Functional Movement Disorders Research Articles

Empathy in Motion: Unravelling the Layers of Caregiver Burden in Functional Movement Disorders (S35.010)

Empathy in Motion: Unravelling the Layers of Caregiver Burden in Functional Movement Disorders (S35.010)

Therapeutic Efficacy of Repetitive Nerve Stimulation (RNS) Therapy in Functional Movement Disorders: A Quantitative and Qualitative Analysis (N6.003)

Therapeutic Efficacy of Repetitive Nerve Stimulation (RNS) Therapy in Functional Movement Disorders: A Quantitative and Qualitative Analysis (N6.003)

Batman & Robin vs. The Riddler: Is ChatGPT a reliable sidekick to Neurologists for diagnosis and management of functional movement disorders (N6.002)

Batman & Robin vs. The Riddler: Is ChatGPT a reliable sidekick to Neurologists for diagnosis and management of functional movement disorders (N6.002)

Increase in Functional Tic Presentations in Sexual Orientation and Gender Identity Minority Youth During Coronavirus Disease 2019

BackgroundFunctional tic disorders are among the least common functional movement disorders, but their prevalence rose during the coronavirus disease 2019 (COVID-19) pandemic. Although female adolescents develop functional neurological disorders at higher rates than males, investigations into sexual orientation and gender identity (SOGI) status of these patients are limited. MethodsWe completed a retrospective, cross-sectional time series examining the incidence of new-onset functional tic disorders in youth presenting to the Massachusetts General Hospital Movement Disorder clinics before and during the COVID-19 pandemic. Data were collected by searching for relevant International Classification of Diseases (ICD)-10 diagnostic codes in youth aged nine to 26 years using a hospital-wide data repository. Individual cases were reviewed for inclusion based on clinical criteria and expert consensus. ResultsThe prevalence of functional tic presentations in youth rose 8.6-fold from pre- to postpandemic levels (Fisher exact test P < 0.001), whereas the prevalence of developmental tic presentations pre- and postpandemic remained stable (114 vs 112). SOGI minority youth comprised 37% of those with functional tics (total n = 19). Ninety five percent of patients with functional tics identified as female, with 10% of these identifying as transgender. ConclusionsOur data confirm previously demonstrated dramatic rises in functional tic presentations during the COVID-19 pandemic and, more notably, reveal a strong association with SOGI minority status. We highlight the potential link between functional tic disorders and SOGI minority status. Providing a safe and supportive clinical environment and addressing stress linked to SOGI minority status may help to improve patient prognosis.

Abnormal cerebrospinal fluid cytology in functional movement disorders.

The role of inflammation and neuroimmune mechanisms, which have been documented in various neuropsychiatric disorders including the seizure subtype of functional neurological disorder, remains unclear in functional movement disorders (FMD). To explore these mechanisms, we analyzed selected inflammatory markers in cerebrospinal fluid (CSF) in patients with FMD. We compared CSF markers in 26 patients with clinically established FMD (20 females; mean (SD) age 43.3 (10.9); disease duration 3.9 (3); range 0.1-11 years; mean follow-up after lumbar puncture 4.3 (2) years, range 0.5-7 years) and 26 sex and age-matched clinical controls with non-inflammatory non-neurodegenerative neurological disorders, mostly sleep disorders. 65% of FMD patients vs. 15% of controls showed cytological abnormalities (i.e., increased white blood cells (WBC) count, signs of WBC activation, or both (odds ratio (OR) = 9.85, 95% confidence interval [2.37, 52.00], p < 0.01, corrected), with a significantly higher frequency of an isolated lymphocytic activation 35% vs. 0% (OR = ∞, 95% confidence interval [2.53, ∞], p < 0.05, corrected). There were no differences in CSF protein and albumin levels, quotient albumin, IgG index, and oligoclonal bands. CSF abnormalities were not associated with more severe motor symptoms or a higher frequency of depression in FMD. Our results suggest a possible involvement of immune mechanisms in the pathophysiology of (at least a subtype of) FMD that deserves further investigation.

Social cognition in Parkinson's disease and functional movement disorders.

