Department of Neurology, Tianjin Medical University General Hospital, People's Republic of China.
Ann Nucl Med. 2010 Aug;24(7):515-21. doi: 10.1007/s12149-010-0389-3. Epub 2010 Jun 11.
Clinical evidence indicates that the Tourette's syndrome (TS) is associated with hyperactivity of the dopaminergic system; however, imaging studies of dopamine transporter (DAT) in TS patients remain controversial. In this study, we aimed to study DAT binding capacities in a relatively larger sample of drug-naive patients with TS in comparison with controlled subjects by (99m)Tc-TRODAT-1 SPECT/CT imaging. We also aimed to look for any possible correlations between DAT and age, disease duration or tic severity of TS, which have not been thoroughly investigated in previous studies. We tried to provide more evidence for the understanding of the physiopathological mechanism of TS from the molecular imaging perspective.
Eighteen drug-naive patients with TS and 8 age- and gender-matched healthy subjects were recruited. Severity of TS was measured with Yale Global Tic Severity Scale. Brain SPECT/CT was performed 2.5 h after injection of (99m)Tc-TRODAT-1. Regions of interest were drawn on the striatum including its sub-regions of caudate and putamen. The cerebellum was used as the reference region. DAT uptake ratio was calculated by subtracting the mean counts per pixel in the cerebellum from the mean counts per pixel in the striatum, caudate or putamen and by dividing the result by the mean counts per pixel in the cerebellum. Comparisons of DAT uptake ratios between TS patients and controls, and comparisons in bilateral striatum and sub-regions in TS patients were carried out. Correlation analysis between DAT uptake ratios and clinical data were also conducted.
TS patients showed significantly higher uptake of (99m)Tc-TRODAT-1 in bilateral striatum in comparison with the controls. There was no group-specific preferential lateralization in striatal uptake. DAT uptake ratios were not correlated with age and tic severity scores, but significant negative correlation with disease duration was found.
High level of DAT was demonstrated in drug-naive TS patients compared with normal controls, and it was negatively correlated with TS duration. Therefore, with the extension of the disease duration, certain degree of adaptation might occur in TS patients to compensate for the DAT increase, which suggested that hyper-functional DAT might be involved in the early pathophysiological changes of TS.
临床证据表明，妥瑞氏综合征（TS）与多巴胺能系统的过度活跃有关；然而，TS 患者多巴胺转运体（DAT）的成像研究仍存在争议。在这项研究中，我们旨在通过（99m）Tc-TRODAT-1 SPECT/CT 成像，在一个相对较大的未经药物治疗的 TS 患者样本中，与对照组比较，研究 DAT 结合能力。我们还旨在寻找 DAT 与 TS 的年龄、疾病持续时间或 tic 严重程度之间的任何可能的相关性，这些相关性在以前的研究中没有得到深入研究。我们试图从分子成像的角度为理解 TS 的生理病理机制提供更多的证据。
招募了 18 名未经药物治疗的 TS 患者和 8 名年龄和性别匹配的健康受试者。使用耶鲁总体 tic 严重程度量表（Yale Global Tic Severity Scale）测量 TS 的严重程度。注射（99m）Tc-TRODAT-1 后 2.5 小时进行脑 SPECT/CT。在纹状体（包括尾状核和壳核的亚区）上画出感兴趣区。小脑用作参考区域。通过从纹状体的每个像素的平均计数中减去小脑的每个像素的平均计数，并将结果除以小脑的每个像素的平均计数，来计算 DAT 摄取率。对 TS 患者与对照组之间的 DAT 摄取率进行比较，对 TS 患者双侧纹状体及其亚区之间的比较。还进行了 DAT 摄取率与临床数据的相关性分析。
与对照组相比，TS 患者双侧纹状体对（99m）Tc-TRODAT-1 的摄取明显增加。纹状体摄取没有特定的侧化。DAT 摄取率与年龄和 tic 严重程度评分无关，但与疾病持续时间呈显著负相关。
与正常对照组相比，未经药物治疗的 TS 患者 DAT 水平较高，且与 TS 持续时间呈负相关。因此，随着疾病持续时间的延长，TS 患者可能会发生一定程度的适应，以代偿 DAT 的增加，这表明高功能 DAT 可能参与了 TS 的早期病理生理变化。
