Abstract

Introduction: Hyperkinetic movement disorders are characterized by their intricate and overlapping movement patterns (Figure 1), posing significant challenges in their classification and treatment. Their complexity is further heightened by evolving definitions and the involvement of multiple medical specialties. The inconsistency in definitions and descriptors complicates both research and clinical communication. Our aim is to provide an overview of current terms and definitions related to spastic movement disorders and other hyperkinetic movement disorders associated with central nervous system lesions. We propose a unified terminology and classification system for spastic movement disorders to improve communication among healthcare professionals.

Methods: We review the definitions of spasticity, dystonia, tremor, chorea, hemiballismus, athetosis, dys-synergia and myoclonus, emphasizing the overlaps and challenges in distinguishing these disorders. Various hyperkinetic movement disorders are similarly defined by their clinical features and etiologies, often showing significant overlap with spasticity.

Results: The proposed classification system for spasticity integrates elements from the Movement Disorder Society's (MDS) classification of dystonia and tremor, focusing on clinical features and etiology (Tables 1 and 2). This approach aims to establish a common language for describing phenotypes observed in clinical practice (Figure 2), facilitating better communication and collaboration among healthcare professionals.

Conclusion: By adopting a phenomenological approach, we highlight the importance of consistent descriptors and propose a systematic method to classify movement disorders, particularly spasticity. We aim to encourage the use of unified terminology in clinical practice and research, ultimately improving patient care and advancing the field of spastic movement disorders.