How "psychogenic" are psychogenic movement disorders?

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.

We Move or Are We Moved? Unpicking the Origins of Voluntary Movements to Better Understand Semivoluntary Movements

The capacity for voluntary control is seen as essential to human movements; the sense that one intended to move (willing) and those actions were self-generated (self-agency) gives the sense of voluntariness and of being in control. While the mechanisms underlying voluntary movement have long been unclear, recent neuroscientific tools have identified networks of different brain areas, namely, the prefrontal cortex, supplementary motor area, and parietal cortex, that underlie voluntary action. Dysfunction in these brain areas can result in different forms of semivoluntary movement as the borderland of voluntary and involuntary movement where a person may experience a disordered sense of will or agency, and thus the movement is experienced as unexpected and involuntary, for an otherwise voluntary-appearing movement. Tics, functional movement disorders, stereotypies, perseveration, compulsions, utilization behaviors, and motor mannerism have been described elsewhere in the context of psychoses, and are often mistaken for each other. Yet, they reflect an impairment of prefrontal cortices and related circuits rather than simple motor systems, which results in the absence of subjective recognition of the movements, in contrast to other neurological movement disorders where principal abnormalities are located within the basal ganglia and its connections. Therefore, their recognition is clinically important since they are usually associated with neurodevelopmental and neurodegenerative disorders. In this review, we first defined a conceptual framework, from both a neuroanatomical and a neurophysiological point of view, for the generation of voluntary movement. We then examined the evidence linking dysfunctions in different motor pathways to each type of movement disorder. We looked at common semivoluntary movement disorders providing an overview, where possible, of their phenomenology and brain network abnormalities for each condition. We also emphasized important clinical feature similarities and differences to increase recognition of each condition in practice.

In Patients With Functional Movement Disorders, Is Specialized Physical Therapy Effective in Improving Motor Symptoms?: A Critically Appraised Topic

BACKGROUND

Functional movement disorders (FMD, aka psychogenic movement disorders) are very common and frequently chronic and disabling. Despite this, there is a paucity of evidence-based treatment to manage and alleviate these conditions. Specialized physical therapy (PT), involving sequential motor relearning and redirecting attention, has shown promise as a therapeutic intervention for motor symptoms.

METHODS

The objective of this study was to critically assess current evidence regarding specialized PT compared with usual care in improving motor symptoms among patients with FMD. This was addressed through the development of a structured critically appraised topic. This included a clinical scenario with a clinical question, literature search strategy, critical appraisal, results, evidence summary, commentary, and bottom-line conclusions. Participants included consultant and resident neurologists, a medical librarian, and content experts in the fields of physical medicine and rehabilitation, physical and occupational therapy, psychiatry, and psychology.

RESULTS

A randomized controlled feasibility trial was identified and selected for critical appraisal. This study randomized 60 patients with FMD to a 5-day specialized outpatient PT program or to general outpatient PT referral, and measured patient-reported and clinician-measured outcomes. At 6 months, 72% of patients in the intervention group had a good outcome compared with 18% of control group patients. Patients in the specialized outpatient PT program had significantly better outcomes in 3 Short-Form 36 (SF36) domains (d=0.46 to 0.79) and multiple other scales of physical and social function as well as clinician-measured outcomes. The intervention resulted in 0.08 additional quality-adjusted life years in a cost-effective manner.

CONCLUSIONS

Current evidence suggests that in patients with FMD, specialized PT improves motor symptoms in a clinically significant, sustained, and cost-effective manner. This promising intervention warrants further investigation and replication.

Management of Functional Neurological Disorders (FND): Experience from a Swiss FND Clinic

Functional neurological disorder (FND) represent a common disorder with significant socio-economic impact. In this context and alongside recent new neuroscientific insights, FND attracts a growing interest both in clinical practice and academic activities. New international recommendation and expert opinions suggest that therapy of FND should be a tailored multidisciplinary management involving the neurologist, the physiotherapist, and in most cases the psychotherapist/psychiatrist. A first decisive step is the establishment of a definitive diagnosis, based on the presence of clinical positive signs during neurological assessment together with a clear communication and explanation of the diagnosis by the neurologist. A second important step is based on individual therapeutic sessions, involving different disciplines (neurology and psychotherapy or neurology and physiotherapy). Comorbidities, such as pain or fatigue and psychiatric comorbidities (anxiety, depression, dissociation etc.) should be carefully evaluated, as they need an individualized treatment path. New FND clinics have been created worldwide over the last decades to offer such multidisciplinary settings and this article will present the experience of a first Swiss FND clinic created in 2016. The aim is to highlight in the form of a narrative review the current literature supporting the usefulness and importance of FND clinics, by reviewing the latest evidence on multidisciplinary interventions in FND.

What Does Neuroscience Tell Us About the Conversion Model of Functional Neurological Disorders?

