Edelstyn Nicky, Di Rosa Elisa, Martini Alice
School of Psychology, Keele University, Staffordshire, UK.
Department of General Psychology, University of Padova, Padova, Italy.
Eur Neurol. 2023;86(2):81-84. doi: 10.1159/000528900. Epub 2023 Jan 19.
This review article integrates findings from published behavioural and neuroimaging studies of impulsive-compulsive behaviours (ICBs) in Parkinson's disease, with the aim of identifying the basic correlates of these problematic and distressing behaviours. The underlying premise is that for any feature to be a reliable marker of ICBs, it should be evident across multiple levels of analyses. When changes are evident only at one level, but not in the others, their reliability as indicators of ICBs should be questioned.
To this end, we draw on the conclusions from three published systematic reviews of dopamine metabolic processes in the striatum, functional magnetic resonance imaging and cognitive, affective, and motivational assessments of medicated Parkinson's patients with and without ICBs (ICB+ and ICB-, respectively). The key findings are as follows: ICB+ showed abnormal dopaminergic of the striatum, including the brain network supporting reward processing. Fronto-striatal connectivity was also reduced. These findings are consistent with the broader evidence of psychological dysfunction, evident on assessments of cognitive control (goal-driven behaviour, impulsivity), reward-driven decision-making (temporal discounting, gambling), and elevated rates of self-report negative affect (anxiety, depression, anhedonia). The implications of these findings are discussed with reference to the research domain criteria and, relatedly, directions for future research.
The identification of markers of ICB that allow early diagnosis, monitoring, and optimisation of therapy is an ambitious goal. And whilst we have pulled together a number of convergent findings identified using different paradigms, we are still some distance off understanding the mechanism(s) that increase vulnerability to ICB. It is our hope that this review spurs future studies to further investigate the interaction between motivation and cognition with the twin aims of identifying markers of ICB that have both clinical utility and function as outcome measures in therapeutic clinical trials.
这篇综述文章整合了已发表的帕金森病冲动强迫行为（ICB）的行为学和神经影像学研究结果，旨在确定这些有问题且令人苦恼行为的基本相关因素。潜在前提是，对于任何特征要成为ICB的可靠标志物，它应在多个分析层面都很明显。当变化仅在一个层面明显，而在其他层面不明显时，其作为ICB指标的可靠性就应受到质疑。
为此，我们借鉴了三项已发表的系统综述的结论，这些综述涉及纹状体多巴胺代谢过程、功能磁共振成像以及对有和没有ICB的帕金森病患者（分别为ICB+和ICB-）的认知、情感和动机评估。主要发现如下：ICB+显示纹状体多巴胺能异常，包括支持奖赏处理的脑网络。额纹状体连接性也降低。这些发现与心理功能障碍的更广泛证据一致，在认知控制（目标导向行为、冲动性）、奖赏驱动决策（时间折扣、赌博）以及自我报告负面情绪（焦虑、抑郁、快感缺失）发生率升高的评估中很明显。参考研究领域标准讨论了这些发现的意义以及相关的未来研究方向。
识别能够实现早期诊断、监测和优化治疗的ICB标志物是一个宏伟目标。虽然我们汇集了一些使用不同范式确定的趋同发现，但我们距离理解增加ICB易感性的机制仍有一段距离。我们希望这篇综述能激发未来的研究，进一步调查动机与认知之间的相互作用，以实现识别具有临床效用且可作为治疗性临床试验结果指标的ICB标志物这一双重目标。
