The thalamus is a brain region consisting of anatomical and functional connections between various spinal, subcortical, and cortical regions, which has a putative role in the clinical manifestation of Multiple System Atrophy (MSA). Previous stereological studies have reported significant anatomical alterations in diverse brain regions of MSA patients, including the cerebral cortex, basal ganglia and white matter, but no quantitative studies have examined the thalamus. To establish the extent of thalamic involvement, we applied stereological methods to estimate the total number of neurons and glial cells (oligodendrocytes, astrocytes and microglia) as well as the volume in two thalamic sub-regions, the mediodorsal nucleus (MDT) and the anterior principal nucleus (APn), in brains from ten MSA patients and 11 healthy control subjects. Compared to healthy controls, MSA patients had significantly fewer neurons (26%) in the MDT, but not the APn. We also found significantly more astrocytes (32%) and microglia (54%) in the MDT, with no such changes in the APn. Finally, we saw no group differences in the total number of oligodendrocytes. Our findings show a region-specific loss of thalamic neurons that occurs without loss of oligodendrocytes, whereas thalamic microgliosis seems to occur alongside astrogliosis. These pathological changes in the thalamus may contribute to the cognitive impairment seen in most patients with MSA.

丘脑是由各种脊柱，皮质下和皮质区域之间的解剖和功能连接组成的大脑区域，在多系统萎缩（MSA）的临床表现中具有假定的作用。先前的立体学研究报道了MSA患者不同大脑区域的显着解剖学改变，包括大脑皮层，基底神经节和白质，但尚无定量研究检查丘脑。为了确定丘脑受累的程度，我们应用了体视学方法来估计神经元和神经胶质细胞（少突胶质细胞，星形胶质细胞和小胶质细胞）的总数，以及两个丘脑子区域，中嗅核（MDT）和前壁的体积10名MSA患者和11名健康对照者的大脑中存在主核（APn）。与健康对照相比，MSA患者的MDT中神经元明显减少（26％），但APn则没有。我们还发现，MDT中的星形胶质细胞（32％）和小胶质细胞（54％）明显更多，而APn中没有这种变化。最后，我们没有看到少突胶质细胞总数的组差异。我们的发现表明，丘脑神经元的区域特定损失发生而没有少突胶质细胞的损失，而丘脑小胶质细胞增生似乎与星形胶质细胞增生同时发生。丘脑中的这些病理变化可能会导致大多数MSA患者所见的认知障碍。我们发现少突胶质细胞总数没有群体差异。我们的发现表明，丘脑神经元的区域特定损失发生而没有少突胶质细胞的损失，而丘脑小胶质细胞增生似乎与星形胶质细胞增生同时发生。丘脑中的这些病理变化可能会导致大多数MSA患者所见的认知障碍。我们发现少突胶质细胞总数没有群体差异。我们的发现表明，丘脑神经元的区域特定损失发生而没有少突胶质细胞的损失，而丘脑小胶质细胞增生似乎与星形胶质细胞增生同时发生。丘脑中的这些病理变化可能会导致大多数MSA患者所见的认知障碍。