ABSTRACT
Background: Information on specialist physiotherapeutic treatment for functional movement disorders is scarce. Previous studies focussed on functional gait disorders and availability of descriptions of the practical application especially for other body regions is very limited. Cases: We present two illustrative cases, demonstrating the key elements of physiotherapy for the treatment of functional movement disorders beyond gait difficulties. The individual applicability of the specific core elements of physiotherapy, adapted to the individual needs of each patient, are described. We also explain, how different sensory stimuli can be used to shift attention away from symptoms and thus reduce them. Moreover, we discuss how patients' agency can be encouraged and how this results in therapy key moments, contributing to a sustained improvement of symptoms. Conclusion: Thus, our case series are intended to guide clinicians and therapists alike, to promote disease-specific physiotherapy for this common and treatable neuropsychiatric disorder.
Subject(s)
Physical Therapy Modalities , Humans , Female , Male , Movement Disorders/therapy , Movement Disorders/physiopathology , Movement Disorders/rehabilitation , Middle Aged , Adult , Upper Extremity/physiopathologyABSTRACT
BACKGROUND: Freezing of gait (FOG) is a debilitating symptom of Parkinson's disease (PD) characterized by paroxysmal episodes in which patients are unable to step forward. A research priority is identifying cortical changes before freezing in PD-FOG. METHODS: We tested 19 patients with PD who had been assessed for FOG (n=14 with FOG and 5 without FOG). While seated, patients stepped bilaterally on pedals to progress forward through a virtual hallway while 64-channel EEG was recorded. We assessed cortical activities before and during lower limb motor blocks (LLMB), defined as a break in rhythmic pedaling, and stops, defined as movement cessation following an auditory stop cue. This task was selected because LLMB correlates with FOG severity in PD and allows recording of high-quality EEG. Patients were tested after overnight withdrawal from dopaminergic medications ("off" state) and in the "on" medications state. EEG source activities were evaluated using individual MRI and standardized low resolution brain electromagnetic tomography (sLORETA). Functional connectivity was evaluated by phase lag index between seeds and pre-defined cortical regions of interest. RESULTS: EEG source activities for LLMB vs. cued stops localized to right posterior parietal area (Brodmann area 39), lateral premotor area (Brodmann area 6), and inferior frontal gyrus (Brodmann area 47). In these areas, PD-FOG (n=14) increased alpha rhythms (8-12 Hz) before LLMB vs. typical stepping, whereas PD without FOG (n=5) decreased alpha power. Alpha rhythms were linearly correlated with LLMB severity, and the relationship became an inverted U-shape when assessing alpha rhythms as a function of percent time in LLMB in the "off" medication state. Right inferior frontal gyrus and supplementary motor area connectivity was observed before LLMB in the beta band (13-30 Hz). This same pattern of connectivity was seen before stops. Dopaminergic medication improved FOG and led to less alpha synchronization and increased functional connections between frontal and parietal areas. CONCLUSIONS: Right inferior parietofrontal structures are implicated in PD-FOG. The predominant changes were in the alpha rhythm, which increased before LLMB and with LLMB severity. Similar connectivity was observed for LLMB and stops between the right inferior frontal gyrus and supplementary motor area, suggesting that FOG may be a form of "unintended stopping." These findings may inform approaches to neurorehabilitation of PD-FOG.
Subject(s)
Electroencephalography , Gait Disorders, Neurologic , Parkinson Disease , Humans , Parkinson Disease/physiopathology , Parkinson Disease/drug therapy , Male , Female , Gait Disorders, Neurologic/physiopathology , Gait Disorders, Neurologic/etiology , Aged , Electroencephalography/methods , Middle Aged , Lower Extremity/physiopathology , Cerebral Cortex/physiopathology , Cerebral Cortex/diagnostic imaging , Magnetic Resonance ImagingABSTRACT
Functional neurological movement disorders are common in neurological practice and lead to a high degree of impairment and chronification. Affected patients usually receive a diagnosis 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 a consequence, 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 a diagnosis, 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.
