Neurological disorders associated with anti-glutamic acid decarboxylase (GAD) autoimmunity are rare and include a variety of neurological syndromes: stiff-person syndrome, cerebellar ataxia or limbic encephalitis. The diagnosis remains challenging due to the variety of symptoms and normal brain imaging.

The morphological MRI of 26 patients (T1-weighted and Fluid-attenuated inversion recovery (FLAIR)-weighted images) was analyzed at the initial stage of diagnosis, matched by age and sex to 26 healthy subjects. We performed a vertex-wise analysis using a generalized linear model, adjusting by age, to compare the brain cortical thickness of both populations. In addition, we used a voxel-based morphometry of cerebellum thickness obtained by CEREbellum Segmentation (CERES), as well as the hippocampus volumetry comparison using HIPpocampus subfield Segmentation (HIPS). Finally, we extracted 62 radiomics features using LifeX to assess the classification performance using a random forest model to identify an anti-GAD related MRI.

The results suggest a peculiar profile of atrophy in patients with anti-GAD, with a significant atrophy in the temporal and frontal lobes (adjusted p-value < 0.05), and a focal cerebellar atrophy of the V-lobule, independently of the anti-GAD phenotype. Finally, the MRIs from anti-GAD patients were correctly classified when compared to the control group, with an area under the curve (AUC) of 0.98.

This study suggests a particular pattern of cortical atrophy throughout all anti-GAD phenotypes. These results reinforce the notion that the different neurological anti-GAD phenotypes should be considered as a continuum due to their similar cortical thickness profiles.

与抗谷氨酸脱羧酶 (GAD) 自身免疫相关的神经系统疾病很少见，包括多种神经系统综合征：僵人综合征、小脑共济失调或边缘性脑炎。由于各种症状和正常的脑成像，诊断仍然具有挑战性。

在诊断的初始阶段分析了 26 名患者的形态学 MRI（T1 加权和流体衰减反转恢复 (FLAIR) 加权图像），并按年龄和性别与 26 名健康受试者匹配。我们使用根据年龄调整的广义线性模型进行顶点分析，以比较两个人群的大脑皮层厚度。此外，我们使用了通过 CEREbellum Segmentation (CERES) 获得的基于体素的小脑厚度形态测量，以及使用 HIPpocampus subfield Segmentation (HIPS) 的海马体积比较。最后，我们使用 LifeX 提取了 62 个放射组学特征，以评估分类性能，使用随机森林模型识别抗 GAD 相关 MRI。

结果表明抗 GAD 患者有一种特殊的萎缩特征，颞叶和额叶明显萎缩（调整后的 p 值 < 0.05），V 小叶局灶性小脑萎缩，与抗 GAD 无关。 GAD 表型。最后，与对照组相比，抗 GAD 患者的 MRI 分类正确，曲线下面积 (AUC) 为 0.98。

这项研究表明在所有抗 GAD 表型中都存在一种特定的皮质萎缩模式。这些结果强化了这样一种观点，即不同的神经学抗 GAD 表型应被视为一个连续体，因为它们具有相似的皮质厚度分布。