The clinical approach to movement disorders

Enhanced Infant Movement Analysis Using Transformer-Based Fusion of Diverse Video Features for Neurodevelopmental Monitoring

Neurodevelopment is a highly intricate process, and early detection of abnormalities is critical for optimizing outcomes through timely intervention. Accurate and cost-effective diagnostic methods for neurological disorders, particularly in infants, remain a significant challenge due to the heterogeneity of data and the variability in neurodevelopmental conditions. This study recruited twelve parent-infant pairs, with infants aged 3 to 12 months. Approximately 25 min of 2D video footage was captured, documenting natural play interactions between the infants and toys. We developed a novel, open-source method to classify and analyse infant movement patterns using deep learning techniques, specifically employing a transformer-based fusion model that integrates multiple video features within a unified deep neural network. This approach significantly outperforms traditional methods reliant on individual video features, achieving an accuracy of over 90%. Furthermore, a sensitivity analysis revealed that the pose estimation contributed far less to the model's output than the pre-trained transformer and convolutional neural network (CNN) components, providing key insights into the relative importance of different feature sets. By providing a more robust, accurate and low-cost analysis of movement patterns, our work aims to enhance the early detection and potential prediction of neurodevelopmental delays, whilst providing insight into the functioning of the transformer-based fusion models of diverse video features.

Automatic two-dimensional & three-dimensional video analysis with deep learning for movement disorders: A systematic review

The advent of computer vision technology and increased usage of video cameras in clinical settings have facilitated advancements in movement disorder analysis. This review investigated these advancements in terms of providing practical, low-cost solutions for the diagnosis and analysis of movement disorders, such as Parkinson's disease, ataxia, dyskinesia, and Tourette syndrome. Traditional diagnostic methods for movement disorders are typically reliant on the subjective assessment of motor symptoms, which poses inherent challenges. Furthermore, early symptoms are often overlooked, and overlapping symptoms across diseases can complicate early diagnosis. Consequently, deep learning has been used for the objective video-based analysis of movement disorders. This study systematically reviewed the latest advancements in automatic two-dimensional & three-dimensional video analysis using deep learning for movement disorders. We comprehensively analyzed the literature published until September 2023 by searching the Web of Science, PubMed, Scopus, and Embase databases. We identified 68 relevant studies and extracted information on their objectives, datasets, modalities, and methodologies. The study aimed to identify, catalogue, and present the most significant advancements, offering a consolidated knowledge base on the role of video analysis and deep learning in movement disorder analysis. First, the objectives, including specific PD symptom quantification, ataxia assessment, cerebral palsy assessment, gait disorder analysis, tremor assessment, tic detection (in the context of Tourette syndrome), dystonia assessment, and abnormal movement recognition were discussed. Thereafter, the datasets used in the study were examined. Subsequently, video modalities and deep learning methodologies related to the topic were investigated. Finally, the challenges and opportunities in terms of datasets, interpretability, evaluation methods, and home/remote monitoring were discussed.

Prevalence of spontaneous movement disorders (dyskinesia, parkinsonism, akathisia and dystonia) in never-treated patients with chronic and first-episode psychosis: a systematic review and meta-analysis

BACKGROUND

The aim of this systematic review and meta-analysis is to evaluate and compare the prevalence rates of spontaneous movement disorders (SMDs), including dyskinesia, parkinsonism, akathisia and dystonia, in antipsychotic-naïve individuals with chronic psychosis and first-episode psychosis (FEP) and gain a more nuanced understanding of factors influencing their presence.

METHODS

Several literature databases were systematically searched and screened based on predetermined eligibility criteria. Included articles underwent risk of bias assessment. The prevalence rates of SMDs were calculated using a random-effects model.

RESULTS

Out of 711 articles screened, 27 were included in this meta-analysis. The pooled prevalence of spontaneous dyskinesia was 7% (3% FEP and 17% chronic schizophrenia) across 24 studies (95% CI 3 to 11; I2=94%, p<0.01) and 15% for spontaneous parkinsonism (14% FEP and 19% chronic schizophrenia) in 21 studies (95% CI 12 to 20; I2=81%, p<0.01). A meta-regression analysis found a significant positive correlation between age (p<0.05) and duration of untreated psychosis (DUP) (p<0.05) with dyskinesia but not parkinsonism prevalence. Akathisia and dystonia appear to be both less studied and less frequent in occurrence with a pooled prevalence of 4% (95% CI: 3 to 6; I2=0%, p=0.65) for akathisia in eight studies and a mean prevalence of 6% (range 0%-16%) for dystonia in five studies.

CONCLUSION

The presence of varying degrees of neurodysfunction in antipsychotic-naïve patients with schizophrenia underscores the need for individualised treatment approaches that consider each patient's unique predisposition and neuromotor profile. Further research is warranted into the role of specific SMDs and risk factors including sex, race and diagnostic variations.

PROSPERO REGISTRATION NUMBER

CRD42024501951.

Serotonin syndrome caused by escitalopram in Parkinson's disease psychosis: a case report

BACKGROUND

Serotonin syndrome and Parkinson's disease (PD) are two diseases whose symptoms partially overlap; this poses challenges in distinguishing them in clinical practice. Early manifestations such as tremor, akathisia, diaphoresis, hypertonia and hyperreflexia are common in mild-to-moderate serotonin syndrome and can also occur in PD. Without prompt recognition and treatment, serotonin syndrome can rapidly progress, potentially leading to severe complications such as multiple organ failure within hours. Given their disparate treatment strategies, accurate clinical distinction is crucial for effective treatment. This case study explores a patient with serotonin syndrome triggered by escitalopram in the context of PD psychosis (PDP), providing insights into diagnosis and treatment planning.

CASE PRESENTATION

A 75-year-old Asian woman with a one-year history of PD, a two-month history of PDP, and a six-year history of depression presented with symptoms including hyperreflexia, tremor, hypertonia, impaired level of consciousness, and inappropriate behavior following a recent one-month adjustment in medication. Initially suspected of being drug-induced parkinsonism or worsening PD, therapeutic drug monitoring revealed warning levels of escitalopram. Subsequent diagnoses confirmed serotonin syndrome. This syndrome may result from increased cortical serotonin activity at the serotonin2A receptor due to dopamine and serotonin imbalances in PDP, compounded by increased dopamine-mediated serotonin release. Additionally, being an intermediate metabolizer of cytochrome P450 enzyme 2C19, the patient experienced excessive escitalopram accumulation, exacerbating her condition.

CONCLUSIONS

This case underscores the critical need to differentiate between symptoms of serotonin syndrome and PD, particularly in manifestations like tremor and hypertonia. Careful consideration of receptor profiles in patients with PDP is essential when selecting antidepressants to mitigate the risk of serotonin syndrome.

Next move in movement disorders: neuroimaging protocols for hyperkinetic movement disorders

Introduction

The Next Move in Movement Disorders (NEMO) study is an initiative aimed at advancing our understanding and the classification of hyperkinetic movement disorders, including tremor, myoclonus, dystonia, and myoclonus-dystonia. The study has two main objectives: (a) to develop a computer-aided tool for precise and consistent classification of these movement disorder phenotypes, and (b) to deepen our understanding of brain pathophysiology through advanced neuroimaging techniques. This protocol review details the neuroimaging data acquisition and preprocessing procedures employed by the NEMO team to achieve these goals.

