Emotion and cognition in Parkinson’s disease:etiology and neurobiological mechanisms

This dissertation describes studies carried out into the neurobiological mechanisms and risk factors for mood symptoms and cognitive deficits in Parkinson’s disease. Although patients suffering from Parkinson’s disease showed emotional brain system abnormalities, the actual emotional experience was undisturbed. This may be an indication of a compensatory brain mechanism that could be important in the treatment of mood symptoms. Furthermore, a reduction in brain cell volume was found even in patients suffering from Parkinson’s disease with mild cognitive symptoms. Therefore, it is essential to monitor and treat these patients in an early stage. This dissertation also shows that the development of depression in patients suffering from Parkinson’s disease is associated with general risk factors for depression rather than disease-related aspects

Cognitive Behavioral Therapy for Anxiety in Parkinsonʼs Disease: A Randomized Controlled Trial

Background Anxiety disorders are among the most prevalent and disabling neuropsychiatric syndromes in patients with Parkinson & apos;s disease (PD), but no randomized controlled treatment trials of anxiety have been published to date.Objective The aim of this study was to assess the effectiveness of cognitive behavioral therapy (CBT) in the treatment of anxiety in patients with PD.Methods Forty-eight patients with PD with anxiety were randomized 1:1 between CBT and clinical monitoring only (CMO). The CBT program was developed to specifically address anxiety symptoms in PD and consisted of 10 weekly sessions. Assessments were conducted by blinded assessors at baseline, at the end of the intervention, after 3 months, and after 6 months (CBT group only). Main outcome measures were the Hamilton Anxiety Rating Scale (HARS) and the Parkinson Anxiety Scale (PAS).Results Both the CBT and CMO groups showed clinically relevant improvement. Although there was no between-group difference in outcome on the Hamilton Anxiety Rating Scale (6.7-point reduction in the CBT group versus 3.9-point reduction in the CMO group; P = 0.15), there was both a statistically significant and a clinically relevant between-group difference on the total PAS in favor of CBT (9.9-point reduction in the CBT group versus 5.2-point reduction in the CMO group; P = 0.012), which was due to improvement on the PAS subscales for episodic (situational) anxiety and avoidance behavior. This greater improvement was maintained at 3- and 6-month follow-ups.Conclusion CBT is an effective treatment for anxiety in patients with PD and reduces situational and social anxiety, as well as avoidance behavior. (c) 2021 International Parkinson and Movement Disorder Societ

Functional connectivity disruptions correlate with cognitive phenotypes in Parkinson's disease

International audienceCognitive deficits in Parkinson's disease are thought to be related to altered functional brain connectivity. To date, cognitive-related changes in Parkinson's disease have never been explored with dense-EEG with the aim of establishing a relationship between the degree of cognitive impairment, on the one hand, and alterations in the functional connectivity of brain networks, on the other hand. This study was aimed at identifying altered brain networks associated with cognitive phenotypes in Parkinson's disease using dense-EEG data recorded during rest with eyes closed. Three groups of Parkinson's disease patients (N = 124) with different cognitive phenotypes coming from a data-driven cluster analysis, were studied: G1) cognitively intact patients (63), G2) patients with mild cognitive deficits (46) and G3) patients with severe cognitive deficits (15). Functional brain networks were identified using a dense-EEG source connectivity method. Pairwise functional connectivity was computed for 68 brain regions in different EEG frequency bands. Network statistics were assessed at both global (network topology) and local (inter-regional connections) level. Results revealed progressive disruptions in functional connectivity between the three patient groups, typically in the alpha band. Differences between G1 and G2 (p < 0.001, corrected using permutation test) were mainly frontotemporal alterations. A statistically significant correlation (ρ = 0.49, p < 0.001) was also obtained between a proposed network-based index and the patients' cognitive score. Global properties of network topology in patients were relatively intact. These findings indicate that functional connectivity decreases with the worsening of cognitive performance and loss of frontotemporal connectivity may be a promising neuromarker of cognitive impairment in Parkinson's disease