Movement disorders phenomenology in focal motor seizures

Introduction Although focal motor seizures may resemble one or more movement disorders their phenomenology and prevalence remain uncertain. Methods To examine the extent to which focal motor seizures can present with a phenomenology fulfilling diagnostic criteria for movement disorders, 100 consecutive patients with focal motor seizures were rated by movement disorders experts, epileptologists, and general neurologists. Results A focal motor seizure phenomenologically manifested as a defined movement disorder in 29% of the patients from a consecutive video-EEG documented cohort as per consensus among experts: myoclonus and dystonia (10 and 9 cases, respectively) were the most common movement disorders, followed by chorea (4), stereotypies (3) myoclonus-dystonia (2), and tremor (1). Conclusions Movement disorders and focal motor epilepsy share overlapping movement phenomenology.