Objective

To evaluate possible differences between brain dopamine transporter (DAT) binding in a group of symptomatic parkinsonism patients without dopaminergic degeneration and healthy individuals.

Background

Dopaminergic neuroimaging studies of Parkinson’s disease (PD) have often used control groups formed from symptomatic patients with apparently normal striatal dopamine function. We sought to investigate whether symptomatic patients can be used to represent dopaminergically normal healthy controls.

Methods

Forty healthy elderly individuals were scanned with DAT [¹²³I]FP-CIT SPECT and compared to 69 age- and sex-matched symptomatic patients with nondegenerative conditions (including essential tremor, drug-induced parkinsonism and vascular parkinsonism). An automated region-of-interest based analysis of the caudate nucleus and the anterior/posterior putamen was performed. Specific binding ratios (SBR = [ROI-occ]/occ) were compared between the groups.

Results

DAT binding in symptomatic patients was 8.6% higher in the posterior putamen than in healthy controls (p = 0.03). Binding correlated negatively with age in both groups but not with motor symptom severity, cognitive function or depression ratings.

Conclusions

Putaminal DAT binding, as measured with [¹²³I]FP-CIT SPECT, was higher in symptomatic controls than in healthy individuals. The reason for the difference is unclear but can include selection bias when DAT binding is used to aid clinical diagnosis and possible self-selection bias in healthy volunteerism. This effect should be taken into consideration when designing and interpreting neuroimaging trials investigating the dopamine system with [¹²³I]FP-CIT SPECT.

中文翻译：

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症状对照和健康志愿者中的多巴胺转运蛋白结合：神经影像学试验的注意事项

客观的

评估一组没有多巴胺能变性的症状性帕金森症患者和健康个体的脑多巴胺转运蛋白 (DAT) 结合之间可能存在的差异。

背景

帕金森病 (PD) 的多巴胺能神经影像学研究通常使用由具有明显正常纹状体多巴胺功能的有症状患者组成的对照组。我们试图调查有症状的患者是否可以用来代表多巴胺能正常的健康对照。

方法

^{用 DAT [ 123} I]FP-CIT SPECT 对40 名健康老年人进行了扫描，并与 69 名年龄和性别匹配的非退行性疾病（包括原发性震颤、药物性帕金森症和血管性帕金森症）的有症状患者进行了比较。对尾状核和前/后壳核进行了基于感兴趣区域的自动分析。比较各组之间的特异性结合率（SBR = [ROI-occ]/occ）。

结果

有症状患者后壳核中的 DAT 结合比健康对照组高 8.6%（p = 0.03）。绑定与两组的年龄呈负相关，但与运动症状严重程度、认知功能或抑郁评分无关。

结论

^{用[ 123} I]FP-CIT SPECT测量的壳聚糖 DAT 结合在症状对照中高于健康个体。差异的原因尚不清楚，但可能包括当 DAT 结合用于帮助临床诊断时的选择偏差和健康志愿服务中可能的自我选择偏差。^{在设计和解释使用 [ 123} I]FP-CIT SPECT研究多巴胺系统的神经影像学试验时，应考虑到这种影响。