Pelizzari Laura, Di Tella Sonia, Rossetto Federica, Laganà Maria Marcella, Bergsland Niels, Pirastru Alice, Meloni Mario, Nemni Raffaello, Baglio Francesca
IRCCS, Fondazione Don Carlo Gnocchi, Milan, Italy.
Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States.
Front Neurol. 2020 Jun 23;11:562. doi: 10.3389/fneur.2020.00562. eCollection 2020.
Fronto-parietal regions are involved in cognitive processes that are commonly affected in Parkinson's disease (PD). The aims of this study were to investigate cerebral blood flow (CBF) and gray matter (GM) volume within the regions belonging to the fronto-parietal circuit in people with PD (pwPD) without dementia, and to assess their association with cognitive performance. Twenty-seven pwPD without dementia (mean [SD] age = 67.4 [8.1] years, 20 males, mean [SD] Montreal Cognitive Assessment, MoCA score = 24.2 [2.9], median [IQR] Hoehn and Yahr scale = 1.5 [1-2]) and twenty-six age- and sex-matched healthy controls (HC) were scanned with arterial spin labeling (ASL) and T1-weighted magnetic resonance imaging (MRI) sequences to investigate CBF and GM volume, respectively. The cognitive performance of the enrolled pwPD was assessed with MoCA, Trail Making Test (TMT, part A, B, B-A), phonemic fluency and semantic fluency tests. The scores were adjusted for age and education. After standard preprocessing, CBF differences between pwPD and HC were tested with a voxel-wise approach. Voxel-based morphometry was used to compare pwPD and HC in terms of GM volume. Both voxel-wise comparisons between pwPD and HC were restricted to regions of the fronto-parietal circuit. The following additional voxel-wise analyses were performed within regions showing either perfusion or GM volume alterations: (1) correlation with neuropsychological test scores; (2) subgroup comparison after median split on each neuropsychological test score. Family-wise error-corrected (FWE) -values lower than 0.05 were considered significant. Significant hypoperfusion was identified in the left inferior parietal lobule (IPL, p = 0.037) and in the bilateral superior parietal lobule (SPL, left hemisphere: p = 0.037; right hemisphere: p = 0.049) of pwPD when compared to HC. No significant GM atrophy was observed. Local hypoperfusion did not correlate with any neuropsychological test scores. However, significantly lower CBF was observed in the left SPL and IPL of the pwPD subgroup who performed poorer on TMT part A in comparison with the pwPD subgroup that performed better. Perfusion alterations may occur in parietal regions of pwPD without dementia, and may be associated with lower visuomotor skills. Parietal CBF may be considered as a suitable early biomarker for longitudinal studies investigating cognitive decline in PD.
额顶叶区域参与帕金森病（PD）中通常会受到影响的认知过程。本研究的目的是调查无痴呆的帕金森病患者（pwPD）额顶叶回路所属区域内的脑血流量（CBF）和灰质（GM）体积，并评估它们与认知表现的关联。27名无痴呆的pwPD患者（平均[标准差]年龄=67.4[8.1]岁，20名男性，平均[标准差]蒙特利尔认知评估，MoCA评分=24.2[2.9]，中位数[四分位间距]Hoehn和Yahr量表=1.5[1-2]）和26名年龄及性别匹配的健康对照者（HC）分别接受动脉自旋标记（ASL）和T1加权磁共振成像（MRI）序列扫描，以研究CBF和GM体积。采用MoCA、连线测验（TMT，A、B、B-A部分）、语音流畅性和语义流畅性测试评估入组pwPD患者的认知表现。对分数进行年龄和教育程度校正。经过标准预处理后，采用体素水平的方法测试pwPD和HC之间的CBF差异。基于体素的形态测量法用于比较pwPD和HC的GM体积。pwPD和HC之间的体素水平比较均限于额顶叶回路区域。在显示灌注或GM体积改变区域内进行以下额外的体素水平分析：（1）与神经心理学测试分数的相关性；（2）根据每个神经心理学测试分数进行中位数分割后的亚组比较。家族性错误校正（FWE）值低于0.05被认为具有显著性。与HC相比，pwPD患者的左侧顶下小叶（IPL，p=0.037）和双侧顶上小叶（SPL，左侧半球：p=0.037；右侧半球：p=0.049）存在显著灌注不足。未观察到显著的GM萎缩。局部灌注不足与任何神经心理学测试分数均无相关性。然而，与表现较好的pwPD亚组相比，在TMT A部分表现较差的pwPD亚组的左侧SPL和IPL中观察到显著较低的CBF。无痴呆的pwPD患者的顶叶区域可能会出现灌注改变，且可能与较低的视运动技能有关。顶叶CBF可被视为用于研究PD认知衰退的纵向研究的合适早期生物标志物。
