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The diagnosis of functional dystonia is challenging because it is difficult to distinguish functional dystonia from other types of dystonia. After diagnostic explanation, multidisciplinary care is recommended, but some patients are resistant to treatments. We used motor blocks in three patients with severe resistant functional dystonia of the upper limbs to test (i) whether joint contracture was present and (ii) whether motor blocks have a therapeutic effect on functional dystonia. Patient 1 showed a good and sustained therapeutic response, Patient 2 experienced a resolution of the dystonic posture that lasted for 10 days, and Patient 3 experienced no effect. Motor blocks may be a useful therapeutic option in chronic treatment‐resistant functional dystonia. The treatment effect might be achieved through the experience of normal positioning and functioning of the limb. [ABSTRACT FROM AUTHOR]

Background: Functional movement disorders (FMD) are a diagnostic and therapeutic challenge, both to the neurologist and psychiatrists. The phenomenology is varied and can present as tremors, dystonia, jerks/myoclonus, gait disorder, other abnormal movements or a combination. There has been an increase in the use of electrophysiological studies that are an important tool in the evaluation of FMDs. Methods: We searched the database platforms of MEDLINE, Google scholar, Web of Sciences, Scopus using the Medical Subject Heading terms (MeSH) for all the articles from 1st January 1970 till November 2022. A total of 658 articles were obtained by the search mechanism. A total of 79 relevant articles were reviewed thoroughly, of which 26 articles that had electrophysiological data were included in the present review. Results: Variability, distractibility and entertainability can be demonstrated in functional tremors by using multichannel surface electromyography. Voluntary ballistic movements tend to decrease the tremor, while loading the tremulous limb with weight causes the tremor amplitude to increase in functional tremor. Presence of Bereitschaftspotential demonstrates the functional nature of palatal tremor and myoclonus. Co-contraction testing may be helpful in differentiating functional from organic dystonia. The R2 blink reflex recovery cycle has been found to be abnormally enhanced in organic blepharospasm, whereas it is normal in presumed functional blepharospasm. Plasticity is found to be abnormally high in organic dystonia and normal in functional dystonia, in addition to enhanced facilitation in patients with organic dystonia. Conclusions: Electrophysiological tests supplement clinical examination and helps in differentiating FMD from organic movement disorders. [ABSTRACT FROM AUTHOR]

The prevalence of dystonia has been studied since the 1980s. Due to different methodologies and due to varying degrees of awareness, resulting figures have been extremely different. We wanted to determine the prevalence of dystonia according to its current definition, using quality-approved registries and based on its relevance for patients, their therapy and the health care system. We applied a service-based chart review design with the City of Hannover as reference area and a population of 525,731. Barrier-free comprehensive dystonia treatment in few highly specialised centres for the last 30 years should have generated maximal dystonia awareness, a minimum of unreported cases and a high degree of data homogeneity. Prevalence [n/1mio] and relative frequency is 601.1 (100%) for all forms of dystonia, 251.1 (42%) for cervical dystonia, 87.5 (15%) for blepharospasm, 55.2 (9%) for writer's cramp, 38.0 (6%) for tardive dystonia, 32.3 (5%) for musician's dystonia, 28.5 (5%) for psychogenic dystonia, 26.6 (4%) for generalised dystonia, 24.7 (4%) for spasmodic dysphonia, 20.9 (3%) for segmental dystonia, 15.2 (3%) for arm dystonia and 13.3 (2%) for oromandibular dystonia. Leg dystonia, hemidystonia and complex regional pain syndrome-associated dystonia are very rare. Compared to previous meta-analytical data, primary or isolated dystonia is 3.3 times more frequent in our study. When all forms of dystonia including psychogenic, generalised, tardive and other symptomatic dystonias are considered, our dystonia prevalence is 3.7 times higher than believed before. The real prevalence is likely to be even higher. Having based our study on treatment necessity, our data will allow better allocation of resources for comprehensive dystonia treatment. [ABSTRACT FROM AUTHOR]

