Buhour M-S, Doidy F, Mondou A, Pélerin A, Carluer L, Eustache F, Viader F, Desgranges B
Normandie Univ, UNICAEN, EPHE, INSERM, U1077, CHU de Caen, Neuropsychologie et Imagerie de la Mémoire Humaine, 14000, Caen, France.
EJNMMI Res. 2017 Dec;7(1):21. doi: 10.1186/s13550-017-0267-2. Epub 2017 Mar 6.
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive disease of the nervous system involving both upper and lower motor neurons. The patterns of structural and metabolic brain alterations are still unclear. Several studies using anatomical MRI yielded a number of discrepancies in their results, and a few PET studies investigated the effect of ALS on cerebral glucose metabolism. The aim of this study was threefold: to highlight the patterns of grey matter (GM) atrophy, hypometabolism and hypermetabolism in patients with ALS, then to understand the neurobehavioral significance of hypermetabolism and, finally, to investigate the regional differences between the morphologic and functional changes in ALS patients, using a specially designed voxel-based method. Thirty-seven patients with ALS and 37 age- and sex-matched healthy individuals underwent both structural MRI and [F]-fluorodeoxyglucose (FDG) PET examinations. PET data were corrected for partial volume effects. Structural and metabolic abnormalities were examined in ALS patients compared with control subjects using two-sample t tests in statistical parametric mapping (SPM). Then, we extracted the metabolic values of clusters presenting hypermetabolism to correlate with selected cognitive scores. Finally, GM atrophy and hypometabolism patterns were directly compared with a one-paired t test in SPM.
We found GM atrophy as well as hypometabolism in motor and extra motor regions and hypermetabolism in medial temporal lobe and cerebellum. We observed negative correlations between the metabolism of the right and left parahippocampal gyri and episodic memory and between the metabolism of right temporal pole and cognitive theory of mind. GM atrophy predominated in the temporal pole, left hippocampus and right thalamus, while hypometabolism predominated in a single cluster in the left frontal superior medial cortex.
Our findings provide direct evidence of regional variations in the hierarchy and relationships between GM atrophy and hypometabolism in ALS. Moreover, the FDG-PET investigation suggests that cerebral hypermetabolism is deleterious to cognitive function in ALS.
肌萎缩侧索硬化症（ALS）是一种迅速进展的神经系统疾病，累及上、下运动神经元。大脑结构和代谢改变的模式仍不清楚。多项使用解剖磁共振成像（MRI）的研究结果存在诸多差异，少数正电子发射断层扫描（PET）研究调查了ALS对脑葡萄糖代谢的影响。本研究的目的有三个：突出ALS患者灰质（GM）萎缩、代谢减低和代谢增高的模式，进而了解代谢增高的神经行为学意义，最后使用专门设计的基于体素的方法研究ALS患者形态学和功能变化的区域差异。37例ALS患者和37例年龄及性别匹配的健康个体接受了结构MRI和[F] - 氟脱氧葡萄糖（FDG）PET检查。PET数据针对部分容积效应进行了校正。在统计参数映射（SPM）中，使用双样本t检验比较ALS患者与对照受试者的结构和代谢异常情况。然后，我们提取呈现代谢增高的簇的代谢值，以与选定的认知评分进行相关性分析。最后，在SPM中使用单样本t检验直接比较GM萎缩和代谢减低模式。
我们发现运动和运动外区域存在GM萎缩以及代谢减低，而内侧颞叶和小脑存在代谢增高。我们观察到右侧和左侧海马旁回的代谢与情景记忆之间以及右侧颞极的代谢与心理理论认知之间呈负相关。GM萎缩主要出现在颞极、左侧海马和右侧丘脑，而代谢减低主要出现在左侧额上内侧皮质的单个簇中。
我们的研究结果提供了直接证据，证明ALS患者GM萎缩和代谢减低在层次结构及相互关系上存在区域差异。此外，FDG - PET研究表明，脑代谢增高对ALS患者的认知功能有害。
