Functional imaging work has made it possible to identify the brain regions involved in anxiety disorders but is insufficient to study the pathophysiological mechanisms that cause anxiety symptoms. Brain regions involved in anxiety disorders are located deep in the human brain, and their electrophysiological study requires invasive recording methods.~Intracerebral electroencephalographic recordings (stereoelectroencephalography - sEEG) made for care in hospital before surgery in patients with drug-resistant epilepsy, offer this unique opportunity. Indeed, the brain regions involved in anxiety are among the structures registered to delimit the epilepticogenic zone, and 20% of patients with drug-resistant epilepsy suffer from an anxiety disorder.~This study propose to compare 10 patients suffering from drug-resistant epilepsy and generalized anxiety disorders (GAD), explored by intracranial sEEG, and 10 patients suffering from drug-resistant epilepsy without GAD (controls),explored by sEEG.~During sEEG patient will be proposed to undergo a custom-made behavioral task design to allow clinically-relevant anxiogenic exposure.~Patients will so be exposed to anxiety scenarios, while intracerebral sEEG, physiological stress parameters and the level of anxiety experienced will be monitored.~Electrophysiological parameters will be compared and correlated with clinical characteristics of the population and outcomes of the task.
Anxiety disorders have the highest prevalence among mental disorders and cause considerable individual and financial costs. Current treatments do not relieve mental suffering of many patients. Understanding neurobiological mechanisms involved in pathological anxiety is a major scientific challenge.