BACKGROUND Although pure cerebellar ataxia is usually emphasized as the characteristic clinical feature of spinocerebellar ataxia type 6 (SCA6), parkinsonism has been repeatedly described in patients with genetically confirmed SCA6. METHODS We conducted a positron emission tomography study using a combination of [18F]fluoro-L-dopa for dopamine synthesis and [11C]raclopride for dopamine D2 receptor function on six genetically confirmed SCA6 patients, both with and without parkinsonism. To the best of our knowledge, this is the first dopamine receptor imaging study of patients with SCA6. RESULTS Most patients had somewhat decreased dopaminergic function, and this decrease was significant in the caudate nucleus. In addition, one SCA6 patient with parkinsonism had whole striatal dysfunction of both dopamine synthesis and dopamine D2 receptor function. CONCLUSIONS The pathology of SCA6 may not be restricted to the cerebellum, but may also be distributed across various regions, including in both presynaptic and postsynaptic dopaminergic neurons to some degree. Patients with SCA6 may show apparent parkinsonism after the progression of neurodegeneration.

中文翻译：

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多巴胺能功能在伴或不伴帕金森病的6型脊髓小脑性共济失调患者中的作用。

背景技术虽然通常强调纯小脑共济失调是6型脊髓小脑共济失调（SCA6）的特征性临床特征，但在遗传学确诊的SCA6患者中已反复描述了帕金森病。方法我们对6名经遗传学证实为SCA6的，有或没有帕金森病的SCA6患者进行了正电子发射断层扫描研究，使用[18F]氟-L-多巴用于多巴胺合成，[11C]雷氯必利用于多巴胺D2受体功能。据我们所知，这是SCA6患者的第一项多巴胺受体成像研究。结果大多数患者的多巴胺能功能有所降低，而这种降低在尾状核中是显着的。此外，一名患有帕金森氏症的SCA6患者同时患有多巴胺合成和多巴胺D2受体功能的整个纹状体功能障碍。结论SCA6的病理可能不限于小脑，还可能分布在各个区域，包括在一定程度上在突触前和突触后多巴胺能神经元中。SCA6患者在神经退行性疾病发展后可能显示明显的帕金森氏病。