Epilepsy in Cerebral Amyloid Angiopathy: an observational retrospective study of a large population.

OBJECTIVE: Cerebral amyloid angiopathy (CAA) is a major cause of spontaneous intracranial haemorrhage in older adults. Epilepsy represents a possible sequelae of the disease. To date studies on epilepsy in CAA are missing and the few data available mainly focus on CAA-related inflammation (CAA-ri), the inflammatory form of the disease.

METHODS: In this retrospective observational study, we consecutively recruited CAA patients observed in a time span of ten years, collecting demographic, clinical, and instrumental data. Significant baseline characteristics were evaluated as potential risk factors for the development of epilepsy in the CAA population, in the subgroups of CAA-ri and CAA without inflammatory reaction (CAA-nri). The effect of potential risk factors for epilepsy was measured as odds ratio with 95% confidence interval.

RESULTS: Within 96 recruited CAA cases, 33 (34.4%) developed epilepsy during follow-up (median 13.5 months). The prevalent type of seizures was focal (81.3%); 12.1% of the epileptic patients presented status epilepticus and 6.1% developed drug resistant epilepsy. Electroencephalographic traces revealed slow and epileptic discharge activity in the majority of epileptic patients, but also in those without epilepsy. The presence of focal or disseminated cortical superficial siderosis (cSS) was associated with an increased risk of epilepsy in the CAA-nri group, while the association with CAA-ri and epilepsy was present in the overall population.

SIGNIFICANCE: Epilepsy is a common manifestation during the course of CAA, where CAA-ri and cSS represent predisposing factors for the development of seizures. These data suggest the importance of a deep characterization of CAA patients, in order to better select those more prone to develop epilepsy.