Psychogenic movement disorders: aetiology, phenomenology, neuroanatomical correlates and therapeutic approaches

Healthcare employment as a risk factor for functional neurological disorder: A case-control study

BACKGROUND AND PURPOSE

Female gender, younger age and stressful life events are known predisposing factors for functional neurological disorders (FNDs). Employment in a healthcare profession has also been suggested to be a predisposing factor. We set out to conduct a large-scale case-control study to estimate the rate employment in a healthcare profession among people with FND.

METHODS

We included 200 consecutive patients with a confirmed diagnosis of FND, referred to our clinic at University Hospital Bern Switzerland between October 1, 2016, and August 1, 2019. In addition, we included a control group of 200 patients with a confirmed neurological disorder, matched for age and gender, seen during the same period. The primary endpoint was to compare the prevalence of healthcare professionals between the groups. We also describe the clinical manifestations and concomitant psychiatric diagnoses in the FND cohort.

RESULTS

Female gender was predominant (70%), and the participants' mean age was 37 years. The proportion of healthcare professionals in the FND patients was 18% (33/186), which was significantly higher than in the control group, in which it was 10.6% (17/189; p = 0.019, 95% confidence interval odds ratio 1.168-4.074). Most healthcare professionals in both cohorts were nurses (21/33 among FND patients, 10/17 among controls). Among FND patients, 140 (70%) had motor symptoms and 65 (32.5%) had a concomitant psychiatric diagnosis.

CONCLUSION

This case-control study confirmed a higher rate of employment in healthcare professions in patients with FND, suggesting two potential mechanisms of FND: exposure to models/specific knowledge about neurological symptoms or stress-related professional factors. This warrants further studies on underlying mechanisms and prevention.

The neural basis of somatosensory temporal discrimination threshold as a paradigm for time processing in the sub-second range: An updated review

BACKGROUND AND OBJECTIVE

The temporal aspect of somesthesia is a feature of any somatosensory process and a pre-requisite for the elaboration of proper behavior. Time processing in the milliseconds range is crucial for most of behaviors in everyday life. The somatosensory temporal discrimination threshold (STDT) is the ability to perceive two successive stimuli as separate in time, and deals with time processing in this temporal range. Herein, we focus on the physiology of STDT, on a background of the anatomophysiology of somesthesia and the neurobiological substrates of timing.

METHODS

A review of the literature through PubMed & Cochrane databases until March 2023 was performed with inclusion and exclusion criteria following PRISMA recommendations.

RESULTS

1151 abstracts were identified. 4 duplicate records were discarded before screening. 957 abstracts were excluded because of redundancy, less relevant content or not English-written. 4 were added after revision. Eventually, 194 articles were included.

CONCLUSIONS

STDT encoding relies on intracortical inhibitory S1 function and is modulated by the basal ganglia-thalamic-cortical interplay through circuits involving the nigrostriatal dopaminergic pathway and probably the superior colliculus.

A dimensional approach to functional movement disorders: Heresy or opportunity

Functional movement disorders (FMD) are a common and disabling neuropsychiatric condition, part of the spectrum of functional neurological/conversion disorder. FMD represent one of the most enigmatic disorders in the history of medicine. However, in the twenty years after the first report of distinctive abnormal brain activity associated with functional motor symptoms, there have been tremendous advances in the pathophysiologic understanding of these disorders. FMD can be characterized as a disorder of aberrant neurocircuitry interacting with environmental and genetic factors. These developments suggest that research on FMD could be better served by an integrative, neuroscience-based approach focused on functional domains and their neurobiological substrates. This approach has been developed in 'Research Domain Criteria' (RDoC) project, which promotes a dimensional approach to psychiatric disorders. Here, we use the RDoC conceptualization to review recent neuroscience research on FMD, focusing on the domains most relevant to these disorders. We discuss how the adoption of a similar integrative framework may facilitate the identification of the mechanisms underlying FMD and could also have potential clinical applicability.

Neural activity in functional movement disorders after inpatient rehabilitation

Functional movement disorders (FMD) are a common source of disability in neurology.While treatment of FMD can reduce motor severity and disability, the neural mechanisms implicated in such a response remain unclear. We aimed to investigate neural changes in patients with FMD after a one-week multidisciplinary motor retraining (MoRe) treatment program. Fourteen FMD patients completed an emotional Go/No-Go fMRI task before and after MoRe treatment. Standardized pre- and post-treatment videos were rated for motor severity by a blinded reviewer using the psychogenic movement disorder rating scale (PMDRS). PMDRS scores before and after treatment were used for whole-brain regression. PMDRS scores were significantly reduced after MoRe treatment. Worse severity prior to treatment was associated with greater primary motor cortex (M1) activation at baseline and a larger response to treatment. Globally, increased connectivity between bilateral amygdala and premotor regions was observed following treatment. Lower post-treatment PMDRS scores were associated with increased connectivity between amygdala and ventromedial prefrontal cortex, whereas higher post-treatment PMDRS scores (and poorer treatment response) were associated with increased connectivity between amygdala and M1. Motor retraining in FMD may reorganize activity and connectivity in emotion processing and motor planning networks, with shifts in amygdala connectivity from posterior to frontal/prefrontal regions.

