PhD Defence Guillaume Carey

Keywords: Parkinson’s disease; anxiety; MRI; fear circuit
 

"Imaging Anxiety in Parkinson's Disease"

Anxiety in Parkinson’s disease (PD) is a frequent and debilitating symptom. Although it is a topic of high interest for patients and clinicians, few is known about the underlying mechanisms. The objective of this thesis is to identify the mechanisms of PD-related anxiety using multimodal brain MRI. 

First, a systematic review about neuroimaging of anxiety in PD is made in order to generate the first hypotheses. Then, using different methods of brain MRI, this thesis shows that structural and functional alteration within two specific brain circuits could be associated with PD-related anxiety. The fear circuit, involved in fear processing and anxiety regulation, would be overactivated. While the limbic loop of the cortico-striato-thalamo-cortical dopaminergic circuit, involved in cognitive regulation of emotions, would be underactivated. This imbalance could enhance anxiety in PD-patients. 

This thesis also promotes the use of non-pharmacological treatment for PD-related anxiety. It shows that this imbalance is reduced after a cognitive behavioural therapy. 

Further works using high-resolution 7-tesla MRI will help to better decipher these specific mechanisms in order to improve the management of this symptom. 

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