Functional movement disorders (FMD) can overlap with Parkinson's disease (PD), and distinguishing between the two clinical conditions can be complex. Framing social cognition (theory of mind) (TOM) disorder, attention deficit, and psychodynamic features of FMD and PD may improve diagnosis. Subjects with FMD and PD and healthy controls (HC) were administered tasks assessing TOM abilities and attention. The psychodynamic hypothesis of conversion disorder was explored by a questionnaire assessing dissociative symptoms. A comprehensive battery of neuropsychological tasks was also administered to FMD and PD. Although both FMD and PD scored lower than HC on all TOM tests, significant correlations between TOM and neuropsychological tasks were found only in PD but not in FMD. Only PD showed a reduction in attentional control. Dissociative symptoms occurred only in FMD. Cognitive-affective disturbances are real in FMD, whereas they are largely dependent on cognitive impairment in PD. Attentional control is preserved in FMD compared to PD, consistent with the hypothesis that overload of voluntary attentional orientation may be at the basis of the onset of functional motor symptoms. On a psychodynamic level, the confirmation of dissociative symptoms in FMD supports the conversion disorder hypothesis. FMD and PD can be distinguished on an affective and cognitive level. At the same time, however, the objective difficulty often encountered in distinguishing between the two pathologies draws attention to how blurred the boundary between 'organic' and 'functional' can be.

Similarities and Differences in Functional Movement Disorders and Functional Seizures at a Tertiary Care Center: A Prospective Study

Background: Functional movement disorders (FMDs) and functional seizure (FS) are the two most important subcategories of functional neurologic disorders (FNDs). Objectives: This study aimed to discern similarities and differences between patients with FMD and FS. Methods: A prospective comparative study of 94 patients with FNDs (FMD = 47, FS = 47) was conducted. Results: Tremor and pauci-kinetic attack with preserved responsiveness were the most common subtypes observed in patients with FMD and FS, respectively. A significantly higher number of patients with FMD had more than one precipitating factor (P = 0.03). Headache was significantly more common in patients with FS (P = 0.03). More patients came for follow-up in the FMD group (P = 0.01). More patients in the FS group reported “very much improvement” (P = 0.04), and “no change” was more commonly reported by the FMD group patients (P = 0.009). Conclusion: Emotional stress was the most common precipitating factor in patients with FMD and FS. The prognosis was better in patients with FS.

EEG beta oscillations as an indicator of increased perception-action integration in functional movement disorders

EEG beta oscillations as an indicator of increased perception-action integration in functional movement disorders

Factors Influencing Triage to Rehabilitation in Functional Movement Disorder.

Treatment of functional movement disorder (FMD) should be individualized, yet factors determining rehabilitation engagement have not been evaluated. Subspecialty FMD clinics are uniquely poised to explore factors influencing treatment suitability and triage. To describe our approach and explore factors associated with triage to FMD rehabilitation. We conducted a retrospective chart review of 158 consecutive patients with FMD seen for integrated assessment by movement disorders neurology and psychiatry, with the purpose of triage to rehabilitation. Demographic and clinical variables were compared between patients triaged to therapy versus no therapy, and logistic regression was used to explore factors predictive of triage outcome. Change in primary outcome scores were analyzed. Sixty-six patients (42%) were triaged to FMD therapy from July 2019 to December 2021. Patients triaged to therapy were more likely to have a constant movement disorder, gait disorder and/or tremor, hyperarousal, readiness for change, and people pleasing traits. Patients triaged to no therapy demonstrated persistent diagnostic disagreement, an inability to appreciate motor symptom inconsistency, low self-agency, a propensity to dissociate, and cluster B traits. 90% of patients triaged to rehabilitation had improved outcomes. The ability to "opt-in" to FMD rehabilitation relies on different factors than those relevant to establishing a diagnosis. Unlike many other neurological disorders, a triage and treatment planning step is recommended to identify those likely to meaningfully engage at that time. Holistic assessment through a transdisciplinary lens, and working collaboratively with the patient is essential to prioritize symptoms, determine engagement, and identify treatment targets.

Cortisol in functional neurological disorders: State, trait and prognostic biomarkers

ObjectiveBiological stress dysregulation, such as a flattened cortisol awakening response (CAR), has been identified in functional neurological disorder (FND). This longitudinal study aimed to explore whether CAR alterations in FND serve as state or trait biomarkers, assessing temporal changes in cortisol and clinical outcomes to test its prognostic value. MethodsSalivary cortisol was measured in 53 patients with mixed FND at two visits separated by eight months (M0 and M8). CAR was calculated based on five consecutive samples, each taken with 15-min time intervals, collected upon awakening, whereas cortisol amplitude (CAmp) was calculated as the difference between the morning peak and the afternoon trough. Clinical outcome was assessed with the Functional Movement Disorder Rating Scale (S-FMDRS), Clinical global impression (CGI) scores for severity (CGI-S) and improvement (CGI-I) and the short-form health survey (SF-36). ResultsNo differences in CAR levels were found between M0 and M8 regardless of clinical outcome (remained flattened). However, a good clinical outcome was associated with an earlier peak in the CAR (p = .013, odds ratio: 1.78; 95%-confidence interval: 0.095–1.13). A higher CAmp at M0 predicted a better outcome at M8 (β = 1.14, 95%-confidence interval:0.15–2.13, p = .03). ConclusionA flattened CAR might represent a trait marker for FND, when an earlier peak in the CAR may serve as a state biomarker. The CAmp demonstrates predictive power for clinical outcome, potentially representing a prognostic biomarker for FND. Further replication and follow-up studies are essential to confirm this suggested role of cortisol as a multifaceted biomarker of FND.

