Trauma, stress, and preconscious threat processing in patients with psychogenic nonepileptic seizures

Psychogenic nonepileptic seizures (PNES) have long been considered as paroxysmal dissociative symptoms characterized by an alteration of attentional functions caused by severe stress or trauma. Although interpersonal trauma is common in PNES, the proposed relation between trauma and attentional functions remains under explored. We examined the attentional processing of social threat in PNES in relation to interpersonal trauma and acute psychological stress.

A masked emotional Stroop test, comparing color-naming latencies for backwardly masked angry, neutral, and happy faces, was administered to 19 unmedicated patients with PNES and 20 matched healthy controls, at baseline and in a stress condition. Stress was induced by means of the Trier Social Stress Test and physiologic stress parameters, such as heart rate variability (HRV) and cortisol, were measured throughout the experiment.

No group differences related to the acute stress induction were found. Compared to controls, however, patients displayed a positive attentional bias for masked angry faces at baseline, which was correlated to self-reported sexual trauma. Moreover, patients showed lower HRV at baseline and during recovery.

These findings are suggestive of a state of hypervigilance in patients with PNES. The relation with self-reported trauma, moreover, offers the first evidence linking psychological risk factors to altered information processing in PNES.