Predictors of early recurrent seizure after first seizure presentation to an emergency service: A retrospective cohort study

Purpose: To identify the predictors of seizure recurrence after a first seizure (FS) presentation to an emergency service. Methods: The clinical characteristics of FS patients presenting to the emergency department (ED) of our university hospital from January 2001 to December 2014 were retrospectively reviewed. Recurrence of seizures following the FS was classified as: early recurrence (0-1 month), intermediate recurrence (> 1-3 months), and late recurrence (> 3-12 months). The significant predictors of seizure recurrence in each period were identified by Cox proportional hazard ratios (p < 0.05). Results: 648 FS patients of the 1248 overall seizures patients were initially enrolled. 414 FS patients were eligible for statistical analysis. Following the FS, 134 patients (32.4%) had recurrent seizures in which half of the first recurrences occurred within 3 months. The significant predictors of overall recurrence were remote symptomatic seizure (RSS) (adjusted hazard ratio [adj. HR] = 2.21 (1.38, 3.55), p = 0.003) and nocturnal onset seizure (NOS) (adj. HR = 1.53 (1.03, 2.26), p = 0.039). Those of early recurrence were NOS (adj. HR = 2.78 (1.44, 5.37), p = 0.002) and anti-epileptic drug (AED) prescription (adj. HR = 2.19 (1.00, 4.80), p = 0.038). Those of intermediate recurrence were RSS (adj. HR = 3.96 (1.63, 9.60), p = 0.006) and AED prescription (adj. HR = 4.90 (1.42, 16.95), p = 0.003). No predictor of late recurrence was identified. Conclusion: The seizure recurrence rate was high in the first 3 months following the FS. The significant predictors were RSS, NOS and AED prescription.