Etiologies of patients with adult-onset epilepsy over the past 25 years: a retrospective study in China.

OBJECTIVE: This study aimed to describe the changes in the etiology of adult epilepsy in different age groups over the past 25 years, with consideration of different time periods. METHODS: A retrospective study was conducted using the clinical data of patients with adult-onset epilepsy at The First Medical Center of Chinese PLA General Hospital between February 1999 and March 2024. RESULTS: The study included 5,712 patients from 25 provinces and 4 municipalities in China. The study found that the prevalence of unknown etiology has decreased overall, particularly after 2015, and that the proportion of epilepsy cases caused by metabolic etiologies has declined since 2016. However, since 2021, there has been an increase in immune-related epilepsy. The proportion of patients with structural epilepsy ranged from 29.7% to 90% across all age groups. Among epilepsy patients aged ≥ 51 years, structural epilepsy was predominant, accounting for the majority of cases. In particular, the proportion of epilepsy attributable to cerebrovascular disease increased with age at onset. With regard to gender, structural epilepsy was more common in males than in females. CONCLUSIONS: This study highlights observed trends and changes in clinical diagnosis in epilepsy etiologies, revealing an obvious decrease in unknown etiology. The recent rise in immune-related epilepsy underscores the need for increased clinical vigilance. The observed gender and age disparities in structural epilepsy, particularly cerebrovascular-related cases in elderly males, provide critical insights for targeted preventive and therapeutic strategies.