A dualistic mind-body understanding of functional neurological disorders (FNDs), also known as conversion disorders, has led to the view that the cause of the symptom should be either psychological (psychogenic) or physical (neurogenic-"organic"). One of the most influential psychological approaches is the Freudian model of conversion, which suggests that FNDs arise from a defense process in which emotional stress is converted into physical symptoms. This conversion theory has been challenged in recent years, accompanied by a shift in emphasis toward neuropathophysiological models of FND and away from historical psychological concepts. In this review, the authors consider the contemporary relevance of the conversion model from the neuroscientific perspective to reconcile the role of both psychological and biological factors in FND. A narrative review of recent neuroscientific findings pertaining to the conversion model of FND, encompassing neuroimaging, cognitive psychology, biological markers, and epigenetic studies, was performed. Research on the role of psychological stressors is discussed. Neurobiological mechanisms of repression of traumatic memories and their translation into physical symptoms are then explored. Finally, the role of physical symptoms as a potential protective defense mechanism against social stressors is considered. The authors argue that the conversion concept is consistent with recent neuroscientific research findings, and the model allows psychological and neurobiological concepts to be reconciled within a single account of FND that begins to resolve the dualistic mind-body dichotomy.

A Case of Psychogenic Myoclonus Responding to a Novel Transcranial Magnetic Stimulation Approach: Rationale, Feasibility, and Possible Neurophysiological Basis

Repetitive transcranial magnetic stimulation (rTMS) can relieve motor symptoms related to psychogenic movement disorders (PMDs), but the subtending neurophysiological basis is unclear. We report on a 50-year-old woman with a diagnosis of psychogenic myoclonus in the right lower limb, who was treated with a daily session (in the late morning/early afternoon) of 1 Hz rTMS over the left premotor cortex (PMC), five times a week for 6 weeks. Clinical data and EEG at rest were collected before and immediately and 2-month after the rTMS protocol completion. The patient reported a significant reduction of involuntary movement frequency and intensity and the related disability burden up to the follow-up. In parallel, any abnormality in terms of source current density within and connectivity between the frontal and parietal areas was reset. The short follow–up period, the lack of extensive neurophysiological measures, and the lack of control treatment represent the main limitation of the study. However, low-frequency rTMS over PMC seems a safe and promising approach for the management of psychogenic myoclonus owing to the combination of cortical neuromodulation and non-specific mechanisms suggesting cognitive-behavioral effects.

Adult-Onset Gilles de la Tourette Syndrome: Psychogenic or Organic? The Challenge of Abnormal Neurophysiological Findings

Gilles de la Tourette syndrome (GTS) is characterized by multiple motor and vocal tics. Adult-onset cases are rare and may be due to "reactivation" of childhood tics, or secondary to psychiatric or genetic diseases, or due to central nervous system lesions of different etiologies. Late-onset psychogenic motor/vocal tics resembling GTS have been described. Neurophysiology may serve to differentiate organic from functional GTS. Altered blink reflex pre-pulse inhibition (BR-PPI), blink reflex excitability recovery (BR-ERC), and short-interval intracortical inhibition (SICI) have been described in GTS. We report a 48-years-old male, who developed numerous motor/vocal tics 2 months after sustaining non-commotional craniofacial trauma in a car accident. Both his father and brother had died earlier in car crashes. He presented with blepharospasm-like forced lid closure, forceful lip pursing, noisy suction movements, and deep moaning sounds, occurring in variable combinations, without warning symptoms or internal "urge." Tics showed low distractibility and these increased with attention. Standard magnetic resonance imaging, electroencephalography, and evoked potentials were unremarkable. Neuropsychology diagnosed moderately impaired intellect, attention, and executive functions. Psychiatric assessment revealed somatization disorder and generalized anxiety. BR-PPI was unremarkable, while BR-ERC was enhanced, even showing facilitation at short intervals. SICI was markedly reduced at 1 and 3 ms and intracortical facilitation (ICF) was enhanced at 10 ms. The patient fulfilled Fahn and Williams' diagnostic criteria for a psychogenic movement disorder. Neurophysiology, however, documented hyperexcitability of motor cortex and brainstem. We suggest that-similar to what has been reported in psychogenic dystonia-a pre-existing predisposition may have led to the functional hyperkinetic disorder in response to severe psychic stress.

Functional (psychogenic) gait disorder: diagnosis and management

Functional (psychogenic) gait disorders are a common presentation of functional neurological disorder - one of the commonest diagnoses made in neurology practice. People with functional neurological disorder are as disabled and experience as poor a quality of life as patients with multiple sclerosis and Parkinson's disease. People with functional neurological disorder, including gait disorder, are often perceived as being challenging to diagnose and manage, and as a result attitudes of health professionals towards them are often negative. However, a rapid positive diagnosis of functional gait disorder can often be made, and with a specific approach to diagnostic explanation and treatment, many patients experience improvement in symptoms and disability, with such improvements sustained in the long term. Here I review current evidence regarding the diagnosis, pathophysiology and management of functional gait disturbance with an emphasis on how to make a positive diagnosis and how to select the most appropriate treatment approach. Rehabilitative treatments, with an emphasis on specific physiotherapy interventions, have increasing evidence for benefit, particularly if carried out following a comprehensive explanation of the diagnosis.

Differences in psychopathology and behavioral characteristics of patients affected by conversion motor disorder and organic dystonia

PURPOSE

Typically, the diagnosis of conversion motor disorder (CMD) is achieved by the exclusion of a wide range of organic illnesses rather than by applying positive criteria. New diagnostic criteria are highly needed in this scenario. The main aim of this study was to explore the use of behavioral features as an inclusion criterion for CMD, taking into account the relationship of the patients with physicians, and comparing the results with those from patients affected by organic dystonia (OD).

