomes.

Prevalence of autoimmune diseases in functional neurological disorder: influence of psychiatric comorbidities and biological sex

BACKGROUND

Functional neurological disorder (FND) is a common and disabling neuropsychiatric condition, which disproportionally affects women compared with men. While the etiopathogenesis of this disorder remains elusive, immune dysregulation is emerging as one potential mechanism. To begin to understand the role of immune dysfunctions in FND, we assessed the prevalence of several common autoimmune diseases (ADs) in a large cohort of patients with FND and examined the influence of psychiatric comorbidities and biological sex.

METHODS

Using a large biorepository database (Mass General Brigham Biobank), we obtained demographic and clinical data of a cohort of 643 patients diagnosed with FND between January 2015 and December 2021. The proportion of ADs was calculated overall, by sex and by the presence of psychiatric comorbidities.

RESULTS

The overall prevalence of ADs in our sample was 41.9%, with connective tissue and autoimmune endocrine diseases being the most commonly observed ADs. Among patients with FND and ADs, 27.7% had ≥2 ADs and 8% met criteria for multiple autoimmune syndrome. Rates of ADs were significantly higher in subjects with comorbid major depressive disorder and post-traumatic stress disorder (p= 0.02). Women represented the largest proportion of patients with concurrent ADs, both in the overall sample and in the subgroups of interest (p's < 0.05).

CONCLUSIONS

This study is unique in providing evidence of an association between FND and ADs. Future studies are needed to investigate the mechanisms underlying this association and to understand whether FND is characterised by distinct dysregulations in immune response.

Comorbidity rates of autism spectrum disorder and functional neurological disorders: A systematic review, meta-analysis of proportions and qualitative synthesis

LAY ABSTRACT

Autism spectrum disorder (ASD) and functional neurological disorders (FND) are relatively common conditions, and there has been recent interest in the overlap between them. Both conditions share core features of alexithymia, impaired interoception and deficits in attentional focus. To date, relatively little is known about the comorbidity rates between ASD and FND. This is the first meta-analysis and qualitative synthesis on the subject. We found that around 10% of children presenting with functional seizures have a comorbid ASD diagnosis. People with ASD are more likely than the neurotypical population to have functional somatic disorders, and there is also evidence that ASD rates are higher for other FNDs such as functional motor disorders. Since FND comes with risks of unnecessary medical procedures and investigations, it is important to recognize the potential for people with ASD to have an FND comorbidity.

Functional Neurological Disorders Among Patients With Tremor

OBJECTIVE

Functional neurological disorders (FNDs) are increasingly recognized in the general population and neurology clinics, and there is evidence that patients with neurological disorders are more likely to have a FND. This study was designed to identify the clinical features of FNDs among patients with movement disorders when the two disorders coexist.

METHODS

The clinical histories and video recordings of 150 consecutive patients with tremors were examined: the types of tremor included essential tremor; essential tremor plus; dystonic tremor; tremor associated with dystonia; and drug-induced, myoclonic, orthostatic, task-specific, parkinsonian, Holmes, and unclassified tremor. Using criteria for "possible" and "probable" coexistent FND, clinical features that helped differentiate between functional and other neurological tremors were identified.

RESULTS

There were 27 (18%) patients with functional manifestations, and 17 (11% of full sample) of these patients had signs suggestive of comorbid functional tremor. Patients with comorbid functional manifestations were younger at presentation, and these patients had greater severity of tremor, particularly upper limb postural tremor. Functional manifestations were not more commonly observed among patients with any particular type of tremor, except for patients with Holmes tremor, who were more likely to have comorbid functional neurological manifestations.

CONCLUSIONS

About 18% of patients with diverse types of tremors also had comorbid functional neurological manifestations. Of the coexistent FNDs, functional tremor was the most common. Patients with co-occurring functional and other neurological tremors presented for evaluation at a younger age and had greater severity of arm tremor than those without comorbid functional neurological manifestations.

Observational cohort study of 100 patients presenting with functional visual loss: clinical characteristics and comparison with other functional neurologic disorders

OBJECTIVE

Recent research has helped to develop a more detailed understanding of many functional neurologic disorders. The aim of this study was to increase our knowledge of functional visual loss and to compare the findings with those of other functional syndromes.

