Differential diagnosis of epilepsy.

Elements relevant to differential diagnosis between epileptic seizure and non-epileptic seizure as a consequence of syncope, cardiac arrhythmia or pseudoepilepsy are reviewed and discussed. Our experience with long-term monitoring of closed circuit TV-EEG of 136 medically refractory seizure patients showed that (a) about 19% have pseudoepileptic seizures, (b) only 36% of those verified pseudoepileptic seizure patients had epileptic seizures as well, and (c) 77% of pseudoepileptic seizures mimicked aspects of complex partial seizures. Pseudoepileptic seizures were not suspected by referring clinicians in the majority of cases, while a small but significant number of patients with verified complex partial seizures were suspected of having pseudoepileptic seizures. Failure to identify these non-epileptic seizures has serious medical and psychosocial implications and, therefore, astute clinical judgment is necessary in the differential diagnosis of epilepsy. Despite some technical limitations inherent in its current practice, the judicious use of long-term monitoring significantly enhances the quality of such judgment upon which the development of a management approach most meaningful to those medically refractory patients and society depends.