Pain processing in functional and idiopathic dystonia: An exploratory study.

BACKGROUND: Pain is often experienced by patients with functional dystonia and idiopathic cervical dystonia and is likely to be determined by different neural mechanisms. OBJECTIVE: In this exploratory study, we tested the sensory-discriminative and cognitive-emotional component of pain in patients with functional and idiopathic dystonia. METHODS: Ten patients with idiopathic cervical dystonia, 12 patients with functional dystonia, and 16 age- and sex-matched healthy controls underwent psychophysical testing of tactile and pain thresholds and pain tolerance. We delivered electrical pulses of increasing intensity to the index finger of each hand and the halluces of each foot. Pain threshold and pain tolerance were respectively defined as the (1) intensity at which sensation changed from unpainful to faintly painful and (2) intensity at which painful sensation was intolerable. RESULTS: No differences were found between the three groups for tactile and pain thresholds assessed in hands and feet. Pain tolerance was significantly increased in all body regions only in functional dystonia. Patients with continuous functional dystonia had higher pain tolerance compared to subjects with paroxysmal functional dystonia and idiopathic cervical dystonia. There was no correlation between pain tolerance and pain scores, depression, anxiety, disease duration, and motor disability in both groups. CONCLUSIONS: Patients with functional dystonia have a dissociation between the sensory-discriminative and cognitive-emotional components of pain, as revealed by normal pain thresholds and increased pain tolerance. Abnormal connectivity between the motor and limbic systems might account for abnormal pain processing in functional dystonia. © 2018 International Parkinson and Movement Disorder Society.

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.

The "shirt collar sign" of cervical dystonia.

The diagnosis of cervical dystonia (CD) is clinical. We describe a physical examination observation that has been noted in CD patients. There is a tendency for their shirt collars to be shifted to one side. We validated this apparently consistent finding by having blinded evaluators rating the symmetry of the shirt collars in CD and non-cervical dystonia control subjects. A high correlation was found between the physical finding which we call "shirt collar sign" and the diagnosis. "Shirt collar sign" may be a helpful sign in diagnosing CD.

Alien hand syndrome: Pathophysiology, semiology and differential diagnosis with psychiatric disorders (Review).

Alien hand syndrome (AHS) is an uncommon neurological condition characterized by involuntary, yet seemingly purposeful, movements of a limb, typically an upper extremity, with variable awareness and control by the affected individual. It is associated with a range of peculiar sensations, such as the feeling of limb estrangement, alien control and involuntary mirroring or restraining of movements. AHS indicates a profound disruption in volitional motor control and personal agency. The aetiology of AHS is the dysfunction of critical brain regions secondary to diverse neurological insults, such as tumours, vascular disorders, infarction or neurodegenerative diseases. It is clinically categorized into the parietal and callosal types, depending on the affected region, with manifestations often linked to the specific brain region affected. The callosal type is particularly challenging to diagnose due to its rarity and potential for nonspecific or concealed symptoms amid concurrent brain injuries. Distinguishing AHS from psychiatric disorders is crucial for accurate diagnosis and improved patient outcomes. Further research is imperative for a deeper understanding of the pathophysiology of AHS and the development of effective treatments. AHS predominantly affects adults and is frequently associated with multiple comorbidities. The syndrome is also exemplified by three distinct motor behaviours: Involuntary grasping, inter-manual conflict and limb levitation accompanied by the sensation of an alien limb or the perception of external control over one's movements. It has a generally good prognosis with partial or total recovery following appropriate rehabilitation techniques, including pharmacological and psychological measures.

The epidemiology of dystonia: the Hannover epidemiology study.

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.

Clinical Characteristics of Functional Movement Disorders in the Stomatognathic System.

Background: Functional (psychogenic) movement disorders often have distinguishable clinical features in the orofacial region. Tonic mandibular deviation accompanying ipsilateral downward and lateral lip pulling is the most common phenotype seen in patients with facial functional movement disorders. However, functional movement disorders in the stomatognathic system are underrecognized. Objective: This study aimed to evaluate clinical characteristics and phenomenology in patients with functional movement disorders in the stomatognathic system. Methods: Ten-item inclusion criteria (point range: 0-10) for functional movement disorders in the stomatognathic system was produced, based on previously established criteria for functional movement disorders and general signs of functional facial dystonia, to determine subject inclusion. The criteria included inconsistency, incongruence, and paroxysm in symptoms; rapid onset; distractibility; suggestibility; static course; spreading to multiple sites; spontaneous remission; and lack of sensory tricks. Fifty-eight patients [42 women (72.4%), 16 men (27.6%); mean age: 46.2 years] scored over 7 points on the criteria and were included in further analyses. Characteristic features, including the pattern and site of abnormal movements, were assessed in clinical examination. Results: Frequent items in the scale were inconsistent symptoms (93.1%), incongruous symptoms (91.4%), spreading to multiple sites (89.7%), paroxysmal symptoms (86.2%), and lack of sensory tricks (81%). Sixty percent of patients exhibited a pattern resembling dystonia. Some patients had a combination of organic and functional disease. Common involuntary movements included jaw deviation (74.1%), jaw closing (50%), lip pulling (34.5%), and tongue movement (31%). A functional dystonia phenotype (unilateral lower lip pulling and jaw deviation) was observed in 26 patients (44.8%). Characteristic features of functional stomatognathic movement disorders were rapidly repeating mandibular (lateral or tapping) and tongue movements (27.6%), which fluctuated in speed and direction. Conclusion: In 58 patients with functional movement disorders in the stomatognathic system, the functional dystonia phenotype was observed in 44.8%. Furthermore, 27.6% of patients showed the most characteristic type of functional stomatognathic movement disorders: very fast repeated jaw and/or lingual movements.