DESIGN

Prospective and retrospective observational cohort study.

METHODS

This study took place at neuro-ophthalmology clinics at 3 major hospitals in London, United Kingdom, over a 12-month period. The study population consisted of 157 participants, 100 with functional visual loss, 21 pathologic control subjects with organic visual loss, and 36 healthy nonpathologic control subjects. All participants had their diagnosis confirmed with a full neuro-ophthalmic examination, neuroimaging, and visual electrophysiology. A full assessment of all participants' medical history was obtained from their general practitioner, and all participants completed a series of questionnaires assessing relevant associations.

RESULTS

Data were obtained on 157 participants, 100 with functional visual loss, 21 pathologic control subjects with organic visual loss, and 36 healthy nonpathologic control subjects. Participants with functional visual loss were typically female (74%) with a mean age at vision loss of 40.0 ± 16 years. Sixty-four percent of participants had bilateral vision loss; the remainder, unilateral loss. Twenty-six percent of the total cohort had organic visual loss with functional overlay. Fifty percent of participants with functional visual loss had a preexisting psychiatric diagnosis, the most common being a depressive disorder. Sixty-two percent of participants had an ocular history, and 87% had a previously diagnosed medical illness, most commonly neurologic (45%). Thirty-five percent of participants self-reported at least 1 additional functional symptom.

CONCLUSIONS

Our population of functional visual loss subjects shares many similarities with the majority of patients with other functional neurologic disorders. They are generally young and female and have a greater than expected rate of psychiatric, medical, and coexisting ocular conditions. We found increased rates of precipitating stressors, clinical depression, and organic eye problems in subjects with functional visual loss.

Functional Tic-Like Behaviors: A Common Comorbidity in Patients with Tourette Syndrome

BACKGROUND

Comorbid functional tic-like behaviors (FTB) have been described only rarely in patients with Tourette syndrome (TS).

OBJECTIVES

We present the first large sample of patients suffering from TS and FTB to raise awareness of this clinical presentation and to guide how to differentiate one from the other.

METHODS

We analyzed clinical data of 71 patients (n = 27 [38.0%] female, mean age: 21.5, range: 11-55) with TS + FTB.

RESULTS

In the majority of patients, FTB started abruptly on average 15 years after tic onset with "treatment-resistant" complex movements and ("coprophenomena-like") vocalizations preceded by timely related psychological stressors. Psychological evaluation revealed evidence for internal conflicts (79%), emotional dysregulation (56%), and maintaining factors (70%). About one third of patients had a positive history for further medically unexplained symptoms. Compared to a large TS sample (n = 1032), patients with TS + FTB were more likely to be female, and presented significantly more common with "coprophenomena-like" symptoms, atypical influential factors, atypical descriptions of premonitory sensations, and higher rates of comorbid obsessive-compulsive disorder and "self-injurious" behavior.

CONCLUSIONS

Based on our data it can be assumed that FTB is a common comorbidity in TS, similar to functional overlay in other movement disorders and epilepsy. Before classifying a patient as suffering from treatment-resistant TS, FTB should be ruled out.

Functional Neurological Disorder Among Sexual and Gender Minority People

Sexual and gender minority (SGM) people can face unique stressors and structural discrimination that result in higher rates of neuropsychiatric symptoms, such as depression, anxiety, and suicidality. Although more rigorous studies are needed, emerging data suggest a possible higher prevalence of functional neurological disorder and other brain-mind-body conditions in SGM people. Representation and iterative feedback from affected community members is critical to the process of developing affirming environments. More research is needed to explore the relevance of functional neurologic disorder in SGM people within a biopsychosocial framework.

Functional neurological disorder is a feminist issue

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

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.

Neurodevelopmental versus functional tics: A controlled study

BACKGROUND

An unprecedented increase in newly developed functional tics, mainly in young females, has been reported during the COVID-19 pandemic. We set out to complement existing case series with the largest controlled study to date on the clinical phenomenology of functional tics versus neurodevelopmental tics.

METHODS

Data from 166 patients were collected at a specialist clinic for tic disorders during a three-year period overlapping with the COVID-19 pandemic (2020-2023). We compared the clinical features of patients who developed functional tics during the COVID-19 pandemic (N = 83) to patients with Tourette syndrome matched for age and gender (N = 83).

