The value of provocation methods in patients suspected of having non-epileptic seizures

Non-epileptic seizures (NES) are reported in 18-23% of patients referred to comprehensive epilepsy centres. Non-epileptic seizures may also be present in 5-20% of the patients who are diagonised as having refractory seizures. Because of their prevalence, financial and psychosocial outcomes cannot be ignored and accurate diagnosis is of the utmost importance. Various method s of seizure induction have been developed with the aim of differentiating epileptic from non-epileptic seizures. However, recording the attacks by vi deo-EEG monitoring is the gold standard. In our outpatient EEG laboratory w e try to induce seizures with verbal suggestion or IV saline infusion in pa tients who are referred by a clinician with the diagnosis of probable nonep ileptic seizures. In this study we investigated the results of 72 patients who were referred between January 1992-June 1996. Non-epileptic seizures we re observed in 52 (72.2%) patients. Thirteen of these patients still had ri sk factors for epilepsy. We could not decide whether all of their previous attacks were non-epileptic because 10-30% of the patients with NES also hav e epileptic seizures. For a more accurate diagnosis it was decided that the se 13 patients, together with the 20 patients who did not have seizures wit h induction, needed video-EEG monitoring. Thirty-nine patients who had NES and no risk factors for epilepsy were thought to have pure non-epileptic se izures. We claim that not all patients suspected of having NES need long-te rm video-BEG monitoring and almost half (54.2%) of the cases can be elimina ted by seizure induction with some provocative techniques.