Ictal SPECT in Psychogenic Nonepileptic and Epileptic Seizures

BACKGROUND

Psychogenic nonepileptic seizures (PNES) are a common and debilitating problem in patients with epilepsy. They can be virtually indistinguishable from epileptic seizures, demanding video-electroencaphalogram monitoring, which is costly and not widely available, for differential diagnosis. Specific functional brain correlates of PNES have not been demonstrated so far. We hypothesized that PNES and epileptic seizures have distinct brain activation patterns, assessed by functional neuroimaging during ictal events of both conditions.

OBJECTIVE

Compare ictal brain activation patterns of PNES and epileptic seizures using single-photon emission computerized tomography.

METHODS

We prospectively assessed brain functional activation using single-photon emission computerized tomography 99mTc-ethyl cysteinate dimer in 26 patients with PNES, confirmed by trained psychiatrists in epileptology, who had their seizures induced by provocative tests compared with 22 age- and sex-matched subjects with temporal lobe epilepsy who underwent prolonged intensive video-electroencaphalogram monitoring.

RESULTS

In PNES patients compared with temporal lobe epilepsy group, we found a consistent increase in regional cerebral blood flow in the right precuneus (Brodmann area 7; P = 0.003) and right posterior cingulate cortex (Brodmann area 31; P = 0.001), as well as a decrease in regional cerebral blood flow in the right amygdala (P = 0.027).

CONCLUSIONS

Activation of default mode network brain areas and temporoparietal junction may be a distinct feature of ictal PNES and could be explained by a disruption between movement prediction input and sensory outcome. Such information mismatch might be the neurobiological underpinning of dissociative episodes.

Cortical Inhibitory Imbalance in Functional Paralysis

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Erratic movement disorders disclosing Graves' disease and paralleling thyroid function but not autoantibody levels

Graves’ disease (GD) is an autoimmune pathology characterized by hyperthyroidism and the presence of specific anti-thyroid antibodies. Neurological symptoms such as seizures, cognitive impairment, and tremor can be observed during the course of GD, but more complex movement disorders such as chorea and myoclonus are less frequent. The mechanisms underlying movement disorders in GD are not fully understood. While some authors relate movement disorders to thyroid dysfunction, others claim an autoimmune origin. We herein report a case involving a 60-year-old woman who presented with erratic, intricate movement disorders for which a medical workup revealed GD. During the 2-year follow-up period, her neurological symptoms evolved in parallel with her thyroid function, but not with her autoimmune anti-thyroid antibody level. Her neurological symptoms completely disappeared when she became euthyroid. We herein discuss the complicated clinicobiological relationship between thyroid function and movement disorders. This relationship involves several factors, including the impact of radioactive treatment. The present case emphasizes the importance of including thyroid function screening in the workup of unexplained movement disorders.

Psychogenic non-epileptic seizures treated with guided transcranial direct current stimulation: A case report

INTRODUCTION

Psychogenic non-epileptic seizures (PNES) are paroxysms of either altered subjective or objective manifestations that may mimic epileptic seizures (ES), without abnormal neuronal epileptiform activity. In this report, we present the case of a 39-year-old woman with PNES and functional movement disorders, who was successfully treated with neuro-guided transcranial direct current stimulation (tDCS).

METHODS

We used a PET-guided tDCS approach, as a hypometabolism of the frontal region was revealed by FDG TEP scan. TDCs was performed 5 days/week, 2 times/day, during 3 weeks. All clinical manifestations were reported in a seizure diary. We also assessed dissociation, depression, alexithymia, psychotraumatic scales, and involuntary movements.

RESULTS

The treatment was followed by a decrease of both psychogenic involuntary movements and PNES at 5 weeks. At the same time, PTSD symptoms, dissociative symptoms, depression and alexithymia improved.

CONCLUSION

PET-scan and tDCS seems to be promising tools for the evaluation and treatment of PNES in clinical practice, and may have a specific role on dissociative symptoms.

Lorazepam-Assisted Interview in a Resistant Case of Functional Dysphonia

BACKGROUND

Functional neurological symptom disorder presents with varied neurological signs often as a result of stress. It is usually treated with supportive psychotherapy and occasionally antidepressants. Literature regarding treatment for resistant cases is scarce. We describe on such presentation.

CASE PRESENTATION

A 40-year-old man who presented with a history of sudden onset dysphonia for 5 days. There were no immediate stressors. Physical examination revealed that he was unable to make movements of the tongue while speaking although power and range of movement were normal. Magnetic resonance imaging and computed tomography of brain and endoscopic examination of oral cavity and larynx did not reveal any organic cause. Functional magnetic resonance imaging imaging was conducted under a language protocol to determine neurophysiological circuits involved in this unique presentation. The patient failed conventional pharmacotherapy and supportive psychotherapy. Thereafter, he underwent lorazepam-assisted interviews where he would be asked to made purposive movements of the tongue and attempt to pronounce basic phonemes. He would converse normally during the lorazepam interviews and made gradual improvements after each session. The patient was able speak clearly after 12 such sessions and continues to maintain well since.

CONCLUSIONS

We describe a resistant case of functional dysphonia. The patient presented without any stressor and failed conventional treatments. The case demonstrates that Lorazepam can be used effectively in drug-assisted interviews for functional dysphonia. It also provides information regarding functional activity of the brain during a dissociative state.

