Epileptiform electroencephalogram discharges increase seizure recurrence risk in patients with acute symptomatic seizure due to a structural brain lesion

Objective: The risk factors for seizure recurrence after acute symptomatic seizure due to a structural brain lesion are not well established. The aim of this study was to analyze possible associations between demographic, clinical, and electroencephalographic variables and epilepsy development in patients with acute symptomatic seizure due to an acute structural brain lesion.

Methods: We designed an observational prospective study of patients with acute symptomatic seizure due to an acute structural brain lesion (hemorrhagic stroke, ischemic stroke, traumatic brain injury, or meningoencephalitis) who underwent EEG during their initial admission between January 2015 and January 2020. We analyzed prospectively recorded demographic, clinical, electroencephalographic (EEG), and treatment-related variables. All variables were compared between patients with and without seizure recurrence during 2 years of follow up.

Results: We included 194 patients (41.2 % women; mean [SD] age, 57.3 [15.8] years) with acute symptomatic seizure due to an acute structural brain lesion. They all underwent EEG during admission and were followed for at least 2 years. The identifiable causes were hemorrhagic stroke (44.8 %), ischemic stroke (19.5 %), traumatic brain injury (18.5 %), and meningoencephalitis (17 %). Fifty-six patients (29 %) experienced a second seizure during follow-up. Seizure recurrence was associated with epileptiform discharges on EEG (52% vs 32 %; OR 2.3 [95 % CI, 1.2-4.3], p = 0.008) and onset with status epilepticus (17% vs 0.05 %, OR 4.03 [95 % CI 1.45-11.2], p = 0.009).

Conclusions: Epileptiform discharges on EEG and status epilepticus in patients with acute symptomatic seizure due to an acute structural brain lesion are associated with a higher risk of epilepsy development.