Cushman Laura A, Stein Karen, Duffy Charles J
Department of Neurology, Brain and Cognitive Sciences, Center for Visual Science, The University of Rochester Medical Center, Rochester, NY14642, USA.
Neurology. 2008 Sep 16;71(12):888-95. doi: 10.1212/01.wnl.0000326262.67613.fe.
Older adults get lost, in many cases because of recognized or incipient Alzheimer disease (AD). In either case, getting lost can be a threat to individual and public safety, as well as to personal autonomy and quality of life. Here we compare our previously described real-world navigation test with a virtual reality (VR) version simulating the same navigational environment.
Quantifying real-world navigational performance is difficult and time-consuming. VR testing is a promising alternative, but it has not been compared with closely corresponding real-world testing in aging and AD. We have studied navigation using both real-world and virtual environments in the same subjects: young normal controls (YNCs, n = 35), older normal controls (ONCs, n = 26), patients with mild cognitive impairment (MCI, n = 12), and patients with early AD (EAD, n = 14).
We found close correlations between real-world and virtual navigational deficits that increased across groups from YNC to ONC, to MCI, and to EAD. Analyses of subtest performance showed similar profiles of impairment in real-world and virtual testing in all four subject groups. The ONC, MCI, and EAD subjects all showed greatest difficulty in self-orientation and scene localization tests. MCI and EAD patients also showed impaired verbal recall about both test environments.
Virtual environment testing provides a valid assessment of navigational skills. Aging and Alzheimer disease (AD) share the same patterns of difficulty in associating visual scenes and locations, which is complicated in AD by the accompanying loss of verbally mediated navigational capacities. We conclude that virtual navigation testing reveals deficits in aging and AD that are associated with potentially grave risks to our patients and the community.
老年人会迷路，在很多情况下是由于已确诊或早期的阿尔茨海默病（AD）。无论哪种情况，迷路都可能对个人和公共安全以及个人自主性和生活质量构成威胁。在此，我们将我们之前描述的现实世界导航测试与模拟相同导航环境的虚拟现实（VR）版本进行比较。
量化现实世界的导航性能既困难又耗时。VR测试是一种有前景的替代方法，但尚未与老龄化和AD中密切对应的现实世界测试进行比较。我们在同一组受试者中研究了现实世界和虚拟环境中的导航：年轻正常对照（YNC，n = 35）、老年正常对照（ONC，n = 26）、轻度认知障碍患者（MCI，n = 12）和早期AD患者（EAD，n = 14）。
我们发现现实世界和虚拟导航缺陷之间存在密切相关性，这种相关性在从YNC到ONC、再到MCI以及到EAD的各组中都有所增加。子测试性能分析显示，在所有四个受试者组中，现实世界和虚拟测试中的损伤情况相似。ONC、MCI和EAD受试者在自我定向和场景定位测试中都表现出最大困难。MCI和EAD患者在回忆两个测试环境的言语信息方面也存在受损。
虚拟环境测试可有效评估导航技能。衰老和阿尔茨海默病（AD）在关联视觉场景和位置方面存在相同的困难模式，在AD中，由于伴随的言语介导导航能力丧失，这种情况变得更加复杂。我们得出结论，虚拟导航测试揭示了衰老和AD中的缺陷，这些缺陷与对我们的患者和社区的潜在严重风险相关。
