Background Spinal cord damage is a feature of many spinocerebellar ataxias (SCAs), but well-powered in vivo studies are lacking and links with disease severity and progression remain unclear. Here we characterise cervical spinal cord morphometric abnormalities in SCA1, SCA2, SCA3 and SCA6 using a large multisite MRI dataset. Methods Upper spinal cord (vertebrae C1–C4) cross-sectional area (CSA) and eccentricity (flattening) were assessed using MRI data from nine sites within the ENIGMA-Ataxia consortium, including 364 people with ataxic SCA, 56 individuals with preataxic SCA and 394 nonataxic controls. Correlations and subgroup analyses within the SCA cohorts were undertaken based on disease duration and ataxia severity. Results Individuals in the ataxic stage of SCA1, SCA2 and SCA3, relative to non-ataxic controls, had significantly reduced CSA and increased eccentricity at all examined levels. CSA showed large effect sizes ( d >2.0) and correlated with ataxia severity (r<−0.43) and disease duration (r<−0.21). Eccentricity correlated only with ataxia severity in SCA2 (r=0.28). No significant spinal cord differences were evident in SCA6. In preataxic individuals, CSA was significantly reduced in SCA2 ( d =1.6) and SCA3 ( d =1.7), and the SCA2 group also showed increased eccentricity ( d =1.1) relative to nonataxic controls. Subgroup analyses confirmed that CSA and eccentricity are abnormal in early disease stages in SCA1, SCA2 and SCA3. CSA declined with disease progression in all, whereas eccentricity progressed only in SCA2. Conclusions Spinal cord abnormalities are an early and progressive feature of SCA1, SCA2 and SCA3, but not SCA6, which can be captured using quantitative MRI. No data are available. All code and data processing instructions are available at .

中文翻译：

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脊髓小脑共济失调中的基因型特异性脊髓损伤：ENIGMA-共济失调研究

背景 脊髓损伤是许多脊髓小脑性共济失调 (SCAs) 的一个特征，但缺乏有力的体内研究，并且与疾病严重程度和进展的联系仍不清楚。在这里，我们使用大型多站点 MRI 数据集来表征 SCA1、SCA2、SCA3 和 SCA6 的颈脊髓形态异常。方法 使用 ENIGMA-Ataxia 联盟内 9 个地点的 MRI 数据评估上脊髓（椎骨 C1-C4）横截面积 (CSA) 和偏心度（扁平化），其中包括 364 名共济失调性 SCA 患者、56 名共济失调前 SCA 患者和 56 名共济失调前 SCA 患者。 394 非共济失调控制。根据疾病持续时间和共济失调严重程度，对 SCA 队列进行相关性和亚组分析。结果 与非共济失调对照相比，处于 SCA1、SCA2 和 SCA3 共济失调阶段的个体在所有检查水平上的 CSA 均显着降低，偏心度增加。CSA 显示出较大的效应量 (d >2.0)，并与共济失调严重程度 (r<-0.43) 和疾病持续时间 (r<-0.21) 相关。偏心率仅与 SCA2 中的共济失调严重程度相关 (r=0.28)。SCA6 中没有明显的脊髓差异。在共济失调前期个体中，SCA2 ( d = 1.6) 和 SCA3 ( d = 1.7) 组的 CSA 显着降低，并且相对于非共济失调对照组，SCA2 组还表现出偏心率增加 ( d = 1.1)。亚组分析证实，SCA1、SCA2 和 SCA3 在疾病早期阶段 CSA 和偏心率异常。CSA 随疾病进展而下降，而离心率仅在 SCA2 中进展。结论 脊髓异常是 SCA1、SCA2 和 SCA3 的早期和进展特征，但不是 SCA6，可以使用定量 MRI 捕获。无可用数据。所有代码和数据处理说明均可在。