Response inhibition in patients with functional neurological symptom disorder.

Abnormal response inhibition has been demonstrated in psychogenic movement disorders (PMD) and is a plausible mechanism for other forms of functional neurological symptom disorder (FNSD), in which response inhibition has not yet been investigated. Response inhibition was therefore studied in patients with FNSD, including patients with psychogenic non-epileptic seizures (PNES), functional weakness (FW) or both. Twenty-nine patients with FNSD and 29 age and sex-matched healthy volunteers underwent a go-nogo task, a stop-signal reaction time (SSRT) task, and a negative priming flanker task.