[Understanding and explaining functional movement disorders].

Functional movement disorders are not uncommon in neurological consultations, hospitals and emergency departments. Although the disorder can usually be recognized clinically, the communication of the diagnosis is often unsatisfactory. Those affected are indirectly accused of alack of insight or openness but it is often the doctors who fail to formulate acoherent and comprehensible explanation of the underlying disorder. In this review an integrative model for the development of functional movement disorders is presented, which places the motor (and nonmotor) symptoms in aneuroscientific light. In addition, explanations and metaphors are presented that have proven helpful in conveying an understanding of the disorder.

[Interpretation of aconcept for functional movement disorders from the perspective of older patients].

Arecently published concept considers asignificant proportion of the occurrence and persistence of functional movement disorders (FMD) to be explained by increased/incorrect weighting of the expected movement (feedforward signal) in the presence of decreased/altered actual feedback of the movement. In the context of aging and age-associated diseases, there is an increased likelihood that these prerequisites will occur, also in combination. For example, the feedforward signal can be enhanced by accumulation of awealth of experience but can for example become prone to error due to changes in attention and (fear of) falling. Conversely, the actual feedback is subject to age-related changes, such as reduction of sensory functions. This could explain why FMDs also occur in old age and offer treatment approaches for this so far poorly studied disorder. It follows that aspecific focus on (the correction of) feedforward signals and strengthening as well as training of the actual feedback are potentially promising therapeutic approaches for older people with FMD.

[Conclusion instead of exclusion-The clinical diagnosis of functional movement disorders].

Functional neurological movement disorders are common in neurological practice and lead to ahigh degree of impairment and chronification. Affected patients usually receive adiagnosis with considerable delay and often do not get disease-specific treatment. The reasons for this delay are related to extensive diagnostic measures to exclude other nonfunctional neurological diseases. As aconsequence, functional movement disorders are typically communicated as diagnoses of exclusion, which makes it difficult for patients to understand and accept the diagnosis. This is particularly unfortunate, because in the majority of patients the diagnosis can be made with confidence based on clinical features, i.e., inconsistency and incongruence. The clarification of the symptoms and the resulting treatment options should be supplemented by patient-friendly explanations of the pathophysiological basis of the disease. In this way, patients are enabled to understand and accept the diagnosis. Moreover, it can put an end to the search for adiagnosis, which can sometimes take decades, and paves the way for treatment. Thus, the diagnosis by exclusion itself becomes the starting point for treatment and can itself have a therapeutic effect.

[Transdisciplinary treatment of functional movement disorders: integration instead of dissociation].

Successful treatment of patients with functional motor disorders is integrative in several ways: the primary treatment goal is the (re)integration of sensorimotor, cognitive and social functioning. The prerequisites for this are an integrated biopsychosocial model of everyone involved as well as close transdisciplinary cooperation. Instead of asimple addition of treatment components, all care providers and patients act in concert.

[Additional functional symptoms in Parkinson's disease and tremor syndromes].

Patients with Parkinson's Disease or a tremor syndrome may present with additional functional movement disorders. The differential diagnosis is particularly difficult. In some cases, functional symptoms occur either before the manifestation of the organic disease or can emerge as an additional symptom after Parkinson's disease or tremor became apparent. In patients with Parkinson's disease the prevalence for additional functional symptoms is 7 %. In the case that patients with Parkinson's diseases have one side that is more severely affected, additional functional motor symptoms such as functional rest tremor also occur on that same, predominantly affected side. Functional gait disorders occur frequently. Clinically, patients appear notably slow in automatized, daily tasks. Their speech is more whispering than hypophonic, bradykinesia during finger tapping manifest without a decrement. The Dopamintransporterszintigraphy (123) I FP-CIT SPECT; DaTSCANTM) may be helpful to differentiate between functional Parkinsonism and Parkinson's disease. Functional tremor in patients with an organic tremor syndrome is diagnosed with the same distraction techniques as in solely functional tremor. This includes cognitive, motor, and suggestive distraction maneuvers. In some cases, additional neurophysiological investigations such as accelerometry are useful for the differential diagnosis. It is most important to identify patients with additional functional symptoms in non-functional movement disorders, because the therapeutic approach differs and a multi professional team is required to initiate effective treatment strategies.

Perspectives on the Novel Multifunctional Nerve Guidance Conduits: From Specific Regenerative Procedures to Motor Function Rebuilding.