Methods and analysis

To meet the study's objectives, NEMO utilizes multiple imaging techniques, including T1-weighted structural MRI, resting-state fMRI, motor task fMRI, and 18F-FDG PET scans. We will outline our efforts over the past 4 years to enhance the quality of our collected data, and address challenges such as head movements during image acquisition, choosing acquisition parameters and constructing data preprocessing pipelines. This study is the first to employ these neuroimaging modalities in a standardized approach contributing to more uniformity in the analyses of future studies comparing these patient groups. The data collected will contribute to the development of a machine learning-based classification tool and improve our understanding of disorder-specific neurobiological factors.

Ethics and dissemination

Ethical approval has been obtained from the relevant local ethics committee. The NEMO study is designed to pioneer the application of machine learning of movement disorders. We expect to publish articles in multiple related fields of research and patients will be informed of important results via patient associations and press releases.

Review of the Brain's Behaviour after Injury and Disease for Its Application in an Agent-Based Model (ABM)

The brain is the most complex organ in the human body and, as such, its study entails great challenges (methodological, theoretical, etc.). Nonetheless, there is a remarkable amount of studies about the consequences of pathological conditions on its development and functioning. This bibliographic review aims to cover mostly findings related to changes in the physical distribution of neurons and their connections-the connectome-both structural and functional, as well as their modelling approaches. It does not intend to offer an extensive description of all conditions affecting the brain; rather, it presents the most common ones. Thus, here, we highlight the need for accurate brain modelling that can subsequently be used to understand brain function and be applied to diagnose, track, and simulate treatments for the most prevalent pathologies affecting the brain.

Negative Myoclonus: Neurophysiological Study and Clinical Impact in Progressive Myoclonus Ataxia

INTRODUCTION

Negative myoclonus (NM) is an involuntary movement caused by a sudden interruption of muscular activity, resulting in gait problems and falls.

OBJECTIVE

To establish frequency, clinical impact, and neurophysiology of NM in progressive myoclonus ataxia (PMA) patients.

METHODS

Clinical, neurophysiological, and genetic data of 14 PMA individuals from University Medical Centre Groningen (UMCG) Expertise Center Movement Disorder Groningen were retrospectively collected. Neurophysiological examination included video-electromyography-accelerometry assessment in all patients and electroencephalography (EEG) examination in 13 individuals. Jerk-locked (or silent period-locked) back-averaging and cortico-muscular coherence (CMC) analysis aided the classification of myoclonus.

RESULTS

NM was present in 6 (NM+) and absent in 8 (NM-) PMA patients. NM+ individuals have more frequent falls (100% vs. 37.5%) and higher scores on the Gross Motor Function Classification System (GMFCS) (4.3 ±0.74 vs. 2.5 ±1.2) than NM- individuals. Genetic background of NM+ included GOSR2 and SEMA6B, while that of NM- included ATM, KCNC3, NUS1, STPBN2, and GOSR2. NM was frequently preceded by positive myoclonus (PM) and silent-period length was between 88 and 194 ms. EEG epileptiform discharges were associated with NM in 2 cases. PM was classified as cortical in 5 NM+ and 2 NM- through EEG inspection, jerk-locked back-averaging, or CMC analysis.

DISCUSSION

Neurophysiological examination is crucial for detecting NM that could be missed on clinical examination due to a preceding PM. Evidence points to a cortical origin of NM, an association with more severe motor phenotype, and suggests the presence of genetic disorders causing either a PMA or progressive myoclonus epilepsy, rather than pure PMA phenotype. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

The Spontaneous Incidence of Neurological Clinical Signs in Preclinical Species Using Cage-side Observations or High-definition Video Monitoring: A Retrospective Analysis

When conducting toxicology studies, the interpretation of drug-related neurological clinical signs such as convulsions, myoclonus/myoclonic jerks, tremors, ataxia, and salivation requires an understanding of the spontaneous incidence of those observations in commonly used laboratory animal species. The spontaneous incidence of central nervous system clinical signs in control animals from a single facility using cage-side observations or high definition video monitoring was retrospectively analyzed. Spontaneous convulsions were observed at low incidence in Beagle dogs and Sprague-Dawley rats but were not identified in cynomolgus monkeys and Göttingen minipigs. Spontaneous myoclonic jerks and muscle twitches were observed at low incidence in Beagle dogs, cynomolgus monkeys, and Sprague-Dawley rats but were not seen in Göttingen minipigs. Spontaneous ataxia/incoordination was identified in all species and generally with a higher incidence when using video monitoring. Salivation and tremors were the two most frequent spontaneous clinical signs and both were observed in all species. Data from the current study unveil potential limitations when using control data obtained from a single study for toxicology interpretation related to low incidence neurological clinical signs while providing historical control data from Beagle dogs, cynomolgus monkeys, Sprague-Dawley rats, and Göttingen minipigs.

Next-generation sequencing and bioinformatics in rare movement disorders

The ability to sequence entire exomes and genomes has revolutionized molecular testing in rare movement disorders, and genomic sequencing is becoming an integral part of routine diagnostic workflows for these heterogeneous conditions. However, interpretation of the extensive genomic variant information that is being generated presents substantial challenges. In this Perspective, we outline multidimensional strategies for genetic diagnosis in patients with rare movement disorders. We examine bioinformatics tools and computational metrics that have been developed to facilitate accurate prioritization of disease-causing variants. Additionally, we highlight community-driven data-sharing and case-matchmaking platforms, which are designed to foster the discovery of new genotype-phenotype relationships. Finally, we consider how multiomic data integration might optimize diagnostic success by combining genomic, epigenetic, transcriptomic and/or proteomic profiling to enable a more holistic evaluation of variant effects. Together, the approaches that we discuss offer pathways to the improved understanding of the genetic basis of rare movement disorders.

Eye movements in Parkinson's disease: from neurophysiological mechanisms to diagnostic tools

Movement disorders such as Parkinson's disease (PD) impact oculomotor function - the ability to move the eyes accurately and purposefully to serve a multitude of sensory, cognitive, and secondary motor tasks. Decades of neurophysiological research in monkeys and behavioral studies in humans have characterized the neural basis of healthy oculomotor control. This review links eye movement abnormalities in persons living with PD to the underlying neurophysiological mechanisms and pathways. Building on this foundation, we highlight recent progress in using eye movements to gauge symptom severity, assess treatment effects, and serve as potential precision biomarkers. We conclude that whereas eye movements provide insights into PD mechanisms, based on current evidence they appear to lack sufficient sensitivity and specificity to serve as a standalone diagnostic tool. Their full potential may be realized when combined with other disease indicators in big datasets.

Social cognition in hyperkinetic movement disorders: a systematic review

Numerous lines of research indicate that our social brain involves a network of cortical and subcortical brain regions that are responsible for sensing and controlling body movements. However, it remains unclear whether movement disorders have a systematic impact on social cognition. To address this question, we conducted a systematic review examining the influence of hyperkinetic movement disorders (including Huntington disease, Tourette syndrome, dystonia, and essential tremor) on social cognition. Following the PRISMA guidelines and registering the protocol in the PROSPERO database (CRD42022327459), we analyzed 50 published studies focusing on theory of mind (ToM), social perception, and empathy. The results from these studies provide evidence of impairments in ToM and social perception in all hyperkinetic movement disorders, particularly during the recognition of negative emotions. Additionally, individuals with Huntington's Disease and Tourette syndrome exhibit empathy disorders. These findings support the functional role of subcortical structures (such as the basal ganglia and cerebellum), which are primarily responsible for movement disorders, in deficits related to social cognition.

