Department of Neurology, National Hospital Organization, Higashinagoya National Hospital, Nagoya, Japan.
Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
J Parkinsons Dis. 2020;10(1):123-130. doi: 10.3233/JPD-191710.
Both Parkinson's disease (PD) and multiple system atrophy (MSA) are neurodegenerative disorder affecting striatonigral system. Although various lines of evidence demonstrate that dopaminergic neuron degeneration emerges before the onset of motor symptoms in PD, preclinical/prodromal progression of neurodegeneration is far less understood in MSA.
The aim of this study was to clarify the difference in the progression of dopaminergic degeneration in MSA and PD using dopamine transporter single-photon emission computed tomography (DAT SPECT).
We analyzed longitudinal data of the specific binding ratio (SBR), a measure of striatal radiotracer uptake, in DAT SPECT from 7 patients with MSA-C, 5 patients with MSA-P, and 18 patients with PD. We performed 2.7±0.7 scans with an interval of 9.85±6.00 months for MSA and 2 scans with an interval of 2.16±0.16 years for PD.
The rate of SBR decline was faster in both subtypes of MSA compared with PD, but the value was similar between MSA-P and MSA-C. The estimated SBR at the onset of initial motor symptoms was lower in PD and MSA-P than in MSA-C, especially in the predominantly affected side. SBR of the predominantly affected side starts to decrease before the onset of motor symptoms in PD and MSA-P, whereas the initiation of SBR decline is around the onset in MSA-C individuals. The decline of SBR in the less affected side was not clearly shown before the onset in MSA-P or MSA-C.
Our results suggest that the SBR in DAT SPECT analysis is an important pathophysiological marker reflecting the disease- and subtype-specific progression of dopaminergic degeneration in MSA and PD.
帕金森病（PD）和多系统萎缩（MSA）都是影响纹状体黑质系统的神经退行性疾病。虽然有大量证据表明，在 PD 出现运动症状之前，多巴胺能神经元就已经发生变性，但 MSA 中神经退行性变的临床前/前驱期进展知之甚少。
本研究旨在使用多巴胺转运体单光子发射计算机断层扫描（DAT SPECT）来阐明 MSA 和 PD 中多巴胺能变性进展的差异。
我们分析了 7 例 MSA-C 患者、5 例 MSA-P 患者和 18 例 PD 患者 DAT SPECT 的特异性结合比（SBR）的纵向数据，这是衡量纹状体示踪剂摄取的一种指标。我们对 MSA 进行了 2.7±0.7 次扫描，间隔 9.85±6.00 个月，对 PD 进行了 2 次扫描，间隔 2.16±0.16 年。
两种 MSA 亚型的 SBR 下降速度均快于 PD，但 MSA-P 和 MSA-C 之间的数值相似。在 PD 和 MSA-P 中，初始运动症状出现时的 SBR 估计值低于 MSA-C，尤其是在优势侧。PD 和 MSA-P 中，优势侧 SBR 在运动症状出现前开始下降，而 MSA-C 个体的 SBR 下降始于发病时。在 MSA-P 或 MSA-C 中，在发病前不太受影响的一侧 SBR 下降并不明显。
我们的结果表明，DAT SPECT 分析中的 SBR 是反映 MSA 和 PD 中多巴胺能变性进展的重要病理生理学标志物，具有疾病和亚型特异性。