Peripheral nerve injury potentially destroys the quality of life by inducing functional movement disorders and sensory capacity loss, which results in severe disability and substantial psychological, social, and financial burdens. Autologous nerve grafting has been commonly used as treatment in the clinic; however, its rare donor availability limits its application. A series of artificial nerve guidance conduits (NGCs) with advanced architectures are also proposed to promote injured peripheral nerve regeneration, which is a complicated process from axon sprouting to targeted muscle reinnervation. Therefore, exploring the interactions between sophisticated NGC complexes and versatile cells during each process including axon sprouting, Schwann cell dedifferentiation, nerve myelination, and muscle reinnervation is necessary. This review highlights the contribution of functional NGCs and the influence of microscale biomaterial architecture on biological processes of nerve repair. Progressive NGCs with chemical molecule induction, heterogenous topographical morphology, electroactive, anisotropic assembly microstructure, and self-powered electroactive and magnetic-sensitive NGCs are also collected, and they are expected to be pioneering features in future multifunctional and effective NGCs.

Transient resting-state salience-limbic co-activation patterns in functional neurological disorders

BackgroundFunctional neurological disorders were historically regarded as the manifestation of a dynamic brain lesion which might be linked to trauma or stress, although this association has not yet been directly tested yet. Analysing large-scale brain network dynamics at rest in relation to stress biomarkers assessed by salivary cortisol and amylase could provide new insights into the pathophysiology of functional neurological symptoms. MethodsCase-control resting-state functional magnetic resonance imaging study of 79 patients with mixed functional neurological disorders (i.e., functional movement disorders, functional seizures, persistent perceptual-postural dizziness) and 74 age- and sex-matched healthy controls. Using a two-step hierarchical data-driven neuroimaging approach, static functional connectivity was first computed between 17 resting-state networks. Second, dynamic alterations in these networks were examined using co-activation pattern analysis. Using a partial least squares correlation analysis, the multivariate pattern of correlation between altered temporal characteristics and stress biomarkers as well as clinical scores were evaluated. ResultsCompared to healthy controls, patients presented with functional aberrancies of the salience-limbic network connectivity. Thus, the insula and amygdala were selected as seed-regions for the subsequent analyses. Insular co-(de)activation patterns related to the salience network, the somatomotor network and the default mode network were detected, which patients entered more frequently than controls. Moreover, an insular co-(de)activation pattern with subcortical regions together with a wide-spread co-(de)activation with diverse cortical networks was detected, which patients entered less frequently than controls. In patients, dynamic alterations conjointly correlated with amylase measures and duration of symptoms. ConclusionThe relationship between alterations in insular co-activation patterns, stress biomarkers and clinical data proposes inter-related mechanisms involved in stress regulation and functional (network) integration. In summary, altered functional brain network dynamics were identified in patients with functional neurological disorder supporting previously raised concepts of impaired attentional and interoceptive processing.

Electrophysiology in Functional Movement Disorders: An Update.

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. 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. 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. Electrophysiological tests supplement clinical examination and helps in differentiating FMD from organic movement disorders.

Identifying and Treating Functional “Nonnative [Foreign] Accent Syndrome”: Perspectives From the Patient and Speech-Language Pathologist

Purpose: When nonnative speaking patterns emerge following neurologic insult or injury, it has often been referred to as foreign, or nonnative, accent syndrome (FAS). In many other cases, FAS can occur as a manifestation of a functional speech disorder (FSD). The purpose of this clinical focus article is to (a) describe the methods utilized in identifying and managing a functional communication disorder characterized by nonnative speech, language, and nonverbal communication intrusions, accompanied by a functional movement disorder and (b) describe the patient's lived experience. Method and Results: The patient is a 59-year-old monolingual English-speaking gentleman with a remote history of episodic stuttering, who later developed an abrupt onset of a nonnative speaking style that changed in quality over time. He also developed gait difficulties that, after visiting with several neurologists, were judged to reflect a functional neurological disorder. During the speech evaluation session, an “Eastern European accent” was noted, along with nonnative word use and word order. A diagnosis of FSD characterized by foreign accent was made, and intervention was undertaken as detailed in the clinical focus article and demonstrated in the accompanying video. With behavioral intervention, the patient was able to correct sound-level changes in structured tasks such as reading and repetition and then in conversation. Language dialect–like changes resolved without direct intervention. The nonspeech movement disorder was addressed with intensive occupational and physical therapy. Conclusions: The patient presented with functional FAS, which was effectively managed with symptomatic, targeted behavioral intervention. His experience demonstrates the importance of patient advocacy in acquiring an accurate diagnosis and appropriate management recommendations. Supplemental Material: https://doi.org/10.23641/asha.24653430

Managing functional movement disorder in a neurology service

Managing functional movement disorder in a neurology service