Mark J Edwards

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Verified

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• MBBS, PhD, BSc(Hons)
• Professor at King's College London

Background Functional cognitive disorder is an increasingly recognised subtype of functional neurological disorder for which treatment options are currently limited. We have developed a brief online group acceptance and commitment therapy (ACT)-based intervention. Aims To assess the feasibility of conducting a randomised controlled trial of this i...

Background Functional neurological disorder (FND) is a common cause of neurological symptoms including seizures and movement disorders. It can be debilitating, is associated with high health and social care costs, and can have a poor prognosis. Functional magnetic resonance imaging (fMRI) has suggested FND is a multi-network disorder. Converging ev...

Background Functional cognitive disorder (FCD) poses a diagnostic challenge due to its resemblance to other neurocognitive disorders and limited biomarker accuracy. We aimed to develop a new diagnostic checklist to identify FCD versus other neurocognitive disorders. Methods The clinical checklist was developed through mixed methods: (1) a literatu...

Purpose: Functional cognitive disorder (FCD) is an increasingly recognised condition which causes significant disability and distress. While it is known to be associated with depression, anxiety and reduced functioning, like other functional neurological disorders it may be marred by stigma. To date, little is known about the lived experience of t...

Introduction Functional neurological disorder (FND) and autism spectrum disorder (ASD) are two complex neuropsychiatric conditions that have been historically classified within psychiatric domains, resulting in a lack of extensive research, insufficient clinical recognition, and persistent societal stigma. In recent years, there has been an increas...

Objective: To assess the effect of overall, between- and within-day subjectively rated fluctuations in motor and non-motor symptoms in people with functional motor disorder (FMD) on the health-related quality of life (HRQoL). Background: FMD is a complex condition characterized by fluctuating motor and non-motor symptoms that may negatively impact...

Background Little is known about factors modulating pain and pain‐related functional impairment in isolated cervical dystonia (CD). Objective The aim was to assess the prevalence and interrelationship between pain‐modulating factors and pain‐related determinants of functional impairment and quality of life in CD. Methods We analyzed pain‐aggravat...

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 Eu...

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, suggesti...

Background Functional neurological disorder (FND) is a common cause of neurological symptoms including paralysis, seizures, and movement disorders. It is often debilitating, is associated with high health and social care costs, and can have a poor prognosis. Functional magnetic resonance imaging (fMRI) has suggested FND is a multi-network disorder;...

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 fing...

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 virtua...

Introduction Advances have been made in understanding the aetiology of functional neurological disorder (FND); however, its pathophysiological mechanisms have not been definitively demonstrated. Evidence suggests interacting roles for altered emotional processing and interoception, elevated autonomic arousal, and dissociation, but there is limited...

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 peo...

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. I...

Introduction Advances have been made in understanding the aetiology of functional neurological disorder (FND); however, its pathophysiological mechanisms have not been definitively demonstrated. Evidence suggests interacting roles for altered emotional processing and interoception, elevated autonomic arousal, and dissociation, but there is limited...

Introduction Functional neurological disorder (FND) is a common cause of referral to neurology services. FND has been shown to lead to significant healthcare resource use and is associated with significant disability, comorbidity and distress. This leads to substantial direct, indirect and intangible costs to the patient and society. Methods We re...

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 s...

Remote monitoring technologies (RMT) could provide critical insights into the mechanisms underlying functional neurological symptoms (FNS). We examined the feasibility and acceptability of a novel RMT protocol, aiming to identify psychobiological correlates and antecedents of FNS in everyday life. Seventeen individuals with FNS (seizures/motor) and...

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 ge...

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 pa...

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...

Functional Motor Disorders are common and disabling. Clinical diagnosis has moved from one of exclusion of other causes for symptoms to one where positive clinical features on history and examination are used to make a “rule in” diagnosis wherever possible. Clinical neurophysiological assessments have developed increasing importance in assisting wi...

Sleep symptoms, including excessive sleepiness, are frequently reported by patients with functional motor disorders (FMD). We aimed to classify the comorbid sleep disorders in FMD, and to investigate the relationship between subjective sleepiness and objective measures of hypersomnia, comparing them with data from people with central hypersomnia. A...

Objectives/Aims Altered interoception may be a core pathophysiological mechanism in functional neurological disorder (FND). However, there have been inconsistent findings from interoceptive accuracy paradigms, with several studies reporting no significant group differences in comparisons to controls when tested at rest/baseline. This is contrary to...

Background Interoception describes the predictive representation and control of the internal physiological state of the body. Disturbances in interoception have been demonstrated in people with functional seizures. Little is known about interoception in epilepsy. Aim To compare dimensions of interoception across three groups - people with function...

Objectives/Aims Biopsychosocial perspectives have highlighted the multifactorial and diverse aetiology of functional neurological disorder (FND). We aimed to assess a range of potential predisposing, precipitating and perpetuating factors in FND, and to explore relationships between aetiological factors and current functioning or health-related qua...

