Clinical features, hemorrhage risk and epilepsy outcomes of familial cerebral cavernous malformation: A 20-year observational pragmatic single-center study

•Long-term follow-up reveals ongoing symptomatic risks in fCCM patients.•Baseline epilepsy and age over 20 predict higher seizure risk.•60 % of fCCM patients remained asymptomatic, with a bleeding rate of 1.02 % per patient-year. Familial Cerebral Cavernous Malformations (fCCMs) are rare, hereditary conditions characterized by multiple central nervous system lesions. Despite their rarity, CCMs can cause significant clinical challenges when symptomatic, manifesting as seizure and symptomatic hemorrhage (CASH). Guidelines suggest neurosurgical intervention for symptomatic or previously symptomatic lesions, while conservative management is recommended for new-onset epilepsy. However, the natural history and optimal management remain unclear, necessitating further research. This study aims to provide a comprehensive analysis of the clinical features, hemorrhage risk, and epilepsy outcomes in fCCM patients over an extended follow-up period, offering a more precise estimate of CASH and epilepsy rates in this population. This retrospective longitudinal cohort study included fCCM patients enrolled from 2001 to May 2024. Data collected included demographic information, new neurological symptoms, symptomatic hemorrhages, seizures, and modified Rankin Scale (mRS) scores. Incidence rates of first symptomatic events and Kaplan-Meier survival curves were calculated, with logistic and Cox-proportional hazard regression models used to evaluate outcomes. A total of 47 patients were included in this study, with a mean age at diagnosis of 37.51 years. At diagnosis, 68 % were symptomatic, with 30 % having CASH and 36 % experiencing seizures without CASH. During a median follow-up of 126.0 months (interquartile range, 110.5 months), 17 % had a new CASH event, 20 % had seizures without CASH, and 60 % remained asymptomatic. The bleeding rate was 1.02 % per patient-year, with new focal neurological symptoms at 2.045 per 1000 patient-years and new CASH at 10.225 per 1000 patient-years. Most patients maintained minimal or no disability (mRS 0 or 1). Presenting with epilepsy at baseline significantly increased the odds of future seizures (OR 18.13, p = 0.001). This study highlights the complex presentation and progression of fCCMs, emphasizing the necessity for long-term monitoring. Baseline epilepsy is a significant predictor of future seizures, underscoring the need for individualized management strategies. Future research with larger cohorts and standardized criteria is essential