Knapp W H, Dannenberg C, Marschall B, Zedlick D, Löschmann K, Bettin S, Barthel H, Seese A
Department of Nuclear Medicine, University of Leipzig, Germany.
Eur J Nucl Med. 1996 Aug;23(8):878-88. doi: 10.1007/BF01084360.
Imaging of local cerebral blood flow (lCBF) may serve as an important supplementary tool in the aetiological assessment of dementias. In early or preclinical disease, however, there are less characteristic changes in lCBF. In the present study it was investigated whether vasoactivation or neuroactivation may produce more pronounced local lCBF deficits. Local CBF was investigated by using technetium-99m hexamethylpropylene amine oxime and single-photon emission tomography (SPET) in 80 patients (50 with mild cognitive impairment and 30 with dementia of Alzheimer type (DAT), all without evidence of cerebrovascular disease) at rest (baseline) and during activation. In 31 studies patients underwent vasomotor activation with acetazolamide, while 62 studies were performed under cognitive challenge (neuroactivation by labyrinth task). Cortical activity relative to that of cerebellum increased significantly in a right temporal region and tended to increase in other cortical regions upon vasoactivation. In contrast, neuroactivation reduced cortical activity relative to that of cerebellum in several left and right temporal and in left parietal regions. Visual classification of SPET images of patients with probable DAT by three observers resulted in a reduction of the number of definitely abnormal patterns from 9/12 to 4/12 by vasoactivation and an increase from 10/18 to 15/18 by neuroactivation. Correspondingly, abnormal ratings in patients with mild cognitive dysfunction were reduced from 7/19 to 5/19 by vasoactivation and were increased from 12/21 to 18/21 by neuroactivation. In conclusion, vasoactivation does not enhance local relative perfusion deficits in patients with cognitive impairment of non-vascular aetiology, whereas neuroactivation by labyrinth task produces more pronounced local flow differences and enhances abnormal patterns in lCBF imaging.
局部脑血流量（lCBF）成像可作为痴呆病因评估的重要辅助工具。然而，在疾病早期或临床前期，lCBF的特征性变化较少。在本研究中，探讨了血管激活或神经激活是否会导致更明显的局部lCBF缺损。使用锝-99m六甲基丙烯胺肟和单光子发射断层扫描（SPET）对80例患者（50例轻度认知障碍患者和30例阿尔茨海默病型痴呆（DAT）患者，均无脑血管疾病证据）在静息状态（基线）和激活过程中进行局部CBF研究。在31项研究中，患者接受乙酰唑胺进行血管运动激活，而62项研究是在认知挑战（通过迷宫任务进行神经激活）下进行的。血管激活后，相对于小脑，右侧颞叶区域的皮质活动显著增加，其他皮质区域也有增加趋势。相比之下，神经激活使几个左右颞叶和左侧顶叶区域相对于小脑的皮质活动降低。三名观察者对可能患有DAT的患者的SPET图像进行视觉分类，结果显示血管激活后明确异常模式的数量从9/12减少到4/12，神经激活后从10/18增加到15/18。相应地，血管激活使轻度认知功能障碍患者的异常评级从7/19降低到5/19，神经激活使其从12/21增加到18/21。总之，血管激活不会增强非血管病因性认知障碍患者的局部相对灌注缺损，而迷宫任务引起的神经激活会产生更明显的局部血流差异，并增强lCBF成像中的异常模式。