Functional dystonia represents a condition where psychological distress is being expressed as involuntary muscle contractions. In the foot and ankle, it most commonly presents as a sudden onset of a painful fixed ankle/hindfoot deformity in a female patient with a history of trivial trauma or surgery. The "fixed deformity" found on clinical examination is usually correctable under general anesthesia. Less commonly, it can present in the toes or may present as paroxysmal muscle movements rather than a fixed deformity. CRPS may occur concurrently with the dystonia. Failure to consider the diagnosis leads to a long delay in appropriate diagnosis, patient distress and unnecessary or even harmful surgery. A better approach to this clinical syndrome is to define it as fixed abnormal posturing that is most commonly psychogenic. Early referral to a movement disorder clinic is recommended. The prognosis is generally poor as less than a quarter of patients report subjective long-term improvement even when managed in a movement disorder clinic. Foot and ankle surgeons should, whenever possible, avoid operating on patients with functional dystonia in order to avoid symptomatic deterioration. [ABSTRACT FROM AUTHOR]

Introduction: Functional motor disorders (FMDs) are usually categorized according to the predominant phenomenology; however, it is unclear whether this phenotypic classification mirrors the underlying pathophysiologic mechanisms. Objective: To compare the characteristics of patients with different FMDs phenotypes and without co-morbid neurological disorders, aiming to answer the question of whether they represent different expressions of the same disorder or reflect distinct entities. Methods: Consecutive outpatients with a clinically definite diagnosis of FMDs were included in the Italian registry of functional motor disorders (IRFMD), a multicenter data collection platform gathering several clinical and demographic variables. To the aim of the current work, data of patients with isolated FMDs were extracted. Results: A total of 176 patients were included: 58 with weakness, 40 with tremor, 38 with dystonia, 23 with jerks/facial FMDs, and 17 with gait disorders. Patients with tremor and gait disorders were older than the others. Patients with functional weakness had more commonly an acute onset (87.9%) than patients with tremor and gait disorders, a shorter time lag from symptoms onset and FMDs diagnosis (2.9 ± 3.5 years) than patients with dystonia, and had more frequently associated functional sensory symptoms (51.7%) than patients with tremor, dystonia and gait disorders. Patients with dystonia complained more often of associated pain (47.4%) than patients with tremor. No other differences were noted between groups in terms of other variables including associated functional neurological symptoms, psychiatric comorbidities, and predisposing or precipitating factors. Conclusions: Our data support the evidence of a large overlap between FMD phenotypes. [ABSTRACT FROM AUTHOR]

Background: The differentiation of functional dystonia from idiopathic dystonia may be clinically challenging. Objective: To identify clinical features suggestive of functional dystonia to guide physicians to distinguish functional dystonia from idiopathic dystonia. Methods: Patient data were extracted from the Italian Registry of Functional Motor Disorders and the Italian Registry of Adult Dystonia. Patients with functional and idiopathic dystonia were followed up at the same clinical sites, and they were similar in age and sex. Results: We identified 113 patients with functional dystonia and 125 with idiopathic dystonia. Sudden onset of dystonia, evidence of fixed dystonia, and acute peripheral trauma before dystonia onset were more frequent in the functional dystonia group. No study variable alone achieved satisfactory sensitivity and specificity, whereas a combination of variables yielded 85% sensitivity and 98% specificity. A diagnostic algorithm was developed to reduce the risk of misclassifying functional dystonia. Conclusion: Our findings extend the current diagnostic approach to functional dystonia by showing that clinical information about symptom onset, fixed dystonia, and history of peripheral trauma may provide key clues in the diagnosis of functional dystonia. [ABSTRACT FROM AUTHOR]

Background and purpose: The aims of this study were to describe the clinical manifestations of functional motor disorders (FMDs) coexisting with other neurological diseases ("comorbid FMDs"), and to compare comorbid FMDs with FMDs not overlapping with other neurological diseases ("pure FMDs"). Methods: For this multicenter observational study, we enrolled outpatients with a definite FMD diagnosis attending 25 tertiary movement disorder centers in Italy. Each patient with FMDs underwent a detailed clinical assessment including screening for other associated neurological conditions. Group comparisons (comorbid FMDs vs. pure FMDs) were performed in order to compare demographic and clinical variables. Logistic regression models were created to estimate the adjusted odds ratios (95% confidence intervals) of comorbid FMDs (dependent variable) in relation to sociodemographic and clinical characteristics (independent variables). Results: Out of 410 FMDs, 21.7% of patients (n = 89) had comorbid FMDs. The most frequent coexisting neurological diseases were migraine, cerebrovascular disease and parkinsonism. In the majority of cases (86.5%), FMDs appeared after the diagnosis of a neurological disease. Patients with comorbid FMDs were older, and more frequently had tremor, non‐neurological comorbidities, paroxysmal non‐epileptic seizures, major depressive disorders, and benzodiazepine intake. Multivariate regression analysis showed that diagnosis of comorbid FMDs was more likely associated with longer time lag until the final diagnosis of FMD, presence of tremor and non‐neurological comorbidities. Conclusions: Our findings highlight the need for prompt diagnosis of FMDs, given the relatively high frequency of associated neurological and non‐neurological diseases. [ABSTRACT FROM AUTHOR]