Background Differences in affective processing have previously been shown in functional neurological disorder (FND); however, the mechanistic relevance is uncertain. We tested the hypotheses that highly arousing affective stimulation would result in elevated subjective functional neurological symptoms (FNS), and this would be associated with elevat...

Background The demonstration of positive signs during neurological examination is a cornerstone of the diagnosis of functional movement disorders, however, the available data supporting the diagnostic value of some of these signs is limited. Objectives To determine the diagnostic value (sensitivity and specificity) of the “whack‐a‐mole” (WAM) and...

Introduction This study aimed to provide a preliminary assessment of objective and subjective neurocognitive functioning in individuals with functional motor symptoms (FMS) and/or functional seizures (FS). We tested the hypotheses that the FMS/FS group would display poorer objective attentional and executive functioning, altered social cognition, a...

Objective Although interoceptive abnormality in patients with functional seizure (FSs) has been demonstrated using explicit tasks, implicit measurements of interoception such as the effect of interoception on perceptual brain processes have not been investigated. It has been shown that perception is normally modulated by interoceptive signals relat...

Introduction: Functional Neurological Disorder (FND) is a common cause of referral to neurology services. FND has been shown to lead to significant healthcare resource use, and is associated with significant disability, comorbidity, and distress. This leads to substantial direct, indirect, and intangible costs to the patient and society. Methods: W...

Background: Differences in affective processing have previously been shown in functional neurological disorder (FND); however, the mechanistic relevance is uncertain. We tested the hypotheses that highly arousing affective stimulation would result in elevated subjective functional neurological symptoms (FNS), and this would be associated with eleva...

Introduction: Previous studies have suggested an association between Impulsive Compulsive Behaviour (ICB) and dyskinesia in Parkinson's disease (PD). However, none of these studies have employed an objective home-based measure of dyskinesia. Objectives: To evaluate in advanced PD the relationship between ICB and dyskinesia, objectively measured...

Subthalamic nucleus (STN) beta-triggered adaptive deep brain stimulation (ADBS) has been shown to provide clinical improvement comparable to conventional continuous DBS (CDBS) with less energy delivered to the brain and less stimulation induced side-effects. However, several questions remain unanswered. First, there is a normal physiological reduct...

Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a disabling long-term condition of unknown cause. The National Institute for Health and Care Excellence (NICE) published a guideline in 2021 that highlighted the seriousness of the condition, but also recommended that graded exercise therapy (GET) should not be used and cognitive–behavi...

Altered interoception may be a pathophysiological mechanism in functional neurological disorder (FND). However, findings have been inconsistent across interoceptive dimensions in FND including functional motor symptoms (FMS) and seizures (FS). Here, individuals with FMS/FS (n = 17) and healthy controls (HC, n = 17) completed measures of interocepti...

Introduction Functional Neurological Disorder (FND) represents genuine involuntary neurological symptoms and signs including seizures, weakness and sensory disturbance which have characteristic clinical features, and represent a problem of voluntary control and perception despite normal basic structure of the nervous system. The historical view of...

Background: Pain in a common symptom in adult-onset idiopathic dystonia (AOID). An appropriate tool to understand this symptom is needed to improve AOID patients’ care. We developed a rating instrument for pain in AOID and validated it in cervical dystonia (CD). Methods: Development and validation of the Pain in Dystonia Scale (PIDS) in three phase...

Introduction: Functional neurological disorder (FND) refers to an involuntary loss of control over and/or aberrant perception of the body. Common presenting symptoms are functional (non-epileptic) seizures, and functional motor disorder, for example, walking difficulties, weakness or tremor. Greater access to effective treatments would lead to red...

Background: A better understanding of pain in adult-onset idiopathic dystonia (AOID) is needed to implement effective therapeutic strategies. Objective: To develop a new rating instrument for pain in AOID and validate it in cervical dystonia (CD). Methods: Development and validation of the Pain in Dystonia Scale (PIDS) comprised three phases....

Background Patients with functional seizures (FS) can experience dissociation (depersonalisation) before their seizures. Depersonalisation reflects disembodiment, which may be related to changes in interoceptive processing. The heartbeat-evoked potential (HEP) is an electroencephalogram (EEG) marker of interoceptive processing. Aim To assess wheth...

Introduction Functional cognitive disorder (FCD) is seen increasingly in clinics commissioned to assess cognitive disorders. Patients report frequent cognitive, especially memory, failures. The diagnosis can be made clinically, and unnecessary investigations avoided. While there is some evidence that psychological treatments can be helpful, they ar...

Functional neurological disorder (FND) can be a difficult diagnosis for patients to understand and for clinicians to explain. The postdiagnostic support that patients with other chronic neurological illnesses normally receive is often not available to patients with FND. Here, we share our experience of how to set up an FND education group, includin...