Dysfunction in emotion processing underlies functional (psychogenic) dystonia

OBJECTIVE

We sought to determine whether abnormalities in emotion processing underlie functional (psychogenic) dystonia, one of the most common functional movement disorders.

METHODS

Motor and emotion circuits were examined in 12 participants with functional dystonia, 12 with primary organic dystonia, and 25 healthy controls using functional magnetic resonance imaging at 4T and a finger-tapping task (motor task), a basic emotion-recognition task (emotional faces task), and an intense-emotion stimuli task.

RESULTS

There were no differences in motor task activation between groups. In the faces task, when compared with the other groups, functional dystonia patients showed areas of decreased activation in the right middle temporal gyrus and bilateral precuneus and increased activation in the right inferior frontal gyrus, bilateral occipital cortex and fusiform gyrus, and bilateral cerebellum. In the intense-emotion task, when compared with the other groups, functional dystonia patients showed decreased activation in the left insular and left motor cortices (compared to organic dystonia, they showed an additional decrease in activation in the right opercular cortex and right motor cortex) and increased activation in the left fusiform gyrus.

CONCLUSIONS

Functional dystonia patients exhibited stimulus-dependent altered activation in networks involved in motor preparation and execution, spatial cognition, and attentional control. These results support the presence of network dysfunction in functional dystonia. © 2017 International Parkinson and Movement Disorder Society.

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.

Impaired emotion processing in functional (psychogenic) tremor: A functional magnetic resonance imaging study

Background

Despite its high prevalence and associated disability, the neural correlates of emotion processing in patients with functional (psychogenic) tremor (FT), the most common functional movement disorder, remain poorly understood.

Methods

In this cross sectional functional magnetic resonance imaging (fMRI) study at 4T, 27 subjects with FT, 16 with essential tremor (ET), and 25 healthy controls (HCs) underwent a finger-tapping motor task, a basic-emotion task, and an intense-emotion task to probe motor and emotion circuitries. Anatomical and functional MRI data were processed with FSL (FMRIB Software Library) and AFNI (Analysis of Functional Neuroimages), followed by seed-to-seed connectivity analyses using anatomical regions defined from the Harvard-Oxford subcortical atlas; all analyses were corrected for multiple comparisons.

Results

After controlling for depression scores and correcting for multiple comparisons, the FT group showed increased activation in the right cerebellum compared to ET during the motor task; and increased activation in the paracingulate gyrus and left Heschl's gyrus compared with HC with decreased activation in the right precentral gyrus compared with ET during the basic-emotion task. No significant differences were found after adjusting for multiple comparisons during the intense-emotion task but increase in connectivity between the left amygdala and left middle frontal gyrus survived corrections in the FT subjects during this task, compared to HC.

Conclusions

In response to emotional stimuli, functional tremor is associated with alterations in activation and functional connectivity in networks involved in emotion processing and theory of mind. These findings may be relevant to the pathophysiology of functional movement disorders.

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Patients with functional tremor exhibit altered emotion processing circuitry.

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There is increased activation in the paracingulate gyrus after emotional stimuli.

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Increased connectivity between the left amygdala and middle frontal gyrus

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Functional disorders may be associated with disturbances in the theory of mind.

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.

Disentangling Stigma from Functional Neurological Disorders: Conference Report and Roadmap for the Future

A multidisciplinary expert review of key issues and future directions from the conference “Controversial labels and clinical uncertainties: psychogenic disorders, conversion disorder, and functional symptoms.”

On October 9 and 10, 2015, a conference entitled “Controversial labels and clinical uncertainties: psychogenic disorders, conversion disorder, and functional symptoms” was held at the Center for Ethics, Emory University, Atlanta, GA, USA. This conference brought together a select group of 30 distinguished thought leaders and practitioners, including ethicists, researchers, clinicians, humanities scholars, and advocates to discuss the unique challenges and controversies related to the diagnosis, treatment, and stigma for patients with what is currently recognized as functional (“psychogenic”) neurological disorders. Our group of experts explored the conflicts and ethical tensions within health care that must be addressed in order to advance care for these disorders. What follows is a reflection on the conversations between conference attendees outlining key challenges and value conflicts in the diagnosis and treatment of patients with functional disorders. With this report, we aim to provide a roadmap for reducing stigma and improving care for functional neurological disorders (FND). A path forward would involve (1) setting a multifactorial research agenda that equally prioritized access to effective psychotherapy as well as identification of novel biomarkers; (2) empowering patients with FND to be heard and to drive changes in care; and (3) reducing isolation for clinicians by providing formal training and setting up multidisciplinary care teams and support networks.

Are Patients with Psychogenic Movement Disorders More Likely to be Healthcare Workers?

Background

Reported risk factors for the development of a psychogenic movement disorder (PMD) include young age, female gender, history of abuse, current or past psychiatric disorder, lower levels of education and socioeconomic status, and employment as a healthcare worker. Although employment in healthcare is included in several diagnostic criteria for PMD, as well as in many case series, this association has never been validated.