Dystonia is a common movement disorder, involving sustained muscle contractions, often resulting in twisting and repetitive movements and abnormal postures. Dystonia may be primary, as the sole feature (isolated) or in combination with other movement disorders (combined dystonia), or as one feature of another neurological process (secondary dystonia). The current hypothesis is that dystonia is a disorder of distributed brain networks, including the basal ganglia, cerebellum, thalamus and the cortex resulting in abnormal neural motor programs. In comparison, functional dystonia (FD) may resemble other forms of dystonia (OD) but has a different pathophysiology, as a subtype of functional movement disorders (FMD). FD is the second most common FMD and amongst the most diagnostically challenging FMD subtypes. Therefore, distinguishing between FD and OD is important, as the management of these disorders is distinct. There are also different pathophysiological underpinnings in FD, with for example evidence of involvement of the right temporoparietal junction in functional movement disorders that is believed to serve as a general comparator of internal predictions/motor intentions with actual motor events resulting in disturbances in self-agency. In this article, we present a comprehensive review across the spectrum of FD, including oromandibular and vocal forms and discuss the history, clinical clues, evidence for adjunctive “laboratory-based” testing, pathophysiological research and prognosis data. We also provide the approach used at the Massachusetts General Hospital Dystonia Center toward the diagnosis, management and treatment of FD. A multidisciplinary approach, including neurology, psychiatry, physical, occupational therapy and speech therapy, and cognitive behavioral psychotherapy approaches are frequently required; pharmacological approaches, including possible targeted use of botulinum toxin injections and inpatient programs are considerations in some patients. Early diagnosis and treatment may help prevent unnecessary investigations and procedures, while facilitating the appropriate management of these highly complex patients, which may help to mitigate frequently poor clinical outcomes.

Dystonia is a common movement disorder, involving sustained muscle contractions, often resulting in twisting and repetitive movements and abnormal postures. Dystonia may be primary, as the sole feature (isolated) or in combination with other movement disorders (combined dystonia), or as one feature of another neurological process (secondary dystonia). The current hypothesis is that dystonia is a disorder of distributed brain networks, including the basal ganglia, cerebellum, thalamus and the cortex resulting in abnormal neural motor programs. In comparison, functional dystonia (FD) may resemble other forms of dystonia (OD) but has a different pathophysiology, as a subtype of functional movement disorders (FMD). FD is the second most common FMD and amongst the most diagnostically challenging FMD subtypes. Therefore, distinguishing between FD and OD is important, as the management of these disorders is distinct. There are also different pathophysiological underpinnings in FD, with for example evidence of involvement of the right temporoparietal junction in functional movement disorders that is believed to serve as a general comparator of internal predictions/motor intentions with actual motor events resulting in disturbances in self-agency. In this article, we present a comprehensive review across the spectrum of FD, including oromandibular and vocal forms and discuss the history, clinical clues, evidence for adjunctive "laboratory-based" testing, pathophysiological research and prognosis data. We also provide the approach used at the Massachusetts General Hospital Dystonia Center toward the diagnosis, management and treatment of FD. A multidisciplinary approach, including neurology, psychiatry, physical, occupational therapy and speech therapy, and cognitive behavioral psychotherapy approaches are frequently required; pharmacological approaches, including possible targeted use of botulinum toxin injections and inpatient programs are considerations in some patients. Early diagnosis and treatment may help prevent unnecessary investigations and procedures, while facilitating the appropriate management of these highly complex patients, which may help to mitigate frequently poor clinical outcomes. [ABSTRACT FROM AUTHOR]