Subject(s)
Movement Disorders , Humans , Movement Disorders/diagnosis , Movement Disorders/physiopathology , Movement Disorders/therapy , Diagnosis, Differential , Neurologic Examination , Conversion Disorder/diagnosis , Conversion Disorder/physiopathology , Conversion Disorder/therapyABSTRACT
Cerebellar transcranial alternating current stimulation (tACS) is an emerging non-invasive technique that induces electric fields to modulate cerebellar function. Although the effect of cortical tACS seems to be state-dependent, the impact of concurrent motor activation and the duration of stimulation on the effects of cerebellar tACS has not yet been examined. In our study, 20 healthy subjects received neuronavigated 50 Hz cerebellar tACS for 40 s or 20 min, each during performance using a motor sequence learning task (MSL) and at rest. We measured the motor evoked potential (MEP) before and at two time points after tACS application to assess corticospinal excitability. Additionally, we investigated the online effect of tACS on MSL. Individual electric field simulations were computed to evaluate the distribution of electric fields, showing a focal electric field in the right cerebellar hemisphere with the highest intensities in lobe VIIb, VIII and IX. Corticospinal excitability was only increased after tACS was applied for 40 s or 20 min at rest, and motor activation during tACS (MSL) cancelled this effect. In addition, performance was better (shorter reaction times) for the learned sequences after 20 min of tACS, indicating more pronounced learning under 20 min of tACS compared to tACS applied only in the first 40 s.
ABSTRACT
To compare the inter-rater reliability (IRR) of five clinical rating scales for video-based assessment of hemifacial spasm (HFS) motor severity. We evaluated the video recordings of 45 HFS participants recruited through the Dystonia Coalition. In Round 1, six clinicians with expertise in HFS assessed the participants' motor severity with five scales used to measure motor severity of HFS: the Jankovic rating scale (JRS), Hemifacial Spasm Grading Scale (HSGS), Samsung Medical Center (SMC) grading system for severity of HFS spasms (Lee's scale), clinical grading of spasm intensity (Chen's scale), and a modified version of the Abnormal Involuntary Movement Scale (Tunc's scale). In Round 2, clinicians rated the same cohort with simplified scale wording after consensus training. For each round, we evaluated the IRR using the intraclass correlation coefficient [ICC (2,1) single-rater, absolute-agreement, 2-way random model]. The scales exhibited IRR that ranged from "poor" to "moderate"; the mean ICCs were 0.41, 0.43, 0.47, 0.43, and 0.65 for the JRS, HSGS, Lee's, Chen's, and Tunc's scales, respectively, for Round 1. In Round 2, the corresponding IRRs increased to 0.63, 0.60, 0.59, 0.53, and 0.71. In both rounds, Tunc's scale exhibited the highest IRR. For clinical assessments of HFS motor severity based on video observations, we recommend using Tunc's scale because of its comparative reliability and because clinicians interpret the scale easily without modifications or the need for consensus training.
Subject(s)
Dystonia , Hemifacial Spasm , Humans , Hemifacial Spasm/diagnosis , Reproducibility of ResultsABSTRACT
BACKGROUND: Although functional neurological movement disorders (FMD) are characterized by motor symptoms, sensory processing has also been shown to be disturbed. However, how the integration of perception and motor processes, essential for the control of goal-directed behavior, is altered in patients with FMD is less clear. A detailed investigation of these processes is crucial to foster a better understanding of the pathophysiology of FMD and can systematically be achieved in the framework of the theory of event coding (TEC). OBJECTIVE: The aim was to investigate perception-action integration processes on a behavioral and neurophysiological level in patients with FMD. METHODS: A total of 21 patients and 21 controls were investigated with a TEC-related task, including concomitant electroencephalogram (EEG) recording. We focused on EEG correlates established to reflect perception-action integration processes. Temporal decomposition allowed to distinguish between EEG codes reflecting sensory (S-cluster), motor (R-cluster), and integrated sensory-motor processing (C-cluster). We also applied source localization analyses. RESULTS: Behaviorally, patients revealed stronger binding between perception and action, as evidenced by difficulties in reconfiguring previously established stimulus-response associations. Such hyperbinding was paralleled by a modulation of neuronal activity clusters, including reduced C-cluster modulations of the inferior parietal cortex and altered R-cluster modulations in the inferior frontal gyrus. Correlations of these modulations with symptom severity were also evident. CONCLUSIONS: Our study shows that FMD is characterized by altered integration of sensory information with motor processes. Relations between clinical severity and both behavioral performance and neurophysiological abnormalities indicate that perception-action integration processes are central and a promising concept for the understanding of FMD. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Subject(s)
