Predictors of seizure outcome in newly diagnosed partial epilepsy: memory performance as a prognostic factor

The epilepsy patients whose seizures will prove to be refractory should be identified as early as possible, and thus the need for new prognostic factors of intractable epilepsy is evident. The aim of the study was to investigate predictors of seizure outcome in a multivariate analysis. Neurological, electroencephalography (EEG) and neuropsychological variables were analyzed as potential predictors of epilepsy. Eighty-nine newly diagnosed adult patients with partial epilepsy were, after a prospective 2-year follow-up period, categorized into one of the two groups: patients with satisfactorily controlled epilepsy, and patients with refractory epilepsy. Six variables predicted 2-year seizure outcome: presence of spike focus in EEG, partial complex or mixed seizure type, remote symptomatic etiology, moderately impaired memory performance in immediate recall and in delayed recognition of the word list, and age at the time of diagnosis. The correct seizure outcome could be predicted with the model in 94% of newly diagnosed epilepsy patients. The presence of verbal memory impairment at the time of the diagnosis of partial epilepsy is a significant predictor of seizure outcome and, together with clinical and EEG variables, it predicts seizure outcome in the majority of the patients. Memory performance as a prognostic factor is of most value in patients with risk of refractory epilepsy and when used in a multidisciplinary setting.