Previous studies suggested that brain regions subtending affective‐cognitive processes can be implicated in the pathophysiology of functional dystonia (FD). In this study, the role of the affective‐cognitive network was explored in two phenotypes of FD: fixed (FixFD) and mobile dystonia (MobFD). We hypothesized that each of these phenotypes would show peculiar functional connectivity (FC) alterations in line with their divergent disease clinical expressions. Resting state fMRI (RS‐fMRI) was obtained in 40 FD patients (12 FixFD; 28 MobFD) and 43 controls (14 young FixFD‐age‐matched [yHC]; 29 old MobFD‐age‐matched [oHC]). FC of brain regions of interest, known to be involved in affective‐cognitive processes, and independent component analysis of RS‐fMRI data to explore brain networks were employed. Compared to HC, all FD patients showed reduced FC between the majority of affective‐cognitive seeds of interest and the fronto‐subcortical and limbic circuits; enhanced FC between the right affective‐cognitive part of the cerebellum and the bilateral associative parietal cortex; enhanced FC of the bilateral amygdala with the subcortical and posterior cortical brain regions; and altered FC between the left medial dorsal nucleus and the sensorimotor and associative brain regions (enhanced in MobFD and reduced in FixFD). Compared with yHC and MobFD patients, FixFD patients had an extensive pattern of reduced FC within the cerebellar network, and between the majority of affective‐cognitive seeds of interest and the sensorimotor and high‐order function ("cognitive") areas with a unique involvement of dorsal anterior cingulate cortex connectivity. Brain FC within the affective‐cognitive network is altered in FD and presented specific features associated with each FD phenotype, suggesting an interaction between brain connectivity and clinical expression of the disease. [ABSTRACT FROM AUTHOR]

Background: Functional neurological disorders are generally more common in females than males, but the reason for this gender difference is not well understood. Objectives: In this study, we aim to compare the clinical and demographic features of functional movement disorders (FMDs) between males and females. Methods: We examined clinical data and video‐recordings of patients with FMDs evaluated at the Baylor College of Medicine Movement Disorders Clinic. Results: Of the 196 patients with FMDs, males represented only 30% (n = 59) of the entire cohort. Men had an older age at onset: 40.5 versus 34.1 years (P = 0.026) and an older age at evaluation: 43.8 versus 38.1 years (P = 0.041) compared to women. Functional dystonia was more frequently observed in women: 47.5 versus 20.3% (P < 0.001), but there was a trend for higher frequency of functional gait disorder in men: 44 versus 30% (P = 0.056). Females were particularly over‐represented (73.7%) in children and adolescents; but the genders were equally represented in patients aged ≥50 years. Conclusions: Female patients are over‐represented in FMDs, except in individuals aged ≥50 years. Compared to female patients, males with FMDs present later in life and are less likely to have functional dystonia. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: Pallidal deep brain stimulation (GPi-DBS) is an effective therapy for isolated dystonia, but 10-20% of patients show improvement below 25-30%. We here investigated causes of insufficient response to GPi-DBS in isolated dystonia in a cross-sectional study.Methods: Patients with isolated dystonia at time of surgery, and <30% improvement on the Burke-Fahn-Marsden dystonia-rating-scale (BFMDRS) after ≥6 months of continuous GPi-DBS were videotaped ON and OFF stimulation, and history, preoperative videos, brain MRI, medical records, stimulation settings, stimulation system integrity, lead location, and genetic information were obtained and reviewed by an expert panel.Results: 22 patients from 11 centres were included (8 men, 14 women; 9 generalized, 9 segmental, 3 focal, 1 bibrachial dystonia; mean (range): age 48.7 (25-72) years, disease duration 22.0 (2-40) years, DBS duration 45.5 (6-131) months). Mean BFMDRS-score was 31.7 (4-93) preoperatively and 32.3 (5-101) postoperatively. Half of the patients (n = 11) had poor lead positioning alone or in combination with other problems (combined with: other disease n = 6, functional dystonia n = 1, other problems n = 2). Other problems were disease other than isolated inherited or idiopathic dystonia (n = 5), fixed deformities (n = 2), functional dystonia (n = 3), and other causes (n = 1). Excluding patients with poor lead location from further analysis, non-isolated dystonia accounted for 45.5%, functional dystonia for 27.3%, and fixed deformities for 18.2%. In patients with true isolated dystonia, lead location was the most frequent problem.Conclusion: After exclusion of lead placement and stimulation programming issues, non-isolated dystonia, functional dystonia and fixed deformities account for the majority of GPi-DBS failures in dystonia. [ABSTRACT FROM AUTHOR]

