Altered brain connectivity in patients with psychogenic non-epileptic seizures: a scalp electroencephalography study.

OBJECTIVE To determine the role of altered brain connectivity in patients with psychogenic non-epileptic seizures (PNES). METHODS Patients with PNES and age- and sex-matched healthy control subjects were enrolled. Participants underwent neuropsychological evaluation (anxiety, depression and dissociation) and interictal scalp electroencephalography (EEG). A brain network was constructed. Between-group differences in clustering coefficient and global efficiency were analysed. RESULTS Patients with PNES (n = 15) had significantly decreased clustering coefficients in the gamma band compared with controls (n = 15). Difference topology revealed that patients with PNES had decreased long linkage between the frontal region and other regions compared with controls. There were no significant between-group differences in global efficiency. Neuropsychological scores were significantly higher in patients than controls, but there were no correlations with network properties. CONCLUSION Altered brain connectivity in patients with PNES suggests an underlying pathophysiological mechanism. EEG and network analysis allow noninvasive exploration of the neurological processes of this disease.