Alterations of consciousness in psychogenic nonepileptic seizures: emotion, emotion regulation and dissociation.

Impairment of consciousness and reduced self-control are key features of most psychogenic nonepileptic seizures (PNESs), although, compared with patients with epilepsy, those with PNESs demonstrate greater conscious awareness during their seizures. The neurobiological underpinnings of PNESs and of alterations of awareness associated with PNESs remain relatively unknown. We suggest that an understanding of conscious experiences and discrepancies between subjective impairment of consciousness and the lack of objectifiable neurobiological changes in PNESs may benefit from an examination of emotion processing, including understanding sensory, situational, and emotional triggers of PNESs; emotional and physiological changes during the attacks; and styles of emotional reactivity and regulatory capacity. We also suggest that in addition to the typical comparisons between patients with PNESs and those with epilepsy, studies of PNESs would benefit from the inclusion of comparison groups such as those with PTSD, dissociation, and other forms of psychopathology where dissociative and emotion regulatory mechanisms have been explored more fully. We conclude that current evidence and theory suggest that impairment of consciousness in PNESs is only "dissociative" in one subgroup of these seizures, when consciousness is suppressed as a collateral effect of the excessive inhibition of emotion processing. We propose that PNES behaviors and experiences of reduced control or awareness may also represent direct behavioral manifestation of overwhelming emotions, or that minor emotional fluctuations or relatively neutral stimuli may trigger PNESs through conditioning or other preconscious processes. Future studies exploring the neurobiological mechanisms underpinning PNESs are likely to be more fruitful if researchers bear in mind that it is unlikely that all PNESs result from the same processes in the brain.