Use of virtual reality for targeted physical rehabilitation: Case report on managing functional motor disorder

Virtual reality (VR) technology has seen increasing use in physical rehabilitation and in the management of acute and chronic pain. Functional movement disorders (FMDs) are a source of disability with no known association to neurologic pathology, and patients are generally offered multidisciplinary treatment approaches to improve functional movement. However, patients who are not compliant with rehabilitation may have persistent FMD and long-term disability. Given VR's use in physical rehabilitation, it may serve as a useful adjunct for the management of FMD. Utilizing an application called MovementTM to create a playlist of targeted applications for the restoration of motor function and balance, this case study presents the application of VR as a tool to engage patients in physical therapy for the management of FMD. The VR games were selected to encourage movement while customization of levels within the games facilitated achievement of physical therapy goals. Physical rehabilitation aided by VR, when used in collaboration with a multidisciplinary care team, may be used to facilitate recovery from FMD.

A Kinematic Data-Driven Approach to Differentiate Involuntary Choreic Movements in Individuals With Neurological Conditions

OBJECTIVE

The ability to differentiate similar choreic involuntary movements could lay the groundwork for the development of a minimally-invasive screening tool for their etiology and provide in-depth understandings of pathophysiology. As a first step, we investigate kinematic differences between Huntington's disease (HD) chorea and Parkinson's disease (PD) choreic levodopa-induced dyskinesia (LID), which have distinct pathological causes yet share a great kinematic resemblance.

METHODS

Twenty subjects with HD and ten subjects with PD stood with both upper limbs in front of them for approximately 60 seconds. The three-dimensional velocity time-series of involuntary movements of both hands were segmented into one-dimensional sub-movements abutted by velocity zero-crossings. A combination of unsupervised and supervised machine learning algorithms was employed to automatically select data features extracted from sub-movements and distinguish the two types of involuntary choreic movements.

RESULTS

The trained model was able to accurately classify chorea vs. LID with an Area Under the Receiver Operating Characteristic Curve of 99.5%. A set of important features contributing to the construction of the classification model were identified and investigated.

CONCLUSION

The trained model may serve as a tool for the automatic identification of different types of involuntary choreic movements, enabling continuous monitoring and personalized treatment for patients in various clinical settings.

SIGNIFICANCE

The results provide insights into kinematic characteristics of HD chorea and PD LID, which is the first step towards an improved general understanding of involuntary choreic movements.

Research trends and frontiers in exercise for movement disorders: A bibliometric analysis of global research from 2010 to 2021

Objective

To conduct a bibliometric analysis of trends and frontiers on exercise-based non-pharmacological treatments for movement disorders published between 2010 and 2021.

Methods

The Web of Science (WOS) Core Collection database was searched for articles published between 2010 and 2021. The CiteSpace software was used for in-depth analysis of the countries, institutions, journals, and collaboration networks among authors and their types of articles, developmental directions, references, and hot keywords of published articles.

Results

A total of 2,626 published articles were retrieved by search formula and included in the analysis. The number of publications fluctuated during this period, with 96 countries, 3,058 institutions, and 886 academic journals having published articles in this area, with subject classifications that focused on Clinical Neurology and Neurosciences. The United States has maintained its dominant and most influential position in exercise-based non-pharmacological research on movement disorders. Among research institutions and journals, the League of European Research Universities and Movement Disorders journals published the highest number of academic articles. In the last five years, the hot research topics by burst keyword analysis, are focused on treatments, research advances, and clinical treatments.

Conclusion

Research on exercise-based non-pharmacological treatments for movement disorders is generally on the rise from 2010 to 2021. The bibliometric analysis of this area will help provide potential collaborations among researchers, frontiers, and directions for development.

Acute onset movement disorders in diabetes mellitus: A clinical series of 59 patients

Background and purpose

No previous study has assessed the frequency and clinical–radiological characteristics of patients with diabetes mellitus (DM) and acute onset nonchoreic and nonballistic movements. We conducted a prospective study to investigate the spectrum of acute onset movement disorders in DM.

Methods

We recruited all the patients with acute onset movement disorders and hyperglycemia who attended the wards of three hospitals in West Bengal, India from August 2014 to July 2021.

Results

Among the 59 patients (mean age = 55.4 ± 14.3 years, 52.5% men) who were included, 41 (69.5%) had choreic or ballistic movements, and 18 (30.5%) had nonchoreic and nonballistic movements. Ballism was the most common movement disorder (n = 18, 30.5%), followed by pure chorea (n = 15, 25.4%), choreoathetosis (n = 8, 13.6%), tremor (n = 5, 8.5%), hemifacial spasm (n = 3, 5.1%), parkinsonism (n = 3, 5.1%), myoclonus (n = 3, 5.1%), dystonia (n = 2, 3.4%), and restless leg syndrome (n = 2, 3.4%). The mean duration of DM was 9.8 ± 11.4 years (89.8% of the patients had type 2 DM). Nonketotic hyperglycemia was frequently (76.3%) detected. The majority (55.9%) had no magnetic resonance imaging (MRI) changes; the remaining showed striatal hyperintensity. Eight patients with MRI changes exhibited discordance with sidedness of movements. Most of the patients (76.3%) recovered completely.

Conclusions

This is the largest clinical series depicting the clinical–radiological spectrum of acute onset movement disorders in DM. Of note was that almost one third of patients had nonchoreic and nonballistic movements. Our findings highlight the importance of a capillary blood glucose measurement in patients with acute or subacute onset movement disorders, irrespective of their past glycemic status.

Progressive choreodystonia in X-linked hyper-IgM immunodeficiency: a rare but recurrent presentation

An association between movement disorders and immune‐system dysfunction has been described in the context of rare genetic diseases such as ataxia telangiectasia as well as infectious encephalopathies. We encountered a male patient who presented immunodeficiency of unknown etiology since childhood. A medication‐refractory, progressive choreodystonic movement disorder emerged at the age of 42 years and prompted an exome‐wide molecular testing approach. This revealed a pathogenic hemizygous variant in CD40LG, the gene implicated in X‐linked hyper‐IgM syndrome. Only two prior reports have specifically suggested a causal relationship between CD40LG mutations and involuntary hyperkinetic movements. Our findings thus confirm the existence of a particular CD40LG‐related condition, combining features of compromised immunity with neurodegenerative movement abnormalities. Establishing the diagnosis is crucial because of potential life‐threatening immunological complications.

The MDS consensus tremor classification: The best way to classify patients with tremor at present

In 2018, the new Consensus Statement on the Classification of Tremors, by the Task Force on Tremor of the International Parkinson Movement Disorder Society, was published. So far, the article has been cited more than 400 times in peer-reviewed international journals and commonly debated in conferences and meetings due to an enthusiastic welcome from the community. Compared to the previous Consensus Statement (1998), the main novelties are: 1) the classification of tremor according to clinical manifestation (Axis 1) and etiology (Axis 2), and therefore the use of a syndromic approach; 2) the definition of essential tremor as a syndrome; 3) the recognition of the new category essential tremor plus, that derives from the uncertain significance of the soft neurological signs often associated with essential tremor. In this paper, we summarise and explain the most important aspects of the new classification of tremors, highlighting the main novelties, their relevance, and application in clinical practice. Moreover, we discuss its possible weakness and reflect on the critical comments made so far. We believe that this new tremor classification is comprehensive, rigorous, and consistent and, considering our current knowledge of tremor syndromes, it is the best we can do at present. This article is part of the Special Issue "Tremor" edited by Daniel D. Truong, Mark Hallett, and Aasef Shaikh.

Primary orthostatic tremor and orthostatic tremor-plus in dogs: 60 cases (2003-2020)

BACKGROUND

Orthostatic tremor (OT) is a rare movement disorder characterized by high-frequency (>12 Hz) involuntary, rhythmic, sinusoidal movements affecting predominantly the limbs while standing.

