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

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

Functional neurological disorder in Europe: regional differences in education and health policy.

BACKGROUND: Functional neurological disorder (FND) is a common cause of neurological disability. Despite recent advances in pathophysiological understanding and treatments, application of this knowledge to clinical practice is variable and limited. OBJECTIVE: Our aim was to provide an expert overview of the state of affairs of FND practice across Europe, focusing on education and training, access to specialized care, reimbursement and disability policies, and academic and patient-led representation of people with FND. METHODS: We conducted a survey across Europe, featuring one expert per country. We asked experts to compare training and services for people with FND to those provided to people with multiple sclerosis (MS). RESULTS: Responses from 25 countries revealed that only five included FND as a mandatory part of neurological training, while teaching about MS was uniformly included. FND was part of final neurology examinations in 3/17 countries, unlike MS that was included in all 17. Seventeen countries reported neurologists with an interest in FND but the estimated mean ratio of FND-interested neurologists to MS neurologists was 1:20. FND coding varied, with psychiatric coding for FND impacting treatment access and disability benefits in the majority of countries. Twenty countries reported services refusing to see FND patients. Eight countries reported an FND special interest group or network; 11 reported patient-led organizations. CONCLUSIONS: FND is largely a marginal topic within European neurology training and there is limited access to specialized care and disability benefits for people with FND across Europe. We discuss how this issue can be addressed at an academic, healthcare and patient organization level.

Perspectives on the diagnosis and management of functional cognitive disorder: An international Delphi study.

BACKGROUND: Current proposed criteria for functional cognitive disorder (FCD) have not been externally validated. We sought to analyse the current perspectives of cognitive specialists in the diagnosis and management of FCD in comparison with neurodegenerative conditions. METHODS: International experts in cognitive disorders were invited to assess seven illustrative clinical vignettes containing history and bedside characteristics alone. Participants assigned a probable diagnosis and selected the appropriate investigation and treatment. Qualitative, quantitative and inter-rater agreement analyses were undertaken. RESULTS: Eighteen diagnostic terminologies were assigned by 45 cognitive experts from 12 countries with a median of 13 years of experience, across the seven scenarios. Accurate discrimination between FCD and neurodegeneration was observed, independently of background and years of experience: 100% of the neurodegenerative vignettes were correctly classified and 75%-88% of the FCD diagnoses were attributed to non-neurodegenerative causes. There was <50% agreement in the terminology used for FCD, in comparison with 87%-92% agreement for neurodegenerative syndromes. Blood tests and neuropsychological evaluation were the leading diagnostic modalities for FCD. Diagnostic communication, psychotherapy and psychiatry referral were the main suggested management strategies in FCD. CONCLUSIONS: Our study demonstrates the feasibility of distinguishing between FCD and neurodegeneration based on relevant patient characteristics and history details. These characteristics need further validation and operationalisation. Heterogeneous labelling and framing pose clinical and research challenges reflecting a lack of agreement in the field. Careful consideration of FCD diagnosis is advised, particularly in the presence of comorbidities. This study informs future research on diagnostic tools and evidence-based interventions.

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

OBJECTIVE: Neuroimaging studies have identified alterations in both brain structure and functional connectivity in patients with functional neurological disorder (FND). For many patients, FND emerges from physical precipitating events. Nevertheless, there are a limited number of case series in the literature that describe the clinical presentation and neuroimaging correlates of FND following cerebrovascular disease. METHODS: The authors collected data from two clinics in the United Kingdom on 14 cases of acute, improving, or delayed functional neurological symptoms following cerebrovascular events. RESULTS: Most patients had functional neurological symptoms that were localized to cerebrovascular lesions, and the lesions mapped onto regions known to be part of functional networks disrupted in FND, including the thalamus, anterior cingulate gyrus, insula, and temporoparietal junction. CONCLUSIONS: The findings demonstrate that structural lesions can lead to FND symptoms, possibly explained through changes in relevant mechanistic functional networks.

Etiological Factors and Symptom Triggers in Functional Motor Symptoms and Functional Seizures: A Pilot Investigation.