OnabotulinumtoxinA and cognitive behavioral therapy in functional dystonia: A pilot randomized clinical trial.

INTRODUCTION: Functional dystonia (FD) is a disabling movement disorder with limited therapeutic options. We aimed to examine the efficacy and safety of chemodenervation with OnabotulinumtoxinA (BoNT) versus placebo prior to cognitive behavioral therapy (CBT) in FD patients. METHODS: FD patients with a Psychogenic Movement Disorders Rating Scale (PMDRS) score ≥ 10 and persistent dystonic posturing for ≥ 1 year were randomized to BoNT or placebo injections prior to 12 weekly individualized 1-h CBT sessions. Clinical assessments included PMDRS, Hamilton Depression Scale (HAM-D), Hamilton Anxiety Scale (HAM-A), Katz index of independence in activities of daily living (ADL), and Lawton instrumental ADL (iADL). The efficacy endpoints were the change in clinical assessments at 12 weeks from baseline between and within groups. RESULTS: Of 18 screened patients, 14 were randomized, and 10 completed the study. All patients showed reductions in PMDRS irrespective of treatment group at the end of the follow-up period. There was no difference in clinical assessments between groups at 12 weeks. Change from baseline in PMDRS score was significantly improved only in the CBT group with prior administration of placebo (mean change -9.0, 95% CI -16.5, -1.5; p = 0.02). CONCLUSIONS: CBT yielded robust improvement in FD patients but was unaffected by prior administration of BoNT. These pilot data do not eliminate the potential for examining future BoNT benefit in FD patients with selected topographical involvement, such as face or neck.

"The Twisted Mind" - Psychogenic Dystonia in An Adolescent, Responding to Antidepressant Therapy.

Psychogenic dystonia is one of the most common problems encountered in movement disorder patients and accounted mostly for misdiagnosis, management confusion and treatment resistance. Psychiatric morbidities often are the culprit, hence proper psychiatric history taking is of utmost importance. Here we report one case where dystonia was the main presenting complaint of an underlying depressive episode and discuss how managing the cause alleviated the symptoms.

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.

Functional dystonia.

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.

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.

Distonía psicógena / Psychogenic dystonia

RESUMEN La distonía psicógena (funcional) es una condición que representa un reto para el clínico, desde su terminología confusa hasta el tratamiento integral. Este fenómeno se presenta en pacientes con ausencia de una enfermedad neurológica o condición secundaria que explique cabalmente dicha presentación y generalmente con una comorbilidad psiquiátrica marcada.

SUMMARY Psychogenic (functional) dystonia represent a huge challenge to the clinician. Nowadays there is a discussion between which term fit most to this condition (psychogenic vs. functional) but so far a consensus has not been reach. This phenomenon is present in absence of any neurological condition or identifiable secondary cause and usually is accompanied with an important psychiatric comorbidity.

Distonía psicógena / Psychogenic dystonia

La distonía psicógena (funcional) es una condición que representa un reto para el clínico, desde su terminología confusa hasta el tratamiento integral. Este fenómeno se presenta en pacientes con ausencia de una enfermedad neurológica o condición secundaria que explique cabalmente dicha presentación y generalmente con una comorbilidad psiquiátrica marcada.

SUMMARY Psychogenic (functional) dystonia represent a huge challenge to the clinician. Nowadays there is a discussion between which term fit most to this condition (psychogenic vs. functional) but so far a consensus has not been reach. This phenomenon is present in absence of any neurological condition or identifiable secondary cause and usually is accompanied with an important psychiatric comorbidity.

Psychogenic dystonia induced by peripheral trauma: case report

The origin of dystonia is a point of discussion since its first description. A cause-and-effect relationship between brain injury and subsequent movement disorder is well established, but the existence of such a relationship following peripheral injury has not been universally accepted. This paper has the objective to report a patient with fixed dystonic posture of the hand after peripheral trauma.

A origem da distonia continua sendo controversa como nas suas primeiras descrições. A relação de causa e efeito entre traumatismo craniano e distúrbios do movimento está bem estabelecida, no entanto, a existência de tal relação após trauma periférico não é amplamente aceita. Este trabalho tem por objetivo relatar um paciente com postura distônica fixa da mão após trauma periférico.