PATIENTS AND METHODS

Patients from the outpatient Movement Disorder Service were assigned to either the CMD or the OD group based on Fahn and Williams criteria. Differences in sociodemographics, disease history, psychopathology, and degree of satisfaction about care received were assessed. Patient-neurologist agreement about the etiological nature of the disorder was also assessed using the k-statistic. A logistic regression analysis estimated the discordance status as a predictor to case/control status.

RESULTS

In this study, 31 CMD and 31 OD patients were included. CMD patients showed a longer illness life span, involvement of more body regions, higher comorbidity with anxiety, depression, and borderline personality disorder, as well as higher negative opinions about physicians' delivering of proper care. Contrary to our expectations, CMD disagreement with neurologists about the etiological nature of the disorder was not statistically significant. Additional analysis showed that having at least one personality disorder was statistically associated with the discordance status.

CONCLUSION

This study suggests that CMD patients show higher conflicting behavior toward physicians. Contrary to our expectations, they show awareness of their psychological needs, suggesting a possible lack of recognition of psychological distress in the neurological setting.

Personality disorders and somatization in functional and organic movement disorders

Psychiatric disturbances and somatizations are both criteria which support the diagnosis of functional movement disorders. It is unclear, however, whether these factors are helpful in differentiating functional and organic movement disorders. To address this issue, the Structured Clinical Interview for DSM-IV Axis I and II psychiatric disorders, the State-Trait Anxiety Inventory, the Beck Depression Inventory and the "somatization section" of the Dissociative Disorders Interview Schedule were administered to 31 functional movement disorder patients diagnosed, according to Fahn and Williams criteria and 31 sex- and age-matched control outpatients, with adult-onset dystonia. Axis I psychiatric diagnoses were similarly frequent in patients with functional and organic movement disorders. There was a trend to a greater frequency of personality disorders overall; when looking at individual personality disorders, there was no significant between-group difference. Depression and anxiety scores and mean number of somatizations per patient were also greater in the functional group. The number of somatic complaints significantly correlated with depression and anxiety scores. However, the presence of these disturbances in a proportion of patients with organic dystonia indicates that personality disorders and somatizations do not aid in distinguishing functional and organic movement disorders.

Impact of Transcranial Magnetic Stimulation on Functional Movement Disorders: Cortical Modulation or a Behavioral Effect?

Introduction

Recent studies suggest that repeated transcranial magnetic stimulation (TMS) improves functional movement disorders (FMDs), but the underlying mechanisms are unclear. The objective was to determine whether the beneficial action of TMS in patients with FMDs is due to cortical neuromodulation or rather to a cognitive-behavioral effect.

Method

Consecutive patients with FMDs underwent repeated low-frequency (0.25 Hz) magnetic stimulation over the cortex contralateral to the symptoms or over the spinal roots [root magnetic stimulation (RMS)] homolateral to the symptoms. The patients were randomized into two groups: group 1 received RMS on day 1 and TMS on day 2, while group 2 received the same treatments in reverse order. We blindly assessed the severity of movement disorders before and after each stimulation session.

Results

We studied 33 patients with FMDs (dystonia, tremor, myoclonus, Parkinsonism, or stereotypies). The median symptom duration was 2.9 years. The magnetic stimulation sessions led to a significant improvement (>50%) in 22 patients (66%). We found no difference between TMS and RMS.

Conclusion

We suggest that the therapeutic benefit of TMS in patients with FMDs is due more to a cognitive-behavioral effect than to cortical neuromodulation.

Somatoform dissociation and posttraumatic stress syndrome - two sides of the same medal? A comparison of symptom profiles, trauma history and altered affect regulation between patients with functional neurological symptoms and patients with PTSD

BACKGROUND

History of traumatic experience is common in dissociative disorder (DD), and similarity of symptoms and characteristics between DD and posttraumatic stress disorder (PTSD) encouraged to consider DD as trauma-related disorder. However, conceptualization of DD as a trauma-related syndrome would critically affect diagnosis and treatment strategies. The present study addressed overlap and disparity of DD and PTSD by directly comparing correspondence of symptoms, adverse/traumatic experience, and altered affect regulation between patients diagnosed with dissociative disorder (characterized by negative functional neurological symptoms) and patients diagnosed with PTSD.

METHODS

Somatoform and psychoform dissociation, symptoms of posttraumatic stress, general childhood adversities and lifetime traumata, and alexithymia as index of altered affect regulation were screened with standardized questionnaires and semi-structured interviews in 60 patients with DD (ICD-codes F44.4, F44.6, F44.7), 39 patients with PTSD (ICD-code F43.1), and 40 healthy comparison participants (HC).

RESULTS

DD and PTSD patients scored higher than HC on somatoform and psychoform dissociative symptom scales and alexithymia, and reported more childhood adversities and higher trauma load. PTSD patients reported higher symptom severity and more traumata than DD patients. Those 20 DD patients who met criteria of co-occuring PTSD did not differ from PTSD patients in the amount of reported symptoms of somatoform dissociation, physical and emotional childhood adversities and lifetime traumata, while emotional neglect/abuse in childhood distinguished DD patients with and without co-occuring PTSD (DD patients with co-occuring PTSD reporting more emotional maltreatment).