Functional Neurological Disorder (FND) is common and is often accompanied by multiple comorbid symptoms and conditions. There have been no large-scale studies exploring the change of its clinical manifestations and comorbidities. We used an online survey to assess FND patient characteristics, changes to fatigue, sleep and pain and comorbid symptoms...

Introduction: Functional motor disorder (FMD) is a common cause of disabling neurological symptoms such as weakness and tremor. Physio4FMD is a pragmatic, multicentre single blind randomised controlled trial to evaluate effectiveness and cost effectiveness of specialist physiotherapy for FMD. Like many other studies this trial was affected by the...

Introduction Functional cognitive disorder is seen increasingly in clinics commissioned to assess cognitive disorders. Patients complain of frequent cognitive, especially memory, failures. The diagnosis can be made clinically, and unnecessary investigations avoided. While there is some evidence that psychological treatments can be helpful, they are...

Functional neurological disorder (FND) is one of the commonest reasons that people seek help from a neurologist and is for many people a lifelong cause of disability and impaired quality of life. Although the evidence base regarding FND pathophysiology, treatment and service development has grown substantially in recent years, a persistent ambivale...

Tremor is part of the phenomenological spectrum of dystonia. Treatments available for tremor in dystonia are oral medications (OM), botulinum neurotoxin (BoNT), and brain surgery (deep brain stimulation or thalamotomy). There is limited knowledge regarding the outcome of different treatment options, and evidence is especially scarce for the tremor...

Background: Acute health events, including infections, can trigger the onset of functional neurological disorder (FND). We hypothesised that a proportion of people with long-COVID might be experiencing functional symptoms. Methods: We performed a systematic review of studies containing original data on long-COVID. We reviewed the frequency and c...

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 diagnose...

Background: Subthalamic nucleus (STN) stimulation is an effective treatment for Parkinson's disease and induced local field potential (LFP) changes that have been linked with clinical improvement. STN stimulation has also been used in dystonia although the internal globus pallidus is the standard target where theta power has been suggested as a ph...

Subthalamic nucleus (STN) beta-triggered adaptive deep brain stimulation (ADBS) has been shown to provide clinical improvement comparable to conventional continuous DBS (CDBS) in people with Parkinson's disease (PD) with less energy delivered to the brain and less stimulation induced side-effects. However, several questions remain unanswered. First...

Objectives/Aims Patients with functional seizures (FS) can experience dissociation (depersonalisation) before their seizures. Depersonalisation encompasses a feeling of disembodiment, putatively caused by reduced afferent visceral mapping, that is, changes in interoceptive processing. The heartbeat-evoked potential (HEP) is an electroencephalograph...

Objectives Evaluate patients’ and healthcare professionals’ attitudes towards deceptive and open-label placebo treatments, its perceived effectiveness and current use. Methods A sixteen-item anonymous survey explored attitudes towards deceptive and open-label placebo treatments in clinical practice, its perceived effectiveness and current use. The...

We previously hypothesised that Functional Cognitive Disorder is characterised by heightened subjective mental effort, exhausted attentional reserve and metacognitive failure. To test this hypothesis, we administered a colour-word Stroop task in which attentional demand was varied by task difficulty (congruent versus incongruent cues) and the prese...

Musician's dystonia presents with a persistent deterioration of motor control during musical performance. A predominant hypothesis has been that this is underpinned by maladaptive neural changes to the somatotopic organisation of finger representations within primary somatosensory cortex. Here, we tested this hypothesis by investigating the finger-...

Background Patients with functional seizures (FS) can experience dissociation (depersonalisation) before their seizures. Depersonalisation encompasses a feeling of disembodiment, putatively caused by reduced afferent visceral mapping, that is, changes in interoceptive processing. The heartbeat-evoked potential (HEP) is an electroencephalographic (E...

Functional neurological disorder (FND) is characterized by neurological symptoms that cannot be explained by a structural neurological cause. Among the different aetiological models that have been proposed for FND, of note is the Bayesian predictive coding model, which posits that perception relies on top-down cortical predictions (priors) to infer...

Objective Pathophysiology explanations for functional movement disorders often assume a role for emotional hyperarousal. Pupillometry is a validated method for evaluation of emotional arousal by detecting changes in pupil size in response to emotional stimuli. In a case-control study design, we aimed to study objective and subjective emotional arou...

Interoception, the sense of the internal physiological state of the body, theoretically underpins aspects of self-representation. Experimental studies link feelings of body ownership to interoceptive perception, yet few studies have tested for association between the sense of agency and interoceptive processing. Here, we combined an intentional bin...

