Emotion regulation and functional neurological symptoms: Does emotion processing convert into sensorimotor activity?

Functional neurological symptoms (FNS) are hypothetically explained as a shift of emotion processing to sensorimotor deficits, but psychophysiological evidence supporting this hypothesis is scarce. The present study measured neuromagnetic and somatic sensation during emotion regulation to examine frontocortical and sensorimotor activity as signals of altered emotion processing.

Magnetoencephalographic (MEG) activity was mapped during an emotion regulation task in 20 patients with FNS and 20 healthy comparison participants (HC). Participants were instructed to (A) passively watch unpleasant or neutral pictures or (B) down-regulate their emotional response to unpleasant pictures utilizing cognitive reappraisal strategies. Group- and task-specific cortical activity was evaluated via 8-12 Hz (alpha) power modulation, while modulation of somatic sensation was measured via perception and discomfort thresholds of transcutaneous electrical nerve stimulation.

Implementing emotion regulation strategies induced frontocortical alpha power modulation in HC but not in patients, who showed prominent activity modulation in sensorimotor regions. Compared to HC, discomfort threshold for transcutaneous stimulation decreased after the task in patients, who also expressed increased symptom intensity.

Reduced frontocortical, but enhanced sensorimotor involvement in emotion regulation efforts offers a trace to modeling a conversion of (aversive) feelings into (aversive) somatic sensations in FNS.