Cognitive effects of interictal epileptiform discharges in children

Eur J Paediatr Neurol. 2012 Nov;16(6):697-706. doi: 10.1016/j.ejpn.2012.05.010. Epub 2012 Jun 29.

Abstract

Frequent interictal epileptiform discharges (IEDs) may have effects on cognition. We analysed a group of 182 children with different epilepsy syndromes as well as children with IEDs without observed seizures [corrected], with 24-h ambulatory EEG and cognitive tests. The IED index was estimated, in wakefulness and in sleep, as percentage of time in five categories (0%, <1%, 1-10%, ≥10-50% and ≥50%). IEDs were defined as spikes or spike-wave complexes, isolated or occurring serially (in runs) without evident clinical signs of a seizure. The IED categories were correlated to cognitive test results and epilepsy characteristics. The group of patients with diurnal IEDs in ≥10% of the EEG record showed impaired central information processing speed, short-term verbal memory and visual-motor integration. This effect was seen independently from other EEG-related and epilepsy-related characteristics, and independently from epilepsy syndrome diagnosis. The impact of the nocturnal IEDs was of less importance; only contributing partially to the slowing of central information processing speed. We conclude that frequent IEDs (in more than 10% of the record) in the awake EEG can impair cognitive performance in children. Whether children with a high diurnal spike frequency and low seizure frequency can benefit from antiepileptic treatment should be examined in controlled trials.

MeSH terms

  • Child
  • Cognition / physiology*
  • Cognition Disorders / etiology
  • Cognition Disorders / psychology
  • Educational Status
  • Electroencephalography
  • Epilepsy / psychology*
  • Female
  • Humans
  • Intelligence Tests
  • Male
  • Memory / physiology
  • Neuropsychological Tests
  • Psychomotor Performance / physiology
  • Regression Analysis
  • Seizures / psychology*
  • Sleep / physiology
  • Wakefulness / physiology