Psychogenic non-epileptic and epileptic seizures: clues for a differential diagnosis. Findings from a Colombian study

Introduction. Psychogenic non-epileptic seizures (PNES) are paroxysmal changes in behavior that resemble epileptic seizures, although they have no electrophysiological correlation or clinical evidence of epilepsy. Aim. To compare clinical and sociodemographic characteristics of patients diagnosed with PNES-alone and PNES-and-epilepsy. Patients and methods. A cross-sectional study of consecutive patients diagnosed with PNES in a 20-month period was carried out. A video-EEG was performed in all patients. Socio-demographical, clinical and semiological characteristics were compared between those patients with and without concomitant epilepsy. Results. Sixty-five patients were included, 35 (53.9%) had PNES-alone and 30 (46.1%) had PNES-and-epilepsy. The proportion of women in the study was 70.8%. The median age at seizure onset was 16 years. A late start was recorded in PNES-alone group (23 years) compared to PNES-and-epilepsy group (11 years), however, it was not significant. There was a lower frequency of antiepileptic drugs use in the PNES-alone group compared with the PNES-and-epilepsy group. The most frequent semiological features were the gradual onset of events (69.2%) and the duration longer than two minutes(63.1%). Conclusion. The waxing and waning pattern during paroxysmal events suggest a non-epileptic origin. However, it is not uncommon to find patients with concomitant epileptic seizures.