RESULTS

Female adolescents and young adults accounted for 86% of the clinical sample of patients with functional tics, who were less likely to report a family history of tic disorders than their matched controls with Tourette syndrome. Co-morbidity profiles were significantly different: anxiety and other functional neurological disorders were more strongly associated with functional tics, whereas attention-deficit and hyperactivity disorder and tic-related obsessive-compulsive behaviors co-occurred more frequently with neurodevelopmental tics. Overall, absence of tic-related obsessive-compulsive behaviors (t = 8.096; p < 0.001) and absence of a family history of tics (t = 5.111; p < 0.001) were the strongest predictors of the diagnosis of functional tics. Compared to neurodevelopmental tics, functional tics were more likely to present acutely/subacutely at a later age (21 versus 7 years), without a clear rostro-caudal progression. Coprophenomena, self-injurious behaviors, and complex clinical manifestations such as blocking tics, throwing tics, and tic attacks, were all over-represented in the functional group.

CONCLUSIONS

Our findings provide robust confirmation of both patient-related variables and tic characteristics contributing to the differential diagnosis between functional tics developed during the pandemic and neurodevelopmental tics reported by patients with Tourette syndrome.

Functional Neurological Disorder-Old Problem New Perspective

Functional neurological disorder (FND) is a common issue in the pediatric population. The concept and our understanding of functional neurological disorders have changed over the past years, and new etiologic models and treatment plans have been explored. Knowledge about FND in the pediatric population, however, is lacking. The aim of this review is to provide an update on pediatric functional neurological disorder. We conducted a literature search of PubMed and SCOPUS databases and reviewed a total of 85 articles to gain insight into the current understanding of FND etiology, diagnosis, treatment, and prognosis in children and adolescents. Functional and high resolution MRI revealed abnormal connectivity and structural changes in patients with functional symptoms. The diagnostic criteria no longer require the presence of a psychological factor and instead focus on a rule-in diagnosis. Treatment of FND includes a clear communication of the diagnosis and the support of a multidisciplinary team. Although FND typically has a poor prognosis, better outcomes appear to have been achieved in children and young adults. We conclude that pediatric functional neurological disorder is a prevalent pathology and that this patient population has additional specific needs compared to the adult population.

The borderland of multiple sclerosis and functional neurological disorder: A call for clinical research and vigilance

BACKGROUND AND PURPOSE

Functional neurological disorders (FNDs) have attracted much attention from the neurological medical community over the last decades as new developments in neurosciences have reduced stigma around these by showing brain network dysfunctions. An overlap with other neurological conditions such as multiple sclerosis (MS) is well known by clinicians but there is a lack of clinical and fundamental research in this field to better define diagnosis and therapeutic decisions, as well as a lack of deep understanding of the underlying pathophysiology.

AIM

We aimed to provide a critical commentary on the state of knowledge about the borderland between FNDs and MS.

METHODS

We based our commentary on a joint point of view between an FND specialist and an MS expert.

RESULTS

A brief review of the previous literature and relevant new studies covering the overlap between FNDs and MS is presented, along with suggestions for future research directions.

CONCLUSION

There are clear diagnostic criteria for both FNDs and MS and a strict application of these will help better diagnosis and prevent unnecessary treatment escalation in MS or absence of referral to multimodal therapy in FND. Better teaching of younger neurologists is needed as well as prospective research focusing on pathophysiology.

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.

Data-driven clustering of combined Functional Motor Disorders based on the Italian registry

Introduction

Functional Motor Disorders (FMDs) represent nosological entities with no clear phenotypic characterization, especially in patients with multiple (combined FMDs) motor manifestations. A data-driven approach using cluster analysis of clinical data has been proposed as an analytic method to obtain non-hierarchical unbiased classifications. The study aimed to identify clinical subtypes of combined FMDs using a data-driven approach to overcome possible limits related to “a priori” classifications and clinical overlapping.

Methods

Data were obtained by the Italian Registry of Functional Motor Disorders. Patients identified with multiple or “combined” FMDs by standardized clinical assessments were selected to be analyzed. Non-hierarchical cluster analysis was performed based on FMDs phenomenology. Multivariate analysis was then performed after adjustment for principal confounding variables.

