Discipline of Psychiatry, School of Medicine and Trinity College Institute of Neuroscience, Laboratory of Neuroimaging and Biomarker Research, Trinity College Dublin, Adelaide and Meath Hospital incorporating National Children's Hospital, Dublin, Ireland.
Radiology. 2010 Jan;254(1):219-26. doi: 10.1148/radiol.2541090558.
To evaluate whether patients with Alzheimer disease (AD) have altered activation compared with age-matched healthy control (HC) subjects during a task that typically recruits the dorsal visual pathway.
The study was performed in accordance with the Declaration of Helsinki, with institutional ethics committee approval, and all subjects provided written informed consent. Two tasks were performed to investigate neural function: face matching and location matching. Twelve patients with mild AD and 14 age-matched HC subjects were included. Brain activation was measured by using functional magnetic resonance imaging. Group statistical analyses were based on a mixed-effects model corrected for multiple comparisons.
Task performance was not statistically different between the two groups, and within groups there were no differences in task performance. In the HC group, the visual perception tasks selectively activated the visual pathways. Conversely in the AD group, there was no selective activation during performance of these same tasks. Along the dorsal visual pathway, the AD group recruited additional regions, primarily in the parietal and frontal lobes, for the location-matching task. There were no differences in activation between groups during the face-matching task.
The increased activation in the AD group may represent a compensatory mechanism for decreased processing effectiveness in early visual areas of patients with AD. The findings support the idea that the dorsal visual pathway is more susceptible to putative AD-related neuropathologic changes than is the ventral visual pathway.
评估阿尔茨海默病（AD）患者在执行典型招募背侧视觉通路的任务时，与年龄匹配的健康对照组（HC）相比，激活是否发生改变。
本研究遵循赫尔辛基宣言进行，获得了机构伦理委员会的批准，所有受试者均提供了书面知情同意书。进行了两项任务以研究神经功能：面部匹配和位置匹配。纳入了 12 名轻度 AD 患者和 14 名年龄匹配的 HC 受试者。通过功能磁共振成像测量脑激活。组统计分析基于经多重比较校正的混合效应模型。
两组之间的任务表现无统计学差异，且两组内的任务表现无差异。在 HC 组中，视觉感知任务选择性地激活了视觉通路。相反，在 AD 组中，在执行这些相同任务时没有选择性激活。沿着背侧视觉通路，AD 组在执行位置匹配任务时，额外招募了主要位于顶叶和额叶的区域。在执行面部匹配任务时，两组之间的激活没有差异。
AD 组的激活增加可能代表 AD 患者早期视觉区域处理效果降低的代偿机制。这些发现支持这样的观点，即背侧视觉通路比腹侧视觉通路更容易受到与 AD 相关的潜在神经病理学变化的影响。
