Amygdala hypersensitivity in response to emotional faces in Tourette's patients

Abstract

Objectives. Tourette's syndrome is characterised by motor and vocal tics as well as a high level of impulsivity and emotional dysregulation. Neuroimaging studies point to structural changes of the basal ganglia, prefrontal cortex and parts of the limbic system. However, there is no link between behavioural symptoms and the structural changes in the amygdala. One aspect of daily social interaction is the perception of emotional facial expressions, closely linked to amgydala function. Methods. We therefore investigated via fMRI the implicit discrimination of six emotional facial expressions in 19 adult Tourette's patients. Results. In comparison to healthy control group, Tourette's patients showed significantly higher amygdala activation, especially pronounced for fearful, angry and neutral expressions. The BOLD-activity of the left amygdala correlated negatively with the personality trait extraversion. Conclusions. We will discuss these findings as a result of either deficient frontal inhibition due to structural changes or a desynchronization in the interaction of the cortico-striato-thalamo-cortical network within structures of the limbic system. Our data show an altered pattern of implicit emotion discrimination and emphasize the need to consider motor and non-motor symptoms in Tourette's syndrome in the choice of both behavioural and pharmacological treatment.

Key words::

• Amygdala
• Tourette
• tics
• hypersensitivity
• Ekman faces

Acknowledgements

The study was supported by the German Tourette's Association. We thank the Board of Directors Silvia Viertel, Monika Flecken und Wolf Hartmann as well as all members of the German Tourette's Association and particularly the participating Tourette's patients for their commitment. The research activities of IN are supported by the “Rotationsprogramm” of the Faculty of Medicine, RWTH Aachen University. The MRI facility is supported by the Ministry for Education and Research (BMBF) through a grant (BMBF 01GO0104) to NJS and Karl Zilles. The Brain Imaging Centre West is funded by the BMBF (BMBF 01GO0204). We would like to thank Barbara Elghahwagi, Petra Engels, Gabriele Oefler and Tomas Mazza for their excellent technical assistance. We thank Corinna Ehlen for her dedicated care of the patients and neuropsychological data acquisition.

Statement of interest

Irene Neuner, Thilo Kellermann, Tony Stöcker and Utel Habel report no conflict of interest. Tilo Kircher received compensation as a consultant and for investigator initiated projects from AstraZeneca. Frank Schneider received compensation as a consultant for Janssen-Cilag, AstraZeneca, and Otsouka, manufacturers of antipsychotic medication. Frank Schneider received compensation for scientific talks or contribution in a prize jury by Janssen-Cilag, Wyeth, and AstraZeneca. Frank Schneider received funding for investigator initiated projects from AstraZeneca, Lilly and Pfizer.