 Type 1 episodic ataxia (EA1) is characterized by attacks of generalized ataxia induced by emotion or stress, with myokymia both during and between attacks.This disorder is also known as episodic ataxia with myokymia (EAM), hereditary paroxysmal ataxia with neuromyotonia and Isaacs-Mertens syndrome.Onset of EA1 occurs during early childhood to adolescence and persists throughout the patient's life.