Methods

Using the University of Maryland Movement Disorder Database (UMMDD), we identified PMD cases, as well as patients with isolated focal dystonia as controls. An experienced movement disorder specialist diagnosed all patients, and all cases met criteria for clinically established PMD. Demographic and occupational histories were obtained from medical records and were supplemented by telephone interviews. PMD cases and controls were compared using t tests/χ² tests.

Results

Controls (n = 148) were older than PMD cases (n = 132), with an average age of 61.4 and 52.1 years, respectively (P < 0.001); there were no significant differences between groups with respect to gender, education level, and ethnicity. The proportion of healthcare workers was not significantly different between PMD cases and controls (25% of PMD cases vs. 20% of controls; P = 0.28).

Conclusions

In contrast to traditional teaching, this investigation demonstrates that in our patient population, patients with a PMD were no more likely to be employed as healthcare workers than patients with isolated focal dystonia. This study calls into question the use of employment in healthcare as a reliable criterion to support the diagnosis of PMD.

Non-Invasive Brain Stimulation in Conversion (Functional) Weakness and Paralysis: A Systematic Review and Future Perspectives

Conversion (functional) limb weakness or paralysis (FW) can be a debilitating condition, and often causes significant distress or impairment in social, occupational, or other important areas of functioning. Most treatment concepts are multi-disciplinary, containing a behavioral approach combined with a motor learning program. Non-invasive brain stimulation (NIBS) methods, such as electroconvulsive therapy (ECT), and transcranial magnetic stimulation (TMS) have been used in the past few decades to treat FW. In order to identify all published studies that used NIBS methods such as ECT, TMS and transcranial direct current stimulation (tDCS) for treating FW patients a systematic review of the literature was conducted in PubMed and Web of Science. In a second step, narratives were used to retrospectively determine nominal CGI-I (Clinical Global Impression scale–Improvement) scores to describe approximate changes of FW symptoms. We identified two articles (case reports) with ECT used for treatment of FW, five with TMS with a total of 86 patients, and none with tDCS. In 75 out of 86 patients treated with repetitive (r)TMS a nominal CGI-I score could be estimated, showing a satisfactory short-term improvement. Fifty-four out of seventy-five identified patients (72%) had a CGI-I score of 1 (very much improved), 13 (17%) a score of 2 (much improved), 5 (7%) a score of 3 (minimally improved), and 3 (5%) remained unchanged (CGI-I = 4). In no case did patients worsen after rTMS treatment, and no severe adverse effects were reported. At follow-up, symptom improvement was not quantifiable in terms of CGI-I for the majority of the cases. Patients treated with ECT showed a satisfactory short-term response (CGI-I = 2), but deterioration of FW symptoms at follow-up. Despite the predominantly positive results presented in the identified studies and satisfactory levels of efficacy measured with retrospectively calculated nominal CGI-I scores, any assumption of a beneficial effect of NIBS in FW has to be seen with caution, as only few articles could be retrieved and their quality was mostly poor. This article elucidates how NIBS might help in FW and gives recommendations for future study designs using NIBS in this condition.

Neurophysiologic studies of functional neurologic disorders

Functional neurologic disorders are largely genuine and represent conversion disorders, where the dysfunction is unconscious, but there are some that are factitious, where the abnormality is feigned and conscious. Malingering, which can have the same manifestations, is similarly feigned, but not considered a genuine disease. There are no good methods for differentiating these three entities at the present time. Physiologic studies of functional weakness and sensory loss reveal normal functioning of primary motor and sensory cortex, but abnormalities of premotor cortex and association cortices. This suggests a top-down influence creating the dysfunction. Studies of functional tremor and myoclonus show that these disorders utilize normal voluntary motor structures to produce the involuntary movements, again suggesting a higher-level abnormality. Agency is abnormal and studies shows that dysfunction of the temporoparietal junction may be a correlate. The limbic system is overactive and might initiate involuntary movements, but the mechanism for this is not known. The limbic system would then be the source of top-down dysfunction. It can be speculated that the involuntary movements are involuntary due to lack of proper feedforward signaling.

The role of placebo in the diagnosis and treatment of functional neurologic disorders

Placebo therapy can produce meaningful, clinical relief for a variety of conditions. While placebos are not without their ethically fraught history, they continue to be used, largely covertly, even today. Because the prognosis for psychogenic disorders is often poor and recovery may be highly dependent on the patient's belief in the diagnosis and treatment regimen, some physicians find placebo therapy for psychogenic disorders compelling, but also particularly contentious. Yet placebos also have a long tradition of being used for provocative diagnosis (wherein placebo is used to elicit and/or terminate the symptoms as a way of diagnosing symptoms as "psychogenic"). In this chapter we discuss cases describing placebo as therapy for psychogenic disorders and the challenges related to embedded Cartesian beliefs in Western medicine. The legitimate ethical reservations against placebo therapy, in general, have been related to assumptions about their "inertness" and a requirement for deception, both which are being refuted by emerging data. In this chapter, we also re-evaluate the concerns associated with placebo therapy for psychogenic disorders by asking, "Are we harming patients by withholding placebo treatment?"

The differential diagnosis and treatment of tremor

BACKGROUND

Essential tremor is the most common type of tremor, with a prevalence of 0.4% in the overall population and 4-7% in persons over age 65. In general, tremor is so common that patients with tremor are frequently treated not only by neurologists, but also by physicians from other specialties.