OBJECTIVE: This study examined etiological factors and symptom triggers of functional motor symptoms (FMS) or functional seizures (FS) and assessed potential relationships with relevant clinical features (i.e., functional symptoms, quality of life, and general functioning). METHODS: Seventeen participants with FMS or FS and 17 healthy control participants underwent an in-depth clinical interview and completed questionnaires assessing adverse life events, psychological and physical symptoms, alexithymia, autistic traits, illness perceptions, health-related quality of life (HRQoL), and work and social functioning. RESULTS: Participants with FMS or FS perceived various causes of the disorder, including physical symptoms (65%), emotional problems (53%), adverse life events (47%), and work-related factors (29%). Triggers of FMS and FS included physical activity or exertion (59%), stress and emotions (59%), sensory experiences (47%), and fatigue (41%). Compared with healthy control participants, participants with FMS or FS reported more adverse events during adolescence and higher levels of alexithymia, somatoform dissociation, psychological dissociation (disengagement, depersonalization, and derealization), anxiety, depression, and physical symptoms. Participants with FMS or FS had worse HRQoL than healthy control participants and impaired work and social functioning. There were inverse associations between HRQoL scores and somatoform dissociation, anxiety, and adverse life events. CONCLUSIONS: Participants with FMS or FS reported diverse biopsychosocial etiological factors and symptom triggers. Ongoing psychological symptoms and lifetime adverse experiences were associated with worse HRQoL. Future studies will examine these factors in larger samples of individuals with FMS or FS to better understand their shared and distinct etiological underpinnings.

Individualising goal-directed haemodynamic therapy: future iterations will require novel trial designs.

Variants of perioperative cardiac output-guided haemodynamic therapy algorithms have been tested over the last few decades, without clear evidence of effectiveness. Newer approaches have focussed on individualisation of physiological targets and have been tested in early efficacy trials. Uncertainty about the benefits remains. Adoption of novel trial designs could overcome the limitations of smaller trials of this complex intervention and accelerate the exploration of future developments.

Reducing airborne transmissible diseases in perioperative environments.

The COVID-19 pandemic has transformed our understanding of aerosol transmissible disease and the measures required to minimise transmission. Anaesthesia providers are often in close proximity to patients and other hospital staff for prolonged periods while working in operating and procedure rooms. Although enhanced ventilation provides some protection from aerosol transmissible disease in these work areas, close proximity and long duration of exposure have the opposite effect. Surgical masks provide only minimal additional protection. Surgical patients are also at risk from viral and bacterial aerosols. Despite having recently experienced the most significant pandemic in 100 yr, we continue to lack adequate understanding of the true risks encountered from aerosol transmissible diseases in the operating room, and the best course of action to protect patients and healthcare workers from them in the future. Nevertheless, hospitals can take specific actions now by providing respirators for routine use, encouraging staff to utilise respirators routinely, establishing triggers for situations that require respirator use, educating staff concerning the prevention of aerosol transmissible diseases, and providing portable air purifiers for perioperative spaces with low levels of ventilation.

Reduced low-prevalence visual search detriment with increasing age: Implications for cognitive theories of aging and real-world search tasks.

When performing multiple successive visual searches, low-prevalence targets are at elevated risk of being missed. This has important implications for real-world visual search tasks, such as diagnostic medical imaging (e.g., searching for a cancer) and airport baggage security screening (e.g., searching for a weapon), which are characterized by low-prevalence targets and potentially dire consequences of target misses. Previous work on low-prevalence visual search indicates that individuals who spontaneously respond more slowly miss fewer targets, which has been attributed to higher quitting thresholds predicting better performance. Previous aging research indicates that older adults typically respond more slowly across multiple task contexts. This has been attributed to both intrinsic limitations in processing speed and a strategic trade-off to prioritize accuracy with increasing age. Synthesizing these two separate lines of research, here we tested whether older adults had a higher quitting threshold and/or slower processing speed in low-prevalence visual search, and the consequences of these for the magnitude of the low-prevalence visual search detriment. We recruited a large sample (N = 380) across a range of ages (20-80 years) and had them search for targets under low- and high-prevalence conditions. Older adults had both slower processing speed and higher quitting thresholds. Older adults were moderately less susceptible to the low-prevalence detriment, and this relationship was mediated by countervailing effects: slower processing speed exacerbated older adults' low-prevalence detriment, whereas elevated quitting threshold mitigated it. Theoretical implications for cognitive aging and practical implications for professional visual search tasks are discussed.

Different deployments of attentional breadth selectively predict UFOV task performance in older adults.

