Department of Neurology, University of Toronto, Toronto, ON, Canada M5T 2S8.
Parkinsonism Relat Disord. 2009 Nov;15(9):621-6. doi: 10.1016/j.parkreldis.2009.06.001. Epub 2009 Jun 25.
Spinocerebellar ataxia 8 (SCA8), a triplet repeat expansion disorder, is genetically distinct from the other inherited ataxias, but its unusually variable phenotype can make its diagnosis difficult. In this review we describe 3 new cases of genetically verified SCA8 to highlight the broad clinical spectrum of symptoms observed with this disorder and to draw attention to the features of myoclonus and migraine headaches, which in the context of cerebellar ataxia warrants the clinician to consider SCA8 as a potential diagnosis. We also address the controversy surrounding the genetic testing approach for diagnosing SCA8. Finally, we evaluate the evidence that SCA8 may affect calcium channel function and that the presentation of episodic ataxia and migraines suggests a clinical and pathogenic overlap of SCA8 with the channelopathies.
脊髓小脑共济失调 8 型（SCA8）是一种三核苷酸重复扩展障碍，与其他遗传性共济失调在遗传学上有明显不同，但它异常多变的表型可能使其诊断变得困难。在这篇综述中，我们描述了 3 例新的遗传性 SCA8 病例，以突出该疾病观察到的广泛临床症状谱，并提请注意肌阵挛和偏头痛的特征，在小脑共济失调的情况下，这提示临床医生将 SCA8 作为潜在的诊断。我们还解决了围绕 SCA8 基因检测方法诊断的争议。最后，我们评估了 SCA8 可能影响钙通道功能的证据，以及发作性共济失调和偏头痛的出现表明 SCA8 与通道病具有临床和发病机制重叠。
