The dynamics of stereotypic behaviors: Movement variance and invariance in the classification of movement disorders.

Paradoxical performance can be described simply as a sudden decrease in a top athlete’s performance despite the athlete’s having striven for superior performance, such as the lost-skill syndrome in trampolining or “the yips” in golf. There is a growing amount of research on these phenomena, which resemble movement disorders. What appears to be missing, however, is a clear phenomenology of the affected movement characteristics leading to a classification of the underlying cause. This understanding may enable specific diagnostic methods and appropriate interventions. We first review the different phenomena, providing an overview of their characteristics and their occurrence in sports and describing the affected sports and movements. We then analyze explanations for the yips, the most prominent phenomenon, and review the methodological approaches for diagnosing and treating it. Finally, we present and elaborate an action theoretical approach for diagnosing paradoxical performance and applying appropriate interventions.

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The Spectrum of PRRT2-Associated Disorders: Update on Clinical Features and Pathophysiology

Frontiers in Neurology ◽

10.3389/fneur.2021.629747 ◽

2021 ◽

Vol 12 ◽

Author(s):

Annamaria Landolfi ◽

Paolo Barone ◽

Roberto Erro

Keyword(s):

Movement Disorders ◽

Neurodevelopmental Disorders ◽

Transmembrane Protein ◽

Brain Disorders ◽

Hemiplegic Migraine ◽

Causative Gene ◽

Paroxysmal Kinesigenic Dyskinesia ◽

Infantile Epilepsy ◽

Biallelic Mutations

Mutations in the PRRT2 (proline-rich transmembrane protein 2) gene have been identified as the main cause of an expanding spectrum of disorders, including paroxysmal kinesigenic dyskinesia and benign familial infantile epilepsy, which places this gene at the border between epilepsy and movement disorders. The clinical spectrum has largely expanded to include episodic ataxia, hemiplegic migraine, and complex neurodevelopmental disorders in cases with biallelic mutations. Prior to the discovery of PRRT2 as the causative gene for this spectrum of disorders, the sensitivity of paroxysmal kinesigenic dyskinesia to anticonvulsant drugs regulating ion channel function as well as the co-occurrence of epilepsy in some patients or families fostered the hypothesis this could represent a channelopathy. However, recent evidence implicates PRRT2 in synapse functioning, which disproves the “channel hypothesis” (although PRRT2 modulates ion channels at the presynaptic level), and justifies the classification of these conditions as synaptopathies, an emerging rubric of brain disorders. This review aims to provide an update of the clinical and pathophysiologic features of PRRT2-associated disorders.

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Machine learning classification of medication adherence in patients with movement disorders using non-wearable sensors

Computers in Biology and Medicine ◽

10.1016/j.compbiomed.2015.08.012 ◽

2015 ◽

Vol 66 ◽

pp. 120-134 ◽

Cited By ~ 24

Author(s):

Conrad S. Tucker ◽

Ishan Behoora ◽

Harriet Black Nembhard ◽

Mechelle Lewis ◽

Nicholas W. Sterling ◽

...

Keyword(s):

Machine Learning ◽

Medication Adherence ◽

Movement Disorders ◽

Wearable Sensors ◽

Machine Learning Classification

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Consensus on the Definition of Advanced Parkinson’s Disease: A Neurologists-Based Delphi Study (CEPA Study)

Parkinson s Disease ◽

10.1155/2017/4047392 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 9

Author(s):

Maria-Rosario Luquin ◽

Jaime Kulisevsky ◽

Pablo Martinez-Martin ◽

Pablo Mir ◽

Eduardo S. Tolosa

Keyword(s):

