Clinical characteristics of psychogenic nonepileptic seizures across the lifespan: An international retrospective study

Abstract

Purpose: Previous studies from a few countries have reported semiological differences in younger children compared with adolescents or adults with psychogenic nonepileptic seizures (PNESs). This study tested the hypothesis that semiological, demographic, and historical risk factors vary with different ages of PNES onset in a large cohort from different countries. Methods: In this retrospective study, we investigated patients consecutively referred for PNES, who were admitted to epilepsy monitoring units in Iran, Brazil, Venezuela, Canada, Argentina, and USA. Age, gender, age at seizure onset, seizure semiology, and factors predisposing to PNES (abuse, stressors) were documented according to routine diagnostic practices at each center. Participants were grouped according to their age at onset (i.e., childhood, adolescence, or adulthood). Results: A total of 448 patients were studied. Female predominance was associated with adolescent- (85/122, 70%) and adult-onset (190/270, 70%) but not in childhood-onset PNES (28/56, 50%) (p = 0.011). Event frequency in the month preceding the diagnosis was higher in the childhood- [x¯ = 50, standard deviation (sd) = 82, p = 0.025] versus adolescent- (x¯ = 24, sd = 36) or adult-onset groups (x¯ = 29, sd = 61). Significant between-group differences were observed for generalized body movements (p = 0.0001) and ictal injury (p = 0.027), suggesting more severe ictal presentations in adult-onset PNES compared with younger ages. Adult-onset patients were also more likely to be taking an unnecessary antiepileptic medication (p = 0.010). Conclusion: While PNES may present at any age, there appear to be notable differences across the lifespan with respect to some of the clinical characteristics. Further international and cross-cultural studies may reveal other interesting characteristics of PNES.