Abstract：
Spinocerebellar ataxia type 12 (SCA12) is a rare SCA subtype with unclear clinical and imaging features. Also, the radiological changes in prodromal and early stages remain unknown.
Ten symptomatic and two pre-symptomatic cases from three Chinese pedigrees received clinical assessments and imaging studies including routine magnetic resonance imaging (MRI), diffusion kurtosis imaging (DKI), and positron emission tomography (PET) using 18F-flurodeoxyglucose (FDG) to investigate glucose metabolism in brain and 18F-vesicle monoamine transporter 2 (VMAT2) to inspect the integrity of the dopaminergic neuron. Seventy-two healthy individuals were recruited as controls in the quantitative FDG-PET analysis. Imaging parameters were compared between symptomatic and presymptomatic cases with different disease durations.
Patients displayed prominent action tremor, moderate ataxia, and subtle parkinsonism with poor levodopa-response. MRI showed extensive but heterogeneous cerebral atrophy, which was most evident in the frontoparietal lobes. Cerebellar atrophy was apparent in later stages. DKI detected impaired fibers in the cerebellar peduncles. In both symptomatic and pre-symptomatic cases, PET-CT showed an earlier FDG decline than atrophic changes in multiple regions, and the frontoparietal lobes were the earliest and most severe. However, the VMAT2 density were normal in the putamen and caudate nucleus of most cases (7/8).
We first found that hypometabolism in the cerebral cortex, but not cerebellum, is an early and prominent change in SCA12. The integrity of presynaptic dopaminergic neurons remains largely spared during the whole disease process.
Ten symptomatic and two pre-symptomatic cases from three Chinese pedigrees received clinical assessments and imaging studies including routine magnetic resonance imaging (MRI), diffusion kurtosis imaging (DKI), and positron emission tomography (PET) using 18F-flurodeoxyglucose (FDG) to investigate glucose metabolism in brain and 18F-vesicle monoamine transporter 2 (VMAT2) to inspect the integrity of the dopaminergic neuron. Seventy-two healthy individuals were recruited as controls in the quantitative FDG-PET analysis. Imaging parameters were compared between symptomatic and presymptomatic cases with different disease durations.
Patients displayed prominent action tremor, moderate ataxia, and subtle parkinsonism with poor levodopa-response. MRI showed extensive but heterogeneous cerebral atrophy, which was most evident in the frontoparietal lobes. Cerebellar atrophy was apparent in later stages. DKI detected impaired fibers in the cerebellar peduncles. In both symptomatic and pre-symptomatic cases, PET-CT showed an earlier FDG decline than atrophic changes in multiple regions, and the frontoparietal lobes were the earliest and most severe. However, the VMAT2 density were normal in the putamen and caudate nucleus of most cases (7/8).
We first found that hypometabolism in the cerebral cortex, but not cerebellum, is an early and prominent change in SCA12. The integrity of presynaptic dopaminergic neurons remains largely spared during the whole disease process.
摘要：
脊髓小脑共济失调12型（SCA12）是一种罕见的SCA亚型，临床和影像学特征不清楚。此外，前驱和早期的放射学变化仍然未知。
来自三个中国家系的10例症状和2例症状前病例接受了临床评估和影像学研究，包括常规磁共振成像（MRI），扩散峰度成像（DKI），和使用18F-氟脱氧葡萄糖（FDG）的正电子发射断层扫描（PET）来研究大脑中的葡萄糖代谢和18F-囊泡单胺转运蛋白2（VMAT2）来检查多巴胺能神经元的完整性。在定量FDG-PET分析中招募72名健康个体作为对照。比较了不同病程的症状和症状前病例的影像学参数。
患者表现出明显的动作震颤，中度共济失调,和左旋多巴反应不良的微妙帕金森病。MRI显示广泛但不均匀的脑萎缩,这在额顶叶最明显。小脑萎缩在后期阶段很明显。DKI检测到小脑花梗纤维受损。在症状和症状前的情况下，PET-CT显示多个区域的FDG下降比萎缩性变化更早，额顶叶是最早和最严重的。然而,大多数病例的壳核和尾状核的VMAT2密度正常（7/8）。
我们首先发现大脑皮层的低代谢,但不是小脑,是SCA12的早期和突出的变化。在整个疾病过程中，突触前多巴胺能神经元的完整性在很大程度上得以保留。
来自三个中国家系的10例症状和2例症状前病例接受了临床评估和影像学研究，包括常规磁共振成像（MRI），扩散峰度成像（DKI），和使用18F-氟脱氧葡萄糖（FDG）的正电子发射断层扫描（PET）来研究大脑中的葡萄糖代谢和18F-囊泡单胺转运蛋白2（VMAT2）来检查多巴胺能神经元的完整性。在定量FDG-PET分析中招募72名健康个体作为对照。比较了不同病程的症状和症状前病例的影像学参数。
患者表现出明显的动作震颤，中度共济失调,和左旋多巴反应不良的微妙帕金森病。MRI显示广泛但不均匀的脑萎缩,这在额顶叶最明显。小脑萎缩在后期阶段很明显。DKI检测到小脑花梗纤维受损。在症状和症状前的情况下，PET-CT显示多个区域的FDG下降比萎缩性变化更早，额顶叶是最早和最严重的。然而,大多数病例的壳核和尾状核的VMAT2密度正常（7/8）。
我们首先发现大脑皮层的低代谢,但不是小脑,是SCA12的早期和突出的变化。在整个疾病过程中，突触前多巴胺能神经元的完整性在很大程度上得以保留。
