[Diagnostic criteria, epidemiology and assessment of patients with functional neurological disorders]. / Définitions, épidémiologie et démarche diagnostique clinique dans les troubles neurologiques fonctionnels.

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.

Overall comorbidities in functional neurological disorder: A narrative review.

INTRODUCTION: The importance to assess and include the frequent comorbidities in the personalised care management plan of patients with functional neurological disorders (FND) has arisen through the years. FND patients are not only complaining from motor and/or sensory symptoms. They also report some non-specific symptoms that participate to the burden of FND. In this narrative review, we aim to better describe these comorbidities in terms of prevalence, clinical characteristics and their variability depending on the subtype of FND. METHODS: The literature was searched for on Medline and PubMed. The search was narrowed to articles between 2000 and 2022. RESULTS: Fatigue is the most common symptom reported in relation to FND (from 47 to 93%), followed by cognitive symptoms (from 80 to 85%). Psychiatric disorders are reported in 40 to 100% FND patients, depending on the FND subtype (functional motor disorder [FMD], functional dissociative seizures [FDS]…) but also on the type of psychiatric disorder (anxiety disorders being the most frequent, followed by mood disorders and neurodevelopmental disorders). Stress factors such as childhood trauma exposure (emotional neglect and physical abuse predominantly) have also been identified in up to 75% of FND patients, along with maladaptive coping strategies. Organic disorders are commonly reported in FND, such as neurological disorders (including epilepsy in FDS [20%] and FMD in Parkinson's Disease [7%]). Somatic symptom disorders including chronic pain syndromes are frequently associated to FND (about 50%). To be noted, recent data also suggest a high comorbidity between FND and hypermobile Ehlers Danlos Syndrome (about 55%). CONCLUSION: Put together, this narrative review highlights the high burden of FND patients, not only due to somatosensory alterations but also by considering the frequent comorbidities reported. Thus, such comorbidities must be taken into consideration when defining the FND personalised care management strategy for the patients.

Functional tics: Expanding the phenotypes of functional movement disorders?

BACKGROUND AND PURPOSE: Until the outbreak reported during the COVID-19 pandemic, functional tics were considered to be a relatively rare clinical phenotype, as opposed to other functional movement disorders such as functional tremor and dystonia. To better characterize this phenotype, we compared the demographic and clinical characteristics of patients who developed functional tics during the pandemic and those of patients with other functional movement disorders. METHODS: Data from 110 patients were collected at the same neuropsychiatry centre: 66 consecutive patients who developed functional tics without other functional motor symptoms or neurodevelopmental tics and 44 patients with a mix of functional dystonia, tremor, gait, and myoclonus. RESULTS: Both groups were characterized by female sex preponderance (70%-80%) and (sub)acute onset of functional symptoms (~80%). However, patients with functional tics had a significantly earlier age at onset of functional symptoms (21 vs. 39 years). Exposure to relevant social media content was reported by almost half of the patients with functional tics, but by none of the patients with other functional movement disorders. Comorbidity profiles were similar, with relatively high rates of anxiety/affective symptoms and other functional neurological symptoms (nonepileptic attacks). CONCLUSIONS: Patients who developed functional tics during the pandemic represent a phenotypic variant of the wider group of patients with functional movement disorders, associated with younger age at onset and influenced by pandemic-related factors, including increased exposure to specific social media content. Diagnostic protocols and treatment interventions should be tailored to address the specific features of this newly defined phenotype.

Prevalence of autistic traits in functional neurological disorder and relationship to alexithymia and psychiatric comorbidity.