Conversion Disorder , Movement Disorders , Humans , Electroencephalography , Parietal Lobe , Movement/physiology , PerceptionABSTRACT
Increased activity in the left inferior parietal cortex (BA40) plays a role in the generation of tics in the Gilles de la Tourette syndrome (GTS). Thus, inhibitory repetitive transcranial magnetic stimulation (rTMS) applied to BA40 was hypothesized to alleviate symptoms in GTS. We investigated the immediate effects of single-session 1 Hz rTMS and sham stimulation delivered to the left BA40 on tics assessed with the Rush video protocol in 29 adults with GTS. There were no significant effects on tic symptoms following rTMS or sham stimulation. Moreover, there was no difference when comparing the effects of both stimulation conditions. Bayesian statistics indicated substantial evidence against an intervention effect. The left BA40 appears not to be a useful target for 1 Hz rTMS to modulate tic symptoms in GTS patients.
ABSTRACT
Gilles de la Tourette syndrome (GTS) is a neuropsychiatric disorder. Because motor signs are the defining feature of GTS, addressing the neurophysiology of motor processes is central to understanding GTS. The integration of voluntary motor processes is subject to so-called "binding problems", i.e., how different aspects of an action are integrated. This was conceptualized in the theory of event coding, in which 'action files' accomplish the integration of motor features. We examined the functional neuroanatomical architecture of EEG theta band activity related to action file processing in GTS patients and healthy controls. Whereas, in keeping with previous data, behavioral performance during action file processing did not differ between GTS and controls, underlying patterns of neural activity were profoundly different. Superior parietal regions (BA7) were predominantly engaged in healthy controls, but superior frontal regions (BA9, BA10) in GTS indicated that the processing of different motor feature codes was central for action file processing in healthy controls, whereas episodic processing was more relevant in GTS. The data suggests a cascade of cognitive branching in fronto-polar areas followed by episodic processing in superior frontal regions in GTS. Patients with GTS accomplish the integration of motor plans via qualitatively different neurophysiological processes.
ABSTRACT
BACKGROUND: Motor symptoms in functional movement disorders (FMDs) are experienced as involuntary but share characteristics of voluntary action. Clinical and experimental evidence indicate alterations in monitoring, control, and subjective experience of self-performed movements. OBJECTIVE: The objective of this study was to test the prediction that FMDs are associated with a reduced ability to make accurate (metacognitive) judgments about self-performed movements. METHODS: We compared 24 patients with FMD (including functional gait disturbance, functional tremor, and functional tics) with 24 age- and sex-matched healthy control subjects in a novel visuomotor-metacognitive paradigm. Participants performed target-directed movements on a graphics tablet with restricted visual feedback, decided which of two visually presented trajectories was closer to their preceding movement, and reported their confidence in the visuomotor decision. We quantified individual metacognitive performance as participants' ability to assign high confidence preferentially to correct visuomotor decisions. RESULTS: Patients and control subjects showed comparable motor performance, response accuracy, and use of the confidence scale. However, visuomotor sensitivity in the trajectory judgment was reduced in patients with FMD compared with healthy control subjects. Moreover, metacognitive performance was impaired in patients, that is, their confidence ratings were less predictive of the correctness of visuomotor decisions. Exploratory subgroup analyses suggest metacognitive deficits to be most pronounced in patients with a functional gait disturbance or functional tremor. CONCLUSIONS: Patients with FMD exhibited deficits both when making visuomotor decisions about their own movements and in the metacognitive evaluation of these decisions. Reduced metacognitive insight into voluntary motor control may play a role in FMD pathophysiology and could lay the groundwork for new treatment strategies. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Subject(s)