METHOD

This review is based on publications retrieved by a selective PubMed search and on guidelines from Germany and abroad.

RESULTS

Particular tremor syndromes are usually diagnosed on the basis of their typical clinical presentation and whatever accompanying manifestations may be present. Ancillary tests are usually unnecessary. Unilateral rest tremor accompanied by rigidity and bradykinesia is typical of Parkinson's disease. Essential tremor is a bilateral postural tremor. The most common cause of intention tremor is multiple sclerosis. Mild tremor syndromes can often be treated satisfactorily with drugs. In case of severe tremor, which is rarer, a stereotactic operation can be considered. The usual outcome of such procedures is the complete suppression of tremor.

CONCLUSION

Most patients with tremor can be given a precise diagnosis and offered specific treatment. It is important for the physician to inform the patient about the expected course of tremor over time, its possible genetic causes, and the various available treatments.

Exploiting geo-distributed clouds for a e-health monitoring system with minimum service delay and privacy preservation

In this paper, we propose an e-health monitoring system with minimum service delay and privacy preservation by exploiting geo-distributed clouds. In the system, the resource allocation scheme enables the distributed cloud servers to cooperatively assign the servers to the requested users under the load balance condition. Thus, the service delay for users is minimized. In addition, a traffic-shaping algorithm is proposed. The traffic-shaping algorithm converts the user health data traffic to the nonhealth data traffic such that the capability of traffic analysis attacks is largely reduced. Through the numerical analysis, we show the efficiency of the proposed traffic-shaping algorithm in terms of service delay and privacy preservation. Furthermore, through the simulations, we demonstrate that the proposed resource allocation scheme significantly reduces the service delay compared to two other alternatives using jointly the short queue and distributed control law.

Specialist inpatient treatment for severe motor conversion disorder: a retrospective comparative study

BACKGROUND

Gold standard protocols have yet to be established for the treatment of motor conversion disorder (MCD). There is limited evidence to support inpatient, multidisciplinary intervention in chronic, severe cases.

AIMS

To evaluate the characteristics and outcomes of MCD patients admitted to a specialist neuropsychiatric inpatient unit.

METHODS

All patients admitted to the Lishman Unit (years 2007-2011) with a diagnosis of MCD were included. Data relevant to characteristics and status with regard to mobility, activities of daily living (ADLs) and Modified Rankin Scale (MRS) score at admission and discharge were extracted.

RESULTS

Thirty-three cases (78.8% female) were included; the median duration of illness was 48 months. In comparison with brain injury patients admitted to the same unit, more cases had histories of childhood sexual abuse (36.4%, n=12), premorbid non-dissociative mental illness (81.1%, n=27) and employment as a healthcare/social-care worker (45.5%, n=15). Cases showed significant improvements in MRS scores (p<0.001), mobility (p<0.001) and ADL (p=0.002) following inpatient treatment.

CONCLUSIONS

Patients with severe, long-standing MCD can achieve significant improvements in functioning after admission to a neuropsychiatry unit.

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.

Caloric vestibular stimulation as a treatment for conversion disorder: a case report and medical hypothesis

Conversion disorder is a medical condition in which a person has paralysis, blindness, or other neurological symptoms that cannot be clearly explained physiologically. To date, there is neither specific nor conclusive treatment. In this paper, we draw together a number of disparate pieces of knowledge to propose a novel intervention to provide transient alleviation for this condition. As caloric vestibular stimulation has been demonstrated to modulate a variety of cognitive functions associated with brain activations, especially in the temporal-parietal cortex, anterior cingulate cortex, and insular cortex, there is evidence to assume an effect in specific mental disorders. Therefore, we go on to hypothesize that lateralized cold vestibular caloric stimulation will be effective in treating conversion disorder and we present provisional evidence from one patient that supports this conclusion. If our hypothesis is correct, this will be the first time in psychiatry and neurology that a clinically well-known mental disorder, long considered difficult to understand and to treat, is relieved by a simple or common, non-invasive medical procedure.

Conversion, dissociative amnesia, and Ganser syndrome in a case of "chameleon" syndrome: anatomo-functional findings

The term "chameleon" was first used in the seventeenth century by Sydenham to describe a patient with a protean semiology. We report a single case of "chameleon" syndrome that challenges the current international criteria for somatoform disorders, dissociative amnesia, and Ganser syndrome. The florid symptoms were as follows: anterograde and retrograde amnesia (including semantic, episodic, and procedural deficits), loss of identity, atypical neuropsychological impairment (approximate answers), left sensitive and motor deficit, and left pseudochoreoathetosis movement disorders. Additional behavioral disorders included the following: anxiety, clouded consciousness, hallucinations, and "belle indifference". A single photon emission computed tomography examination showed bilateral temporal, frontal and a right caudate (in the head of the caudate nucleus) hypoperfusion concordant with a common mechanism of repression in these disorders.

