Sex differences in demographic and clinical characteristics of psychogenic nonepileptic seizures: A retrospective multicenter international study

Purpose: Sex-related differences have been reported in patients with neurological and psychiatric disorders. It is also plausible to assume that there might be differences between females and males with psychogenic nonepileptic seizures (PNES). Methods: In this retrospective study, we investigated patients with PNES, who were admitted to the epilepsy monitoring units at centers in Iran, the USA, Canada, Brazil, Argentina, and Venezuela. Age, sex, age at seizure onset, seizure semiology, factors potentially predisposing to PNES, and video-electroencephalography recording of all patients were registered routinely. Results: Four hundred and fifty-one patients had PNES-only and were eligible for inclusion; 305 patients (67.6%) were females. We executed a logistic regression analysis, evaluating significant variables in univariate analyses (i.e., age, age at onset, aura, presence of historical sexual or physical abuse, and family dysfunction). The only variables retaining significance were historical sexual abuse (p = 0.005) and presence of aura (p = 0.01); physical abuse was borderline significant (p = 0.05) (all three were more prevalent among females). Conclusion: Similarities between females and males outweigh the differences with regard to the demographic and clinical characteristics of PNES. However, notable differences are that females more often report lifetime adverse experiences (sexual and probably physical abuse) and auras. While social, psychological, and genetic factors may interact with lifetime adverse experiences in the inception of PNES, the link is not yet clear. This is an interesting avenue for future studies. (C) 2019 Elsevier Inc. All rights reserved.