[The borderland between epilepsy and movement disorders]

Epileptic seizures presenting as motor phenomena without concomitant conscious change may be confused with one of the paroxysmal movement disorders. Conversely, the attack of paroxysmal movement disorders may be thought to be epileptic due to a number of factors, including its sudden, unpredictable, and transient nature, its response to anticonvulsants, and the premonitory sensations preceding attacks. The distinction between epilepsy and movement disorders is further confused by the reports that these two conditions frequently occur in the same families or even in the same patients. Recent studies show that a few epilepsy and paroxysmal movement disorders are "channelopathies", indicating that they may share some common pathophysiology and a possible "overlap". A good quality of history, a trial to reproduce the motor phenomena, the application of video-EEG, polysomnography, and other electrophysiological recordings, together with regular follow-up are important for differentiating these two conditions.