The Useful Field of View task (UFOV) is a strong and reliable predictor of crash risk in older drivers. However, while the functional domain of attention is clearly implicated in UFOV performance, the potential role of one specific attentional process remains unclear: attentional breadth (the spatial extent of the attended region around the point of visual fixation). The goal of the present study was to systematically test the role of two distinct aspects of attentional breadth, maintaining a specific breadth of attention and resizing the attended region, in UFOV performance. To this end, 135 older adults completed the UFOV and modified Navon tasks to measure their efficiency in maintaining, contracting, and expanding the breadth of attention. We then examined individual-difference associations between these aspects of attentional breadth deployment and UFOV performance. We found that performance on UFOV Subtask 2 was associated with efficient contraction of attentional breadth (i.e., resizing the attended region to a smaller area), while Subtask 3 performance was associated with the efficiency of expanding attentional breadth (i.e., resizing the attended region to a larger area). The selectivity of these relationships appears to implicate these specific deployments of attentional breadth in how people complete the task, as it suggests that these relationships are not simply attributable to shared variance in a broader domain of cognitive functioning. The implications of these results for our understanding of UFOV, as well as future research directions that test the relative contributions of different cognitive processes in predicting task performance, are discussed.

Openness to experience predicts eye movement behavior during scene viewing.

Individuals' abilities to perform goal-directed spatial deployments of attention are distinguishable from their broader preferences for how they use spatial attention when circumstances do not compel a specific deployment strategy. Although these preferences are likely to play a major role in how we interact with the visual world during daily life, they remain relatively understudied. This exploratory study investigated two key questions about these preferences: firstly, are individuals consistent in their preferences for how they deploy their spatial attention when making shifts of attention versus adopting an attentional breadth? Secondly, which other factors are associated with these preferences? Across two experiments, we measured how participants preferred to deploy both attentional breadth (using an adapted Navon task) and eye movements (using a free-viewing task). We also measured participants' working memory capacities (Experiment 1), and their personalities and world beliefs (Experiment 2). In both experiments, there were consistent individual differences in preference for attentional breadth and eye movement characteristics, but these two kinds of preference were unrelated to each other. Working memory capacity was not linked to these preferences. Conversely, the personality trait of Openness to Experience robustly predicted two aspects of eye movement behavior preference, such that higher levels of Openness predicted smaller saccades and shorter scan paths. This suggests that personality dimensions may predict preferences for more absorbed engagement with visual information. However, it appears that individuals' preferences for shifts of attention during scene viewing do not necessarily relate to the breadth of attention they choose to adopt.

Four best-practice recommendations for improving the conceptualization and operationalization of motivational intensity: Reply to Kaczmarek and Harmon-Jones.

Replies to the comments made by Kaczmarek and Harmon-Jones (see record 2024-44184-002) on the current authors original article (see record 2021-21096-001). Kaczmarek and Harmon-Jones (2023) provide a commentary on our original empirical piece, does motivational intensity exist distinct from valence and arousal? (Campbell et al., 2021). In this response, we articulate the motivation behind our work, including the major issues with the conceptualization and operationalization of motivational intensity in prior literature. For example, while motivational intensity was proposed to replace valence as the determinant of cognitive scope more than a decade and a half ago, in both this original work and ongoing work since then, motivational intensity has been operationalized in a variety of questionable ways, including via participants' ratings of valence, rather than motivational intensity. That is, in multiple studies, differences in cognitive processes measured in two conditions have been attributed to motivational intensity which was not explicitly measured, while the conditions do demonstrably differ in the valence participants experienced. We explain exactly what we found in Campbell et al. (2021) and our subsequent follow-up work (Campbell et al., 2023), and what aspects of our interpretation converge versus diverge with the views offered in Kaczmarek and Harmon-Jones' commentary. We also identify four important recommendations for best-practice research going forward. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Individual differences in emotion-induced blindness: Are they reliable and what do they measure?

The emotion-induced-blindness (EIB) paradigm has been extensively used to investigate attentional biases to emotionally salient stimuli. However, the low reliability of EIB scores (the difference in performance between the neutral and emotionally salient condition) limits the effectiveness of the paradigm for investigating individual differences. Here, across two studies, we investigated whether we could improve the reliability of EIB scores. In Experiment 1, we introduced a mid-intensity emotionally salient stimuli condition, with the goal of obtaining a wider range of EIB magnitudes to promote reliability. In Experiment 2, we sought to reduce the attentional oddball effect, so we created a modified EIB paradigm by removing the filler images. Neither of these approaches improved the reliability of the EIB scores. Reliability for the high- and mid-intensity EIB difference scores were low, while reliability of the scores for absolute performance (neutral, high-, and mid-intensity) were high and the scores were also highly correlated, even though overall performance in the emotionally salient conditions were significantly worse than in the neutral conditions. Given these results, we can conclude that while emotionally salient stimuli impair performance in the EIB task compared with the neutral condition, the strong correlation between the emotionally salient and neutral conditions means that while EIB can be used to investigate individual differences in attentional control, it is not selective to individual differences in attentional biases to emotionally salient stimuli.