OBJECTIVE

To describe the signalment, presenting complaints, phenotype, diagnostic findings, treatment, and outcome of a large sample of dogs with OT.

ANIMALS

Sixty dogs diagnosed with OT based on conscious electromyography.

METHODS

Multicenter retrospective case series study. Dogs were included if they had a conscious electromyography consistent with muscle discharge frequency >12 Hz while standing.

RESULTS

Fifty-three cases were diagnosed with primary OT (POT). Giant breed dogs represented most cases (83%; 44/53). Most dogs (79%; 42/53) were younger than 2 years of age at onset of signs, except for Retrievers which were all older than 3.5 years of age. The most common presenting complaints were pelvic limb tremors while standing (85%; 45/53) and difficulty when rising or sitting down (45%; 24/53). Improvement of clinical signs occurred in most dogs (85%; 45/53) treated medically with phenobarbital, primidone, gabapentin, pregabalin or clonazepam, but it was mostly partial rather than complete. Orthostatic tremor-plus was seen in 7 dogs that had concurrent neurological diseases.

CONCLUSIONS AND CLINICAL IMPORTANCE

Primary OT is a progressive disease of young, purebred, giant/large-breed dogs, which appears to begin later in life in Retrievers. Primary OT apparently responds partially to medications. Orthostatic tremor-plus exists in dogs and can be concomitant or associated with other neurological diseases.

Minocycline Mitigation of Tremor Syndrome and Defect of Cognitive and Balance Induced by Harmaline

Introduction:

Minocycline has anti-inflammatory, anti-apoptotic, and anti-oxidant effects. Preclinical data suggest that minocycline could be beneficial for treating common neurological disorders, including Parkinson disease and multiple sclerosis.

Methods:

In this study, the effects of minocycline on harmaline-induced motor and cognitive impairments were studied in male Wistar rats. The rats were divided into four groups of ten animals each. Harmaline was used for the induction of Essential Tremor (ET). Minocycline (90 mg/kg, IP) was administered 30 minutes before the saline or harmaline. Tremor intensity, spontaneous locomotor activity, passive avoidance memory, anxiety-related behaviors, and motor function were assessed in the rats.

Results:

The results showed that minocycline could recover tremor intensity and step width but failed to recuperate the motor balance. The memory impairments observed in harmaline-treated rats were somewhat reversed by administration of minocycline. The cerebellum and inferior olive nucleus were studied for neuronal degeneration using histochemistry and transmission electron microscopy techniques. Harmaline caused ultrastructural changes and neuronal cell loss in inferior olive and cerebellar Purkinje cells. Minocycline exhibited neuroprotective changes on cerebellar Purkinje cells and inferior olivary neurons.

Conclusion:

These results open new therapeutic perspectives for motor and memory impairments in ET. However, further studies are needed to clarify the exact mechanisms.

Frequency of hand movements as a possible diagnostic tool for parkinsonian bradykinesia. Proposal of a simple bedside test

BACKGROUND

Bradykinesia, dysrhythmia, and decrement in hand movements (HM) are core symptoms of Parkinson's disease (PD). The maximal rate of repetitive rhythm-preserving HM can be a diagnostic tool for PD bradykinesia.

OBJECTIVES

To improve the clinical diagnosis of bradykinesia by identifying the frequencies at which rhythmic HM become irregular in PD patients compared to healthy age-matched controls.

METHOD

Forty PD patients and 16 controls were asked to alternately perform left and right hand movements following the rate of a metronome with sound stimulation beginning at 85 beats per minute (BPM) and increasing in increments of 15 BPM up to 355 BPM. The rhythm of the HM for each rate was assessed visually, and the threshold frequency at which the subject could no longer rhythmically continue HM was measured by the metronome. The increasing rates of HM until reaching that threshold were compared between patients with PD and controls.

RESULTS

The mean rates of a metronome in PD vs. healthy subjects were 173.3 ± 42.0 vs. 248.8 ± 48.5 BPM (p < 0.001) and 164.8 ± 34.2 vs. 241.2 ± 40.1 BPM (p < 0.001) for the dominant and non-dominant hands, respectively. The areas under the ROC curve were 0.929 [95%CI: (0.86-0.99)] for the dominant hand and 0.947 [95%CI: (0.88-1.0)] for the non-dominant hand. The BMP score cut-off value was 208 (sensitivity 72.7%, specificity 100%) for the dominant hand and 206 (sensitivity 87.5%, specificity 95%) for the non-dominant hand.

CONCLUSIONS

The proposed test quantified the frequencies of rhythmic HMs in PD patients vs. controls and improved the diagnosis of bradykinesia in PD patients.

Next move in movement disorders (NEMO): developing a computer-aided classification tool for hyperkinetic movement disorders

INTRODUCTION

Our aim is to develop a novel approach to hyperkinetic movement disorder classification, that combines clinical information, electromyography, accelerometry and video in a computer-aided classification tool. We see this as the next step towards rapid and accurate phenotype classification, the cornerstone of both the diagnostic and treatment process.

METHODS AND ANALYSIS

The Next Move in Movement Disorders (NEMO) study is a cross-sectional study at Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen. It comprises patients with single and mixed phenotype movement disorders. Single phenotype groups will first include dystonia, myoclonus and tremor, and then chorea, tics, ataxia and spasticity. Mixed phenotypes are myoclonus-dystonia, dystonic tremor, myoclonus ataxia and jerky/tremulous functional movement disorders. Groups will contain 20 patients, or 40 healthy participants. The gold standard for inclusion consists of interobserver agreement on the phenotype among three independent clinical experts. Electromyography, accelerometry and three-dimensional video data will be recorded during performance of a set of movement tasks, chosen by a team of specialists to elicit movement disorders. These data will serve as input for the machine learning algorithm. Labels for supervised learning are provided by the expert-based classification, allowing the algorithm to learn to predict what the output label should be when given new input data. Methods using manually engineered features based on existing clinical knowledge will be used, as well as deep learning methods which can detect relevant and possibly new features. Finally, we will employ visual analytics to visualise how the classification algorithm arrives at its decision.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the relevant local ethics committee. The NEMO study is designed to pioneer the application of machine learning of movement disorders. We expect to publish articles in multiple related fields of research and patients will be informed of important results via patient associations and press releases.

Proposed Mobility Assessments with Simultaneous Full-Body Inertial Measurement Units and Optical Motion Capture in Healthy Adults and Neurological Patients for Future Validation Studies: Study Protocol

Healthy adults and neurological patients show unique mobility patterns over the course of their lifespan and disease. Quantifying these mobility patterns could support diagnosing, tracking disease progression and measuring response to treatment. This quantification can be done with wearable technology, such as inertial measurement units (IMUs). Before IMUs can be used to quantify mobility, algorithms need to be developed and validated with age and disease-specific datasets. This study proposes a protocol for a dataset that can be used to develop and validate IMU-based mobility algorithms for healthy adults (18–60 years), healthy older adults (>60 years), and patients with Parkinson’s disease, multiple sclerosis, a symptomatic stroke and chronic low back pain. All participants will be measured simultaneously with IMUs and a 3D optical motion capture system while performing standardized mobility tasks and non-standardized activities of daily living. Specific clinical scales and questionnaires will be collected. This study aims at building the largest dataset for the development and validation of IMU-based mobility algorithms for healthy adults and neurological patients. It is anticipated to provide this dataset for further research use and collaboration, with the ultimate goal to bring IMU-based mobility algorithms as quickly as possible into clinical trials and clinical routine.

