The Genetic Relationship between Paroxysmal Movement Disorders and Epilepsy

Abstract

Movement disorders often arise from the basal ganglia nuclei or when their connections malfunction, resulting in hypokinetic, hyperkinetic, or dystonic disorders [1]. A seizure is the result of abnormally excessive or synchronous neuronal activity in the brain, defined as "momentary arising of signs and/or symptoms, " whereas epilepsy is characterized by one or more seizures with a relatively high recurrence risk [2]. Alth ough they are caused by a number of different conditions, both movement disorders and seizures present abnormal movements with coinciding phenomenology [3]. Both movement disorders and epilepsy occur in many genetic disorders ranging from inborn errors of metabolism to developmental and epileptic encephalopathies, epilepsy syndrome with stereotyp-Seizures and movement disorders both involve abnormal movements and are often difficult to distinguish due to their overlapping phenomenology and possible etiological commonalities. Paroxysmal movement disorders, which include three paroxysmal dyskinesia syndromes (paroxysmal kinesigenic dyskinesia, paroxysmal non-kinesigenic dyskinesia, paroxysmal exercise-induced dyskinesia), hemiplegic migraine, and episodic ataxia, are important examples of conditions where movement disorders and seizures overlap. Recently, many articles describing genes associated with paroxysmal movement disorders and epilepsy have been published, providing much information about their molecular pathology. In this review, we summarize the main genetic disorders that results in co-occurrence of epilepsy and paroxysmal movement disorders, with a presentation of their genetic characteristics, suspected pathogenic mechanisms, and detailed descriptions of paroxysmal movement disorders and seizure types.