Perioperative oxygenation-what's the stress?

Oxygen is the most used drug in anaesthesia. Despite such widespread use, optimal perioperative oxygen administration remains highly controversial because of concerns about the competing harms of both hyperoxia and hypoxia. Notwithstanding a Cochrane review concluding that routinely administering a fractional inspired oxygen concentration (FiO2) >0.6 intraoperatively might increase postoperative morbidity and mortality, the World Health Organization (WHO) currently recommends all anaesthetised patients receive 0.8 FiO2 during and immediately after surgery to reduce surgical site infections. Results from the largest trial available at the time of these two reviews (suggesting long-term survival may be worse with high FiO2, particularly in patients with malignant disease) were considered 'biologically implausible' by the WHO's Guideline Development Group. In addition, the integrity of some perioperative oxygen studies has been challenged. Resolving these controversies is of fundamental importance to all perioperative clinicians. This narrative review is based on the inaugural BJA William Mapleson lecture delivered by the senior author (AC) at the 2023 annual meeting of the Royal College of Anaesthetists in Birmingham. We present the current evidence for perioperative oxygen administration and contrast this with how oxygen therapy is targeted in other specialties (e.g. intensive care medicine). We will explore whether anaesthetists follow the WHO recommendations and consider how oxygen administration affects the stress response to surgery. We reason that novel clinical trial designs in combination with targeted experimental medicine studies will be required to improve our understanding of how best to optimise individualised perioperative oxygenation-a cornerstone of anaesthesia.

Loss and Return of Ticklishness in Functional Neurological Disorder.

BACKGROUND: People with functional neurological disorder (FND) have abnormalities in sensory processing. Loss of ticklishness has been rarely reported. OBJECTIVES: To describe associated clinical features in people with FND and loss of ticklishness and explore correlations with sensory changes. METHODS: Retrospective audit of clinical letters of people diagnosed with FND in a tertiary clinic and further cases identified in a general neurology clinic. RESULTS: Thirty-eight patients with loss of ticklishness are described, of which most had other functional sensory symptoms and signs. It was more often localized to one limb, rather than generalized, in those with pain or weakness. Dissociation for the affected body part was often described. CONCLUSIONS: Loss of ticklishness in FND is frequently described and offers insights into mechanisms of agency, sensory processing and interoception, which are known to be altered in FND.

Boundaries of task-specificity: bimanual finger dexterity is reduced in musician's dystonia.

Task-specific dystonia leads to loss of sensorimotor control for a particular motor skill. Although focal in nature, it is hugely disabling and can terminate professional careers in musicians. Biomarkers for underlying mechanism and severity are much needed. In this study, we designed a keyboard device that measured the forces generated at all fingertips during individual finger presses. By reliably quantifying overflow to other fingers in the instructed (enslaving) and contralateral hand (mirroring) we explored whether this task could differentiate between musicians with and without dystonia. 20 right-handed professional musicians (11 with dystonia) generated isometric flexion forces with the instructed finger to match 25%, 50% or 75% of maximal voluntary contraction for that finger. Enslaving was estimated as a linear slope of the forces applied across all instructed/uninstructed finger combinations. Musicians with dystonia had a small but robust loss of finger dexterity. There was increased enslaving and mirroring, primarily during use of the symptomatic hand (enslaving p = 0.003; mirroring p = 0.016), and to a lesser extent with the asymptomatic hand (enslaving p = 0.052; mirroring p = 0.062). Increased enslaving and mirroring were seen across all combinations of finger pairs. In addition, enslaving was exaggerated across symptomatic fingers when more than one finger was clinically affected. Task-specific dystonia therefore appears to express along a gradient, most severe in the affected skill with subtle and general motor control dysfunction in the background. Recognition of this provides a more nuanced understanding of the sensorimotor control deficits at play and can inform therapeutic options for this highly disabling disorder.

What are the experiences of people with motor and sensory functional neurological disorder? A systematic review and thematic synthesis of qualitative studies.

