Skin conductance response and emotional response in women with psychogenic non-epileptic seizures

Purpose: Recent etiopathogenic models place emotional dysregulation at the core of psychogenic nonepileptic seizure (PNES). Our purpose was to assess physiological, cognitive, and behavioral emotional responses of PNES patients.

Methods: This study compared three types of emotional responses to visual emotional stimuli between 34 female PNES group and 34 matched healthy controls: physiological response measured by skin conductance response (SCR) (rate, amplitude and latency) and heart rate deceleration; cognitive response measured by valence and arousal elicited by the images; and behavioural response measured by latency of ratings. The groups were characterized on psychiatric comorbidities, traumatic history, alexithymia, and dissociation.

Results: Compared to controls, PNES group displayed lower SCR for all images (p = 0.038), shorter amplitude of heart rate deceleration (p = 0.024) and faster arousal rating for all images (p = 0.019), but no difference on cognitive rating of images. Within-groups analyses showed only in PNES subjects increased rate (+19.35%, p = 0.046) SCR for negative stimuli with strong arousal compared to negative with low arousal. PNES physiological response (SCR and heart rate deceleration) was negatively correlated to dissociation tendency (r=-0.48, p = 0.0083) and alexithymia (r=-0.44, p = 0.012)). For cognitive response, no correlation was found.

Conclusion: These results are in favour of a lower physiological emotional response but with an over-reactivity at behavioral level contrasting with similar cognitive assessment. For strong aversive stimuli, PNES might present a trend to overreact at physiological and behavioural levels. Our results suggest that dissociation and difficulty in describing feelings are associated with an altered physiological response in PNES women only.