Department of Electrical and Electronics Engineering, Birla Institute of Technology and Science, Pilani, Hyderabad Campus, Hyderabad, India Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.
Department of Neurology, Neuromuscular Center, Neurological Institute, Cleveland, Ohio, USA Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.
J Neurol Neurosurg Psychiatry. 2015 Sep;86(9):952-8. doi: 10.1136/jnnp-2014-308239. Epub 2014 Dec 17.
Our previous voxel based morphometry (VBM) studies in patients with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (ALS-FTD) showed reduced motor and extramotor grey matter (GM) volume when compared to neurological controls. However, erroneously high GM values can result because VBM analysis includes both cortical gyri and sulci as a single GM region. In addition, the relationship between structural and functional changes is unknown. Therefore, we determined whether GM volumetric changes seen in patients with ALS-FTD were due to changes in cortical thickness, area or both, and compared these structural changes with metabolic changes as revealed by positron emission tomography (PET).
T1-weighted MRIs were obtained in unaffected neurological controls and in patients with ALS-FTD; the latter also underwent PET imaging. We assessed brain GM structural changes using VBM and cortical thickness, and metabolic changes using PET images. Significant (p<0.05) reductions in GM volume and cortical thickness were observed in motor and extramotor regions in patients with ALS-FTD compared to controls. No significant difference in cortical surface area was observed in any of the brain regions. Results Significant (p<0.05) reductions in cerebral glucose metabolism rate were observed in brain regions where structural changes were also observed. Significant reductions primarily in cortical thickness were the likely reason for decreased GM volume in ALS-FTD.
Metabolic changes corresponded well with structural changes in motor and extramotor areas, and sometimes occurred even in the absence of GM volume reduction. Coincident structural and functional GM changes suggest that neurodegeneration may occur as "neuronopathy" in patients with ALS-FTD.
我们之前对肌萎缩侧索硬化症（ALS）和额颞叶痴呆（ALS-FTD）患者进行的基于体素的形态计量学（VBM）研究表明，与神经对照组相比，运动和运动外灰质（GM）体积减少。然而，由于 VBM 分析将皮质脑回和脑沟都包含在单个 GM 区域中，因此可能会导致 GM 值过高的错误。此外，结构和功能变化之间的关系尚不清楚。因此，我们确定在 ALS-FTD 患者中观察到的 GM 体积变化是否是由于皮质厚度、面积或两者的变化引起的，并将这些结构变化与正电子发射断层扫描（PET）显示的代谢变化进行比较。
我们在未受影响的神经对照组和 ALS-FTD 患者中获得了 T1 加权 MRI；后者还接受了 PET 成像。我们使用 VBM 和皮质厚度评估脑 GM 结构变化，并使用 PET 图像评估代谢变化。与对照组相比，ALS-FTD 患者的运动和运动外区域 GM 体积和皮质厚度明显减少（p<0.05）。在大脑的任何区域，皮质表面积均无显著差异。结果：在观察到结构变化的脑区，大脑葡萄糖代谢率显著降低（p<0.05）。主要在皮质厚度方面的显著减少是 ALS-FTD 中 GM 体积减少的可能原因。
代谢变化与运动和运动外区域的结构变化非常吻合，有时甚至在没有 GM 体积减少的情况下也会发生。同时出现的结构和功能 GM 变化表明，在 ALS-FTD 患者中，神经退行性变可能作为“神经元病”发生。