Myoclonus- A Review

Myoclonus is a hyperkinetic movement disorder characterized by a sudden, brief, involuntary jerk. Positive myoclonus is caused by abrupt muscle contractions, while negative myoclonus by sudden cessation of ongoing muscular contractions. Myoclonus can be classified in various ways according to body distribution, relation to activity, neurophysiology, and etiology. The neurophysiological classification of myoclonus by means of electrophysiological tests is helpful in guiding the best therapeutic strategy. Given the diverse etiologies of myoclonus, a thorough history and detailed physical examination are key to the evaluation of myoclonus. These along with basic laboratory testing and neurophysiological studies help in narrowing down the clinical possibilities. Though symptomatic treatment is required in the majority of cases, treatment of the underlying etiology should be the primary aim whenever possible. Symptomatic treatment is often not satisfactory, and a combination of different drugs is often required to control the myoclonus. This review addresses the etiology, classification, clinical approach, and management of myoclonus.

Challenges in Clinicogenetic Correlations: One Gene - Many Phenotypes

Background

Progress in genetics – particularly the advent of next‐generation sequencing (NGS) – has enabled an unparalleled gene discovery and revealed unmatched complexity of genotype–phenotype correlations in movement disorders. Among other things, it has emerged that mutations in one and the same gene can cause multiple, often markedly different phenotypes. Consequently, movement disorder specialists have increasingly experienced challenges in clinicogenetic correlations.

Objectives

To deconstruct biological phenomena and mechanistic bases of phenotypic heterogeneity in monogenic movement disorders and neurodegenerative diseases. To discuss the evolving role of movement disorder specialists in reshaping disease phenotypes in the NGS era.

Methods

This scoping review details phenomena contributing to phenotypic heterogeneity and their underlying mechanisms.

Results

Three phenomena contribute to phenotypic heterogeneity, namely incomplete penetrance, variable expressivity and pleiotropy. Their underlying mechanisms, which are often shared across phenomena and non‐mutually exclusive, are not fully elucidated. They involve genetic factors (ie, different mutation types, dynamic mutations, somatic mosaicism, intragenic intra‐ and inter‐allelic interactions, modifiers and epistatic genes, mitochondrial heteroplasmy), epigenetic factors (ie, genomic imprinting, X‐chromosome inactivation, modulation of genetic and chromosomal defects), and environmental factors.

Conclusion

Movement disorders is unique in its reliance on clinical judgment to accurately define disease phenotypes. This has been reaffirmed by the NGS revolution, which provides ever‐growing sequencing data and fuels challenges in variant pathogenicity assertions for such clinically heterogeneous disorders. Deep phenotyping, with characterization and continual updating of “core” phenotypes, and comprehension of determinants of genotype–phenotype complex relationships are crucial for clinicogenetic correlations and have implications for the diagnosis, treatment and counseling.

International veterinary canine dyskinesia task force ECVN consensus statement: Terminology and classification

Movement disorders are a heterogeneous group of clinical syndromes in humans and animals characterized by involuntary movements without changes in consciousness. Canine movement disorders broadly include tremors, peripheral nerve hyperexcitability disorders, paroxysmal dyskinesia, and dystonia. Of these, canine paroxysmal dyskinesias remain one of the more difficult to identify and characterize in dogs. Canine paroxysmal dyskinesias include an array of movement disorders in which there is a recurrent episode of abnormal, involuntary, movement. In this consensus statement, we recommend standard terminology for describing the various movement disorders with an emphasis on paroxysmal dyskinesia, as well as a preliminary classification and clinical approach to reporting cases. In the clinical approach to movement disorders, we recommend categorizing movements into hyperkinetic vs hypokinetic, paroxysmal vs persistent, exercise‐induced vs not related to exercise, using a detailed description of movements using the recommended terminology presented here, differentiating movement disorders vs other differential diagnoses, and then finally, determining whether the paroxysmal dyskinesia is due to either inherited or acquired etiologies. This consensus statement represents a starting point for consistent reporting of clinical descriptions and terminology associated with canine movement disorders, with additional focus on paroxysmal dyskinesia. With consistent reporting and identification of additional genetic mutations responsible for these disorders, our understanding of the phenotype, genotype, and pathophysiology will continue to develop and inform further modification of these recommendations.

Risk factors and prognosis of adult-onset post-pump chorea

OBJECTIVES

Post-pump chorea (PPC), defined as the development of chorea after major cardiac surgery utilizing cardiopulmonary bypass (CPB), has been rarely reported in adults.

METHODS

We compared 17 patients with adult-onset PPC to controls who did not develop chorea after cardiac surgery with CPB. Two patients were enrolled using hospital based data and 15 were collected by a systematic literature review. The controls without chorea after CPB (n = 4208) were collected using hospital based data. We described the clinical and surgical features of adult-onset PPC and compared them with those of the controls.

RESULTS

Ten of 17 PPC patients were male, the mean age was 46.8 years, and the mean onset latency was 6.0 days. The adult-onset PPC patients were younger (46.8 ± 16.7 vs. 59.1 ± 15.0, p = 0.001), had a lower minimum body temperature (23.3 ± 5.5 vs. 29.7 ± 3.7, p < 0.001) and a longer total circulatory arrest time (63.7 ± 7.5 vs. 21.0 ± 14.6, p < 0.001) than controls. Forty-three percentage of patients with adult-onset PPC had persistent chorea on follow-up, and these patients showed a higher rate of abnormal initial brain MRI compared with the patients with good clinical outcomes (p = 0.041).

CONCLUSIONS

The onset age, onset latency, underlying disease, treatment response, and surgical features were variable among PPC patients, while abnormal initial brain MRI was associated with persistent chorea. Pooling more cases through multicenter efforts will hopefully provide more knowledge on the underlying pathophysiology, prevention, and management of PPC.

Video electroencephalogram combined with electromyography in the diagnosis of hyperkinetic movement disorders with an unknown cause

OBJECTIVES

Diagnosis of hyperkinetic movement disorders with an unknown cause is usually challenging. The objective of this study is to learn about video electroencephalogram (VEEG) combined with electromyography (EMG) in the diagnosis of hyperkinetic movement disorders with an unknown cause.

METHODS

We performed an observational cohort study by recruiting consecutive patients with hyperkinetic movements as the main manifestation with an unknown cause for VEEG combined with EMG evaluations.

RESULTS

A total of 77 consecutive patients were enrolled for VEEG-EMG examination. Among them, 57 patients changed their diagnosis after VEEG-EMG assessment, with a mean final diagnosis age of 35.4 ± 20.3 years (range, 4-74 years). The mean duration between initial and final diagnosis was 54.8 ± 71.3 months (range 0.5-300 months). The most common misdiagnosed hyperkinetic movement disorders were myoclonus (40.4%), followed by tremors (24.6%), dystonia (15.8%), psychogenic movement disorders (10.5%), and periodic leg movement syndrome (PLMS) (7.0%). Outcomes of therapy were significantly improved after VEEG-EMG examination (p = 0.000).

CONCLUSIONS

Simultaneous VEEG and EMG are important in the diagnosis of hyperkinetic movement disorders with an unknown cause.