Results

From a study population of n = 410 subjects with FMDs, we selected n = 188 subjects [women: 133 (70.7%); age: 47.9 ± 14.4 years; disease duration: 6.4 ± 7.7 years] presenting combined FMDs to be analyzed. Based on motor phenotype, two independent clusters were identified: Cluster C1 (n = 82; 43.6%) and Cluster C2 (n = 106; 56.4%). Cluster C1 was characterized by functional tremor plus parkinsonism as the main clinical phenotype. Cluster C2 mainly included subjects with functional weakness. Cluster C1 included older subjects suffering from anxiety who were more treated with botulinum toxin and antiepileptics. Cluster C2 included younger subjects referring to different associated symptoms, such as pain, headache, and visual disturbances, who were more treated with antidepressants.

Conclusion

Using a data-driven approach of clinical data from the Italian registry, we differentiated clinical subtypes among combined FMDs to be validated by prospective studies.

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 movement disorder gender, age and phenotype study: a systematic review and individual patient meta-analysis of 4905 cases

Functional movement disorder (FMD) is a common manifestation of functional neurological disorder presenting with diverse phenotypes such as tremor, weakness and gait disorder. Our current understanding of the basic epidemiological features of this condition is unclear. We aimed to describe and examine the relationship between age at onset, phenotype and gender in FMD in a large meta-analysis of published and unpublished individual patient cases. An electronic search of PubMed was conducted for studies from 1968 to 2019 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Individual patient data were collected through a research network. We described the distribution of age of onset and how this varied by gender and motor phenotype. A one-stage meta-analysis was performed using multilevel mixed-effects linear regression, including random intercepts for country and data source. A total of 4905 individual cases were analysed (72.6% woman). The mean age at onset was 39.6 years (SD 16.1). Women had a significantly earlier age of onset than men (39.1 years vs 41.0 years). Mixed FMD (23.1%), tremor (21.6%) and weakness (18.1%) were the most common phenotypes. Compared with tremor (40.7 years), the mean ages at onset of dystonia (34.5 years) and weakness (36.4 years) were significantly younger, while gait disorders (43.2 years) had a significantly later age at onset. The interaction between gender and phenotype was not significant. FMD peaks in midlife with varying effects of gender on age at onset and phenotype. The data gives some support to 'lumping' FMD as a unitary disorder but also highlights the value in 'splitting' into individual phenotypes where relevant.

Gender Differences in Emotional Connotative Meaning of Words Measured by Osgood's Semantic Differential Techniques in Young Adults

Semantic differential techniques are a useful, well-validated tool to assess affective processing of stimuli and determine how that processing is impacted by various demographic factors, such as gender. In this paper, we explore differences in connotative word processing between men and women as measured by Osgood's semantic differential and what those differences imply about affective processing in the two genders. We recruited 94 young participants (47 men, 47 women, ages 18-39) using an online survey and collected their affective ratings of 120 words on three rating tasks: Evaluation (E), Potency (P), and Activity (A). With these data, we explored the theoretical and mathematical overlap between Osgood's affective meaning factor structure and other models of emotional processing commonly used in gender analyses. We then used Osgood's three-dimensional structure to assess gender-related differences in three affective classes of words (words with connotation that is Positive, Neutral, or Negative for each task) and found that there was no significant difference between the genders when rating Positive words and Neutral words on each of the three rating tasks. However, young women consistently rated Negative words more negatively than young men did on all three of the independent dimensions. This confirms the importance of taking gender effects into account when measuring emotional processing. Our results further indicate there may be differences between Osgood's structure and other models of affective processing that should be further explored.

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.

Sex differences in patients with Tourette syndrome

BACKGROUND

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by the presence of motor and phonic tics. It is at least three times more common in males compared with females; however, the clinical phenomenology between sexes has not been fully examined. We aimed to contrast the clinical features between males and females with TS and chronic tic disorder.

METHODS

We studied 201 consecutive patients fulfilling the diagnostic criteria for TS, persistent (or chronic) motor and vocal tic disorder and provisional tic disorder that were considered within the TS spectrum disorder. We performed blinded evaluations of video-recordings and retrospectively reviewed the clinical charts of all patients.