Background Symptoms of functional neurological disorder tend to be variable, yet patients often report them being present constantly and of permanently severe intensity. Furthermore, they typically worsen when they are mentioned or during clinical examination. Such phenomena are sometimes interpreted as indicating symptom exaggeration or even fabri...

Objective Our objective was to assess cognitive functioning across multiple cognitive domains using a standardised neuropsychological battery in patients with motor functional neurological disorders (mFND). Methods Thirty patients with clinically established mFND and 30 age-, sex- and education-matched control subjects underwent a thorough neurops...

Background Functional seizures (FS), otherwise known as psychogenic nonepileptic seizures (PNES), are a common symptom presenting to neurology and epilepsy clinics. There is a pressing need for further research to understand the neurobiology of FS to develop mechanistically targeted treatments. Joint hypermobility is an expression of variation in c...

Patients´ and healthcare professionals´ attitudes to deceptive and open-label placebo treatments in clinical practice were evaluated by means of an anonymous survey. The overall attitude to deceptive placebo treatments was favourable amongst the 310 neurological patients and 100 medical patients/healthy participants taking part in the survey. The 9...

Musicians’ dystonia presents with a persistent loss of motor control during musical performance. The pre- dominant hypothesis is that this loss of motor control is underpinned by maladaptive neural changes to the somatotopic organization of finger representations in primary somatosensory cortex. Here, we tested this hypothesis by investigating the...

Recently the similarity of neuropsychiatric profiles across a range of functional syndromes has been high- lighted. This is suggestive of a common underlying mechanism with a theoretical deficit of information processing proposed. In this study, we took the temporal discrimination threshold, as a paradigm that can be used to model sensory processin...

Objective: Functional neurological disorder (FND) causes a high burden of disability and distress. Although it is a common disorder, there is a pressing need for improved access to evidence-based treatments. With difficulties in finding effective treatment, some people with FND may seek alternative means of symptom relief, such as legal and illici...

Persistent symptoms following a minor head injury can cause significant morbidity, yet the underlying mechanisms for this are poorly understood. The shortcomings of the current terminology that refer to non-specific symptom clusters is discussed. This update considers the need for a multi-dimensional approach for the heterogenous mechanisms driving...

Background: Impaired eyeblink conditioning is often cited as evidence for cerebellar dysfunction in isolated dystonia yet the results from individual studies are conflicting and underpowered. Objective: To systematically examine the influence of dystonia, dystonia subtype, and clinical features over eyeblink conditioning within a statistical mod...

While neurologists often devote considerable effort and attention to the process and difficulties of diagnosing patients with functional movement disorder (FMD), less attention is given to the process of deciding how to actually manage individuals after diagnosis has been made. However, this is a critically important aspect of care for people with...

Background Functional motor disorder (FMD) is a common cause of disabling neurological symptoms such as weakness and tremor. We are carrying out a pragmatic, multicentre single blind randomised controlled trial to evaluate effectiveness and cost effectiveness of specialist physiotherapy versus treatment as usual to improve physical functioning at 1...

Background Patients with functional neurological disorders (FND) often present with multiple motor, sensory, psychological and cognitive symptoms. In order to explore the relationship between these common symptoms, we performed a detailed clinical assessment of motor, non-motor symptoms, health-related quality of life (HRQoL) and disability in a la...

Musicians dystonia presents with a persistent deterioration of motor control during musical performance. A predominant hypothesis has been that this is underpinned by maladaptive neural changes to the somatotopic organisation of finger representations within primary somatosensory cortex. Here, we tested this hypothesis by investigating the finger-s...

Background: Complex parkinsonism is the commonest phenotype in late-onset PLA2G6-associated neurodegeneration. Objectives: The aim of this study was to deeply characterize phenogenotypically PLA2G6-related parkinsonism in the largest cohort ever reported. Methods: We report 14 new cases of PLA2G6-related parkinsonism and perform a systematic l...

What if the patients most health professionals actively seek to avoid, people with “medically unexplained” or functional symptoms, were those who hold the key to a more successful, more rewarding and more just system of medical practice for all? I think they do. They force us to answer the question, to paraphrase Wittgenstein: What is left over, if...

Background There is a long-standing research history on the presumed psychological origin of functional movement disorders. Most studies do not address the heterogeneity in functional movement disorders and do not distinguish between risk factors, causes and consequences. We studied the associations between negative affect and objective as well as...

BACKGROUND Parkinson's disease is the second most common neurodegenerative condition and associated with increasing cognitive dysfunction as the disease progresses. However, subtle cognitive deficits can be detected at diagnosis in 42% of individuals, suggesting that damage may already be present. Our aim was to determine clinical and structural di...

Objectives/Aims Previous research into Functional Neurological Disorder (FND) has shown that there are significant barriers in providing multidisciplinary, patient-centred care for these patients, including stigmatising attitudes, poor knowledge about FND, and a lack of structured care pathways. However, there has been no specific research into pat...