Conversion Disorder , Metacognition , Movement Disorders , Humans , Metacognition/physiology , Tremor , Judgment/physiology , Movement/physiologyABSTRACT
Background: Several scales have been proposed to clinically evaluate the Motor Severity of Blepharospasm (BSP) but information about their measurement properties as a multicenter instrument is limited. Objective: To compare the measurement properties of four clinical scales in rating the severity of BSP in a large sample of patients from multiple sites. Methods: The Burke-Fahn-Marsden Scale (BFMS), the Global Dystonia Severity Rating Scale (GDRS), the Jankovic Rating Scale (JRS), and the Blepharospasm Severity Rating Scale (BSRS) were administered to 211 patients across 10 sites who were also requested to self-complete the Blepharospasm Disability Index (BDI). Measurement properties to be assessed included inter-/intra-observer agreement, item-to-total correlation, internal consistency, floor and ceiling effect, convergent/discriminant validity, and adherence to the distribution of BDI. Results: The BFMS had unsatisfactory measurement properties, the GDRS had acceptable reliability but other properties could not be completely testable; the JRS had satisfactory measurement properties but the scale did not accurately reflect the distribution of disability parameter (BDI) in the sample, and the BSRS had satisfactory measurement properties and also showed the best adherence to the distribution of BDI in the assessed sample. Conclusion: The comparison of the measurement properties of four rating scales to assess the motor state of the BSP in a large sample of patients from multiple sites showed that the GDRS should be used to simultaneously assess BSP and dystonia in other body parts, while the JRS (easier to use) and BSRS (better to discriminate severity) should be used to assess BSP alone.
ABSTRACT
Transcranial current stimulation (tCS) techniques have been shown to induce cortical plasticity. As an important relay in the motor system, the cerebellum is an interesting target for plasticity induction using tCS, aiming to modulate its excitability and connectivity. However, until now it remains unclear, which is the most effective tCS method for inducing plasticity in the cerebellum. Thus, in this study, the effects of anodal transcranial direct current stimulation (tDCS), 50 Hz transcranial alternating current stimulation (50 Hz tACS), and high frequency transcranial random noise stimulation (tRNS) were compared with sham stimulation in 20 healthy subjects in a within-subject design. tCS was applied targeting the cerebellar lobe VIIIA using neuronavigation. We measured corticospinal excitability, short-interval intracortical inhibition (SICI), short-latency afferent inhibition (SAI), and cerebellar brain inhibition (CBI) and performed a sensor-based movement analysis at baseline and three times after the intervention (post1 = 15 min; post2 = 55 min; post3 = 95 min). Corticospinal excitability increased following cerebellar tACS and tRNS compared to sham stimulation. This effect was most pronounced directly after stimulation but lasted for at least 55 min after tACS. Cortico-cortical and cerebello-cortical conditioning protocols, as well as sensor-based movement analyses, did not change. Our findings suggest that cerebellar 50 Hz tACS is the most effective protocol to change corticospinal excitability.
ABSTRACT
INTRODUCTION: Idiopathic blepharospasm is a clinically heterogeneous dystonia also characterized by non motor symptoms. METHODS: We used a k-means cluster analysis to assess 188 patients with idiopathic blepharospasm in order to identify relatively homogeneous subpopulations of patients, using a set of motor and psychiatric variables to generate the cluster solution. RESULTS: Blepharospasm patients reached higher scores on scales assessing depressive- and anxiety-related disorders than healthy/disease controls. Cluster analysis suggested the existence of three groups of patients that differed by type of spasms, overall motor severity, and presence/severity of psychiatric problems. The greater severity of motor symptoms was observed in Group 1, the least severity in Group 3, while the severity of blepharospasm in Group 2 was between that observed in Groups 1 and 3. The three motor subtypes also differed by psychiatric features: the lowest severity of psychiatric symptoms was observed in the group with least severe motor symptoms (group 3), while the highest psychiatric severity scores were observed in group 2 that carried intermediate motor severity rather than in the group with more severe motor symptoms (group 1). The three groups did not differ by disease duration, age of onset, sex or other clinical features. CONCLUSIONS: The present study suggests that blepharospasm patients may be classified in different subtypes according to the type of spasms, overall motor severity and presence/severity of depressive symptoms and anxiety.