RESULTS

Age ranges between 4 and 65 years. Males represented 77.6% of patients in the cohort. Overall, no differences were observed in the frequency, distribution and complexity of tics between sexes, except for a higher frequency of attention-deficit/hyperactivity disorder (ADHD) (P = .003) among males. Patients younger than 18-years old, in addition to a higher frequency of ADHD (P = .026), males had a statistically higher frequency of complex motor tics (P = .049) and earlier age at onset (P = .072) than females in the multivariate regression analysis. However, these differences were lost in patients older than 18 years, due to increased complexity of tics in females with aging.

CONCLUSIONS

A sexual dimorphism was observed between patients with TS mainly before age of 18 years, suggesting an earlier onset of some types of tics and ADHD in males compared to females.

Clinical and demographic characteristics of patients with functional movement disorders: a consecutive cohort study from a specialized clinic

There is a growing interest in functional movement disorders (FMD). However, epidemiological data from large cohorts of patients with FMD are scarce and come mainly from General Neurology and Movement Disorders Clinics. Recently, specialized FMD clinics have been developed and epidemiological data from such clinics may provide useful information. We aimed to describe the clinical and sociodemographic features of patients diagnosed with FMD at our specialized FMD clinic. A standardized form was used to extract data from electronic records from the first-100 consecutive patients who were evaluated and diagnosed with FMD at our clinic from 2017 to 2019. Mean age was 40.88 ± (14.02) years, 63% females. Most patients were within working-age range, but only 16% were working at the time of consultation. Mean disease duration was 3.74 ± 5.73 years and was longer among men. The most common FMD were gait disturbance (42%), tremor (22%) and dystonia (15%). A precipitating event (mainly physical) was reported by 74%. The onset was mostly acute (83%) and the clinical course fluctuating (62%). Pain (64%) and fatigue (44%) were common comorbidities. Potential joint-hypermobility was present in 21%, mostly women (90%) and related to the presence of dystonia. FMD affects men and women mostly in working-age. Gait disturbance was the most common diagnosis, possibly because it causes a higher level of disability that may lead to consultation in a specialized clinic. Non-motor symptoms (pain and fatigue) were frequent in this cohort. Further data from specialized units may contribute to both understanding and management of FMD.

The Rise of Functional Tic-Like Behaviors: What Do the COVID-19 Pandemic and Social Media Have to Do With It? A Narrative Review

BACKGROUND

There has been a rise in explosive onset of tic-like behaviors during the COVID-19 pandemic. Historically, this is an uncommon phenomenology of functional movement disorders across all ages. Both the psychological burden of the pandemic and social media usage have been implicated in the rise of these tic-like behaviors.

METHODS

This paper provides a narrative review of the literature on chronic tic disorders, functional tics, and mass functional illness with particular focus on the key distinguishing features, role of social media, and the role of COVID-19.

RESULTS

The COVID-19 pandemic has profoundly affected the mental health of many individuals, including children, adolescents, and their caregivers. Implementation of lockdowns, lifestyle disruptions, school closures, and social distancing have driven a surge in social media and digital technology use. The combination of predisposing factors, the psychological burden of the COVID-19 pandemic, and social media are implicated in the rise and spread of tic-like behaviors; which may represent a modern-day form of mass functional illness. While many of the features overlap with functional tics, there are emerging distinctive features that are important to recognize. A more encompassing term, Functional Tic-Like Behaviors, is used to better reflect multiple contributing factors.

CONCLUSION

Knowledge of these differences is essential to mitigate downstream health effects and poor outcomes.

The Psychiatric Comorbidities of Migraine in Children and Adolescents

PURPOSE OF REVIEW

Understanding comorbidities in migraine is important because it can help us understand disease pathophysiology while also aiding the development of more effective treatment strategies. Additionally, it can provide greater awareness about appropriate diagnosis, the need for additional disease screening, and the natural history of migraine. Psychiatric comorbidities have been independently studied in both adults and children with migraine because their presentations can be distinct, and the physiology in these two groups can be different.

