Decreased duration and altered topography of electroencephalographic microstates in patients with panic disorder

The topography and temporal sequence of scalp electrical fields were analyz ed by adaptive segmentation of the continuous electroencephalogram (EEG) in 27 patients with panic disorder and 28 control subjects during rest phases and during the viewing of a neutral (mushroom) or an emotionally relevant (casualty) picture. The results indicate decreased duration of brain micros tates in panic patients during all conditions. Comparison of the resting ph ases with the viewing conditions revealed a significant acceleration of EEG microstates in both the patients and the control subjects. Patients and co ntrol subjects differed in the topography of the fields during rest: contro l subjects showed a left-anterior/right-posterior orientation, while panic patients showed a predominantly right-anterior/left-posterior orientation. Neither group displayed any topographic changes when viewing the mushroom p icture. However, when viewing the anxiety-specific casualty picture, panic patients shifted fields in a different way than did control subjects. Centr oid topography does not permit clear localization of the cortical generator s. It is concluded that panic patients show a generally increased cortical activation compared with healthy control subjects, and activate different n euronal arrays when viewing an anxiety-specific stimulus. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.