INTRODUCTION: In a cohort of adults with Functional Neurological Disorder (FND), we aim to: METHODS: 91 patients participating in a FND 5-week outpatient program completed baseline self-report questionnaires for total phobia, somatic symptom severity, attention deficit hyperactivity disorder (ADHD) and dyslexia. Patients were grouped by Autism Spectrum Quotient (AQ-10) score of <6 or ≥ 6 and compared for significant differences in tested variables. This analysis was repeated with patients grouped by alexithymia status. Simple effects were tested using pairwise comparisons. Multistep regression models tested direct relationships between autistic traits and psychiatric comorbidity scores, and mediation by alexithymia. RESULTS: 36 patients (40%) were AQ-10 positive (scoring ≥6 on AQ-10). A further 36 patients (across AQ-10 positive and AQ-10 negative groups) (40%) screened positive for alexithymia. AQ-10 positive patients scored significantly higher for alexithymia, depression, generalised anxiety, social phobia, ADHD, and dyslexia. Alexithymia positive patients scored significantly higher for generalised anxiety, depression, somatic symptoms severity, social phobia, and dyslexia. Alexithymia score was found to mediate the relationship between autistic trait and depression scores. CONCLUSION: We demonstrate a high proportion of autistic and alexithymic traits, in adults with FND. A higher prevalence of autistic traits may highlight a need for specialised communication approaches in FND management. Mechanistic conclusions are limited. Future research could explore links with interoceptive data.

The natural history of terms describing functional (neurological) disorders in the medical literature of the last 60 years.

BACKGROUND: Functional neurological disorders (FND), a subtype of functional disorders (FD), are a frequent motive for neurology referrals. The various presentations and the unknown physiopathology of FD have led to the multiplication of terms describing these disorders over the years. METHODS: We examined the FD-related articles published from 1960 to 2020 in PubMed and PsycINFO databases. We searched for: psychogenic, somatization, somatoform, medically unexplained symptoms, hysteria, conversion disorder, dissociative, functional neurological disorder, and functional disorder. Use rates in the title, abstract, keyword, or MeSH fields were collected over successive 5-year periods. After correcting for off-topic results, we examined proportional distribution over time, term associations, and disciplinary fields (neurology and psychiatry). Term impact was estimated via H-index and number of citations. RESULTS: We found that none of the terms is prevailing in the recent medical literature. We observed three trends in the use rates: stability, increase, and decrease of use over time. While most of the terms were present in a stable proportion of the publications, hysteria and psychogenic lost popularity over time. We found a differential preference for terminology between disciplines. Functional neurological disorder showed the highest citation impact, yielding 10% of highly cited publications. CONCLUSION: We found a dynamic and evolving use of the different terms describing FD in the last 60 years. Despite the tendency to use the term functional in the recent highly cited publications, its low prevalence and coexistence with several other terms suggest that a precise, explanatory and non-offensive term remains yet to be found.

Anaesthesia and the development of functional neurological disorder: A systematic review and case series.

OBJECTIVE: There are reports of functional neurological disorder (FND) developing after anaesthesia, though separating any aetiological role from other possible factors is challenging. We aimed to systematically review all published cases of post-anaesthetic FND to see if any common factors supported an anaesthetic role. We also aimed to identify all cases of post-anaesthetic FND arising in our FND clinic, to obtain an estimate of its frequency. METHODS: For the review, a systematic search for published cases of FND developing within 48 h of anaesthesia was conducted in June 2022. For the case series, the medical records of all patients attending an FND clinic in Melbourne between 2017 and 2019 were examined, and all cases with FND within 48 h of anaesthesia extracted. RESULTS: 36 published cases were identified for the review. Sixteen described preceding stressors and 16 psychiatric diagnoses, including 8 with previous FND. Thirty-two (92%) had undergone general anaesthesia, most commonly for obstetric procedures. Motor/sensory loss was the most common presentation, followed by seizures and coma. Most (80.5%) developed symptoms immediately on induction or cessation of anaesthesia. For the case series, 8 of 107 clinic patients (7.5%), developed FND within 48 h of anaesthesia. All had previous psychiatric diagnoses, including 3 with previous FND. Three underwent general anaesthesia and 3 procedural sedation, with seizures the most common presentation. All developed symptoms immediately on induction or cessation of anaesthesia. CONCLUSION: These cases provide some support for an aetiological role for anaesthesia: there is evidence for an anaesthetic 'model' for the symptoms of FND that arise, they largely arise with the onset or termination of anaesthesia, and they arise most frequently during general anaesthesia or sedation.

