对比年轻型与老年型帕金森病的多巴胺转运蛋白及D2受体PET显像

目的 探讨年轻型帕金森病（YOPD）与老年型帕金森病（LOPD）患者纹状体多巴胺神经系统功能变化的差异。方法 回顾性分析临床确诊的13例YOPD患者（YOPD组）和20例LOPD患者（LOPD组）的多巴胺转运蛋白（DAT）、多巴胺D2受体PET显像结果，计算并比较2组患者在起病对侧和起病同侧尾状核、壳核的DAT和多巴胺D2受体结合量指数和不对称指数的差异。结果 13例YOPD患者中，11例双侧纹状体DAT表达减低伴D2受体表达上调，起病对侧明显；2例DAT分布正常伴D2受体表达上调。20例LOPD患者均可见DAT表达减低、D2受体表达上调，起病对侧明显。YOPD与LOPD组间起病对侧和起病同侧尾状核、壳核DAT结合量指数的差异均无统计学意义（P均>0.05），YOPD组尾状核、壳核DAT不对称指数均高于LOPD组（P均<0.05）。YOPD组起病对侧和起病同侧壳核D2受体结合量指数均高于LOPD组（P均<0.05），尾状核D2受体结合量指数差异无统计学意义（P均>0.05）。2组间尾状核、壳核D2受体结合不对称指数差异均无统计学意义（P均>0.05）。结论 YOPD患者纹状体多巴胺能神经元DAT分布减低、D2受体表达上调；相比LOPD患者，YOPD患者纹状体DAT分布表现出明显不对称性，且壳核D2受体上调幅度较大。

Comparison of dopamine transporter and D2 receptor imaging in young and late onset Parkinson disease

Objective To compare the functional changes of striatal dopaminergic system in young onset Parkinson disease (YOPD) and late onset Parkinson disease (LOPD). Methods Dopamine transporter (DAT) and D2 receptor PET imaging of clinically diagnosed YOPD patients (YOPD group, n=13) and LOPD patients (LOPD group, n=20) were retrospectively analyzed. The differences of striatal tracer binding index and asymmetry index were compared between the two groups. Results In all 13 YOPD patients, 11 showed decreased DAT distribution and increased D2 receptor density, and more pronounced on contralaterial side, 2 patients showed visually normal DAT distribution but increased D2 receptor density. All 20 LOPD patients showed decreased DAT distribution and increased D2 receptor density in striatum, and more pronounced on contralaterial side. No statistically significant difference of DAT binding index in caudate and putamen of both ipsilateral and contralateral sides of symptom was found between YOPD and LOPD group (all P>0.05), while the asymmetry index of DAT binding in caudate and putamen in YOPD patients were higher than those in LOPD patients (both P<0.05). D2 receptor binding index of ipsilateral and contralateral putamen in YOPD patients were higher than those in LOPD patients (all P<0.05), while no statistically significant difference of D2 receptor binding index in both sides'' caudate was detected between the two groups (both P>0.05). The asymmetry index of D2 receptor binding at putamen and caudate were not statistically different between the two groups (both P>0.05). Conclusion YOPD patients show typical decreased DAT distribution and increased D2 receptor density in striatum, with more pronounced DAT distribution asymmetry and much higher D2 density in putamen compared with LOPD patients.