Clinical characteristics of functional (psychogenic nonepileptic) seizures: An international retrospective study

Purpose: We conducted a multicenter international cross-cultural comparative study to investigate clinical semiology and predisposing factors of functional seizures in a large cohort of patients living in different countries around the world. We hypothesized that semiology and predisposing factors of functional seizures differ between various world regions.

Methods: We conducted this retrospective observational study in adults with functional seizures admitted to epilepsy centers in Iran, Qatar, USA, France, Georgia, Egypt, and United Arab Emirates (UAE). We assessed and compared the demographic and clinical seizure characteristics of these patients, according to the patients' reports and review of the ictal recordings during video-electroencephalogram (EEG) monitoring.

Results: Five hundred nine patients were included (270 from Iran, 74 from Qatar, 63 from France, 43 from the USA, 22 from Egypt, 20 from UAE, and 17 from Georgia). Although all major manifestations of functional seizures (e.g., aura, loss of responsiveness, generalized motor seizures, ictal injury) were seen in all world regions, seizure semiology differed significantly across countries. Auras, ictal urinary incontinence, and ictal injury were more commonly reported by the American patients than patients from other world regions, whereas loss of responsiveness and generalized motor seizures were more frequently observed in the Iranian and American patients than the European and Arab patients.

Conclusion: Semiology of functional seizures seems to vary across various regions of the world; socioeconomic, cultural, ethnic, and religious differences may play an essential role in the modulation of functional seizures semiology across different nations and cultures.

Keywords: Dissociative; Psychogenic; Risk factors; Seizure; Semiology.