Imaging psychogenic movement disorders

The neurobiological basis of psychogenic movement disorders (PMDs) has been elusive, and they remain difficult to treat. In the last few years, functional neuroimaging studies have provided insight into their pathophysiology and neural correlates. Here, we review the various methodological approaches that have been used in both clinical and research practice to address neural correlates of functional disorders. We then review the dominant hypotheses generated from the literature on psychogenic paralysis. Overall, these studies emphasize abnormalities in the prefrontal and anterior cingulate cortices. Recently, functional neuroimaging has been used to specifically examine PMDs. These studies have addressed a major point of controversy: whether higher frontal brain areas are directly responsible for inhibiting motor areas or whether they reflect modulation by attentional and/or emotional processes. In addition to elucidating the mechanism and cause, recent work has also explored the lack of agency that characterizes PMDs. We describe the results and implications of the results of these imaging studies and discuss possible interpretations.

Neuropsychological profile of psychogenic jerky movement disorders: importance of evaluating non-credible cognitive performance and psychopathology

BACKGROUND

Psychogenic movement disorders are disorders of movements that cannot be explained by a known neurological disorder and are assumed to be associated with psychiatric symptoms such as depression and anxiety.

OBJECTIVE

To examine the neuropsychological profile of patients with psychogenic movement disorders.

METHODS

We examined cognitive functioning using neuropsychological tests in 26 patients with clinically established psychogenic jerky movement disorders (PMD). We included 16 patients with Gilles de la Tourette syndrome (GTS) who served as a patient control group, in addition to 22 healthy control subjects. Non-credible test performance was detected using a Symptom Validity Test (SVT). Psychopathology was also assessed.

RESULTS

Apart from a worse performance on a verbal memory task, no evidence of neuropsychological impairments was found in our PMD sample. Interestingly however, patients with PMD reported more cognitive complaints in daily life and performed worse on the SVT than the two other groups. Patients with GTS did not report, or show, cognitive impairments. In patients with PMD, we found associations between verbal learning, SVT performance and severity of depression and anxiety complaints.

CONCLUSIONS

We conclude that some patients with PMD show non-credible cognitive symptoms. In contrast, no evident cognitive impairments were present in patients with PMD or GTS. Our study underlines the importance of assessment of non-credible response in patients with PMD. Additionally, non-credible response might aid in the differentiation of PMD from other movement disorders.

The functional neuroimaging correlates of psychogenic versus organic dystonia

The neurobiological basis of psychogenic movement disorders remains poorly understood and the management of these conditions difficult. Functional neuroimaging studies have provided some insight into the pathophysiology of disorders implicating particularly the prefrontal cortex, but there are no studies on psychogenic dystonia, and comparisons with findings in organic counterparts are rare. To understand the pathophysiology of these disorders better, we compared the similarities and differences in functional neuroimaging of patients with psychogenic dystonia and genetically determined dystonia, and tested hypotheses on the role of the prefrontal cortex in functional neurological disorders. Patients with psychogenic (n = 6) or organic (n = 5, DYT1 gene mutation positive) dystonia of the right leg, and matched healthy control subjects (n = 6) underwent positron emission tomography of regional cerebral blood flow. Participants were studied during rest, during fixed posturing of the right leg and during paced ankle movements. Continuous surface electromyography and footplate manometry monitored task performance. Averaging regional cerebral blood flow across all tasks, the organic dystonia group showed abnormal increases in the primary motor cortex and thalamus compared with controls, with decreases in the cerebellum. In contrast, the psychogenic dystonia group showed the opposite pattern, with abnormally increased blood flow in the cerebellum and basal ganglia, with decreases in the primary motor cortex. Comparing organic dystonia with psychogenic dystonia revealed significantly greater regional blood flow in the primary motor cortex, whereas psychogenic dystonia was associated with significantly greater blood flow in the cerebellum and basal ganglia (all P < 0.05, family-wise whole-brain corrected). Group × task interactions were also examined. During movement, compared with rest, there was abnormal activation in the right dorsolateral prefrontal cortex that was common to both organic and psychogenic dystonia groups (compared with control subjects, P < 0.05, family-wise small-volume correction). These data show a cortical–subcortical differentiation between organic and psychogenic dystonia in terms of regional blood flow, both at rest and during active motor tasks. The pathological prefrontal cortical activation was confirmed in, but was not specific to, psychogenic dystonia. This suggests that psychogenic and organic dystonia have different cortical and subcortical pathophysiology, while a derangement in mechanisms of motor attention may be a feature of both conditions.

Psychogenic nonepileptic seizures: a current overview

Psychogenic nonepileptic seizures (PNES) resemble epilepsy, but no pathophysiological explanation has been established. Although there have been recent advances in PNES research and various hypotheses as to the psychopathology, no theory has achieved general acceptance. In this overview of selected literature on PNES, we highlight the often contradictory findings that underline the challenges that confront both practitioner and researcher. We first provide a synopsis of the history, diagnosis, treatment, and outcomes, as well as patient characteristics of PNES and the relevance of communication in the clinical context. In the subsequent sections we discuss recent research that may advance the understanding and diagnosis of this disorder. These themes include the use of qualitative methods as a viable research option, the application of nonlinear methods to analyze heterogeneous observations during diagnosis, recent advances in neuroimaging of PNES, and the development of international databases.

Abnormal gait and bradykinesia in the preclinical phase of Huntington's disease - psychogenic movement disorder?

