[Differential diagnosis of the epilepsies]

Epileptic seizures result from excessive neuronal discharge. The diagnosis of epilepsy, defined as spontaneously recurrent seizures, is mainly clinical. The possibility that a patient is experiencing other acute cerebral events, such as syncope or pseudoseizures, must always be considered. Electroencephalography is an important diagnostic aid that facilitates the classification of epilepsies. Magnetic resonance and computerized tomography make it feasible to investigate possible etologies, while functional neuroimaging studies, such as simple photon emission computed tomography and positron emission tomography afford information on the origin of neuronal discharge. Whether or not an epileptic seizure is likely to form part of a specific epileptic syndrome must be assessed, given the therapeutic and prognostic consequences. The diagnosis of epileptic patients must be based on medical history and physical examination.