Subject(s)
Blepharospasm , Dystonic Disorders , Humans , Anxiety , Cluster Analysis , SpasmABSTRACT
Dopa-responsive dystonia (DRD) is caused by an impaired dopamine biosynthesis due to a GTP-cyclohydrolase-1 (GCH1) deficiency, resulting in a combination of dystonia and parkinsonism. However, the effect of GCH1 mutations and levodopa treatment on motor control beyond simple movements, such as timing, action preparation and feedback processing, have not been investigated so far. In an active time estimation task with trial-by-trial feedback, participants indicated a target interval (1200 ms) by a motor response. We compared 12 patients tested (in fixed order) under their current levodopa medication ("ON") and after levodopa withdrawal ("OFF") to matched healthy controls (HC), measured twice to control for repetition effects. We assessed time estimation accuracy, trial-to-trial adjustment, as well as task- and feedback-related pupil-linked arousal responses. Patients showed comparable time estimation accuracy ON medication as HC but reduced performance OFF medication. Task-related pupil responses showed the reverse pattern. Trial-to-trial adjustments of response times were reduced in DRD, particularly OFF medication. Our results indicate differential alterations of time estimation accuracy and task-related arousal dynamics in DRD patients as a function of dopaminergic medication state. A medication-independent alteration of task repetition effects in DRD cannot be ruled out with certainty but is discussed as less likely.
Subject(s)
Dystonic Disorders , Levodopa , Arousal , Case-Control Studies , GTP Cyclohydrolase/genetics , Humans , Levodopa/therapeutic useABSTRACT
BACKGROUND: Blepharospasm is one of the most common subtypes of dystonia, and often spreads to other body regions. Despite published guidelines, the approach to diagnosis and classification of affected body regions varies among clinicians. OBJECTIVE: To delineate the clinical features used by movement disorder specialists in the diagnosis and classification of blepharospasm according to body regions affected, and to develop recommendations for a more consistent approach. METHODS: Cross-sectional data for subjects diagnosed with all types of isolated dystonia were acquired from the Dystonia Coalition, an international, multicenter collaborative research network. Data were evaluated to determine how examinations recorded by movement disorder specialists were used to classify blepharospasm as focal, segmental, or multifocal. RESULTS: Among all 3222 participants with isolated dystonia, 210 (6.5%) had a diagnosis of focal blepharospasm. Among these 210 participants, 34 (16.2%) had dystonia outside of upper face region. Factors such as dystonia severity across different body regions and number of body regions affected influenced the classification of blepharospasm as focal, segmental, or multifocal. CONCLUSIONS: Although focal blepharospasm is the second most common type of dystonia, a high percentage of individuals given this diagnosis had dystonia outside of the eye/upper face region. These findings are not consistent with existing guidelines for the diagnosis and classification of focal blepharospasm, and point to the need for more specific guidelines for more consistent application of existing recommendations for diagnosis and classification.
Subject(s)
Blepharospasm , Dystonia , Dystonic Disorders , Blepharospasm/diagnosis , Cross-Sectional Studies , Dystonia/diagnosis , Dystonic Disorders/diagnosis , HumansABSTRACT
INTRODUCTION: GCH1 mutations have been linked to decreased striatal dopamine and development of dopa-responsive dystonia (DRD) and Parkinsonism. Sensory and sensorimotor integration impairments have been documented in various forms of dystonia. DRD patients with confirmed GCH1 mutations have demonstrated normal short-latency afferent inhibition (SAI), a measure of sensorimotor inhibition, under chronic dopaminergic replacement therapy (DRT), but reduced inhibition after a single l-dopa dose following 24 h withdrawal. Studies have revealed normal SAI in other forms of dystonia but reductions with DRT in Parkinson's disease. Longitudinal changes in sensorimotor inhibition are unknown. METHODS: We analyzed sensorimotor inhibition using two different measures: SAI and somatosensory-motor inhibition using dual-site transcranial magnetic stimulation (ds-TMS). SAI was measured using digit stimulation 25 ms prior to contralateral primary motor cortex (M1) TMS. DS-TMS was measured using TMS over the somatosensory cortex 1 or 2.5 ms prior to ipsilateral M1 stimulation. A total of 20 GCH1 mutation carriers and 20 age-matched controls were included in the study. SAI and ds-TMS were evaluated in GCH1 mutation carriers both OFF and ON DRT compared to controls. Furthermore, longitudinal changes of SAI were examined in a subset of the same individuals that were measured â¼five years earlier. RESULTS: Neither SAI nor ds-TMS were significantly different in GCH1 mutation carriers relative to controls. No effects of DRT on SAI or ds-TMS were seen but SAI decreased over time in mutation carriers OFF DRT. CONCLUSION: Our longitudinal results suggest changes in SAI that could be associated with plasticity changes in sensorimotor networks.