Functional Neurological Disorders: Clinical Spectrum, Diagnosis, and Treatment.

BACKGROUND: Functional neurological disorders (FNDs) are common but often misdiagnosed. REVIEW SUMMARY: The incidence of FNDs is between 4 and 12 per 100,000, comparable to multiple sclerosis and amyotrophic lateral sclerosis, and it is the second most common diagnosis in neurology clinics. Some clues in the history are sudden onset, intermittent time course, variability of manifestation over time, childhood trauma, and history of other somatic symptoms. Anxiety and depression are common, but not necessarily more than in the general population. Although there are no tests currently capable of demonstrating whether symptoms are willfully produced, there may not be a clear categorical difference between voluntary and involuntary symptoms. The prognosis of an FND is linked to early diagnosis and symptom duration, but unfortunately, the majority of the patients are diagnosed after considerable delays. CONCLUSIONS: A positive diagnosis of FNDs can be made on the basis of history and neurological signs without reliance on psychological stressors. Past sensitizing events and neurobiological abnormalities contribute to the pathogenesis of FNDs. Physical rehabilitation and psychological interventions alone or in combination are helpful in the treatment.

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.

Subjective experiences of dissociative and conversion disorders among adolescents in India.

Dissociative/conversion disorders affect almost 31% of children and adolescents in a clinical setting. These children experience significant impairments in their academics, and daily functioning, with high chances of developing other psychiatric comorbidities such as anxiety and depression. However, there are no studies that explore the experiences of suffering from dissociative/conversion disorders from perspective of the sufferer. Therefore, the paper has aimed at exploring the subjective experiences of dissociative and conversion disorders among adolescents in the Indian context by examining their understanding about the illness and the reason they ascribe to the cause of their illness. The study used a qualitative semi-structured interview to understand their illness. In total, 10 adolescents of age group between 12 and 16 years participated. Eight out of the 10 participants were female and the mean age was 12 years. All of them were in-patients in the department of Child and Adolescent Psychiatry, NIMHANS, which is the tertiary mental health care Institute India and pioneer Institute of mental health in Asia. All participants have had at least one or more consultation history either with a traditional healer or/and physician. Thematic analysis identified vital themes such as (1) Adolescents' attributing factors of the illness, (2) Cognitive and emotional appraisal of stressful situation/s, (3) Adolescents' appraisal of different explanatory model, (4) Living with the Impact of the illness. This analysis about dissociative/conversion disorders from adolescents' perspective has a major contribution in enhancing the clinical knowledge and practice in planning and managing children/adolescents diagnosed with dissociative/conversion disorders.

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.

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

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

[Conversion and dissociation: together or separated?] / Conversie en dissociatie: samen of apart in de DSM?

BACKGROUND: Conversion and dissociation in their relationship have made a lot of pendulum movements over time between moving together and away from each other. In the run-up to the introduction of DSM-5, it was argued that conversion should be classified as a dissociative disorder, but this didn't happen. AIM: In this article, the clinical scientific evidence is examined for the relationship between conversion and dissociation. We provide an overview of the recent clinical studies that examine both syndromes together. We also investigate the main overlapping predisposing characteristics and psychopathological explanatory models of both syndromes. METHOD: Literature review in PubMed and PsycArticles. RESULTS: Our findings confirm that there is a large comorbidity between conversive and dissociative symptoms in clinical reality. Both syndromes have a high prevalence of reported trauma and emotion dysregulation. However, evidence for present biomarkers is still llimited. The underlying explanation models are applicable for both conversion and dissociation. CONCLUSION: We want to draw attention to the plea to bring conversion disorders back together with dissociative disorders. Moreover, the possible presence of trauma, the influential role of psychosocial stressors, the present psychiatric co-morbidity and the style of emotion regulation seem to justify the approach to conversion problems from a biopsychosocial perspective rather than from a purely biomedical perspective.

Incidence and prevalence of psychogenic nonepileptic seizures in a Norwegian county: A 10-year population-based study.

