Differential diagnosis of seizures.

Distinguishing epileptic events from nonepileptic paroxysmal neurologic events represents a common diagnostic challenge. Syncope, either cardiac or noncardiac, can appear similar to atonic and even convulsive seizures. Breath holding and benign paroxysmal vertigo in children may be confused with epilepsy. Classic migraine, transient global amnesia, and transient ischemic attacks may resemble epileptic seizures. Sleep disorders, including nocturnal movements, parasomnias, and narcolepsy also may resemble epileptic seizures. Most movement disorders are distinguished easily from epilepsy; however, paroxysmal dyskinesias may resemble atonic or reflex seizures. The correct diagnosis can be established and appropriate treatment can be instituted by relying on routine and prolonged EEG, EKG, and sleep studies, when appropriate.