Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.
Department of Neurology, Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju, South Korea.
Eur J Neurol. 2023 Jun;30(6):1639-1647. doi: 10.1111/ene.15781. Epub 2023 Mar 26.
Nigrosome 1 (NG1), a small cluster of dopaminergic cells in the substantia nigra and visible in the susceptibility map-weighted magnetic resonance image (SMwI), is severely affected in Parkinson's disease (PD). However, the degree of nigrostriatal degeneration according to the visibility of NG1 has not yet been well elucidated.
We consecutively recruited 138 PD and 78 non-neurodegenerative disease (non-ND) patients, who underwent both F-FP-CIT positron emission tomography (PET) and SMwI. Three neurologists and one radiologist evaluated the visibility of NG1 in SMwI. The participants were thereby grouped into visible, intermediate, and non-visible groups. Nigrostriatal dopaminergic input was calculated using the specific binding ratio (SBR) of the F-FP-CIT PET. We determined the threshold of regional SBR for discriminating NG1 visibility and the probability for NG1 visibility according to regional SBR.
Visual rating of NG1 showed excellent interobserver agreements as well as high sensitivity and specificity to differentiate the PD group from the non-ND group. NG1 was visible in seven patients (5.1%) in the PD group, who had relatively short disease duration or less severe loss of striatal dopamine. The threshold of putaminal SBR reduction on the more affected side for the disappearance of NG1 was 45.5%, and the probability for NG1 visibility dropped to 50% after the reduction of putaminal SBR to 41% from the normal mean.
Almost half loss of nigrostriatal dopaminergic input is required to dissipate the hyperintensity of NG1 on SMwI, suggesting its utility in diagnosing PD only after the onset of the motor symptoms.
黑质 1 （NG1）是黑质中一小群多巴胺能细胞，在磁共振成像（MRI）的磁化率加权像（SWI）中可见，在帕金森病（PD）中受到严重影响。然而，根据 NG1 的可见性评估黑质纹状体变性的程度尚未得到很好的阐明。
我们连续招募了 138 例 PD 和 78 例非神经退行性疾病（non-ND）患者，这些患者均接受了 F-FP-CIT 正电子发射断层扫描（PET）和 SWI 检查。三位神经科医生和一位放射科医生评估了 SWI 中 NG1 的可见性。参与者因此被分为可见、中等和不可见组。使用 F-FP-CIT PET 的特异性结合比（SBR）计算黑质纹状体多巴胺能输入。我们确定了区分 NG1 可见性的区域 SBR 阈值以及根据区域 SBR 预测 NG1 可见性的概率。
NG1 的视觉评分显示出良好的观察者间一致性，以及区分 PD 组和 non-ND 组的高敏感性和特异性。在 PD 组中，有七名患者（5.1%）的 NG1 可见，这些患者的疾病持续时间相对较短或纹状体多巴胺损失较轻。对于 NG1 消失的对侧壳核 SBR 减少阈值为 45.5%，并且当壳核 SBR 从正常平均值减少到 41%时，NG1 可见的概率下降到 50%。
几乎需要一半的黑质纹状体多巴胺能输入丢失才能消除 SWI 上 NG1 的高信号强度，这表明其仅在运动症状出现后才能用于诊断 PD。