Activities Of Daily Living ◽

Movement Disorders ◽

Delphi Study ◽

Daily Living ◽

Ad Hoc ◽

Motor Fluctuations ◽

Key Factors ◽

Advanced Parkinson’S Disease ◽

Definition Of

To date, no consensus exists on the key factors for diagnosing advanced Parkinson disease (APD). To obtain consensus on the definition of APD, we performed a prospective, multicenter, Spanish nationwide, 3-round Delphi study (CEPA study). An ad hoc questionnaire was designed with 33 questions concerning the relevance of several clinical features for APD diagnosis. In the first-round, 240 neurologists of the Spanish Movement Disorders Group participated in the study. The results obtained were incorporated into the questionnaire and both, results and questionnaire, were sent out to and fulfilled by 26 experts in Movement Disorders. Review of results from the second-round led to a classification of symptoms as indicative of “definitive,” “probable,” and “possible” APD. This classification was confirmed by 149 previous participating neurologists in a third-round, where 92% completely or very much agreed with the classification. Definitive symptoms of APD included disability requiring help for the activities of daily living, presence of motor fluctuations with limitations to perform basic activities of daily living without help, severe dysphagia, recurrent falls, and dementia. These results will help neurologists to identify some key factors in APD diagnosis, thus allowing users to categorize the patients for a homogeneous recognition of this condition.

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The phenomenology of tics and tic-like behavior in TikTok

10.1101/2021.09.08.21263218 ◽

2021 ◽

Author(s):

Alonso G Zea Vera ◽

Adrienne Bruce ◽

Jordan Garris ◽

Laura Tochen ◽

Poonam Bhatia ◽

...

Keyword(s):

Movement Disorder ◽

Tourette Syndrome ◽

Movement Disorders ◽

Strong Influence ◽

Disease Modeling ◽

Likert Scale ◽

Independent Practice ◽

Spearman Correlation ◽

Conversion Disorders

Background and Objective Pediatricians and pediatric subspecialists worldwide have reported a marked increase in functional (conversion) disorders with tic-like behaviors during the COVID-19 pandemic. These patients often report frequent viewing of Tourette Syndrome (TS) TikTok videos, suggesting disease modeling. We aimed to evaluate tic phenomenology in videos posted on TikTok. Methods The 100 most-viewed videos under #tourettes in TikTok were randomly assigned to two primary reviewers (n=3; <2 years independent practice), all pediatric neurologists specializing in movement disorders, for extraction and classification of tic phenomenology. Initial disagreements were solved by consensus. If not resolved, a senior reviewer (n=5; >2 years independent pediatric movement-disorder practice) served as tiebreaker. In addition, two primary and one senior reviewer rated each video on a Likert scale from 1= All the tics are typical of TS to 5= None of the tics are typical of TS. Mean scores and Spearman correlation between primary and senior reviewers were calculated. Results Six videos without tic-like behaviors were excluded. Most videos depicted coprophenomena (coprolalia: 53.2%; copropraxia: 20.2%), often with unusual characteristics. Frequently, videos demonstrated atypical phenomenology such as very strong influence by the environment (motor: 54.3%; phonic: 54.3%), aggression (19.1%), throwing objects (22.3%), self-injurious behaviors (27.7%), and long phrases (>3 words; 45.7%). Most videos portrayed atypical, non-tic behaviors (Median [IQR] Likert ratings: Primary 4.5 [4-5]; Senior 5 [3-5]). Primary vs. senior rater scores demonstrated moderate agreement (r = 0.46; p<0.001). Conclusions TS symptoms portrayals on highly-viewed TikTok videos are predominantly not representative or typical of TS.

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Tremor Syndromes: An Updated Review

Frontiers in Neurology ◽

10.3389/fneur.2021.684835 ◽

2021 ◽

Vol 12 ◽

Author(s):

Abhishek Lenka ◽

Joseph Jankovic

Keyword(s):

Clinical Practice ◽

Movement Disorders ◽

Task Force ◽

Future Perspectives ◽

New Classification ◽

Predominant Symptom ◽

Wide Range ◽

Key Aspects ◽

Underlying Pathophysiology

Tremor is the most commonly encountered movement disorder in clinical practice. A wide range of pathologies may manifest with tremor either as a presenting or predominant symptom. Considering the marked etiological and phenomenological heterogeneity, it would be desirable to develop a classification of tremors that reflects their underlying pathophysiology. The tremor task force of the International Parkinson Disease and Movement Disorders Society has worked toward this goal and proposed a new classification system. This system has remained a prime topic of scientific communications on tremor in recent times. The new classification is based on two axes: 1. based on the clinical features, history, and tremor characteristics and 2. based on the etiology of tremor. In this article, we discuss the key aspects of the new classification, review various tremor syndromes, highlight some of the controversies in the field of tremor, and share the potential future perspectives.

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