A Textile Embedded Wearable Device for Movement Disorders Quantification

Wearable devices have been showing promising results in a large range of applications: since industry, to entertainment and, in particular, healthcare. In the scope of movement disorders, wearable devices are being widely implemented for motor symptoms objective assessment. Currently, clinicians evaluate patients' motor symptoms resorting to subjective scales and visual perception, such as in Parkinson's Disease. The possibility to make use of wearable devices to quantify this disorder motor symptoms would bring an accurate follow-up on the disease progression, leading to more efficient treatments.Here we present a novel textile embedded low-power wearable device capable to be used in any scenario of movement disorders assessment due to its seamless, comfort and versatility. Regarding our research, it has already improved the setup of a wrist rigidity quantification system for Parkinson's Disease patients: the iHandU system. The wearable comprises a hardware sensing unit integrated in a textile band with an innovative design assuring higher comfort and easiness-to-use in movement disorders assessment. It enables to collect inertial data (9-axis) and has the possibility to integrate two analog sensors. A web platform was developed for data reading, visualization and recording. To ensure inertial data reliability, validation tests for the accelerometer and gyroscope sensors were conducted by comparison with its theoretical behavior, obtaining very good results.

Giving and receiving a diagnosis of a progressive neurological condition: A scoping review of doctors' and patients' perspectives

OBJECTIVE

Delivering a life changing diagnosis can be a distressing experience for patients and a challenging task for professionals. Diagnosis delivery can be especially difficult for individuals with neurodegenerative diseases such as motor neurone disease (MND), multiple sclerosis (MS) and Parkinson's disease (PD). This review aims to scope the literature on doctors' and patients' perspectives on diagnosis delivery for these conditions in order to enhance our understanding in this area and identify potential research gaps.

METHODS

A scoping review methodology was used, and data were summarised using content analysis.

RESULTS

47 studies fulfilled the inclusion criteria. Studies showed that although patients were generally satisfied with diagnosis delivery, a considerable proportion was still dissatisfied with aspects of the consultation, especially the information and time provided and the doctor's approach. Only six studies addressed doctors' perspectives, which focused more on doctors' practice.

CONCLUSION

There was a significant research gap in professionals' perspectives. The review also found that although basic standards of good practice were being met, a significant proportion of patients were dissatisfied with diagnosis communication.

PRACTICE IMPLICATIONS

Professionals delivering such diagnoses need to assess and respond to patients' information needs, provide time for questions and maintain an empathic attitude.

Frequency and Correlates of Acute Dystonic Reactions After Antipsychotic Initiation in 441 Children and Adolescents

Objective: To determine the incidence of acute dystonic reactions (ADRs) and risk factors for ADRs in children and adolescents treated with antipsychotics. Methods: This was a retrospective chart review-based cohort study of consecutive patients who attended a university hospital's child and adolescent psychiatry department between 2015 and 2017 and who were treated with antipsychotics and had at least two follow-up visits. Results: Thirty of 441 patients (6.8%) 4-19 years of age who were treated with antipsychotics for conduct disorders (21.5%), attention-deficit/hyperactivity disorder (13.2%) and, irritability and aggression that accompanied intellectual disability (12.9%) and followed for 99.5 ± 223.3 (median: 34) days developed ADRs. ADRs developed in 11/391 patients (2.8%) treated with one antipsychotic and 19/50 patients (38.0%) treated with two antipsychotics (p < 0.001). In patients treated with one antipsychotic that developed ADRs, the time to ADRs was 4.0 ± 4.0 days after antipsychotic initiation and 2.7 ± 2.4 days after an increase in the antipsychotic dose. The time to ADRs in those treated with two antipsychotics was 3.0 ± 2.3 days after the addition of the second antipsychotic and 1.6 ± 0.8 days after a dose increase in the second antipsychotic. The incidence of ADRs during antipsychotic monotherapy was 10.5% with first-generation antipsychotics (FGAs) and 2.2% with second-generation antipsychotics (SGAs; p = 0.037). The antipsychotic was changed due to ADRs in 12/30 (40.0%) of ADR cases. Independent factors associated with ADRs were antipsychotic polypharmacy (p < 0.0001), inpatient treatment (p = 0.013), FGA use (p = 0.015), and diagnoses of schizophrenia (p = 0.039) or bipolar disorder (p < 0.0001). Conclusion: SGAs and low-potency FGA monotherapy in children and adolescents were associated with a relatively low ADR risk, whereas high- and mid-potency FGAs were associated with a high risk. Independent predictors of ADRs were antipsychotic polypharmacy, inpatient treatment, FGAs, and schizophrenia or bipolar disorder diagnoses, which may be related to more aggressive antipsychotic dosing.

Cervical dystonia incidence and diagnostic delay in a multiethnic population

BACKGROUND

Current cervical dystonia (CD) incidence estimates are based on small numbers in relatively ethnically homogenous populations. The frequency and consequences of delayed CD diagnosis is poorly characterized.

OBJECTIVES

To determine CD incidence and characterize CD diagnostic delay within a large, multiethnic integrated health maintenance organization.

METHODS

We identified incident CD cases using electronic medical records and multistage screening of more than 3 million Kaiser Permanente Northern California members from January 1, 2003, to December 31, 2007. A final diagnosis was made by movement disorders specialist consensus. Diagnostic delay was measured by questionnaire and health utilization data. Incidence rates were estimated assuming a Poisson distribution of cases and directly standardized to the 2000 U.S. census. Multivariate logistic regression models were employed to assess diagnoses and behaviors preceding CD compared with matched controls, adjusting for age, sex, and membership duration.

RESULTS

CD incidence was 1.18/100,000 person-years (95% confidence interval [CI], 0.35-2.0; women, 1.81; men, 0.52) based on 200 cases over 15.4 million person-years. Incidence increased with age. Half of the CD patients interviewed reported diagnostic delay. Diagnoses more common in CD patients before the index date included essential tremor (odds ratio [OR] 68.1; 95% CI, 28.2-164.5), cervical disc disease (OR 3.83; 95% CI, 2.8-5.2), neck sprain/strain (OR 2.77; 95% CI, 1.99-3.62), anxiety (OR 2.24; 95% CI, 1.63-3.11) and depression (OR 1.94; 95% CI, 1.4-2.68).

CONCLUSIONS

CD incidence is greater in women and increases with age. Diagnostic delay is common and associated with adverse effects. © 2019 International Parkinson and Movement Disorder Society.

The Rehapiano-Detecting, Measuring, and Analyzing Action Tremor Using Strain Gauges

We have developed a device, the Rehapiano, for the fast and quantitative assessment of action tremor. It uses strain gauges to measure force exerted by individual fingers. This article verifies the device's capability to measure and monitor the development of upper limb tremor. The Rehapiano uses a precision, 24-bit, analog-to-digital converter and an Arduino microcomputer to transfer raw data via a USB interface to a computer for processing, database storage, and evaluation. First, our experiments validated the device by measuring simulated tremors with known frequencies. Second, we created a measurement protocol, which we used to measure and compare healthy patients and patients with Parkinson's disease. Finally, we evaluated the repeatability of a quantitative assessment. We verified our hypothesis that the Rehapiano is able to detect force changes, and our experimental results confirmed that our system is capable of measuring action tremor. The Rehapiano is also sensitive enough to enable the quantification of Parkinsonian tremors.

Is Parkinson's disease an unique clinical entity? Rigid or tremor dominant PD: Two faces of the same coin

Parkinson's disease is one of the most described neurodegenerative pathologies; though it is one of the most complex pathologies, is not fully understood, correctly identified, with its different types of presentation, its clinical course and the neural networks involved. We report on a series consisting of 432 de novo PD diagnosed patients, and 457 control cases. We identify a possible independent relationship between two clinical PD presentation, akinetic-rigid and tremor-dominant, and cognitive and behavioral changes. A 24-months follow-up allows to identify new information still not fully explored.

