Clinical Neurophysiology, Department of Neurosciences, Ophthalmology and Genetics, University of Genoa, Via De Toni, 5, 16132 Genoa, Italy.
Eur J Nucl Med Mol Imaging. 2011 Dec;38(12):2209-18. doi: 10.1007/s00259-011-1874-1. Epub 2011 Jul 9.
Subtle cognitive impairment is recognized in the first stages of Parkinson's disease (PD), including executive, memory and visuospatial dysfunction, but its pathophysiological basis is still debated.
Twenty-six consecutive, drug-naïve, de novo PD patients underwent an extended neuropsychological battery, dopamine transporter (DAT) and brain perfusion single photon emission computed tomography (SPECT). We previously reported that nigrocaudate impairment correlates with executive functions, and nigroputaminal impairment with visuospatial abilities. Here perfusion SPECT was first compared between the PD group and age-matched controls (CTR). Then, perfusion SPECT was correlated with both DAT SPECT and four neuropsychological factors by means of voxel-based analysis (SPM8) with a height threshold of p < 0.005 at peak level and p < 0.05 false discovery rate-corrected at cluster level. Both perfusion and DAT SPECT images were flipped in order to have the more affected hemisphere (MAH), defined clinically, on the same side.
Significant hypoperfusion was found in an occipital area of the MAH in PD patients as compared to CTR. Executive functions directly correlated with brain perfusion in bilateral posterior cingulate cortex and precuneus in the less affected hemisphere (LAH), while verbal memory directly correlated with perfusion in the precuneus, inferior parietal lobule and superior temporal gyrus in the LAH. Furthermore, positive correlation was highlighted between nigrocaudate and nigroputaminal impairment and brain perfusion in the precuneus, posterior cingulate and parahippocampal gyri of the LAH.
These data support the evidence showing an early involvement of the cholinergic system in the early cognitive dysfunction and point to a more relevant role of parietal lobes and posterior cingulate in executive functions in PD.
帕金森病（PD）的早期阶段即已出现认知功能障碍，包括执行功能、记忆和视空间功能障碍，但目前其病理生理学基础仍存在争议。
26 例连续的、未经药物治疗的初发 PD 患者接受了扩展神经心理学测试、多巴胺转运体（DAT）和脑灌注单光子发射计算机断层扫描（SPECT）检查。我们之前报道过黑质纹状体损伤与执行功能相关，黑质苍白球损伤与视空间能力相关。在此，我们首次将 PD 组与年龄匹配的对照组（CTR）进行了灌注 SPECT 比较。然后，通过基于体素的分析（SPM8），以峰值水平 p < 0.005 和簇水平校正后的假发现率 p < 0.05 的高度阈值，将灌注 SPECT 与 DAT SPECT 和四个神经心理学因素进行了相关分析。为了使更受影响的半球（MAH）与临床定义的一侧一致，对灌注和 DAT SPECT 图像进行了翻转。
与 CTR 相比，PD 患者的 MAH 存在明显的枕叶区域灌注不足。执行功能与双侧后扣带回和 LAH 楔前叶的脑灌注直接相关，而言语记忆与 LAH 楔前叶、下顶叶和颞上回的灌注直接相关。此外，还发现黑质纹状体和黑质苍白球损伤与 LAH 楔前叶、后扣带回和海马旁回的脑灌注之间存在正相关。
这些数据支持了早期认知功能障碍中胆碱能系统早期受累的证据，并指出了顶叶和后扣带回在 PD 患者执行功能中的更重要作用。