CONCLUSION

The pattern of distinctive somatoform and psychoform dissociative symptom severity, type of childhood and lifetime traumata, and amount of alexithymia suggests that DD and PTSD are distinctive syndromes and, therefore, challenges the conceptualization of DD as trauma-related disorder. Together with the detected close correspondence of symptom and experience profiles in DD patients with co-occuring PTSD and PTSD patients, these findings suggest that adverse/traumatic experience may intensify dissociative symptoms, but are not a necessary condition in the generation of functional neurological symptoms. Still, diagnosis and treatment of DD need to consider this impact of traumata and post-traumatic stress symptoms.

A preliminary investigation of sleep quality in functional neurological disorders: Poor sleep appears common, and is associated with functional impairment

PURPOSE

Functional neurological disorders (FND) are disabling conditions for which there are few empirically-supported treatments. Disturbed sleep appears to be part of the FND context; however, the clinical importance of sleep disturbance (extent, characteristics and impact) remains largely unknown. We described sleep quality in two samples, and investigated the relationship between sleep and FND-related functional impairment.

METHODS

We included a sample recruited online via patient charities (N=205) and a consecutive clinical sample (N=20). Participants completed validated measures of sleep quality and sleep characteristics (e.g. total sleep time, sleep efficiency), mood, and FND-related functional impairment.

RESULTS

Poor sleep was common in both samples (89% in the clinical range), which was characterised by low sleep efficiency (M=65.40%) and low total sleep time (M=6.05h). In regression analysis, sleep quality was negatively associated with FND-related functional impairment, accounting for 16% of the variance and remaining significant after the introduction of mood variables.

CONCLUSIONS

These preliminary analyses suggest that subjective sleep disturbance (low efficiency, short sleep) is common in FND. Sleep quality was negatively associated with the functional impairment attributed to FND, independent of depression. Therefore, sleep disturbance may be a clinically important feature of FND.

Using Acceptance and Commitment Therapy to Improve Outcomes in Functional Movement Disorders: A Case Study

Although there are many theories of functional movement disorders (FMD), the causes and prognosis remain unclear, and there are no treatments with high-quality empirical support. Acceptance and commitment therapy (ACT) is an acceptance-based behavior therapy which, via altering a process called psychological flexibility, aims to support behaviors that are consistent with a person’s overarching values—even in difficult, uncertain, or immutable contexts. It may, therefore, have pragmatic benefits in the context of FMD. We outline the theoretical basis for ACT and detail a case study of a brief (six session) intervention for increasing personally meaningful activity with FMD. The participant was in her early 20s and had been diagnosed with functional propriospinal myoclonus. ACT techniques including relational framing, defusion, and mindfulness exercises were used to increase psychological flexibility, with the goal of enabling effective functioning within the difficult context created by FMD. Following treatment, the participant showed a reliable change/clinical recovery in psychological flexibility (Acceptance and Action Questionnaire II [AAQ-II]), FMD symptom interference (Work and Social Adjustment Scale [WSAS]; primary outcome), and mood (Clinical Outcomes in Routine Evaluation 10-item scale [CORE-10]; secondary outcome). This case study demonstrates an approach that focuses first on improving functioning with FMD, as opposed to eliminating or controlling symptoms.

What should we say to patients with unexplained neurological symptoms? How explanation affects offence

OBJECTIVES

Unexplained neurological symptoms (UNS) are common presentations in neurology but there is no consensus as to what they should be called. This is important, as patient acceptance is a predictor of outcome and there is evidence that patients are unhappy with the terms used. Patient understanding of these terms may be limited, however, and, once explained, the terms may seem more or less offensive. We sought to elicit patients' views of 7 frequently used terms for UNS, and whether these changed once definitions were provided.

METHODS

185 participants were recruited from a medical outpatients' waiting area. They were given questionnaires outlining a hypothetical situation of leg weakness, with 7 possible labels. Participants were asked whether they endorsed 4 connotations for each label and the "number needed to offend" (NNO) calculated, before and after definitions were given.

RESULTS

It was found that "functional" was significantly less offensive than other terms used (NNO 17, compared with "Conversion Disorder" NNO 5, p<0.001). Reported understanding of the terms was generally low, however, and many terms became significantly more offensive once definitions were provided. Participants' reported understanding had a significant effect, with low understanding causing terms to be viewed as more offensive after explanation.

CONCLUSION

Much of the 'offence' in UNS lies not in the terminology but in the meaning those terms carry. This study replicated previous findings that "functional" was less offensive than other terms, even after explanation, but in common with most terms this was partly due to patients' limited understanding of its meaning.

Life events and escape in conversion disorder

BACKGROUND

Psychological models of conversion disorder (CD) traditionally assume that psychosocial stressors are identifiable around symptom onset. In the face of limited supportive evidence such models are being challenged.

METHOD

Forty-three motor CD patients, 28 depression patients and 28 healthy controls were assessed using the Life Events and Difficulties Schedule in the year before symptom onset. A novel 'escape' rating for events was developed to test the Freudian theory that physical symptoms of CD could provide escape from stressors, a form of 'secondary gain'.

