Seizure metaphors differ in patients' accounts of epileptic and psychogenic nonepileptic seizures

To increase understanding of the subjective symptomatology of seizure experiences and improve differential diagnosis by studying the seizure metaphors used by patients with (psychogenic) nonepileptic seizures (NES) and epilepsy.

Twenty-one unselected patients taking part in this study were admitted for 48 h of video-EEG (electroenceophalography) observation because of uncertainty about the diagnosis. Eight were proven to have epilepsy, 13 to have psychogenic nonepileptic seizures (PNES). During their admission, patients were interviewed by a neurologist. A linguist blinded to the medical diagnosis identified and categorized all seizure metaphors in verbatim transcripts. Between-group comparisons and logistic regression analysis were carried out.

Of 382 metaphors identified, 80.8% conceptualized seizures as an agent/force, event/situation, or space/place. Most patients used metaphors from all categories, but patients with epilepsy and PNES showed preferences for different metaphoric concepts (differences p = 0.009 to p = 0.039). Patients with epilepsy preferred metaphors depicting the seizure as an agent/force or event/situation. PNES patients more often used metaphors of space/place. Logistic regression analyses predicted the diagnosis of PNES or epilepsy correctly in 85.7% of cases (based on different metaphor types in the each category) or 81.0% (based on all metaphor tokens).

Patients with epilepsy and PNES have different preferences in the metaphoric conceptualization of their seizures. Epileptic seizures are described as a more external, self-directed entity than PNES, which are depicted as a state or place patients go through. The differentiating value of metaphoric conceptualizations suggests that metaphor preference could form the basis of future diagnostic questionnaires or other diagnostic tools.