Even though hypomimia is a hallmark of Parkinson’s disease (PD), objective and easily interpretable tools to capture the disruption of spontaneous and deliberate facial movements are lacking. This study aimed to develop a fully automatic video-based hypomimia assessment tool and estimate the prevalence and characteristics of hypomimia in de-novo PD patients with relation to clinical and dopamine transporter imaging markers. For this cross-sectional study, video samples of spontaneous speech were collected from 91 de-novo, drug-naïve PD participants and 75 age and sex-matched healthy controls. Twelve facial markers covering areas of forehead, nose root, eyebrows, eyes, lateral canthal areas, cheeks, mouth, and jaw were used to quantitatively describe facial dynamics. All patients were evaluated using Movement Disorder Society-Unified PD Rating Scale and Dopamine Transporter Single-Photon Emission Computed Tomography. Newly developed automated facial analysis tool enabled high-accuracy discrimination between PD and controls with area under the curve of 0.87. The prevalence of hypomimia in de-novo PD cohort was 57%, mainly associated with dysfunction of mouth and jaw movements, and decreased variability in forehead and nose root wrinkles (p < 0.001). Strongest correlation was found between reduction of lower lip movements and nigro-putaminal dopaminergic loss (r = 0.32, p = 0.002) as well as limb bradykinesia/rigidity scores (r = −0.37 p < 0.001). Hypomimia represents a frequent, early marker of motor impairment in PD that can be robustly assessed via automatic video-based analysis. Our results support an association between striatal dopaminergic deficit and hypomimia in PD.

尽管低模仿是帕金森病 (PD) 的标志，但缺乏客观且易于解释的工具来捕捉自发和故意面部运动的破坏。本研究旨在开发一种基于视频的全自动低模仿评估工具，并估计与临床和多巴胺转运蛋白成像标志物相关的新发 PD 患者低模仿的患病率和特征。在这项横断面研究中，从 91 名从头开始、未接受药物治疗的 PD 参与者和 75 名年龄和性别匹配的健康对照者收集了自发言语的视频样本。使用覆盖前额、鼻根、眉毛、眼睛、外眦区域、脸颊、嘴巴和下巴区域的十二个面部标记来定量描述面部动态。所有患者均使用运动障碍协会统一 PD 评定量表和多巴胺转运蛋白单光子发射计算机断层扫描进行评估。新开发的自动化面部分析工具能够以 0.87 的曲线下面积对 PD 和对照进行高精度区分。在新发 PD 队列中，低模仿的患病率为 57%，主要与嘴巴和下巴运动功能障碍以及前额和鼻根皱纹的变异性降低有关。p  < 0.001)。下唇运动减少与黑壳多巴胺能损失 ( r  = 0.32, p  = 0.002) 以及肢体运动迟缓/僵硬评分 ( r  = -0.37 p  < 0.001) 之间的相关性最强。Hypomimia 是 PD 运动障碍的常见早期标志，可以通过基于视频的自动分析进行可靠评估。我们的研究结果支持纹状体多巴胺能缺陷与 PD 低模仿之间的关联。