RESULTS

CD patients had significantly more severe life events and 'escape' events than controls. In the month before symptom onset at least one severe event was identified in 56% of CD patients - significantly more than 21% of depression patients [odds ratio (OR) 4.63, 95% confidence interval (CI) 1.56-13.70] and healthy controls (OR 5.81, 95% CI 1.86-18.2). In the same time period 53% of CD patients had at least one 'high escape' event - again significantly higher than 14% in depression patients (OR 6.90, 95% CI 2.05-23.6) and 0% in healthy controls. Previous sexual abuse was more commonly reported in CD than controls, and in one third of female patients was contextually relevant to life events at symptom onset. The majority (88%) of life events of potential aetiological relevance were not identified by routine clinical assessments. Nine per cent of CD patients had no identifiable severe life events.

CONCLUSIONS

Evidence was found supporting the psychological model of CD, the Freudian notion of escape and the potential aetiological relevance of childhood traumas in some patients. Uncovering stressors of potential aetiological relevance requires thorough psychosocial evaluation.

Imaging studies of functional neurologic disorders

Brain imaging techniques provide unprecedented opportunities to study the neural mechanisms underlying functional neurologic disorder (FND, or conversion disorder), which have long remained a mystery and clinical challenge for physicians, as they arise with no apparent underlying organic disease. One of the first questions addressed by imaging studies concerned whether motor conversion deficits (e.g., hysteric paralysis) represent a form of (perhaps unconscious) simulation, a mere absence of voluntary movement, or more specific disturbances in motor control (such as abnormal inhibition). Converging evidence from several studies using different techniques and paradigms has now demonstrated distinctive brain activation patterns associated with functional deficits, unlike those seen in actors simulating similar deficits. Thus, patients with motor FND show consistent hypoactivation of both cortical and subcortical motor pathways, with frequent increases in other brain areas within the limbic system, but no recruitment of prefrontal regions usually associated with voluntary motor inhibition. Other studies point to a dysfunction in sensorimotor integration and agency - related to parietal dysfunction - and abnormal motor planning related to supplementary motor area and prefrontal areas. These findings not only suggest that functional symptoms reflect a genuine brain dysfunction, but also give new insights into how they are produced. However, fewer studies attempted to understand why these symptoms are produced and linked to potential psychologic or emotional risk/triggering factors. Results from such studies point towards abnormal limbic regulation with heightened emotional arousal and amygdalar activity, potentially related to engagement of defense systems and stereotyped motor behaviors, mediated by medial prefrontal cortex and subcortical structures, including the periaqueductal gray area and basal ganglia. In addition, across different symptom domains, several studies reported abnormal recruitment of ventromedial prefrontal cortex (vmPFC), a region known to regulate emotion appraisal, memory retrieval, and self-reflective representations. The vmPFC might provide important modulatory signals to both cortical and subcortical sensorimotor, visual, and even memory circuits, promoting maladaptive self-protective behaviors based on personal affective appraisals of particular events. A better understanding of such a role of vmPFC in FND may help link how and why these symptoms are produced. Further research is also needed to determine brain activation patterns associated with FND across different types of deficits and different evolution stages (e.g., acute vs. chronic vs. recovered).

Uncovering the etiology of conversion disorder: insights from functional neuroimaging

Conversion disorder (CD) is a syndrome of neurological symptoms arising without organic cause, arguably in response to emotional stress, but the exact neural substrates of these symptoms and the underlying mechanisms remain poorly understood with the hunt for a biological basis afoot for centuries. In the past 15 years, novel insights have been gained with the advent of functional neuroimaging studies in patients suffering from CDs in both motor and nonmotor domains. This review summarizes recent functional neuroimaging studies including functional magnetic resonance imaging (fMRI), single photon emission computerized tomography (SPECT), and positron emission tomography (PET) to see whether they bring us closer to understanding the etiology of CD. Convergent functional neuroimaging findings suggest alterations in brain circuits that could point to different mechanisms for manifesting functional neurological symptoms, in contrast with feigning or healthy controls. Abnormalities in emotion processing and in emotion-motor processing suggest a diathesis, while differential reactions to certain stressors implicate a specific response to trauma. No comprehensive theory emerges from these clues, and all results remain preliminary, but functional neuroimaging has at least given grounds for hope that a model for CD may soon be found.

An update on functional (psychogenic) tremor

Functional tremor accounts for at least 50% of patients with functional movement disorders. The diagnostic work-up of these patients can be challenging. It is a multistep process based on patients’ history and clinical criteria finally providing a ‘positive’ diagnosis. Variability of the tremor over the disease course and during clinical examination is characteristic. Patients often show increased attention toward the tremulous body part and distractability of the tremor once attention is drawn away. Sometimes distractability becomes obvious during history taking or neurological examination, in others certain distraction tasks are needed. If uncertainty remains, ancillary investigations such as electrophysiological tests may be helpful. Recent studies suggested that a loss of sense of control of ones actions may help to explain why patients with functional tremor report that they do not experience the abnormal movement as voluntary. Treatment has to be placed in a multidisciplinary team involving neurologists, psychiatrists, physiotherapists and psychologists.

