First Department of Neurology, Aeginition Hospital, Medical School, National & Kapodistrian University of Athens, 72-74 Vas. Sophias Avenue, Athens, 11528, Greece.
Radiology and Medical Imaging Research Unit, Second Department of Radiology, Medical School, National & Kapodistrian University of Athens, Athens, Greece.
Brain Imaging Behav. 2018 Dec;12(6):1730-1741. doi: 10.1007/s11682-018-9841-0.
The association between gray matter (GM) density and neurophysiologic changes is still unclear in amyotrophic lateral sclerosis (ALS). We evaluated the relationship between GM density and motor system integrity combining voxel-based morphometry (VBM) and transcranial magnetic stimulation (TMS) in ALS. We included 17 ALS patients and 22 healthy controls (HC) who underwent 3D-T1-weighted imaging. Among the ALS group, we applied left motor cortex single-pulse TMS. We used whole-brain VBM comparing ALS and HC in GM density. We also conducted regression analysis to examine correlations between GM density and the following TMS parameters: motor evoked potential (MEP)/M ratio and central motor conduction time (CMCT). We found significantly decreased GM density in ALS patients in several frontal, temporal, parietal/occipital and cerebellar regions (p < 0.001 uncorrected; cluster-extent threshold k = 100 voxels per cluster). With regards to TMS parameters, ALS patients showed mostly increased MEP/M ratio and modest prolongation of CMCT. MEP/M ratio was associated with GM density in (a) rolandic operculum/inferior frontal gyrus/precentral gyrus; anterior cingulate gyrus; inferior temporal gyrus; superior parietal lobule; cuneus; superior occipital gyrus and cerebellum (positive association) and (b) paracentral lobule/supplementary motor area (negative association). CMCT was associated with GM density in (a) inferior frontal gyrus and middle cingulated gyrus (positive association) and (b) superior parietal lobule; cuneus and cerebellum (negative association). Our findings support a significant interaction between motor and extra-motor structural and functional changes and highlight that motor and extra-motor GM integrity may underlie TMS parameters of motor function in ALS patients.
在肌萎缩侧索硬化症（ALS）中，灰质（GM）密度与神经生理变化之间的关联尚不清楚。我们通过体素形态测量学（VBM）和经颅磁刺激（TMS）评估了 ALS 中 GM 密度与运动系统完整性之间的关系。我们纳入了 17 名 ALS 患者和 22 名健康对照者（HC），并对其进行了 3D-T1 加权成像。在 ALS 组中，我们应用了左侧运动皮层单脉冲 TMS。我们使用全脑 VBM 比较了 ALS 和 HC 的 GM 密度。我们还进行了回归分析，以检查 GM 密度与以下 TMS 参数之间的相关性：运动诱发电位（MEP）/M 比和中央运动传导时间（CMCT）。我们发现 ALS 患者的几个额、颞、顶/枕和小脑区域的 GM 密度显著降低（未校正 p < 0.001；每个簇的簇扩展阈值 k = 100 个体素）。就 TMS 参数而言，ALS 患者的 MEP/M 比大多增加，CMCT 略有延长。MEP/M 比与 GM 密度在（a） Rolandic 岛盖/额下回/中央前回；前扣带回；颞下回；顶下小叶；楔前叶；上顶叶和小脑（正相关）和（b）旁中央小叶/辅助运动区（负相关）有关。CMCT 与 GM 密度在（a）额下回和中扣带回（正相关）和（b）顶下小叶；楔前叶和小脑（负相关）有关。我们的发现支持运动和运动外结构和功能变化之间存在显著的相互作用，并强调运动和运动外 GM 完整性可能是 ALS 患者 TMS 运动功能参数的基础。
