Area of Neuroscience, SISSA, Via Bonomea, 265, Trieste, TS, Italy.
Department of Decision Neuroscience and Nutrition, German Institute of Human Nutrition, Potsdam Rehbrücke, Nuthetal, Germany.
J Neurol. 2022 Mar;269(3):1557-1565. doi: 10.1007/s00415-021-10733-0. Epub 2021 Jul 31.
Parkinson's disease (PD) patients with impulse control disorders (ICD) frequently report hypersensitivity to rewards. However, a few studies have explored the effectiveness of modulation techniques on symptoms experienced by these patients. In this study, we assessed the effect of anodal tDCS over the DLPFC on reward responsiveness and valuation in PD patients with ICD. 43 participants (15 PD patients with ICD, 13 PD without ICD, and 15 healthy matched controls) were asked to perform a reward-craving test employing both explicit (self-ratings of liking and wanting) and implicit (heart rate and skin conductance response) measures, as well as two temporal discounting tasks with food and money rewards. Each participant performed the experimental tasks during active anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC), anodal tDCS of the primary motor cortex (M1), and sham tDCS. Results showed increased wanting and a steeper temporal discounting of rewards in PD with ICD compared to the other groups. Moreover, we found that PD without ICD exhibit reduced liking for rewards. tDCS results capable to modulate the altered intensity of PD patients' liking, but not wanting and temporal discounting of rewards in PD patients with ICD. These findings confirm that alterations in reward responsiveness and valuation are characteristics of impulse control disorders in patients with PD but suggest that anodal tDCS over the left DLPFC is not capable to influence these processes. At the same time, they provide new insight into affective experience of rewards in PD.
帕金森病（PD）伴有冲动控制障碍（ICD）的患者经常报告对奖励的敏感性增加。然而，少数研究探讨了调制技术对这些患者所经历的症状的有效性。在这项研究中，我们评估了经颅直流电刺激（tDCS）对 PD 伴有 ICD 患者奖赏反应和估值的影响。43 名参与者（15 名 PD 伴有 ICD，13 名 PD 不伴有 ICD，15 名健康匹配对照）被要求执行奖赏渴求测试，采用了显性（自我评估的喜欢和想要）和隐性（心率和皮肤电反应）测量，以及两项使用食物和金钱奖励的时间折扣任务。每个参与者在左侧背外侧前额叶皮层（DLPFC）的阳极 tDCS、初级运动皮层（M1）的阳极 tDCS和假 tDCS期间执行实验任务。结果表明，与其他组相比，PD 伴有 ICD 的患者的想要程度增加，奖赏的时间折扣更加陡峭。此外，我们发现 PD 不伴有 ICD 的患者对奖赏的喜欢程度降低。tDCS 结果能够调节 PD 患者喜欢程度的改变，但不能调节 PD 伴有 ICD 患者的想要程度和奖赏的时间折扣。这些发现证实，奖赏反应和估值的改变是 PD 患者冲动控制障碍的特征，但提示左侧 DLPFC 的阳极 tDCS 不能影响这些过程。同时，它们为 PD 中的奖赏的情感体验提供了新的见解。