Soltan W, Sitek E, Wichowicz H, Wieczorek D, Slawek J. Abnormal gait and bradykinesia in the preclinical phase of Huntington's disease – psychogenic movement disorder?

Objective: Psychiatric symptoms may occur in individuals at risk of Huntington's disease (HD) regardless of their genetic status. Psychopathological symptomatology is attributed to both genetic and environmental factors. In case of asymptomatic gene carriers, psychiatric symptoms may precede involuntary movements.

Methods: We report the first case with abnormal gait and bradykinesia in preclinical adult HD. A 33-year-old woman blind to her mother's HD diagnosis and her own genetic status developed motor slowing and gait disturbance. The symptoms withdrew due to counselling and antidepressant medications. Subsequently, she was informed her own and her mother's genetic testing results, but 2-year follow-up did not reveal the onset of choreic movements, cognitive deterioration or depressive symptoms in the patient. Personality assessment (Minnesota Multiphasic Personality Inventory) and neurological examination results are presented, accompanied by 2-year follow-up data. Follow-up examination included Unified Huntington's Disease Rating Scale (motor, behaviour and function), Beck Depression Inventory, Hamilton Depression Rating Scale and neuropsychological assessment (trail-making test, Stroop test, verbal fluency trials, symbol digit modalities test, digit span, serial seven subtraction, Hopkins verbal learning test and nine-hole peg test).

Conclusion: Motor abnormalities in individuals at risk of HD may be of psychogenic origin. It is a matter of debate if this psychogenic reaction presented as hypokinetic syndrome may be a result of choreic movements of her mother (hyperkinetic syndrome) and depression or if this psychogenic reaction represents the preclinical psychiatric abnormalities in an asymptomatic gene carrier preceding the onset of the disease.

An update on psychogenic movement disorders

Psychogenic movement disorders (PMD) and other conversion disorders (CD) with apparent neurologic signs (neurologic CD) plague patients and perplex physicians. Due to a lack of objective evidence of underlying brain lesions, CD were largely abandoned by neurologists and remained poorly understood psychiatric diagnoses throughout most of the 20th century. Modern neuroscience now supports increasingly comprehensive biological models for these complex disorders, definitively establishing their place in both neurology and psychiatry. Although it is often clinically useful to distinguish a movement disorder as either "organic" or "psychogenic," this dichotomy is difficult to defend scientifically. Here we describe the neuroimaging and neurophysiologic evidence for dysfunctional neural networks in PMD, explain the diagnostic potential of clinical neurophysiologic testing, discuss the promising if increasingly complex role of neuropsychiatric genetics, and review current treatment strategies.

Comparison of two treatments for coxarthrosis: local hyperthermia versus radio electric asymmetrical brain stimulation

BACKGROUND

It is well known that psychological components are very important in the aging process and may also manifest in psychogenic movement disorders, such as coxarthrosis. This study analyzed the medical records of two similar groups of patients with coxarthrosis (n = 15 in each) who were treated in two different clinics for rehabilitation therapy.

METHODS

Patients in Group A were treated with a course of traditional physiotherapy, including sessions of local hyperthermia. Group B patients were treated with only a course of radioelectric asymmetrical brain stimulation (REAC) to improve their motor behavior.

RESULTS

Group A showed a significant decrease in symptoms of pain and stiffness, and an insignificant improvement in range of motion and muscle bulk. A single patient in this group developed worsened symptoms, and pain did not resolve completely in any patient. The patients in Group B had significantly decreased levels of pain and stiffness, and a significant improvement in range of motion and muscle bulk. No patients worsened in Group B, and the pain resolved completely in one patient.

CONCLUSION

Both treatments were shown to be tolerable and safe. Patients who underwent REAC treatment appeared to have slightly better outcomes, with an appreciable improvement in both their physical and mental states. These aspects are particularly important in the elderly, in whom functional limitation is often associated with or exacerbated by a psychogenic component.

Psychogenic parkinsonism

Parkinsonism can be psychogenic, and psychogenic parkinsonism is about 10% of psychogenic movement disorder patients. Patients can present with any feature or combination of features of organic Parkinson's disease. There are clinical clues that can lead to the correct diagnosis, and laboratory testing with clinical neurophysiology or DAT (dopamine transporter) scanning can be helpful as well. Patients may have both organic Parkinson's disease and psychogenic parkinsonism, and this might be considered a psychologically induced aggravation of the organic disorder.

Psychogenic movement disorders and motor conversion: a roadmap for collaboration between neurology and psychiatry

BACKGROUND

There are a host of vague terms to describe psychologically-mediated symptoms that mimic neurological disease, such as "functional," "non-organic," "psychogenic," or "medically unexplained." None of these terms has a direct translation in psychiatric classification, and psychiatrists are often faced with patients who do not believe in a psychological origin for their symptoms.

OBJECTIVE

Within the framework of psychogenic movement disorders, we discuss the roadblocks to effective collaboration and treatment in these patients and the current state of the literature regarding diagnosis and treatment.

RESULTS

We describe the approach to these patients from the perspective of neurology and psychiatry, illustrating the differences in terminology and categorization.

CONCLUSION

Psychogenic movement disorders represent a unique opportunity for these fields to collaborate in the care of a potentially curable but significantly disabling disorder.