Clinical and neuroimaging phenotypes of genetic parkinsonism from infancy to adolescence

Genetic early-onset parkinsonism presenting from infancy to adolescence (≤21 years old) is a clinically diverse syndrome often combined with other hyperkinetic movement disorders, neurological and imaging abnormalities. The syndrome is genetically heterogeneous, with many causative genes already known. With the increased use of next-generation sequencing in clinical practice, there have been novel and unexpected insights into phenotype-genotype correlations and the discovery of new disease-causing genes. It is now recognized that mutations in a single gene can give rise to a broad phenotypic spectrum and that, conversely different genetic disorders can manifest with a similar phenotype. Accurate phenotypic characterization remains an essential step in interpreting genetic findings in undiagnosed patients. However, in the past decade, there has been a marked expansion in knowledge about the number of both disease-causing genes and phenotypic spectrum of early-onset cases. Detailed knowledge of genetic disorders and their clinical expression is required for rational planning of genetic and molecular testing, as well as correct interpretation of next-generation sequencing results. In this review we examine the relevant literature of genetic parkinsonism with ≤21 years onset, extracting data on associated movement disorders as well as other neurological and imaging features, to delineate syndromic patterns associated with early-onset parkinsonism. Excluding PRKN (parkin) mutations, &gt;90% of the presenting phenotypes have a complex or atypical presentation, with dystonia, abnormal cognition, pyramidal signs, neuropsychiatric disorders, abnormal imaging and abnormal eye movements being the most common features. Furthermore, several imaging features and extraneurological manifestations are relatively specific for certain disorders and are important diagnostic clues. From the currently available literature, the most commonly implicated causes of early-onset parkinsonism have been elucidated but diagnosis is still challenging in many cases. Mutations in ∼70 different genes have been associated with early-onset parkinsonism or may feature parkinsonism as part of their phenotypic spectrum. Most of the cases are caused by recessively inherited mutations, followed by dominant and X-linked mutations, and rarely by mitochondrially inherited mutations. In infantile-onset parkinsonism, the phenotype of hypokinetic-rigid syndrome is most commonly caused by disorders of monoamine synthesis. In childhood and juvenile-onset cases, common genotypes include PRKN, HTT, ATP13A2, ATP1A3, FBX07, PINK1 and PLA2G6 mutations. Moreover, Wilson’s disease and mutations in the manganese transporter are potentially treatable conditions and should always be considered in the differential diagnosis in any patient with early-onset parkinsonism.

Gait Cycle Validation and Segmentation Using Inertial Sensors

In this paper, we develop an algorithm to automatically validate and segment a gait cycle in real time into three gait events, namely midstance, toe-off, and heel-strike, using inertial sensors. We first use the physical models of sensor data obtained from a foot-mounted inertial system to differentiate stationary and moving segments of the sensor data. Next, we develop an optimization routine called sparsity-assisted wavelet denoising (SAWD), which simultaneously combines linear time invariant filters, orthogonal multiresolution representations such as wavelets, and sparsity-based methods, to generate a sparse template of the moving segments of the gyroscope measurements in the sagittal plane for valid gait cycles. Thereafter, to validate any moving segment as a gait cycle, we compute the root-mean-square error between the generated sparse template and the sparse representation of the moving segment of the gyroscope data in the sagittal plane obtained using SAWD. Finally, we find the local minima for the stationary and moving segments of a valid gait cycle to detect the gait events. We compare our proposed method with existing methods, for a fixed threshold, using real data obtained from three groups, namely controls, participants with Parkinson disease, and geriatric participants. Our proposed method demonstrates an average F1 score of 87.78% across all groups for a fixed sampling rate, and an average F1 score of 92.44% across all Parkinson disease participants for a variable sampling rate.

Diagnostic Yield of a Targeted Next-Generation Sequencing Gene Panel for Pediatric-Onset Movement Disorders: A 3-Year Cohort Study

In recent years, genetic techniques of diagnosis have shown rapid development, resulting in a modified clinical approach to many diseases, including neurological disorders. Movement disorders, in particular those arising in childhood, pose a diagnostic challenge. First, from a purely phenomenological point of view, the correct clinical classification of signs and symptoms may be difficult and require expert evaluation. This is because the clinical picture is often a mixture of hyperkinetic and hypokinetic disorders, and within hyperkinetic movement disorders, combined phenotypes are not unusual. Second, although several genes that cause movement disorders in children are now well-known, many of them have only been described in adult populations or discovered in patients after many years of disease. Furthermore, diseases that alter their mechanisms from childhood to adulthood are still little known, and many phenotypes in children are the result of a disruption of normal neurodevelopment. High-throughput gene screening addresses these difficulties and has modified the approach to genetic diagnosis. In the exome-sequencing era, customized genetic panels now offer the ability to perform fast and low-cost screening of the genes commonly involved in the pathogenesis of the disease. Here, we describe a 3-year study using a customized gene panel for pediatric-onset movement disorders in a selected cohort of children and adolescents. We report a satisfying diagnostic yield, further confirming the usefulness of gene panel analysis.

The Top 50 Most-Cited Articles in Orthostatic Tremor: A Bibliometric Review

Background

Article-level citation count is a hallmark indicating scientific impact. We aimed to pinpoint and evaluate the top 50 most-cited articles in orthostatic tremor (OT).

Methods

The ISI Web of Knowledge database and 2017 Journal Citation Report Science Edition were used to retrieve the 50 top-cited OT articles published from 1984 to April 2019. Information was collected by the Analyze Tool on the Web of Science, including number of citations, publication title, journal name, publication year, and country and institution of origin. Supplementary analyses were undertaken to clarify authorship, study design, level of evidence, and category.

Results

Up to 66% of manuscripts were recovered from five journals: Movement Disorders (n = 18), Brain (n = 4), Journal of Clinical Neurophysiology (n = 4), Neurology (n = 4), and Clinical Neurophysiology (n = 3). Articles were published between 1984 and 2018, with expert opinion as the predominant design (n = 22) and review as category (n = 17). Most articles had level 5 evidence (n = 26). According to their countries of origin, 34% of articles belonged to the United States (n = 17) leading the list, followed by United Kingdom (n = 15). University College London yielded the greater number of articles (n = 12), followed by the University of Kiel (n = 9). Most popular authors were G. Deuschl (n = 10), C.D. Marsden (n = 6), J. Jankovic (n = 5), P.D. Thompson (n = 5), J.C. Rothwell (n = 5), L.J. Findley (n = 4), and P. Brown (n = 4), who together accounted for 48% of them. All papers were in English.

Discussion

Publishing high-cited OT articles could be facilitated by source journal, study design, category, publication language, and country and institution of origin.

How to spot ocular abnormalities in progressive supranuclear palsy? A practical review

Background

For parkinsonian disorders, progressive supranuclear palsy (PSP) continues to be significant for differential diagnosis. PSP presents a range of ocular abnormalities that have been suggested as optional tools for its early detection, apart from the principal characteristic of postural unsteadiness. Nonetheless, such symptoms may be difficult to identify, particularly during the early onset stage of the disorder. It may also be problematic to recognize these symptoms for general practitioners who lack the required experience or physicians who are not specifically educated and proficient in ophthalmology or neurology.

Main body

Thus, here, a methodical evaluation was carried out to identify seven oculomotor abnormalities occurring in PSP, comprising square wave jerks, the speed and range of saccades (slow saccades and vertical supranuclear gaze palsy), ‘round the houses’ sign, decreased blink rate, blepharospasm, and apraxia of eyelid opening. Inspections were conducted using direct visual observation. An approach to distinguish these signs during a bedside examination was also established. When presenting in a patient with parkinsonism or dementia, the existence of such ocular abnormalities could increase the risk of PSP. For the distinction between PSP and other parkinsonian disorders, these signs hold significant value for physicians.

