A review of diagnostic techniques in the differential diagnosis of epileptic and nonepileptic seizures.

The diagnosis of psychogenic nonepileptic seizures (PNES) is complex. Long-term electroencephalogram monitoring with video recording (video EEG) is the most common method of differential diagnosis of epilepsy and PNES. However, video EEG is complex, costly, and unavailable in some areas. Thus, alternative diagnostic techniques have been studied in the search for a diagnostic method that is as accurate as video EEG, but more cost effective, convenient, and readily available. This paper reviews the literature regarding possible diagnostic alternatives and organizes findings into 7 areas of study: demographic and medical history variables, seizure semiology, provocative testing, prolactin levels, single photon emission computed tomography, psychological testing, and neuropsychological testing. For each area, the literature is summarized, and conclusions about the accuracy of the technique as a diagnostic tool are drawn. Overall, it appears unlikely that any of the reviewed alternative techniques will replace video EEG monitoring; rather they may be more successful as complementary diagnostic tools. An important focus for further investigations involves combinations of diagnostic techniques for the differential diagnosis of epilepsy and PNES.