title: Changes of oscillatory activity in the subthalamic nucleus during obsessive-compulsive disorder symptoms: two case reports.
abstract: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has positive and negative effects on mood and cognition, as shown in patients suffering from Parkinson's disease (PD) and severe obsessive-compulsive disorders (OCD). Such behavioural and clinical effects suggest that the STN has an important function in limbic circuitry, which still needs to be clarified from electrophysiological recordings. Here we report two exceptional cases of OCD patients in whom local field potentials (LFP) of the anterior STN were directly recorded during acute obsessive-compulsive symptoms. We found significant symptom-related changes in different frequency bands, with no clear preferential oscillatory pattern. The overall modified STN activity during OCD symptoms suggests a mixture of both pathological and compensatory mechanisms that would reflect the maintenance of an over stable motor/cognitive/emotional set. Whether this activity propagates throughout the entire cognitive-limbic loops that are impaired in OCD is an interesting question for future research in larger series of patients.
authors.affiliation: Fonctions Cérébrales et Neuromodulation, Université Joseph Fourier, Grenoble, France; Grenoble Institut des Neurosciences, INSERM, U836, Grenoble, France. Electronic address: julien.bastin@ujf-grenoble.fr.
authors.forename: Julien
authors.initials: J
authors.lastname: Bastin
authors.affiliation: Fonctions Cérébrales et Neuromodulation, Université Joseph Fourier, Grenoble, France; Grenoble Institut des Neurosciences, INSERM, U836, Grenoble, France; Clinique de Psychiatrie, Pôle Neurologie Psychiatrie, Centre Hospitalier Universitaire, Grenoble, France.
authors.forename: Mircea
authors.initials: M
authors.lastname: Polosan
authors.affiliation: Fonctions Cérébrales et Neuromodulation, Université Joseph Fourier, Grenoble, France; Grenoble Institut des Neurosciences, INSERM, U836, Grenoble, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Piallat
authors.affiliation: Fonctions Cérébrales et Neuromodulation, Université Joseph Fourier, Grenoble, France; Grenoble Institut des Neurosciences, INSERM, U836, Grenoble, France; Clinique de Neurologie, Pôle Neurologie Psychiatrie, Centre Hospitalier Universitaire, Grenoble, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Krack
authors.affiliation: Clinique de Psychiatrie, Pôle Neurologie Psychiatrie, Centre Hospitalier Universitaire, Grenoble, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Bougerol
authors.affiliation: Fonctions Cérébrales et Neuromodulation, Université Joseph Fourier, Grenoble, France; Grenoble Institut des Neurosciences, INSERM, U836, Grenoble, France; Clinique de Neurochirurgie, Pôle Tête et Cou, Centre Hospitalier Universitaire, Grenoble, France.
authors.forename: Stéphan
authors.initials: S
authors.lastname: Chabardès
authors.affiliation: Fonctions Cérébrales et Neuromodulation, Université Joseph Fourier, Grenoble, France; Grenoble Institut des Neurosciences, INSERM, U836, Grenoble, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: David
mesh_terms: D000328:Adult; D046690:Deep Brain Stimulation; D006801:Humans; D008297:Male; D009771:Obsessive-Compulsive Disorder / Q000503:physiopathology* / Q000628:therapy; D020531:Subthalamic Nucleus / Q000503:physiopathology*
keywords: Deep brain stimulation; Obsessive-compulsive disorders; Oscillations; Subthalamic nucleus