OBJECTIVE: This study was undertaken to measure the incidence and prevalence of active psychogenic nonepileptic seizures (PNES) in a Norwegian county. METHODS: Using the Norwegian patient registry, we identified patients in Møre and Romsdal County in Norway diagnosed with F44.5 (conversion disorder with seizures or convulsions) or R56.8 (convulsions, not elsewhere classified) in the period January 2010 to January 2020. A review of the patients' medical records and an assessment of diagnostic validity were performed. PNES were diagnosed according to the recommendations by the International League Against Epilepsy Nonepileptic Seizures Task Force. Point prevalence of PNES on January 1, 2020 and incidence rates for the period 2010-2019 were determined. RESULTS: Based on PNES within the past 5 years, we found a PNES prevalence of 23.8/100 000 (95% confidence interval [CI] = 17.9-29.6), including all levels of diagnostic certainty. For the highest level of diagnostic certainty (video-electroencephalographically confirmed), the prevalence was 10.6/100 000 (95% CI = 6.7-14.5). The highest prevalence was found in the age group 15-19 years, at 59.5/100 000 (95% CI = 22.6-96.3). The mean annual incidence rate between 2010 and 2019 was 3.1/100 000/year (95% CI = 2.4-3.7). SIGNIFICANCE: We report for the first time a population-based estimate of the prevalence of PNES. Our findings suggest that the prevalence of PNES is within the range of estimates from non-population-based data. We found a strikingly high prevalence of PNES in the 15-19-year age group.

The Psychopathology, Depression, and Anxiety Levels of Children and Adolescents With Vasovagal Syncope: A Case-Control Study.

ABSTRACT: Vasovagal syncope constitutes 61% to 80% of syncope cases in the pediatric age group. Syncope is frequently associated with psychopathologies such as depressive disorders, anxiety disorders, somatization disorders, etc. Our study aims to evaluate vasovagal syncope cases in terms of additional psychopathologies, depression, and anxiety levels with a control group. A total of 97 people were included in the study (47 cases and 50 controls). After conducting a cardiological examination, the participants were evaluated for psychopathologies using Kiddie-Sads-Present and Lifetime Version, Child Depression Inventory, and Screen for Child Anxiety Related Emotional Disorders. The case group had a higher rate of psychopathology compared with the control group. Depression, social anxiety disorder, generalized anxiety disorder, separation anxiety, and conversion disorder were significantly higher in the case group than in the control group. Syncope in children can be an underlying psychopathology or the clinical manifestation of a psychosomatic condition. Psychological assessment, which could offer beneficial contributions to the diagnosis and treatment of syncope, was considered necessary for a holistic evaluation of patients.

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

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

Characteristics of men with conversion disorder.

OBJECTIVE: Women comprise the majority of subjects with conversion disorders in nearly all studies. The authors previously identified 96 subjects with psychogenic non-epileptic seizures (PNES) and found that female sex, alexithymia and childhood trauma were strongly correlated with the development of PNES. In order to characterize men with PNES, the authors collected questionnaire data on a series of male subjects recruited from an epilepsy monitoring unit (EMU). METHODS: Only male patients admitted to the EMU were asked to complete the Toronto Alexithymia Scale-20 (TAS-20) and the Childhood Trauma Questionnaire (CTQ). Results were correlated with diagnosis at discharge, either epileptic seizures (ES) or PNES. RESULTS: Ninety-two subjects submitted complete questionnaire data. Sixty-nine subjects (74%) were diagnosed with ES, 13 subjects (14%) were diagnosed with PNES and 10 subjects (11%) had an undetermined diagnosis. There were no significant differences on the TAS-20 or the CTQ by diagnosis. CONCLUSION: In this sample of men admitted to an EMU there was no difference in the extent of alexithymia or childhood trauma between men with ES and PNES. There was a small number of men with a PNES diagnosis, which may have limited our ability to identify differences in the groups. The clear correlation of childhood trauma and alexithymia with development of conversion disorder in women could not be demonstrated in men.

