Yamashita Ken-Ichiro, Taniwaki Yoshihide, Utsunomiya Hidetsuna, Taniwaki Takayuki
Division of Respirology, Neurology and Rheumatology, Department of Medicine, Kurume University School of Medicine, Fukuoka, Japan.
Department of Neurology, Fukuoka Sanno Hospital, Fukuoka, Japan.
J Neuroimaging. 2014 Nov-Dec;24(6):590-594. doi: 10.1111/jon.12096. Epub 2014 Mar 5.
Impairment of orientation for time (OT) is a characteristic symptom of Alzheimer disease (AD). However, the brain regions underlying OT remain to be elucidated. Using single photon emission computed tomography (SPECT), we examined the brain regions exhibiting hypoperfusion that were associated with OT.
We compared regional cerebral blood flow (rCBF) differences between AD and amnesic mild cognitive impairment (aMCI) or normal subjects using 3-dimensional stereotactic surface projection (3D-SSP) analysis. AD patients were divided into OT good and poor groups according to their mean OT scores, and rCBF then compared between the groups to elucidate OT-specific brain areas.
3D-SSP analysis showed reduced rCBF in the left superior parietal lobule (SPL) and bilateral inferior parietal lobule (IPL) in AD patients. In the poor OT group, 3D-SSP analysis revealed hypoperfusion in the bilateral SPL, IPL, posterior cingulated cortex (PCC), and precuneus. Among these areas, region of interest analysis revealed a significant higher number of hypoperfused pixels in the left PCC in the OT poor AD group.
Our SPECT study suggested that hypoperfusion in the left SPL and bilateral IPL was AD specific, and reduced rCBF in the left PCC was specifically associated with OT.
时间定向障碍（OT）是阿尔茨海默病（AD）的一个特征性症状。然而，OT背后的脑区仍有待阐明。我们使用单光子发射计算机断层扫描（SPECT）来检查与OT相关的灌注不足的脑区。
我们使用三维立体定向表面投影（3D-SSP）分析比较了AD患者与遗忘型轻度认知障碍（aMCI）患者或正常受试者之间的局部脑血流量（rCBF）差异。根据平均OT评分将AD患者分为OT良好组和OT较差组，然后比较两组之间的rCBF，以阐明OT特异性脑区。
3D-SSP分析显示AD患者左侧顶上小叶（SPL）和双侧顶下小叶（IPL）的rCBF降低。在OT较差组中，3D-SSP分析显示双侧SPL、IPL、后扣带回皮质（PCC）和楔前叶灌注不足。在这些区域中，感兴趣区分析显示OT较差的AD组左侧PCC灌注不足像素的数量明显更多。
我们的SPECT研究表明，左侧SPL和双侧IPL灌注不足是AD特有的，左侧PCC的rCBF降低与OT特异性相关。
