Sha Runhua, Wu Chao, Qiu Haishan, Liang Jiahui, Hu Manshi, Ma Ling, Liu Mengting, Liu Hanjun, Zhao Jing
Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58th, The Second Zhongshan Road, Guangzhou, 518000, Guangdong, People's Republic of China.
Department of Neurology, The First Affiliated Hospital, Sun Yat-Sen University, 58th, The Second Zhongshan Road, Guangzhou, 518000, Guangdong, People's Republic of China.
J Neurol. 2025 Aug 4;272(9):556. doi: 10.1007/s00415-025-13284-w.
Spinocerebellar ataxia type 3 (SCA3) is characterized by extensive supra- and infra-tentorial brain injuries, beginning in the pre-symptomatic stage. However, the alterations and evolution of spontaneous brain activity in SCA3 patients remain poorly understood.
This study aimed to investigate the abnormal brain activity of SCA3, classified it into distinct patterns, and explored the association between spontaneous brain activity in affected regions and clinical variables.
Ninety-nine SCA3 patients (76 sym- and 23 pre-SCA3 patients, mean age: 39.97 ± 10.83y; 28.74 ± 7.99y) and 49 healthy controls underwent 3.0T MRI and acquired T1 and resting-state functional MRI images. The static and dynamic amplitude of low-frequency fluctuation (s/dALFF) and regional homogeneity (s/dReHo) were used to estimate local brain activity alterations.
SCA3 patients exhibited significantly abnormal spontaneous brain activities in multiple regions, classified into four patterns (P < 0.001). Patterns 1 and 2 were found in the pre-symptomatic stage, involving the right opercular part of inferior frontal gyrus, right rolandic operculum, right insula, right angular gyrus, right crus I of cerebellar hemisphere and left superior frontal gyrus. Pattern 3 emerged in symptomatic SCA3, with expanded involvement of supra- to infra-tentorial regions. Pattern 4 showed increased activity in the right cerebellar lobule IX. Negative correlations were found between sReHo value in the right anterior cingulate cortex with the disease duration and severity (P ≤ 0.04).
SCA3 patients exhibit different patterns of brain activity damage at different stages. These findings provide new insight into brain dysfunction in SCA3 and suggest potential imaging markers for disease staging and monitoring.
3型脊髓小脑共济失调（SCA3）的特征是幕上和幕下广泛的脑损伤，始于症状前期。然而，SCA3患者自发脑活动的改变和演变仍知之甚少。
本研究旨在调查SCA3患者的异常脑活动，将其分类为不同模式，并探讨受累区域自发脑活动与临床变量之间的关联。
99例SCA3患者（76例有症状患者和23例症状前期患者，平均年龄：39.97±10.83岁；28.74±7.99岁）和49名健康对照者接受了3.0T磁共振成像（MRI）检查，并采集了T1加权像和静息态功能MRI图像。使用低频波动的静态和动态幅度（s/dALFF）以及局部一致性（s/dReHo）来估计局部脑活动改变。
SCA3患者在多个区域表现出明显异常的自发脑活动，分为四种模式（P<0.001）。模式1和模式2出现在症状前期，涉及右侧额下回岛盖部、右侧中央前回岛盖、右侧岛叶、右侧角回、右侧小脑半球 Crus I和左侧额上回。模式3出现在有症状的SCA3患者中，幕上至幕下区域受累范围扩大。模式4显示右侧小脑小叶IX活动增加。右侧前扣带回皮质的sReHo值与病程和严重程度之间存在负相关（P≤0.04）。
SCA3患者在不同阶段表现出不同模式的脑活动损伤。这些发现为SCA3的脑功能障碍提供了新的见解，并提示了疾病分期和监测的潜在影像学标志物。