Conclusion

The authors urge all concerned physicians to check for such abnormalities with the naked eye in patients with parkinsonism. This method has advantages, including ease of application, reduced time-consumption, and requirement of minimal resources. It will also help physicians to conduct efficient diagnoses since many patients with PSP could intially present with ocular symptoms in busy outpatient clinics.

Electronic supplementary material

The online version of this article (10.1186/s40035-019-0160-1) contains supplementary material, which is available to authorized users.

Acute Post-stroke Hemiparkinsonism and Hemiparesis: A Unique Case with Successful Therapy

The diagnosis of a new onset movement disorder after a stroke has important clinical implications. The early assessment and timely diagnosis of post-stroke disorders is essential for influencing long-term outcomes. Localizing lesions and determining the underlying etiology is vital in targeting appropriate therapy. New and sudden onset of hemiparkinsonism with hemiparesis, rigidity, and tremor following an acute ischemic stroke is described here. This presentation was clinically diagnosed as acute post-stroke parkinsonism (APSP). The patient’s level of impairment was significant enough to compromise his activities of daily living (ADL), physical therapy (PT), and occupational therapy (OT) in an inpatient rehabilitation center. In the inpatient rehabilitation center, the patient received a trial of levodopa for suspected APSP. After levodopa therapy was initiated, we observed an improvement of his parkinsonian features with a sustained response and reached the conclusion that the clinical recognition of post-stroke parkinsonism treated with a targeted trial with levodopa may improve the quality of life. Proper treatment of APSP has the potential to provide the best opportunity for recovery and positively influence the long-term outcomes in similar patients.

Erythropoietin ameliorates harmaline-induced essential tremor and cognition disturbances

There are conflicting reports concerning the association of motor disabilities with increased risk of mental disorders. This investigation will provide a good understanding about defining the possible association between tremor and risk of anxiety and cognitive alterations. Beside, a secondary objective of the current study was to determine the effect of erythropoietin (EPO) on harmaline-induced motor and cognitive impairments. Male Wistar rats were used for the present study. The animal model of Esential tremor (ET) was established by the intraperitoneal injection of harmaline. EPO (5000 U/kg, i.p.) administered to the animals 1 h prior to harmaline injection. Exploratory, balance, anxiety related behaviors and cognitive function were assessed using footprint, open field, wire grip, rotarod and shuttle box tests. Findings demonstrated EPO ameliorated tremor scores that was induced by harmaline. Harmaline impaired cognitive functions of the treated rats, whereas EPO showed a promising effect against the cognitive impairments induced by harmaline. EPO can be offered as a potential neuroprotective agent in the treatment of patients with ET that manifest locomotor and cognitive impairments; however, further studies are needed to clarify the exact mechanisms.

Efficient and Robust Skeleton-Based Quality Assessment and Abnormality Detection in Human Action Performance

Elderly people can be provided with safer and more independent living by the early detection of abnormalities in their performing actions and the frequent assessment of the quality of their motion. Low-cost depth sensing is one of the emerging technologies that can be used for unobtrusive and inexpensive motion abnormality detection and quality assessment. In this study, we develop and evaluate vision-based methods to detect and assess neuromusculoskeletal disorders manifested in common daily activities using three-dimensional skeletal data provided by the SDK of a depth camera (e.g., MS Kinect and Asus Xtion PRO). The proposed methods are based on extracting medically -justified features to compose a simple descriptor. Thereafter, a probabilistic normalcy model is trained on normal motion patterns. For abnormality detection, a test sequence is classified as either normal or abnormal based on its likelihood, which is calculated from the trained normalcy model. For motion quality assessment, a linear regression model is built using the proposed descriptor in order to quantitatively assess the motion quality. The proposed methods were evaluated on four common daily actions-sit to stand, stand to sit, flat walk, and gait on stairs-from two datasets, a publicly released dataset and our dataset that was collected in a clinic from 32 patients suffering from different neuromusculoskeletal disorders and 11 healthy individuals. Experimental results demonstrate promising results, which is a step toward having convenient in-home automatic health care services.

Kinematic Analysis of Handwriting Movements in Individuals with Intellectual Disabilities with and without Obsessive Compulsive Symptoms

Theory/calculation: Movement disorders such as disturbances of coordination, clumsiness, and hand-related stereotypies are a frequent phenomenon in individuals with intellectual disabilities (ID). Obsessive-compulsive symptoms are also common in persons with ID. Our aim was to investigate hand motor dysfunction in persons with ID with and without OCD, using a digitizing tablet and the kinematic analysis of handwriting and drawing movements.

METHODS

We examinedthe hand motor performance of 23 individuals (12 males, 11 females, 42.6 ± 13.7 years old) with ID of heterogeneous aetiology. All subjects were required to write a sentence and draw circles under various conditions. Kinematic parameters were calculated to quantify hand motion.

RESULTS

Individuals with ID exhibit serious hand motor impairments suggestive of bradykinesia, irregularity, and micrographia. More than half of our ID patients (60.9%) displayed obsessive-compulsive symptoms of moderate severity (Y-BOCS total score: 16.6 ± 8.3). Interestingly, the ID patients with OCD displayed smaller amplitudes of hand motor movements than did patients with no obsessive-compulsive symptoms, while differences observed in the writing and drawing concentric circles trials were significant.

CONCLUSIONS

The results of this pilot study support the use of kinematic analyses of handwriting movements to evaluate motor abnormalities in patients with ID and comorbid mental illnesses.

Functional imaging correlates of akinesia in Parkinson's disease: Still open issues

Akinesia is a major manifestation of Parkinson's disease (PD) related to difficulties or failures of willed movement to occur. Akinesia is still poorly understood and is not fully alleviated by standard therapeutic strategies. One reason is that the area of the clinical concept has blurred boundaries referring to confounded motor symptoms. Here, we review neuroimaging studies which, by providing access to finer-grained mechanisms, have the potential to reveal the dysfunctional brain processes that account for akinesia. It comes out that no clear common denominator could be identified across studies that are too heterogeneous with respect to the clinical/theoretical concepts and methods used. Results reveal, however, that various abnormalities within but also outside the motor and dopaminergic pathways might be associated with akinesia in PD patients. Notably, numerous yet poorly reproducible neural correlates were found in different brain regions supporting executive control by means of resting-state or task-based studies. This includes for instance the dorsolateral prefrontal cortex, the inferior frontal cortex, the supplementary motor area, the medial prefrontal cortex, the anterior cingulate cortex or the precuneus. This observation raises the issue of the multidimensional nature of akinesia. Yet, other open issues should be considered conjointly to drive future investigations. Above all, a unified terminology is needed to allow appropriate association of behavioral symptoms with brain mechanisms across studies. We adhere to a use of the term akinesia restricted to dysfunctions of movement initiation, ranging from delayed response to freezing or even total abolition of movement. We also call for targeting more specific neural mechanisms of movement preparation and action triggering with more sophisticated behavioral designs/event-related neurofunctional analyses. More work is needed to provide reliable evidence, but answering these still open issues might open up new prospects, beyond dopaminergic therapy, for managing this disabling symptom.

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No clear picture of the neural bases of PD akinesia can be drawn from the literature.

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Akinesia should be disentangled from bradykinesia and hypokinesia.

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Movement initiation dysfunctions may arise from both motor and executive disorders.

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Future neuroimaging studies should probe more specific neurocognitive processes.

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Future studies should look beyond the dopaminergic basal-ganglia circuitry.