PURPOSE: Functional neurological disorders are common, highly stigmatised and associated with significant disability. This review aimed to synthesise qualitative research exploring the experiences of people living with motor and/or sensory FND. Identifying their needs should inform service development, education for healthcare professionals and generate future research questions. METHOD: Five databases were systematically searched (Medline, PsychInfo, Web of Science, Embase and Cinahl) in November 2022, updated in June 2023. Data from included papers was extracted by two authors and studies were critically appraised using the Critical Appraisal Skills Programme (CASP). Data was thematically analysed and synthesised. RESULTS AND CONCLUSIONS: 12 papers were included in the synthesis describing the views of 156 people with FND. The overarching theme was uncertainty; about what caused FND and how to live with it. Uncertainty was underpinned by four analytic themes; challenging healthcare interactions, loss of power and control, who or what is responsible and living with a visible disability and an invisible illness. Early and clear diagnosis, validation and support for living with FND should form part of multidisciplinary care. Co-produced service development, research agendas and education for clinicians, patients and the public would reduce stigma and improve the experiences of people with FND.

A clear diagnosis and explanation of motor and/or sensory functional neurological disorder is validating and an important first step in recovery.People with motor and/or sensory functional neurological disorder experience significant disability, stigma, self-blame and functional impairment.Multidisciplinary care pathways for functional neurological disorder urgently need to be developed.There is a need for co-produced education and training for healthcare professionals which covers how to deliver diagnoses and personalised formulations, communicate concepts of applied neuroscience and challenges stigma and discrimination.

Virtual reality in functional neurological disorder: a theoretical framework and research agenda for use in the real world.

Functional neurological disorder (FND) is a common and disabling condition at the intersection of neurology and psychiatry. Despite remarkable progress over recent decades, the mechanisms of FND are still poorly understood and there are limited diagnostic tools and effective treatments. One potentially promising treatment modality for FND is virtual reality (VR), which has been increasingly applied to a broad range of conditions, including neuropsychiatric disorders. FND has unique features, many of which suggest the particular relevance for, and potential efficacy of, VR in both better understanding and managing the disorder. In this review, we describe how VR might be leveraged in the treatment and diagnosis of FND (with a primary focus on motor FND and persistent perceptual-postural dizziness given their prominence in the literature), as well as the elucidation of neurocognitive mechanisms and symptom phenomenology. First, we review what has been published to date on the applications of VR in FND and related neuropsychiatric disorders. We then discuss the hypothesised mechanism(s) underlying FND, focusing on the features that are most relevant to VR applications. Finally, we discuss the potential of VR in (1) advancing mechanistic understanding, focusing specifically on sense of agency, attention and suggestibility, (2) overcoming diagnostic challenges and (3) developing novel treatment modalities. This review aims to develop a theoretical foundation and research agenda for the use of VR in FND that might be applicable or adaptable to other related disorders.

Illness perceptions, experiences of stigma and engagement in functional neurological disorder (FND): exploring the role of multidisciplinary group education sessions.

Background: A critical first step in managing functional neurological disorder (FND) is a positive diagnosis and clear explanation using an understandable illness model. Multidisciplinary group education sessions are one way to achieve this, with some evidence they improve understanding, confidence in diagnosis and outcomes with further treatment. In many conditions, illness perceptions and stigma affect distress, functioning, quality of life and engagement. Exploring relationships between these factors could lead to deeper understanding of the impact of education. Methods: Questionnaires assessing illness perceptions, quality of life, mood, anxiety, comorbidities, treatment engagement and stigma (both experienced and anticipated) were completed before, immediately and 1 month after a multidisciplinary online group education session for FND at a regional neurosciences centre. Free-text data on causal attributions and needs were also collected. Results: 166 patients attended online education sessions from January 2022 to July 2023; 61 (37%) completed presession surveys, 42 (25%) completed postsession and 35 (21%) completed 1 month postsession surveys. Patients reported multiple comorbidities, poor quality of life, functioning and high levels of stigma. Illness perception scores indicated FND as threatening, mysterious and unpredictable, with low personal or treatment control over symptoms. Illness coherence/understanding (mean difference 2.27, p<0.01, 95% CI 1.22 to 4.23) and engagement (mean difference 2.42, p<0.01, 95% CI 0.46 to 4.36) increased after the session. There were no significant changes in stigma, distress, sense of control or anticipated discrimination. Free-text analysis revealed stress and trauma as the most common causal attributions, followed by physical illnesses. Patients requested personalised formulations, practical disability advice, help with explaining the condition to others (eg, employers), peer support and treatment. Conclusion: Multidisciplinary group FND education sessions potentially improve patient understanding and engagement. Clinicians should consider the possible benefits of personalised formulations and linking to practical and peer support. Further work assessing illness perceptions is needed, such as adapting measures for FND.