title: Subgroup classification in patients with psychogenic non-epileptic seizures.
abstract: BACKGROUND
  In this open non-controlled clinical cohort study, the applicability of a theoretical model for the diagnosis of psychogenic non-epileptic seizures (PNES) was studied in order to define a general psychological profile and to specify possible subgroups.
  
  
  METHODS
  Forty PNES patients were assessed with a PNES "test battery" consisting of eleven psychological instruments, e.g., a trauma checklist, the global cognitive level, mental flexibility, speed of information processing, personality factors, dissociation, daily hassles and stress and coping factors.
  
  
  RESULTS
  The total PNES group was characterized by multiple trauma, personality vulnerability (in a lesser extent, neuropsychological vulnerabilities), no increased dissociation, many complaints about daily hassles that may trigger seizures and negative coping strategies that may contribute to prolongation of the seizures. Using factor analysis, specific subgroups were revealed: a 'psychotrauma subgroup', a 'high vulnerability somatizing subgroup' (with high and low cognitive levels) and a 'high vulnerability sensitive personality problem subgroup'.
  
  
  CONCLUSIONS
  Using a theoretical model in PNES diagnosis, PNES seem to be a symptom of distinct underlying etiological factors with different accents in the model. Hence, describing a general profile seems to conceal specific subgroups with subsequent treatment implications. This study identified three factors, representing two dimensions of the model, that are essential for subgroup classification: psychological etiology (psychotrauma or not), vulnerability, e.g., the somatization tendency, and sensitive personality problems/characteristics ('novelty seeking'). For treatment, this means that interventions could be tailored to the main underlying etiological problem. Also, further research could focus on differentiating subgroups with subsequent treatment indications and possible different prognoses.
authors.affiliation: Department of Behavioral Research and Psychological Services, Epilepsy Center Kempenhaeghe, Heeze, The Netherlands. Bodden@kempenhaeghe.nl
authors.forename: N M G
authors.initials: NM
authors.lastname: Bodde
authors.forename: S J M
authors.initials: SJ
authors.lastname: van der Kruijs
authors.forename: D M
authors.initials: DM
authors.lastname: Ijff
authors.forename: R H C
authors.initials: RH
authors.lastname: Lazeron
authors.forename: K E J
authors.initials: KE
authors.lastname: Vonck
authors.forename: P A J M
authors.initials: PA
authors.lastname: Boon
authors.forename: A P
authors.initials: AP
authors.lastname: Aldenkamp
mesh_terms: D003291:Conversion Disorder / Q000150:complications*; D003937:Diagnosis, Differential; D004827:Epilepsy / Q000145:classification / Q000150:complications / Q000523:psychology; D006801:Humans; D011602:Psychophysiologic Disorders / Q000150:complications*