Emotion-motion interactions in conversion disorder: an FMRI study

Objectives

To evaluate the neural correlates of implicit processing of negative emotions in motor conversion disorder (CD) patients.

Methods

An event related fMRI task was completed by 12 motor CD patients and 14 matched healthy controls using standardised stimuli of faces with fearful and sad emotional expressions in comparison to faces with neutral expressions. Temporal changes in the sensitivity to stimuli were also modelled and tested in the two groups.

Results

We found increased amygdala activation to negative emotions in CD compared to healthy controls in region of interest analyses, which persisted over time consistent with previous findings using emotional paradigms. Furthermore during whole brain analyses we found significantly increased activation in CD patients in areas involved in the ‘freeze response’ to fear (periaqueductal grey matter), and areas involved in self-awareness and motor control (cingulate gyrus and supplementary motor area).

Conclusions

In contrast to healthy controls, CD patients exhibited increased response amplitude to fearful stimuli over time, suggesting abnormal emotional regulation (failure of habituation / sensitization). Patients with CD also activated midbrain and frontal structures that could reflect an abnormal behavioral-motor response to negative including threatening stimuli. This suggests a mechanism linking emotions to motor dysfunction in CD.

Increased variability in spiral drawing in patients with functional (psychogenic) tremor

Increased variability is a characteristic clinical and physiologic feature of functional (psychogenic) tremor. In this study, we use computerized spiral analysis to show that the variability of a motor task is a quantifiable characteristic of functional tremor. We compare functional tremor patients to phenomenologically similar dystonic tremor patients and to normal controls. We used the spiral severity score, a measure that does not incorporate spiral tightness, as a marker of spiral drawing performance, and inter-spiral tightness variability (based on the 25-75%(ile) range in tightness across ten spirals) to evaluate the effects of functional tremor on drawing spirals. The spirals of 74 participants: 22 functional tremor, 21 dystonic tremor, and 31 normal controls were analyzed. Spiral severity was higher in both tremor groups compared to controls, but did not differentiate them. Inter-spiral variability, however, was higher in the functional tremor group compared to both other groups. Thus, spiral analysis captures variability of a motor task and may be used as an objective test for functional tremor. The effect of functional tremor in other motor tasks should be investigated.

Disease modeling in functional movement disorders

INTRODUCTION

The mechanisms underlying functional movement disorders are poorly known. We examined whether experience of a movement disorder model in the family and/or the friendships contributes to functional movement disorders.

METHODS

The hypothesis was tested in a case-control study including 33 patients with functional movement disorders and 66 age- and sex-matched patients with organic movement disorders and using a conditional logistic multivariable analysis (adjusted by age, education, disease duration, chronic medical illnesses and clinical phenotype).

RESULTS

Case-control comparison yielded a significant association between functional movement disorders and exposure to phenotypically congruent movement disorder models (Odds ratio, 3.9, p = 0.01), mainly when disease model came from friendships (Odds ratio, 5.9, p = 0.04). By contrast no association was found between functional movement disorders and phenotypically different neurological or non neurological disease models. A significant inverse relationship between exposure to a phenotypically concordant movement disorder model and age of disease onset was also observed.

CONCLUSIONS

These findings support disease modeling as a factor contributing to the phenomenology of functional movement disorders.

Tactile and proprioceptive temporal discrimination are impaired in functional tremor

Background and Methods

In order to obtain further information on the pathophysiology of functional tremor, we assessed tactile discrimination threshold and proprioceptive temporal discrimination motor threshold values in 11 patients with functional tremor, 11 age- and sex-matched patients with essential tremor and 13 healthy controls.

Results

Tactile discrimination threshold in both the right and left side was significantly higher in patients with functional tremor than in the other groups. Proprioceptive temporal discrimination threshold for both right and left side was significantly higher in patients with functional and essential tremor than in healthy controls. No significant correlation between discrimination thresholds and duration or severity of tremor was found.

Conclusions

Temporal processing of tactile and proprioceptive stimuli is impaired in patients with functional tremor. The mechanisms underlying this impaired somatosensory processing and possible ways to apply these findings clinically merit further research.

Pathological mechanism of musculoskeletal manifestations associated with CRPS type II: an animal study

Patients with complex regional pain syndrome (CRPS) often complain of abnormal sensations beyond the affected body part, but causes of this spread of musculoskeletal manifestations into contiguous areas remain unclear. In addition, immobilization can predispose to the development of CRPS. We examined functional, biochemical, and histological alterations in affected parts, including contiguous zones, using an animal model. Ten-week-old male Wistar rats were assigned to 5 groups: a normal group receiving no treatment, a sham operation group with surgical exploration, an immobilization group with surgical exploration plus internal knee joint immobilization, a surgical neuropathy group prepared by spinal nerve ligation (SNL) of the left L5 nerve root, and a surgical neuropathy+immobilization group with simultaneous SNL and knee joint immobilization. Mechanical allodynia and knee contracture were compared between groups, and tissues were harvested for histological assessments and gene and protein expression analyses. Neither surgical procedures nor immobilization induced detectable mechanical sensitivity. However, the addition of nerve injury resulted in detectable mechanical allodynia, and immobilization not only accelerated hyperalgesia, but also resulted in muscle fibrosis. Nerve growth factor (NGF) and other mediators of neurogenic inflammation were highly expressed not only in denervated muscles, but also in innervated muscles in contiguous areas, suggesting the spread of NGF production beyond the myotome of the injured nerve. Transforming growth factor β was involved in the development of contracture in CRPS. These findings imply that neuroinflammatory components play major roles in the progression and dispersion of both sensory pathologies and pathologies that are exacerbated by immobilization.

The Phenomenology of Functional (Psychogenic) Dystonia

From the very first descriptions of dystonia, there has been a lack of agreement on the differentiation of organic from functional (psychogenic) dystonia. This lack of agreement has had a significant effect on patients over the years, most particularly in the lack of access to appropriate management, whether for those with organic dystonia diagnosed as having a functional cause or vice versa. However, clinico-genetic advances have led to greater certainty about the phenomenology of organic dystonia and therefore recognition of atypical forms. The diagnosis of functional dystonia rests on recognition of its phenomenology and should not be, as far as possible, a diagnosis of exclusion. Here, we present an overview of the phenomenology of functional dystonia, concentrating on the three main phenotypic presentations: functional cranial dystonia; functional fixed dystonia; and functional paroxysmal dystonia. We hope that this review of phenomenology will aid in the positive diagnosis of functional dystonia and, through this, will lead to more rapid access to appropriate management.

Neurobiology of functional (psychogenic) movement disorders

Purpose of review

This review explores recent developments in understanding the neurobiological mechanism of functional (psychogenic) movement disorders (FMDs). This is particularly relevant given the resurgence of academic and clinical interest in patients with functional neurological symptoms and the clear shift in diagnostic and treatment approaches away from a pure psychological model of functional symptoms.

Recent findings

Recent research findings implicate three key processes in the neurobiology of FMD (and by extension other functional neurological symptoms): abnormal attentional focus, abnormal beliefs and expectations, and abnormalities in sense of agency. These three processes have been combined in recent neurobiological models of FMD in which abnormal predictions related to movement are triggered by self-focused attention, and the resulting movement is generated without the normal sense of agency that accompanies voluntary movement.

Summary

New understanding of the neurobiology of FMD forms an important part of reappraising the way that patients with FMD (and other functional disorders) are characterized and treated. It also provides a testable framework for further exploring the pathophysiology of these common causes of ill health.

The value of 'positive' clinical signs for weakness, sensory and gait disorders in conversion disorder: a systematic and narrative review

Experts in the field of conversion disorder have suggested for the upcoming DSM-V edition to put less weight on the associated psychological factors and to emphasise the role of clinical findings. Indeed, a critical step in reaching a diagnosis of conversion disorder is careful bedside neurological examination, aimed at excluding organic signs and identifying 'positive' signs suggestive of a functional disorder. These positive signs are well known to all trained neurologists but their validity is still not established. The aim of this study is to provide current evidence regarding their sensitivity and specificity. We conducted a systematic search on motor, sensory and gait functional signs in Embase, Medline, PsycINfo from 1965 to June 2012. Studies in English, German or French reporting objective data on more than 10 participants in a controlled design were included in a systematic review. Other relevant signs are discussed in a narrative review. Eleven controlled studies (out of 147 eligible articles) describing 14 signs (7 motor, 5 sensory, 2 gait) reported low sensitivity of 8-100% but high specificity of 92-100%. Studies were evidence class III, only two had a blinded design and none reported on inter-rater reliability of the signs. Clinical signs for functional neurological symptoms are numerous but only 14 have been validated; overall they have low sensitivity but high specificity and their use should thus be recommended, especially with the introduction of the new DSM-V criteria.

Treatment of functional (psychogenic) movement disorders

Functional (psychogenic) movement disorders are a common source of disability and distress. Despite this, little systematic evidence is available to guide treatment decisions. This situation is likely to have been influenced by the "no man's land" that such patients occupy between neurologists and psychiatrists, often with neither side feeling a clear responsibility or ability to direct management. The aim of this narrative review is to provide an overview of the current state of the evidence regarding management of functional movement disorders. This reveals that there is some evidence to support the use of specific forms of cognitive behavioral therapy and physiotherapy. Such treatments may be facilitated in selected patients with the use of antidepressant medication, and may be more effective for those with severe symptoms when given as part of inpatient multidisciplinary rehabilitation. Other treatments, for example hypnosis and transcranial magnetic stimulation, are of interest, but further evidence is required regarding mechanism of effect and long-term benefit. Though prognosis is poor in general, improvement in symptoms is possible in patients with functional movement disorders, and there is a clear challenge to clinicians and therapists involved in their care to conduct and advocate for high-quality clinical trials.

Fixed dystonia of the left hand in a violinist: a rare functional disorder

BACKGROUND

Fixed dystonia leads to an immobile abnormal posturing of the affected limb. There is an ongoing debate whether this condition is psychogenic in origin.

CASE REPORT

We present a 21-year-old violinist with fixed dystonia after an acute overuse injury with a transient cyanosis but no signs for psychological trauma. After Incobotulinumtoxin injection, symptoms subsided within 8 hours.