RECENT FINDINGS

While symptoms of anxiety and depression seem to be comorbid with migraine in children, clinically significant disease does not appear to be, though the clarity of these data is limited by overlap between migraine symptomatology and that assessed by many screening tools. Functional neurologic disorders like psychogenic non-epileptic episodes (PNEE) and other functional movement disorders are not common but can be comorbid with migraine in this population and tend to improve with migraine treatment. The number of adverse childhood experiences (ACEs) a child is exposed to seems to be near-linearly associated with risk of migraine, but not with tension-type headache (TTH). The findings from these studies underscore the importance of utilizing appropriate screening methodologies for identifying psychiatric disorders in children with migraine. Additionally, the role of the insula, the hypothalamic-pituitary-adrenal axis, the serotonergic system, and the instability of hyperactivated neural networks may underlie the pathophysiology of both migraine and its psychiatric comorbidities.

Identification and initial treatment of involuntary psychogenic movement (conversion) disorder in a 25-year-old male patient

Psychogenic movement disorders present a diagnostically challenging entity that is often frightening for patients. Differentiating movement disorders, providing clear explanations, and addressing underlying conditions with a multidisciplinary approach are essential to successful treatment.

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.

Functional motor phenotypes: to lump or to split?

INTRODUCTION

Functional motor disorders (FMDs) are usually categorized according to the predominant phenomenology; however, it is unclear whether this phenotypic classification mirrors the underlying pathophysiologic mechanisms.

OBJECTIVE

To compare the characteristics of patients with different FMDs phenotypes and without co-morbid neurological disorders, aiming to answer the question of whether they represent different expressions of the same disorder or reflect distinct entities.

METHODS

Consecutive outpatients with a clinically definite diagnosis of FMDs were included in the Italian registry of functional motor disorders (IRFMD), a multicenter data collection platform gathering several clinical and demographic variables. To the aim of the current work, data of patients with isolated FMDs were extracted.

RESULTS

A total of 176 patients were included: 58 with weakness, 40 with tremor, 38 with dystonia, 23 with jerks/facial FMDs, and 17 with gait disorders. Patients with tremor and gait disorders were older than the others. Patients with functional weakness had more commonly an acute onset (87.9%) than patients with tremor and gait disorders, a shorter time lag from symptoms onset and FMDs diagnosis (2.9 ± 3.5 years) than patients with dystonia, and had more frequently associated functional sensory symptoms (51.7%) than patients with tremor, dystonia and gait disorders. Patients with dystonia complained more often of associated pain (47.4%) than patients with tremor. No other differences were noted between groups in terms of other variables including associated functional neurological symptoms, psychiatric comorbidities, and predisposing or precipitating factors.

CONCLUSIONS

Our data support the evidence of a large overlap between FMD phenotypes.

Diagnosis and therapy of functional tremor a systematic review illustrated by a case report

Background

Diagnosis of functional movement disorders and specifically functional tremor (FT) (representing 50% of them) remains demanding. Additionally, due to heterogeneity of the disorders, structured concepts and guidelines for diagnosis and therapy are difficult to establish. Ascertaining the state of knowledge to derive instructions for operating procedures is the aim of this review.

Main text

Based on a standardized systematic literature research using the term “psychogenic tremor” in the MEDLINE database dating back ten years, 76 studies were evaluated. Conventional features of FT are variability of frequency and amplitude. Further, response to distraction by motor and cognitive tasks is a key diagnostic feature in differentiation between organic and functional origin. A variety of electrophysiological tests have been evaluated including surface electromyography and accelerometry to establish laboratory-supported criteria for diagnosing tremor. Also, finger tapping tests have been used to identify FT, showing positive potential as supplementary evidence.

Imaging studies in general are mostly underpowered and imaging cannot be used on an individual basis. Therapeutic studies in FT often have a diagnostic component. Cognitive behavioral therapy should be the preferred psychological treatment independent of additional psychiatric symptoms. Other psychotherapeutic methods show lack of evidence concerning FT. Relaxation techniques and physiotherapy are an important additional feature, especially in children and adolescents. In regard to drug therapy, randomized and blinded trials are not available. A significant decrease in rating scales could be detected after active, not sham repetitive transcranial magnetic stimulation with a long-lasting effect. Also root magnetic stimulation seems to be effective. The clinical feature of tremor entrainment in FT can be used in combination with biofeedback as so-called tremor retrainment, using self-modulation of frequency and severity, to bring the movements under volitional control.

