Syncope and seizures-differential diagnosis and evaluation.

Syncope and seizures are common conditions and pose diagnostic challenges for the clinician. The cumulative lifetime incidence of epilepsy is 3%, and the incidence of a first attack of syncope is 6.2 per 1000 person-years in the general population. Although the underlying pathophysiological processes are distinct, seizures and syncope share some clinical characteristics which may lead to diagnostic confusion. Confounding matters further is the fact that seizures and syncope may coexist in a given patient. For example, some conditions such as prolonged QT syndrome may result in both arrhythmia-associated syncope and seizures, and in some cases, seizures may result in cardiac arrhythmia and syncope. The clinical history, examination, electrocardiography, and combined EEG/ECG telemetry are all helpful in the diagnosis of seizures and syncope.