DISCUSSION

Our case corroborates the notion that fixed dystonias after minor injuries are functional disorders. It underlines the necessity of a biopsychosocial approach to functional disorders, considering the possibility of an overlay between organic and non-organic disorders.

Neuroinflammation, neuroautoimmunity, and the co-morbidities of complex regional pain syndrome

Complex Regional Pain Syndrome (CRPS) is associated with non-dermatomal patterns of pain, unusual movement disorders, and somatovisceral dysfunctions. These symptoms are viewed by some neurologists and psychiatrists as being psychogenic in origin. Recent evidence, however, suggests that an autoimmune attack on self-antigens found in the peripheral and central nervous system may underlie a number of CRPS symptoms. From both animal and human studies, evidence is accumulating that neuroinflammation can spread, either anterograde or retrograde, via axonal projections in the CNS, thereby establishing neuroinflammatory tracks and secondary neuroinflammatory foci within the neuraxis. These findings suggest that neuroinflammatory lesions, as well as their associated functional consequences, should be evaluated during the differential diagnosis of non-dermatomal pain presentations, atypical movement disorders, as well as other "medically unexplained symptoms", which are often attributed to psychogenic illness.

Neurology of volition

Neurological disorders of volition may be characterized by deficits in willing and/or agency. When we move our bodies through space, it is the sense that we intended to move (willing) and that our actions were a consequence of this intention (self-agency) that gives us the sense of voluntariness and a general feeling of being "in control." While it is possible to have movements that share executive machinery ordinarily used for voluntary movement but lack a sense of voluntariness, such as psychogenic movement disorders, it is also possible to claim volition for presumed involuntary movements (early chorea) or even when no movement is produced (anosognosia). The study of such patients should enlighten traditional models of how the percepts of volition are generated in the brain with regard to movement. We discuss volition and its components as multi-leveled processes with feedforward and feedback information flow, and dependence on prior expectations as well as external and internal cues.

Functional (psychogenic) movement disorders

PURPOSE OF REVIEW

This review provides an overview of recent developments in diagnosis, pathophysiology, neuroimaging and management of functional (psychogenic) movement disorders (FMD).

RECENT FINDINGS

There has been increasing interest to study the underlying pathophysiology of FMD, which has resulted in a broadened disease model, taking neurobiologic and psychosocial factors equally into account. In this context, the term 'psychogenic' has been replaced by 'functional' movement disorders by many authors in the field to express the changing focus toward a multifactorial disease model. The need for establishing a positive diagnosis of FMD as opposed to providing a diagnosis of exclusion is increasingly recognized and reflected by the introduction of 'laboratory-supported' diagnostic criteria of FMD. Important advances have been made through behavioral, electrophysiological and neuroimaging studies, although the fundamental cause of FMD remains poorly understood. Of particular interest have been several reports on abnormal sensorimotor features and cortical inhibition in both organic and functional dystonia, highlighting possible shared traits of both conditions. In terms of treatment, recent studies have reported benefit from both psychiatric and physical therapy-based interventions.

SUMMARY

Increasing efforts have been made toward better understanding of FMD, and the disease model has been broadened to include neurobiologic and psychosocial factors. Laboratory-based diagnostic criteria have been established for many FMD to support the clinical diagnosis. To determine the most effective management strategies for FMD, a closer collaboration between neurologists and psychiatrists and intensified research efforts with prospective treatment trials are needed.

Functional (psychogenic) movement disorders: merging mind and brain

Functional (psychogenic) movement disorders (FMD) are part of the wide spectrum of functional neurological disorders, which together account for over 16% of patients referred to neurology clinics. FMD have been described as a "crisis for neurology" and cause major challenges in terms of diagnosis and treatment. As with other functional disorders, a key issue is the absence of pathophysiological understanding. There has been an influential historical emphasis on causation by emotional trauma, which is not supported by epidemiological studies. The similarity between physical signs in functional disorders and those that occur in feigned illness has also raised important challenges for pathophysiological understanding and has challenged health professionals' attitudes toward patients with these disorders. However, physical signs and selected investigations can help clinicians to reach a positive diagnosis, and modern pathophysiological research is showing an appreciation of the importance of both physical and psychological factors in FMD.

Diagnostic agreement in patients with psychogenic movement disorders

BACKGROUND

The reliability and applicability of published diagnostic criteria for psychogenic movement disorders (PMDs) have never been examined.

METHODS

Eight movement disorder and six general neurologists rated 14 patients diagnosed with PMD and 14 patients diagnosed with organic movement disorders. Raters provided a dichotomous judgment (i.e., psychogenic or organic) upon review of video-based movement phenomenology and a category of diagnostic certainty based on the Fahn-Williams and Shill-Gerber criteria after accessing standardized clinical information. We measured interobserver agreement on the diagnosis and clinical certainty judgment of PMD.

RESULTS

In both groups of raters, agreements were "fair" on the video-based dichotomous judgment, but improved to "substantial" after access to standardized clinical information. "Slight" to "poor" agreement was reached for the "probable" and "possible" categories of diagnostic certainty corresponding to both diagnostic criteria.

CONCLUSIONS

Diagnosis according to clinical available criteria for PMD yields poor diagnostic agreement.