Conclusion

Diagnosis and treatment of FT is challenging and should include a combination of intensive clinical examination and targeted addition of standardized testing, especially electrophysiological methods. Often therapeutic effects have a diagnostic component. A multimodal strategy, considering psychological factors as a potential origin as well as maintaining effects seems to be most effective.

Functional Movement Disorders in Children

Functional movement disorders (FMDs) are not uncommon in children. The age at onset may have a bearing on the phenomenological pattern of abnormal movement, risk factors, and response to different treatment modalities in this age group. FMDs in children resemble their adult counterparts in terms of gender preponderance, but risk factors are quite different, and often influenced by cultural and demographic background. FMDs contribute to a significant proportion of acute pediatric movement disorder patients seen in emergency settings, ranging from 4.3 to 23% in different case series. The most common movement phenomenologies observed in pediatric FMDs patients are tremor, dystonia, gait disturbances, and functional tics. Various social, physical, and familial precipitating factors have been described. Common social risk factors include divorce of parents, sexual abuse, bullying at school, examination pressure, or other education-related issues, death of a close friend, relative, or family members. Physical trauma like minor head injury, immunization, tooth extraction, and tonsillectomy are also known to precipitate FMDs. The response to treatment appears to be better among pediatric patients. We aim to review FMDs in children to better understand the different aspects of their frequency, clinical features, precipitating factors, diagnosis, treatment, and outcome.

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.

Effects of TPH2 gene variation and childhood trauma on the clinical and circuit-level phenotype of functional movement disorders

BACKGROUND

Functional movement disorders (FMDs), part of the wide spectrum of functional neurological disorders (conversion disorders), are common and often associated with a poor prognosis. Nevertheless, little is known about their neurobiological underpinnings, particularly with regard to the contribution of genetic factors. Because FMD and stress-related disorders share a common core of biobehavioural manifestations, we investigated whether variants in stress-related genes also contributed, directly and interactively with childhood trauma, to the clinical and circuit-level phenotypes of FMD.

METHODS

Sixty-nine patients with a 'clinically defined' diagnosis of FMD were genotyped for 18 single-nucleotide polymorphisms (SNPs) from 14 candidate genes. FMD clinical characteristics, psychiatric comorbidity and symptomatology, and childhood trauma exposure were assessed. Resting-state functional connectivity data were obtained in a subgroup of 38 patients with FMD and 38 age-matched and sex-matched healthy controls. Amygdala-frontal connectivity was analysed using a whole-brain seed-based approach.

RESULTS

Among the SNPs analysed, a tryptophan hydroxylase 2 (TPH2) gene polymorphism-G703T-significantly predicted clinical and neurocircuitry manifestations of FMD. Relative to GG homozygotes, T carriers were characterised by earlier FMD age of onset and decreased connectivity between the right amygdala and the middle frontal gyrus. Furthermore, the TPH2 genotype showed a significant interaction with childhood trauma in predicting worse symptom severity.

CONCLUSIONS

This is, to our knowledge, the first study showing that the TPH2 genotype may modulate FMD both directly and interactively with childhood trauma. Because both this polymorphism and early-life stress alter serotonin levels, our findings support a potential molecular mechanism modulating FMD phenotype.

Cortical Inhibitory Imbalance in Functional Paralysis

BACKGROUND

Functional neurological disorders are characterized by neurological symptoms that have no identifiable pathology and little is known about their underlying pathophysiology.

OBJECTIVES

To analyze motor cortex excitability and intracortical inhibitory and excitatory circuits' imbalance in patients with flaccid functional weakness.

METHODS

Twenty-one consecutive patients with acute onset of flaccid functional weakness were recruited. Single and paired-pulse transcranial magnetic stimulation (TMS) protocols were used to analyze resting motor thresholds (RMT) and intracortical inhibitory (short interval intracortical inhibition - SICI) and excitatory (intracortical facilitation - ICF) circuits' imbalance between the affected and non-affected motor cortices.

RESULTS

We observed a significant increase in RMT and SICI in the affected motor cortex (p < 0.001), but not for ICF, compared to the contralateral unaffected side.

CONCLUSION

This study extends current knowledge of functional weakness, arguing for a specific central nervous system abnormality which may be involved in the symptoms' pathophysiology.