Abstracts

Rationale: Patients with psychogenic nonepileptic seizures (PNES) are a heterogeneous patient population that may differ in their social adverse life experiences (e.g., sexual abuse or physical abuse) and psychiatric comorbidities. Therefore, it is plausible to assume that there would be clinical differences among different cultures and different ethnic populations. We compared a large sample regarding various clinical characteristics of PNES between adult patients from multiple countries. This multi-center, international, cross-cultural comparative study is intended to advance our understanding of PNES in adults.  Methods: In this retrospective study, we investigated consecutive patients with PNES with an age at onset of above 16 years, who were admitted to the epilepsy monitoring units at centers in Iran (Shiraz Comprehensive Epilepsy Center, from 2008 until 2019), Brazil (Clinics Hospital, Faculty of Medicine of the University of São Paulo, from 2006 to 2016), Argentina (Buenos Aires University, Epilepsy Center, Ramos Mejía and EL Cruce Hospitals, from 2014 until 2018), and Venezuela (Epilepsy Unit. La Trinidad Medical Center, from 2014 until 2018). We compared these patients regarding their age, gender, PNES semiology, and possible predisposing factors.This study was conducted with the approval by Institutional Review Boards of all centers.  Results: We included 389 patients (244 from Iran, 66 from Brazil, 51 from Venezuela, and 28 from Argentina). Age at diagnosis was 32 ± 9 years (range: 17-64 years) and age at onset of seizures was 27 ± 8 years (range: 17-49 years). There was a female predominance in all countries. Demographic characteristics (i.e., the age at onset, duration of illness, and the sex ratio) of the patients were not statistically different among the nations. Clinical characteristics of psychogenic seizures in adult patients with PNES showed significant differences among the nations. The most common (>50%) PNES semiological features in the Iranian sample included aura before seizures, unresponsiveness, eyes closed during the attacks, intermittent movements, and generalized motor seizures. In Brazil, the majority of the patients had generalized motor seizures, but less frequently reported other semiological features. In Venezuela, the majority of the patients had a similar semiology as in Iran, with the addition of side to side head turnings. Finally, in Argentina, the most common seizure semiology included auras and generalized motor seizures. Factors associated with PNES in these four nations were similar.  Conclusions: This study corroborates the notion that PNES share more similarities than differences cross-culturally and across international borders. However, the background determined by cultural, ethnic, and religious differences may influence the semiology of PNES. Further cross-cultural studies involving more than two continents may advance our understanding of PNES.  Funding: No funding