Dissociation in epilepsy and conversion nonepileptic seizures

Epilepsia. 1997 Sep;38(9):991-7. doi: 10.1111/j.1528-1157.1997.tb01481.x.


Purpose: We examined the dimensionality of the item content of the Dissociative Experiences Scale (DES) in relation to the clinical diagnosis of conversion nonepileptic seizures (C-NES) versus complex partial epilepsy (CPE).

Methods: The DES was administered to a sex- and age-matched sample of 132 patients with C-NES and 169 with CPE and was factor analyzed with principal components analysis (PCA) with varimax rotation.

Results: The mean total DES score was 15.1 in the C-NES group and 12.7 in the CPE group (p = 0.079). The factors obtained by PCA differentiated the CPE and C-NES groups more strongly than did the total DES score. The factor accounting for the most variance, interpreted as "depersonalization-derealization," was significantly greater in C-NES than CPE (p = 0.005). An "absorption-imaginative involvement" factor, which included some of the clinical features of posttraumatic stress disorder was elevated only in subjects reporting histories of childhood abuse (p = 0.001) regardless of the diagnosis of CPE or C-NES. An "amnestic" factor appearing to represent memory problems related to neurologic impairment showed a trend toward elevation in CPE (p = 0.056) and may have confounded the CPE versus C-NES distinction using total DES scores.

Conclusions: The DES has separate underlying dimensions that appear to relate distinctively to depersonalization and derealization, childhood trauma, and neurologic impairment. The heterogeneous item content of the DES is a potential confound that should be appreciated when this instrument is used to study dissociation in neuropsychiatric populations.

MeSH terms

  • Adult
  • Amnesia / diagnosis
  • Child
  • Child Abuse / diagnosis
  • Confounding Factors, Epidemiologic
  • Conversion Disorder / diagnosis*
  • Diagnosis, Differential
  • Dissociative Disorders / diagnosis*
  • Educational Status
  • Epilepsy, Complex Partial / diagnosis*
  • Factor Analysis, Statistical
  • Female
  • Humans
  • Male
  • Marital Status
  • Psychiatric Status Rating Scales / statistics & numerical data
  • Racial Groups
  • Seizures / diagnosis*
  • Sex Factors
  • Stress Disorders, Post-Traumatic / diagnosis