Which patients with epilepsy are at risk for psychogenic nonepileptic seizures (PNES)? A multicenter case-control study

Epilepsy Behav. 2016 Aug;61:180-184. doi: 10.1016/j.yebeh.2016.05.032. Epub 2016 Jun 27.

Abstract

Objective: We sought to examine the clinical and electrographic differences between patients with combined epileptic (ES) and psychogenic nonepileptic seizures (PNES) and age- and gender-matched patients with ES-only and PNES-only.

Methods: Data from 138 patients (105 women [77%]), including 46 with PNES/ES (39±12years), 46 with PNES-only (39±11years), and 46 with ES-only (39±11years), were compared using logistic regression analysis after adjusting for clustering effect.

Results: In the cohort with PNES/ES, ES antedated PNES in 28 patients (70%) and occurred simultaneously in 11 (27.5%), while PNES were the initial presentation in only 1 case (2.5%); disease duration was undetermined in 6. Compared with those with ES-only, patients with PNES/ES had higher depression and anxiety scores, shorter-duration electrographic seizures, less ES absence/staring semiology (all p≤0.01), and more ES arising in the right hemisphere, both in isolation and in combination with contralateral brain regions (61% vs. 41%; p=0.024, adjusted for anxiety and depression) and tended to have less ES arising in the left temporal lobe (13% vs. 28%; p=0.054). Compared with those with PNES-only, patients with PNES/ES tended to show fewer right-hemibody PNES events (7% vs. 23%; p=0.054) and more myoclonic semiology (10% vs. 2%; p=0.073).

Conclusions: Right-hemispheric electrographic seizures may be more common among patients with ES who develop comorbid PNES, in agreement with prior neurobiological studies on functional neurological disorders.

Keywords: Epilepsy; Epileptic seizures; Functional disorders; Psychogenic nonepileptic seizures.

MeSH terms

  • Adult
  • Anxiety / psychology
  • Case-Control Studies
  • Cohort Studies
  • Depression / psychology
  • Electroencephalography
  • Epilepsy / epidemiology*
  • Epilepsy, Temporal Lobe / psychology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Risk Assessment
  • Seizures / epidemiology*
  • Seizures / psychology
  • Somatoform Disorders / epidemiology*