Subject(s)
Dystonia , Dystonic Disorders , Dystonic Disorders/drug therapy , Dystonic Disorders/genetics , Humans , Neural Inhibition/physiology , Transcranial Magnetic Stimulation/methodsABSTRACT
BACKGROUND: Deep brain stimulation of the subthalamic nucleus is effective to alleviate motor symptoms in advanced Parkinson's disease. Using a novel conditioning paradigm, it has been shown that deep brain stimulation pulses from electrodes in the subthalamic nucleus modulate corticospinal excitability as determined with transcranial magnetic stimulation applied to the motor cortex. The mechanism of action is unclear. OBJECTIVE: To investigate the effects of subthalamic nucleus and dorsal premotor cortex conditioning on corticospinal excitability as a function of interstimulus intervals between target areas and deep brain stimulation frequencies. METHODS: In 19 patients with Parkinson's disease with subthalamic nucleus deep brain stimulation, the premotor-motor interaction was investigated in four different deep brain stimulation conditions (off, clinically used settings, 3 Hz, 20 Hz). Transcranial magnetic pulses were applied to the premotor and motor cortex and paired at certain intervals with deep brain stimulation pulses. The volume of tissue activated by deep brain stimulation was correlated with neurophysiological findings. RESULTS: There was distinct motor cortex inhibition by premotor cortex conditioning at an interstimulus interval of 1 ms before the motor cortex stimulation. Subthalamic nucleus conditioning with deep brain stimulation frequencies of 3 and 20 Hz at an interstimulus interval of 10 ms between subthalamic nucleus and primary motor cortex reduced premotor-motor inhibition. The volume of tissue activated by deep brain stimulation correlated positively with this effect. Corticospinal excitability was not affected by subthalamic nucleus conditioning as used here. CONCLUSIONS: Premotor-motor inhibition is modulated by subthalamic nucleus conditioning, presumably through the monosynaptic hyperdirect pathway.
Subject(s)
Deep Brain Stimulation , Motor Cortex , Parkinson Disease , Subthalamic Nucleus , Humans , Parkinson Disease/therapy , Subthalamic Nucleus/physiology , Transcranial Magnetic StimulationABSTRACT
BACKGROUND: Pathogenic variants in 5 genes (GCH1, TH, PTS, SPR, and QDPR), involved in dopamine/tetrahydrobiopterin biosynthesis or recycling, have been linked to Dopa-responsive dystonia (DRD). Diagnosis and treatment are often delayed due to high between- and within-group variability. OBJECTIVES: Comprehensively analyzed individual genotype, phenotype, treatment response, and biochemistry information. METHODS: 734 DRD patients and 151 asymptomatic GCH1 mutation carriers were included using an MDSGene systematic literature review and an automated classification approach to distinguish between different forms of monogenic DRDs. RESULTS: Whereas dystonia, L-Dopa responsiveness, early age at onset, and diurnal fluctuations were identified as red flags, parkinsonism without dystonia was rarely reported (11%) and combined with dystonia in only 18% of patients. While sex was equally distributed in autosomal recessive DRD, there was female predominance in autosomal dominant DYT/PARK-GCH1 patients accompanied by a lower median age at onset and more dystonia in females compared to males. Accordingly, the majority of asymptomatic heterozygous GCH1 mutation carriers (>8 years of age) were males. Multiple other subgroup-specific characteristics were identified, showing high accuracy in the automated classification approach: Seizures and microcephaly were mostly seen in DYT/PARK-PTS, autonomic symptoms appeared commonly in DYT/PARK-TH and DYT/PARK-PTS, and sleep disorders and oculogyric crises in DYT/PARK-SPR. Biochemically, homovanillic acid and 5-hydroxyindoleacetic acid in CSF were reduced in most DRDs, but neopterin and biopterin were increased only in DYT/PARK-PTS and DYT/PARK-SPR. Hyperphenylalaninemia was seen in DYT/PARK-PTS, DYT/PARK-QDPR, and rarely reported in autosomal recessive DYT/PARK-GCH1. CONCLUSIONS: Our indicators will help to specify diagnosis and accelerate start of treatment. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Subject(s)
