Traumatic events and posttraumatic stress disorder in patients with psychogenic nonepileptic seizures: a critical review.

Although video-EEG monitoring has revolutionized the diagnosis of psychogenic nonepileptic seizure (PNES), the etiology of this condition remains poorly understood. This article is a critical review of studies on the prevalence of traumatic events, abuse, and/or posttraumatic stress disorder (PTSD) in patients with PNES. Searches carried out on MEDLINE (1966-2004) and Web of Science (1945-2004) identified 17 relevant studies. PNES samples showed very high rates of trauma (44-100%) and abuse (23-77%), which were 15-40% higher than those found in control groups. This suggests that traumatic experiences may be a potential risk factor for PNES. PNES samples also showed a higher prevalence of PTSD than control groups, raising the possibility that PNES may arise as a clinical expression of a hypothetical PTSD subtype the core symptoms of which are dissociative. Methodological limitations do not permit the confirmation of these hypotheses. Stronger research designs are needed, such as prospective and case-control studies in both hospital and community settings.