Background Whether scan without evidence of dopaminergic deficit (SWEDD) can be a reliable indication of a clinical entity of Parkinson’s disease (PD) is controversial. Objective To evaluate the proportion of SWEDD patients with mild parkinsonian signs who are classifiable as idiopathic PD. Methods 32 SWEDD patients with unilateral or asymmetric finger tremor with a rest component and unilateral rigidity (Unified Parkinson’s Disease Rating Scale (UPDRS)-III scores of 3-5) were enrolled. They underwent longitudinal examination by UPDRS-III, Mini–Mental State Examination (MMSE), smell test and 123I-FP-CIT SPECT (DaTSCAN) at baseline (first DaTSCAN) and at follow-up (second DaTSCAN) after 27–83 months. Age-matched controls (n=112) also underwent MMSE and smell test. Results At follow-up, 21 of 32 SWEDD patients (65.6%) showed significantly reduced specific binding ratios below the normal range, that is, positive DaTSCAN, sometimes with increased asymmetry index (n=11). Among these 21 patients, the mean (SD) UPDRS-III score at follow-up was significantly higher than that at baseline (5.5 (2.2) vs 4.0 (0.5)) (p=0.003). The mean (SD) MMSE scores in SWEDD patients (n=32) at baseline and follow-up were not significantly different compared with those in controls. Olfactory function both in SWEDD patients with positive and negative DaTSCAN was significantly impaired versus controls (p<0.001), although no significant difference was recognised between patients with positive (n=21) and negative (n=11) second DaTSCAN. Conclusion The majority of SWEDD patients with mild rest tremor and rigidity could be classified as having idiopathic PD in this longitudinal and long-term follow-up study. No data are available.

中文翻译：

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轻度帕金森症状 SWEDD 患者的长期随访研究

背景 无多巴胺能缺陷证据的扫描 (SWEDD) 是否可以作为帕金森病 (PD) 临床实体的可靠指征尚存在争议。目的 评估具有轻度帕金森症状的 SWEDD 患者中可归类为特发性帕金森病的比例。方法 纳入 32 例 SWEDD 患者，其患有单侧或不对称手指震颤，伴有休息成分和单侧强直（统一帕金森病评定量表（UPDRS）-III 评分为 3-5 分）。他们在基线（第一次 DaTSCAN）和 27-83 个月后的随访（第二次 DaTSCAN）时接受了 UPDRS-III、简易精神状态检查 (MMSE)、嗅觉测试和 123I-FP-CIT SPECT (DaTSCAN) 纵向检查。年龄匹配的对照 (n=112) 也接受了 MMSE 和嗅觉测试。结果 随访时，32 例 SWEDD 患者中有 21 例（65.6%）表现出特异性结合率显着降低至正常范围以下，即 DaTSCAN 阳性，有时不对称指数升高（n=11）。在这 21 名患者中，随访时的平均 (SD) UPDRS-III 评分显着高于基线（5.5 (2.2) vs 4.0 (0.5)）（p=0.003）。 SWEDD 患者 (n=32) 在基线和随访时的平均 (SD) MMSE 评分与对照组相比没有显着差异。与对照组相比，具有阳性和阴性 DaTSCAN 的 SWEDD 患者的嗅觉功能均显着受损 (p<0.001)，但在第二次 DaTSCAN 呈阳性 (n=21) 和阴性 (n=11) 的患者之间没有发现显着差异。结论 在本次纵向长期随访研究中，大多数伴有轻度静止性震颤和强直的 SWEDD 患者可归类为特发性 PD。无可用数据。