Dystonia , Dystonic Disorders , Dystonia/drug therapy , Dystonia/genetics , Dystonic Disorders/genetics , Female , GTP Cyclohydrolase/genetics , Genotype , Humans , Male , PhenotypeABSTRACT
From shell shock tremors to TikTok tics, functional movement disorders have long been assumed to be motor expressions of emotional turmoil. However, psychodynamic explanations are increasingly complemented by neurophysiological findings, meaning that specialized physiotherapy is gaining in importance alongside psychotherapy. Still, there is no disease-specific outcome measure that adequately assesses patient-relevant aspects of this heterogeneous condition. Such a questionnaire was developed and its content was validated in a multistage development process. The relevance and comprehensibility of the items were first evaluated by a panel of experts and then by affected patients, and questions and possible response categories were adjusted accordingly. The resultant revised questionnaire yields good content-related validity and thus allows, for the first time, a quantification of the subjective complaints and implications associated with functional movement disorders. The next step will be a multicenter study to analyze the psychometric properties and factorial structure of this new instrument.
Subject(s)
Conversion Disorder , Humans , Outcome Assessment, Health Care , Psychometrics , Psychotherapy , Reproducibility of Results , Surveys and QuestionnairesABSTRACT
Tourette syndrome is a common neurodevelopmental disorder defined by multiple motor and phonic tics. Tics in Tourette syndrome resemble spontaneously occurring movements in healthy controls and are therefore sometimes difficult to distinguish from these. Tics may in fact be mis-interpreted as a meaningful action, i.e. a signal with social content, whereas they lack such information and could be conceived a surplus of action or 'motor noise'. These and other considerations have led to a 'neural noise account' of Tourette syndrome suggesting that the processing of neural noise and adaptation of the signal-to-noise ratio during information processing is relevant for the understanding of Tourette syndrome. So far, there is no direct evidence for this. Here, we tested the 'neural noise account' examining 1/f noise, also called scale-free neural activity as well as aperiodic activity, in n = 74 children, adolescents and adults with Tourette syndrome and n = 74 healthy controls during task performance using EEG data recorded during a sensorimotor integration task. In keeping with results of a previous study in adults with Tourette syndrome, behavioural data confirmed that sensorimotor integration was also stronger in this larger Tourette syndrome cohort underscoring the relevance of perceptual-action processes in this disorder. More importantly, we show that 1/f noise and aperiodic activity during sensorimotor processing is increased in patients with Tourette syndrome supporting the 'neural noise account'. This implies that asynchronous/aperiodic neural activity during sensorimotor integration is stronger in patients with Tourette syndrome compared to healthy controls, which is probably related to abnormalities of GABAergic and dopaminergic transmission in these patients. Differences in 1/f noise and aperiodic activity between patients with Tourette syndrome and healthy controls were driven by high-frequency oscillations and not lower-frequency activity currently discussed to be important in the pathophysiology of tics. This and the fact that Bayesian statistics showed that there is evidence for the absence of a correlation between neural noise and clinical measures of tics, suggest that increased 1/f noise and aperiodic activity are not directly related to tics but rather represents a novel facet of Tourette syndrome.