title: Dissociation in epilepsy and conversion nonepileptic seizures.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Psychiatry, New York University Medical Center, Hospital for Joint Diseases, NY 10003, USA.
authors.forename: K
authors.initials: K
authors.lastname: Alper
authors.forename: O
authors.initials: O
authors.lastname: Devinsky
authors.forename: K
authors.initials: K
authors.lastname: Perrine
authors.forename: D
authors.initials: D
authors.lastname: Luciano
authors.forename: B
authors.initials: B
authors.lastname: Vazquez
authors.forename: S
authors.initials: S
authors.lastname: Pacia
authors.forename: E
authors.initials: E
authors.lastname: Rhee
mesh_terms: D000328:Adult; D000647:Amnesia / Q000175:diagnosis; D002648:Child; D002649:Child Abuse / Q000175:diagnosis; D015986:Confounding Factors, Epidemiologic; D003291:Conversion Disorder / Q000175:diagnosis*; D003937:Diagnosis, Differential; D004213:Dissociative Disorders / Q000175:diagnosis*; D004522:Educational Status; D017029:Epilepsy, Complex Partial / Q000175:diagnosis*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D017533:Marital Status; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D044469:Racial Groups; D012640:Seizures / Q000175:diagnosis*; D012737:Sex Factors; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis