Mukai Yohei, Murata Miho
National Center Hospital, National Center of Neurology and Psychiatry.
Brain Nerve. 2016 Jan;68(1):73-81. doi: 10.11477/mf.1416200350.
Dopamine transporter (DaT) single-photon emission computed tomography (SPECT) and [18F]fluoro-L-DOPA ([18F]DOPA) positron emission tomography (PET) facilitate the investigation of dopaminergic hypofunction in neurodegenerative diseases. DaT SPECT and [18F]DOPA PET have been adopted as survey tools in clinical trials. In a large study on Parkinson's disease, 4-15% of subjects clinically diagnosed with early-stage Parkinson's disease had normal dopaminergic functional imaging scans. These are called Scans without Evidence of Dopamine Deficit (SWEDDs), and are considered to represent a state different from Parkinson's disease. Neurological diseases that exhibit parkinsonism and have normal dopaminergic cells in the nigrostriatal system (e.g., essential tremor, psychogenic parkinsonism, DOPA-responsive dystonia, vascular parkinsonism, drug-induced parkinsonism, manganism, brain tumor, myoclonus-dystonia (DYT11), and fragile X syndrome) might be diagnosed with SWEDDs. True bradykinesia with fatigue or decrement may be useful for distinguishing between Parkinson's disease and SWEDDs. However, because SWEDDs encompass many diseases, their properties may not be uniform. In this review, we discuss DaT SPECT, the concept of SWEDDs, and differential diagnosis.
多巴胺转运体（DaT）单光子发射计算机断层扫描（SPECT）和[18F]氟-L-多巴（[18F]DOPA）正电子发射断层扫描（PET）有助于研究神经退行性疾病中的多巴胺能功能减退。DaT SPECT和[18F]DOPA PET已被用作临床试验中的检测工具。在一项关于帕金森病的大型研究中，4%至15%临床诊断为早期帕金森病的受试者多巴胺能功能成像扫描结果正常。这些被称为无多巴胺缺乏证据的扫描（SWEDDs），被认为代表了一种与帕金森病不同的状态。表现为帕金森综合征且黑质纹状体系统中多巴胺能细胞正常的神经疾病（如特发性震颤、心因性帕金森综合征、多巴反应性肌张力障碍、血管性帕金森综合征、药物性帕金森综合征、锰中毒、脑肿瘤、肌阵挛性肌张力障碍（DYT11）和脆性X综合征）可能被诊断为SWEDDs。伴有疲劳或减退的真性运动迟缓可能有助于区分帕金森病和SWEDDs。然而，由于SWEDDs涵盖多种疾病，其特征可能并不一致。在本综述中，我们讨论DaT SPECT、SWEDDs的概念以及鉴别诊断。
