Nitza Thomasson, Rush-Presbyterian-Saint Luke’s Medical Center, Chicago IL
Laurent Pezard, Université de Paris, Paris, France
Patrice Boyer, Université de Paris VII, Pav. Clérambault, Hôpital Salpêtrière, Paris Cedex, France
Bernard Renault, Hôpital Salpêtrière, Paris Cedex, France
Jacques Martinerie, Hôpital Salpêtrière, Paris Cedex, France

Abstract: This research report presents the case study of a 48-hour cyclic manic-depressive patient which further demonstrates the association between nonlinear EEG characteristics and mood variations as previously reported by Thomasson et al. (2000). The evolution of brain dynamics and mood were daily measured during a week. Global complexity of brain electrical activity was estimated by a nonlinear index (entropy) and mood modulations were evaluated by a clinical self-assessment scale (BfS’). Illustrating the concept of “dynamical disease,” a significant co-variation between the nonlinear EEG index and mood evolution (Spearman correlation coefficient  = 0.92, p = .008) was observed. This result strengthens the previous ones and demonstrates a clear association between nonlinear brain dynamics and state of mind in psychopathology.

Keywords: nonlinear analysis, EEG, manic-depressive II illness, bipolar disorder