Mechanisms behind seizure recurrence and quality of life after a first epileptic seizure

The lifetime prevalence of experiencing an epileptic seizure is at approximately 10%. Consecutive treatment and disease trajectories are highly dependent on the diagnostic process following a first epileptic seizure. The ILAE adjusted their definition of epilepsy in 2014 and thereby recommended an altered diagnostic rationale: The diagnosis of epilepsy might be given after a first epileptic seizure if the seizure recurrence risk would be estimated >60%, i.e. if certain clinical parameters would be present (IED on EEG, structural brain lesion). Seizure control might be achieved by ASM. This is especially important in the elderly population given their vulnerability due to an increased rate of structural brain lesions (e.g., ischemic stroke) and other cardiac, psychiatric or neurodegenerative comorbidities. Besides, the impact of experiencing a first epileptic seizure on quality of life might be strong due to feelings of loss of control. Yet this construct has mostly been studied in patients with established epilepsy. This work thus focused on (1) the impact of the altered ILAE definition on treatment decisions, seizure recurrence and respective risk factors; (2) evaluated recurrence rates, seizure management and potential risk factors in elderly; and (3) investigated determinants of QoL in patients with a first epileptic seizure, thereby differentiating between patients diagnosed with epilepsy (PWE) and those with a single seizure (nPWE) during the first year after the seizure. With respect to the impact of the new ILAE definition of epilepsy, we observed a significantly increased rate of ASM treatment compared to those patients treated according the old definition requiring two epileptic seizures, while the recurrence rate remained relatively stable. Our study confirmed, besides the preventive effect of ASM, the importance of the presence of IED in EEG in the diagnostic process, while the influence of structural brain lesions on seizure recurrence did not reach statistical significance. In the elderly population, we could observe a preventive effect of ASM even in the absence of IED in EEG or brain lesions identified by MRI or CT. Results revealed no significant impact of the presence IED in EEG or structural lesions on seizure recurrence rates in the elderly, while ASM treatment was significantly associated with the presence of psychiatric and neurodegenerative diseases. Finally, QoL in patients experiencing a first epileptic seizure might be impaired early after seizure onset and is predominantly determined by depressive symptoms, age and seizure management. Conclusively, we observed a change in ASM treatment following the revised ILAE guideline in the general patient population, while recurrence rates remained relatively stable, thus calling the feasibility of this adjustment into question. Also, IED in EEG are important in the diagnostic process, while the proposed relevance of structural brain lesions was not confirmed. This might be due to the nature of respective lesions (e.g., ischemic stroke) and should be interpreted with caution. Especially in the elderly population, there was a strong protective effect of ASM even without the requested diagnostic criteria, which should be subject to further research, thereby inspecting usefulness and negative side-effects. Key predictors of QoL were affective states, recurrent seizures and age, while QoL appeared to be impaired not only early after a first epileptic seizure but also continuously across an extended period of time especially in patients diagnosed with epilepsy. This underlines the need for comprehensive counselling immediately after a first seizure, taking patients’ clinical, demographic and emotional characteristics into account.