Vitamin B12, folate levels and somatoform dissociation in conversion disorder.

OBJECTIVE: To evaluate the association of folate and vitamin B12 levels in patients with conversion disorder, and to illuminate the aetiology of conversion disorder by examining depression and somatoform dissociation. METHODS: The case-control study was conducted from March 2014 to May 2015 at the Medical Centre of Yuzuncu Yil University, Van, Turkey, and comprised patients diagnosed with conversion disorder and healthy controls. Blood samples were taken from both groups for vitamin B12 and folate levels. Data was collected using the Beck Depression Inventory and Somatoform Dissociation Scale. Data was analysed using SPSS 18. RESULTS: Of the 100 subjects, 55(55%) were cases with a mean age of 27.05±9.04 years and 45(45%) were controls with a mean age of 26.56± 5.96 years. The mean level of B12 was 283.93±122.96 in cases and 324.62±128.82 in controls (p=0.05). The mean level of folic acid was 5.47±1.84 in cases and 6.07±2.26 in controls (p>0.05). CONCLUSIONS: Physicians need to be vigilant about vitamin B12 levels in patients with conversion symptoms.

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

BACKGROUND: Functional neurological disorder (FND), previously known as conversion disorder, is common and often results in substantial distress and disability. Previous research lacks large sample sizes and clinical surveys are most commonly derived from neurological settings, limiting our understanding of the disorder and its associations in other contexts. We sought to address this by analysing a large anonymised electronic psychiatric health record dataset. METHODS: Data were obtained from 322 patients in the South London and Maudsley NHS Foundation Trust (SLaM) who had an ICD-10 diagnosis of motor FND (mFND) (limb weakness or disorders of movement or gait) between 1 January 2006 and 31 December 2016. Data were collected on a range of socio-demographic and clinical factors and compared to 644 psychiatric control patients from the same register. RESULTS: Weakness was the most commonly occurring functional symptom. mFND patients were more likely to be female, British, married, employed pre-morbidly, to have a carer and a physical health condition, but less likely to have had an inpatient psychiatric admission or to receive benefits. No differences in self-reported sexual or physical abuse rates were observed between groups, although mFND patients were more likely to experience life events linked to inter-personal difficulties. CONCLUSIONS: mFND patients have distinct demographic characteristics compared with psychiatric controls. Experiences of abuse appear to be equally prevalent across psychiatric patient groups. This study establishes the socio-demographic and life experience profile of this understudied patient group and may be used to guide future therapeutic interventions designed specifically for mFND.

Epidemiology of functional stroke mimic patients: a systematic review and meta-analysis.

Stroke mimics form a significant proportion of cases in acute stroke services and some present with functional neurological disorder. Little is known about the prevalence or clinical characteristics of functional stroke mimics (FSMs). A systematic literature search and meta-analysis were carried out on published studies reporting suspected stroke and stroke mimic rates; 114 papers met the inclusion criteria of which 70 provided an FSM rate. Random-effects models estimated prevalence rates across settings and moderators of FSM rate. Pooled proportions indicated that 25% [95% confidence intervals (CI), 22-27%] of suspected stroke cases were stroke mimics. Within the 67 studies providing positive FSM rates, FSMs represented 15% (95% CI, 13-18%) of stroke mimics and 2% (95% CI, 2-3%) of suspected strokes. FSMs were younger and more likely to be female, and presented more with weakness/numbness but less with reduced consciousness or language problems. Stratified analyses suggested higher stroke mimic rates in primary care versus acute settings (38% vs. 12%) but higher FSM rates in stroke units compared with primary care (24% vs. 12%). Functional rates were higher in studies that were descriptive, retrospective and in patients receiving thrombolysis. Several studies reported the proportion of functional stroke patients presenting to stroke services. FSMs have discernible demographic and clinical characteristics, but there is a conspicuous lack of evidence on their presentation or guidance for treatment. The social and psychological mechanisms underlying FSM presentations need more accurate quantification to help inform stroke pathways and improve care for these patients.