Dopaminergic treatment may impair the ability to suppress impulsive behaviours in patients with Parkinson's disease, triggering impulse control disorders. It is unclear how dopaminergic medication affects the neural networks that contribute to withholding inappropriate actions. To address this question, we mapped task-related brain activity with whole-brain functional magnetic resonance imaging at 3 Tesla in 26 patients with Parkinson’s disease. Patients performed a sequential gambling task while being ON and OFF their regular dopaminergic treatment. During a gambling round, patients repeatedly decided between the option to continue with gambling and accumulate more monetary reward under increasing risk or the option to bank the current balance and start a new round. 13 patients had an impulse control disorder (ICD + group). These patients did not differ in risk-taking attitude during sequential gambling from 13 patients without impulse control disorder (ICD - group), but they displayed differences in gambling-related activity in cortico-subcortical brain areas supporting inhibitory control. First, the ICD + group showed reduced “continue-to-gamble” activity in right inferior frontal gyrus and subthalamic nucleus. Second, the individual risk-attitude scaled positively with “continue-to-gamble” activity in right subthalamic nucleus and striatum in the ICD - group only. Third, ICD + patients differed in their functional neural responses to dopaminergic treatment from ICD - patients: dopaminergic therapy reduced functional connectivity between inferior frontal gyrus and subthalamic nucleus during “continue-to-gamble” decisions and attenuated striatal responses towards accumulating reward and risk. Together, the medication-independent (trait) and medication-related (state) differences in neural activity may set a permissive stage for the emergence of impulse control disorders during dopamine replacement therapy in Parkinson’s disease.

多巴胺能治疗可能会削弱帕金森氏病患者抑制冲动行为的能力，从而引发冲动控制障碍。尚不清楚多巴胺能药物如何影响导致阻止不当行为的神经网络。为了解决这个问题，我们在26例帕金森氏病患者中，使用3特斯拉的全脑功能磁共振成像技术绘制了与任务相关的大脑活动。患者在进行常规多巴胺能治疗的同时进行连续赌博任务。在赌博回合中，患者反复选择是继续赌博还是在风险增加的情况下积累更多的金钱奖励，或者是选择保留当前余额并开始新一轮的选择。13名患者有冲动控制障碍（ICD +组）。这些患者与13名无冲动控制障碍的患者（ICD-组）在连续赌博期间的冒险态度没有差异，但在支持抑制性控制的皮层-皮层下大脑区域中，与赌博相关的活动表现出差异。首先，ICD +研究组显示右下额回和丘脑下核的“继续赌博”活动减少。第二，仅在ICD-组中，右下丘脑核和纹状体中，个体的风险态度与“继续赌博”活动呈正相关。第三，ICD +患者对多巴胺能治疗的功能神经反应与ICD-患者不同：多巴胺能疗法在“继续赌博”决策过程中降低了额下回和丘脑下核之间的功能连接，并减弱了纹状体对累积奖励和风险的反应。总之，在帕金森氏病中，多巴胺替代疗法期间，神经活动的药物独立性（特征）和药物相关性（状态）差异可能为冲动控制障碍的出现设定了许可阶段。