Characteristics and treatment of midlife-onset epilepsy: A 24-year single-center, retrospective study

This study aimed to analyze the clinical characteristics, etiology, and treatment of midlife-onset epilepsy in a real-world setting at a single center in China.

The clinical data of patients who attended the epilepsy clinic of the Department of Neurology, First Medical Center of Chinese PLA General Hospital from February 1999 to March 2023 were retrospectively analyzed. The clinical characteristics, etiology, and risk factors for midlife-onset epilepsy over the past 24 years were analyzed.

Of the 969 patients with onset at 45-64 years of age, 914 were diagnosed with epilepsy with at least two unprovoked seizures 24 h apart. Of those, 99.7% (911) were of focal origin. The median duration from the initial seizure to follow-up treatment was 2 months (interquartile range [IQR]: 1.0-6.0 months). Before commencing treatment, 30.2% (207/683) of patients experienced more than two seizures. A structural etiology was found in 66.3% (606/914) of patients. Cerebrovascular disease (CVD) and traumatic brain injury (TBI) accounted for 19.9% (182/914) and 16.6% (152/914) of the cases, respectively. Logistic regression analysis showed that patients with abnormal imaging (odds ratio [OR] 2.04; 95% confidence interval [CI] 1.25-3.32; p = .004), focal seizures (OR 2.98; 95%CI 1.82-4.87; p < .001), and seizure clusters (OR 2.40; 95%CI 1.21-4.73; p = .01) had poor drug responses. Treatment outcomes were generally better in patients with epilepsy after CVD (OR .49; 95%CI .28-.85; p = .01). Treatment initiation after two seizures (OR .70; 95%CI .42-1.15; p = .16) or 6 months after the first seizure (OR 1.17; 95%CI .66-2.09; p = .58) did not result in poor drug effectiveness.

Midlife-onset epilepsy is typically of focal etiology, with CVD being the most common cause, and tends to respond well to medication. The median duration from the initial seizure to follow-up treatment was 2 months. Over 30% of patients experienced more than two seizures before commencing treatment, but this did not affect subsequent outcomes.