title: Stimulation of subgenual cingulate area decreases limbic top-down effect on ventral visual stream: A DBS-EEG pilot study.
abstract: Deep brain stimulation (DBS) of the subgenual cingulate gyrus (area CG25) is beneficial in treatment resistant depression. Though the mechanisms of action of Cg25 DBS remain largely unknown, it is commonly believed that Cg25 DBS modulates limbic activity of large networks to achieve thymic regulation of patients. To investigate how emotional attention is influenced by Cg25 DBS, we assessed behavioral and electroencephalographic (EEG) responses to an emotional Stroop task in 5 patients during ON and OFF stimulation conditions. Using EEG source localization, we found that the main effect of DBS was a reduction of neuronal responses in limbic regions (temporal pole, medial prefrontal and posterior cingulate cortices) and in ventral visual areas involved in face processing. In the dynamic causal modeling (DCM) approach, the changes of the evoked response amplitudes are assumed to be due to changes of long range connectivity induced by Cg25 DBS. Here, using a simplified neural mass model that did not take explicitly into account the cytoarchitecture of the considered brain regions, we showed that the remote action of Cg25 DBS could be explained by a reduced top-down effective connectivity of the amygdalo-temporo-polar complex. Overall, our results thus indicate that Cg25 DBS during the emotional Stroop task causes a decrease of top-down limbic influence on the ventral visual stream itself, rather than a modulation of prefrontal cognitive processes only. Tuning down limbic excitability in relation to sensory processing might be one of the biological mechanisms through which Cg25 DBS produces positive clinical outcome in the treatment of resistant depression.
authors.affiliation: Univ. Grenoble Alpes, F-38000 Grenoble, France; Inserm, U1216, Grenoble Institut des Neurosciences, F-38000 Grenoble, France; Clinique Universitaire de Neurochirurgie, Pôle Tête et Cou, Centre Hospitalier Universitaire, Grenoble, France.
authors.forename: Astrid
authors.initials: A
authors.lastname: Kibleur
authors.affiliation: Univ. Grenoble Alpes, F-38000 Grenoble, France; Inserm, U1216, Grenoble Institut des Neurosciences, F-38000 Grenoble, France; Clinique Universitaire de Psychiatrie, Pôle Psychiatrie Neurologie, Centre Hospitalier Universitaire, Grenoble, France; Clinique Universitaire de Neurochirurgie, Pôle Tête et Cou, Centre Hospitalier Universitaire, Grenoble, France.
authors.forename: Mircea
authors.initials: M
authors.lastname: Polosan
authors.affiliation: Univ. Grenoble Alpes, F-38000 Grenoble, France; Laboratoire Psychologie et NeuroCognition, CNRS UMR 5105, F-38040, Grenoble, France; Clinique Universitaire de Neurochirurgie, Pôle Tête et Cou, Centre Hospitalier Universitaire, Grenoble, France.
authors.forename: Pauline
authors.initials: P
authors.lastname: Favre
authors.affiliation: Univ. Grenoble Alpes, F-38000 Grenoble, France; Inserm, U1216, Grenoble Institut des Neurosciences, F-38000 Grenoble, France; Clinique Universitaire de Neurochirurgie, Pôle Tête et Cou, Centre Hospitalier Universitaire, Grenoble, France.
authors.forename: David
authors.initials: D
authors.lastname: Rudrauf
authors.affiliation: Univ. Grenoble Alpes, F-38000 Grenoble, France; Inserm, U1216, Grenoble Institut des Neurosciences, F-38000 Grenoble, France; Clinique Universitaire de Psychiatrie, Pôle Psychiatrie Neurologie, Centre Hospitalier Universitaire, Grenoble, France; Clinique Universitaire de Neurochirurgie, Pôle Tête et Cou, Centre Hospitalier Universitaire, Grenoble, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Bougerol
authors.affiliation: Univ. Grenoble Alpes, F-38000 Grenoble, France; Inserm, U1216, Grenoble Institut des Neurosciences, F-38000 Grenoble, France; Laboratoire Psychologie et NeuroCognition, CNRS UMR 5105, F-38040, Grenoble, France; Clinique Universitaire de Neurochirurgie, Pôle Tête et Cou, Centre Hospitalier Universitaire, Grenoble, France.
authors.forename: Stéphan
authors.initials: S
authors.lastname: Chabardès
authors.affiliation: Univ. Grenoble Alpes, F-38000 Grenoble, France; Inserm, U1216, Grenoble Institut des Neurosciences, F-38000 Grenoble, France; Clinique Universitaire de Neurochirurgie, Pôle Tête et Cou, Centre Hospitalier Universitaire, Grenoble, France. Electronic address: Olivier.David@inserm.fr.
authors.forename: Olivier
authors.initials: O
authors.lastname: David
mesh_terms: D001499:Bayes Theorem; D001931:Brain Mapping; D046690:Deep Brain Stimulation; D061218:Depressive Disorder, Treatment-Resistant / Q000503:physiopathology* / Q000628:therapy; D004569:Electroencephalography; D004644:Emotions / Q000502:physiology; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008032:Limbic System / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D010865:Pilot Projects; D057190:Stroop Test; D014793:Visual Cortex / Q000503:physiopathology*
keywords: Anterior cingulate cortex; Deep brain stimulation; Depression; EEG; Stroop effect