Motor excitability during movement imagination and movement observation in psychogenic lower limb paresis

BACKGROUND

Patients with a psychogenic paresis have difficulties performing voluntary movements. Typically, diagnostic interventions are normal. We tested whether patients with a psychogenic lower limb paresis exhibit abnormal motor excitability during motor imagery or movement observation.

METHODS

Transcranial magnetic stimulation (TMS) with single and paired pulses was used to explore motor excitability at rest, during imagination of ankle dorsiflexions and during watching another person perform ankle dorsiflexions. Results obtained in ten patients with a flaccid psychogenic leg paresis were compared with a healthy age-matched control group. In addition, results of two patients with a psychogenic fixed dystonia of the leg are presented.

RESULTS

During rest, motor excitability evaluated by motor thresholds, size of motor-evoked potentials (MEP) by single pulse TMS, intracortical inhibition and intracortical facilitation tested by paired-pulse TMS were similar in patients and healthy subjects. MEPs recorded in five patients during movement observation were also comparable across the two groups. During motor imagery, patient MEPs were significantly smaller than in the control group and smaller than during rest, indicating an inhibition.

CONCLUSION

In patients with motor conversion disorder, the imagination of own body movements induces a reduction of corticospinal motor excitability whereas it induces an excitability increase in healthy subjects. This discrepancy might be the electrophysiological substrate of the inability to move voluntarily. Watching another person perform movements induces a normal excitability increase, indicating a crucial role of the perspective and suggesting that focusing the patient's attention on a different person might become a therapeutic approach.

Physiology of psychogenic movement disorders

Psychogenic movement disorders (PMDs) are common, but their physiology is largely unknown. In most situations, the movement is involuntary, but in a minority, when the disorder is malingering or factitious, the patient is lying and the movement is voluntary. Physiologically, we cannot tell the difference between voluntary and involuntary. The Bereitschaftspotential (BP) is indicative of certain brain mechanisms for generating movement, and is seen with ordinarily voluntary movements, but by itself does not indicate that a movement is voluntary. There are good clinical neurophysiological methods available to determine whether myoclonus or tremor is a PMD. For example, psychogenic myoclonus generally has a BP, and psychogenic stimulus-sensitive myoclonus has a variable latency with times similar to normal reaction times. Psychogenic tremor will have variable frequency over time, be synchronous in the two arms, and might well be entrained with voluntary rhythmic movements. These facts suggest that PMDs share voluntary mechanisms for movement production. There are no definitive tests to differentiate psychogenic dystonia from organic dystonia, although one has been recently reported. Similar physiological abnormalities are seen in both groups. The question arises as to how a movement can be produced with voluntary mechanisms, but not be considered voluntary.

Emotional stimuli and motor conversion disorder

Conversion disorder is characterized by neurological signs and symptoms related to an underlying psychological issue. Amygdala activity to affective stimuli is well characterized in healthy volunteers with greater amygdala activity to both negative and positive stimuli relative to neutral stimuli, and greater activity to negative relative to positive stimuli. We investigated the relationship between conversion disorder and affect by assessing amygdala activity to affective stimuli. We conducted a functional magnetic resonance imaging study using a block design incidental affective task with fearful, happy and neutral face stimuli and compared valence contrasts between 16 patients with conversion disorder and 16 age- and gender-matched healthy volunteers. The patients with conversion disorder had positive movements such as tremor, dystonia or gait abnormalities. We also assessed functional connectivity between the amygdala and regions associated with motor preparation. A group by affect valence interaction was observed. Post hoc analyses revealed that whereas healthy volunteers had greater right amygdala activity to fearful versus neutral compared with happy versus neutral as expected, there were no valence differences in patients with conversion disorder. There were no group differences observed. The time course analysis also revealed greater right amygdala activity in patients with conversion disorder for happy stimuli (t = 2.96, P = 0.006) (with a trend for fearful stimuli, t = 1.81, P = 0.08) compared with healthy volunteers, with a pattern suggestive of impaired amygdala habituation even when controlling for depressive and anxiety symptoms. Using psychophysiological interaction analysis, patients with conversion disorder had greater functional connectivity between the right amygdala and the right supplementary motor area during both fearful versus neutral, and happy versus neutral 'stimuli' compared with healthy volunteers. These results were confirmed with Granger Causality Modelling analysis indicating a directional influence from the right amygdala to the right supplementary motor area to happy stimuli (P < 0.05) with a similar trend observed to fearful stimuli (P = 0.07). Our data provide a potential neural mechanism that may explain why psychological or physiological stressors can trigger or exacerbate conversion disorder symptoms in some patients. Greater functional connectivity of limbic regions influencing motor preparatory regions during states of arousal may underlie the pathophysiology of motor conversion symptoms.

[Astasia-abasia: psychogenic and non-psychogenic causes]

Astasia-abasia is defined as the inability to stand and to walk, despite sparing of motor function underlying the required balance and gestures. Initially, astasia-abasia was considered a psychogenic gait disorder, but later on, the description of "high-order" gait disorders mimicking this pure functional deficit led authors to refer to "astasia-abasia" as a pure descriptive term, without a presupposed etiological or anatomical substrate. In this paper, the main clinical characteristics of both psychogenic and non-psychogenic astasia-abasia are presented and discussed.