LAPSCO (UMR 6024), Blaise Pascal University, Clermont-Ferrand 63000, France.
LAPSCO (UMR 6024), Blaise Pascal University, Clermont-Ferrand 63000, France; Institut Universitaire de France, Paris 75005, France.
Neuropsychologia. 2012 Oct;50(12):2869-2879. doi: 10.1016/j.neuropsychologia.2012.08.016. Epub 2012 Aug 28.
Deep brain stimulation of the subthalamic nucleus (DBS) is a widely used surgical technique to suppress motor symptoms in Parkinson's disease (PD), and as such improves patients' quality of life. However, DBS may produce emotional disorders such as a reduced ability to recognize emotional facial expressions (EFE). Previous studies have not considered the fact that DBS and l-dopa medication can have differential, common, or complementary consequences on EFE processing. A thorough way of investigating the effect of DBS and l-dopa medication in greater detail is to compare patients' performances after surgery, with the two therapies either being administered ('on') or not administered ('off'). We therefore used a four-condition (l-dopa 'on'/DBS 'on', l-dopa 'on'/DBS 'off', l-dopa 'off'/DBS 'on', and l-dopa 'off'/DBS 'off') EFE recognition paradigm and compared implanted PD patients to healthy controls. The results confirmed those of previous studies, yielding a significant impairment in the detection of some facial expressions relative to controls. Disgust recognition was impaired when patients were 'off' l-dopa and 'on' DBS, and fear recognition impaired when 'off' of both therapies. More interestingly, the combined effect of both DBS and l-dopa administration seems much more beneficial for EFE recognition than the separate administration of each individual therapy. We discuss the implications of these findings in the light of the inverted U curve function that describes the differential effects of dopamine level on the right orbitofrontal cortex (OFC). We propose that, while l-dopa could "overdose" in dopamine the ventral stream of the OFC, DBS would compensate for this over-activation by decreasing OFC activity, thereby restoring the necessary OFC-amygdala interaction. Another finding is that, when collapsing over all treatment conditions, PD patients recognized more neutral faces than the matched controls, a result that concurs with embodiment theories.
深部脑刺激(subthalamic nucleus, STN)是一种广泛应用于抑制帕金森病(Parkinson's disease, PD)运动症状的手术技术，从而提高患者的生活质量。然而，STN 刺激可能会导致情绪障碍，例如降低识别情绪面部表情的能力。先前的研究没有考虑到 STN 刺激和左旋多巴药物治疗可能对 EFE 处理有不同的、共同的或补充的影响。深入研究 STN 刺激和左旋多巴药物治疗的影响的一种彻底方法是比较患者手术后的表现，两种治疗方法要么给予（“on”），要么不给予（“off”）。因此，我们使用了一个四条件（左旋多巴“on”/STN“on”、左旋多巴“on”/STN“off”、左旋多巴“off”/STN“on”和左旋多巴“off”/STN“off”）的 EFE 识别范式，并将植入的 PD 患者与健康对照组进行了比较。结果证实了先前研究的结果，与对照组相比，患者在检测某些面部表情时存在明显的障碍。当患者在停用左旋多巴和给予 STN 刺激时，识别厌恶的能力受损，而当停用两种治疗方法时，识别恐惧的能力受损。更有趣的是，与单独给予每种治疗方法相比，联合给予 STN 刺激和左旋多巴似乎对 EFE 识别更有益。我们根据描述多巴胺水平对眶额皮层（orbital frontal cortex, OFC）腹侧流的不同影响的倒 U 曲线函数来讨论这些发现的意义。我们提出，虽然左旋多巴可能会“过量”激活 OFC 的腹侧流中的多巴胺，但 STN 刺激会通过降低 OFC 的活动来补偿这种过度激活，从而恢复必要的 OFC-杏仁核相互作用。另一个发现是，当将所有治疗条件合并时，PD 患者识别出的中性面孔比匹配的对照组更多，这一结果与体现理论一致。
