Prevalence and predictors of seizure clusters: A prospective observational study of adult patients with epilepsy

Epilepsy Behav. 2018 Nov:88:349-356. doi: 10.1016/j.yebeh.2018.09.035. Epub 2018 Oct 19.

Abstract

Objective: The purpose of this prospective observational study was to describe the prevalence and adverse outcomes associated with seizure clusters (defined as ≥2 seizures in a 6-hour period) in a large sample of adult patients with a range of epilepsy severities and to identify clinical characteristics predictive of clustering.

Methods: Patients maintained a seizure diary and were contacted monthly to verify compliance and data accuracy. Logistic regression models were utilized to test associations between individual patient demographic/clinical characteristics and seizure clustering. Fisher's exact test was utilized to test associations between rescue medication use and adverse seizure-related outcomes.

Results: A total of 300 patients were followed prospectively for one year; 247 patients qualified for final analysis. Six-hour seizure clusters occurred in 45.8% of patients with active epilepsy at enrollment, including 62.7% of those with prior day-clusters and 30.0% of those without prior day-clusters. The odds of clustering were markedly greater among patients who reported a higher seizure frequency (>4 seizures per year vs. 1-4 seizures per year) (adjusted odds ratio (OR): 8.9; 95% confidence interval (CI): 3.2-24.6; p < 0.0001) and among patients with prior day-clusters (adjusted OR: 11.0; 95% CI: 1.2-104.2; p = 0.036). Rescue medication use was associated with significantly fewer injuries and emergency department visits, but rescue medication was underutilized.

Conclusions: Seizure clusters are common, occurring in nearly half of adult patients with active epilepsy followed prospectively over one year, and are more frequent in those with higher seizure frequencies and prior day-clusters. Although underutilized, rescue medication was associated with fewer injuries and emergency department visit.

Keywords: Acute repetitive seizures; Epilepsy; Rescue medication; Seizure clusters; Seizures.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Adolescent
  • Adult
  • Anticonvulsants / therapeutic use
  • Epilepsy / drug therapy
  • Epilepsy / epidemiology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Prevalence
  • Prospective Studies
  • Seizures / drug therapy
  • Seizures / epidemiology*
  • United States / epidemiology
  • Wounds and Injuries / etiology
  • Wounds and Injuries / prevention & control
  • Young Adult

Substances

  • Anticonvulsants