Objective: The aim of this cross-sectional study was to identify if there was a specific difference between patients with functional dystonia (DysF) and those with adult-onset, isolated idiopathic ("primary") dystonia (DysP) in terms of psychiatric disorders, psychological stressor, dissociation correlates, and personality traits.Methods: Thirty-nine clinically definite DysF and 30 DysP patients matched by age, gender and dystonia distribution underwent psychiatric interview based on DSM-5 criteria and additional testings for global cognitive and psychiatric functions (Mini-Mental State Examination, Hamilton Depression and Hamilton Anxiety Rating Scale, Apathy Scale, Somatoform Dissociation Questionnaire-20, Dissociative Experiences Scale II, and the five-dimensional Revised Neuroticism-Extroversion-Openness Personality Inventory).Results: Almost half of our DysF patients had prior psychiatric treatment, which was significantly more frequent when compared to DysP. Patients with DysF in comparison to DysP also had considerably more frequent preceding stress, higher apathy, dissociative and somatoform scores, as well as significantly higher rate of la belle indifférence sign. This sign, stress before dystonia and prior psychiatric disorder independently predicted having DysF. Some of psychiatric disorders (i.e. substance-related disorders, schizophrenia, adjustment disorder, borderline personality disorder, post-traumatic stress disorder, psychotic depression, delusional disorder) were exclusively present among DysF patients. DysF compared to DysP patients had lower scores for both extroversion and openness to experiences.Conclusion: Our data found different pattern of psychiatric comorbidity and personality traits between DysF and DysP patients, including a higher prevalence of psychological stressor and dissociative correlates, indicating at least a partial role of psychological mechanisms in the pathogenesis of DysF. [ABSTRACT FROM AUTHOR]

Aims: To assess the characteristic clinical features, management, and outcome of patients who present to orthopaedic surgeons with functional dystonia affecting the foot and ankle., Methods: We carried out a retrospective search of our records from 2000 to 2019 of patients seen in our adult tertiary referral foot and ankle unit with a diagnosis of functional dystonia., Results: A total of 29 patients were seen. A majority were female (n = 25) and the mean age of onset of symptoms was 35.3 years (13 to 71). The mean delay between onset and diagnosis was 7.1 years (0.5 to 25.0). Onset was acute in 25 patients and insidious in four. Of the 29 patients, 26 had a fixed dystonia and three had a spasmodic dystonia. Pain was a major symptom in all patients, with a coexisting diagnosis of chronic regional pain syndrome (CRPS) made in nine patients. Of 20 patients treated with Botox, only one had a good response. None of the 12 patients who underwent a surgical intervention at our unit or elsewhere reported a subjective overall improvement. After a mean follow-up of 3.2 years (1 to 12), four patients had improved, 17 had remained the same, and eight reported a deterioration in their condition., Conclusion: Patients with functional dystonia typically presented with a rapid onset of fixed deformity after a minor injury/event and pain out of proportion to the deformity. Referral to a neurologist to rule out neurological pathology is advocated, and further management should be carried out in a movement disorder clinic. Response to treatment (including Botulinum toxin (Botox) injections) is generally poor. Surgery in this group of patients is not recommended and may worsen the condition. The overall prognosis remains poor. Cite this article: Bone Joint J  2021;103-B(6):1127-1132.

Although currently lacking a sensitive and specific electrophysiologic battery test, functional (psychogenic) dystonia can sometimes be diagnosed with clinically definite certainty using available criteria. Certain regional phenotypes have been recognized as distinctive, such as unilateral lip and jaw deviation, laterocollis with ipsilateral shoulder elevation and contralateral shoulder depression, fixed wrist and finger flexion with relative sparing of the thumb and index fingers, and fixed foot plantar flexion and inversion. The pathophysiologic abnormalities in functional dystonia overlap substantially with those of organic dystonia, with similar impairments in cortical and spinal inhibition and somatosensory processing, but with emerging data suggesting abnormalities in regional blood flow and activation patterns on positron emission tomography and functional magnetic resonance imaging, respectively. Management of functional dystonia begins with compassionate and assertive debriefing of the diagnosis to ensure full acceptance by the patient, a critical step in enhancing the likelihood of success with physical rehabilitation, and psychodynamic or cognitive therapy. Physical therapy, with or without cognitive behavioral therapy, appears to be of benefit but has not yet been examined in a controlled fashion. While the prognosis remains grim for a substantial majority of patients, partly stemming from restricted mobility, delayed diagnosis, and inappropriate pharmacotherapy, early recognition and initiation of therapy stand to minimize iatrogenic harm and unnecessary laboratory investigations, and potentially reduce the long-term neurologic disability., (© 2016 Elsevier B.V. All rights reserved.)