Departments of Neurology and Psychiatry & Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, and Neurology Service, Neurobehavior Unit, U.S. Department of Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA.
J Alzheimers Dis. 2023;95(2):363-377. doi: 10.3233/JAD-230285.
Alzheimer's disease (AD) is an age-related neurocognitive disorder that is epidemic in the elderly population. Currently, there are limited pharmacological interventions, and this has heightened the urgency to identify potential preventable or modifiable risk factors that promote resilience to the neuropathological effects of AD. The regular use of two or more languages is one such factor that may increases cognitive reserve through the long-standing executive control involved in managing multiple languages in the brain. There is also evidence that bilingualism is associated with increased brain reserve or maintenance, particularly in frontal-executive structures and networks. This review examines the current, sometimes conflicting literature on bi/multilingualism and AD. These studies have confounding variations in the assessment of age of second language onset, language proficiency, language usage, and whether determining incidence of AD or age of symptom onset. Despite these limitations, most publications support the presence of increased frontal-executive reserve that compensates for the development of AD neuropathology and, thereby, delays the emergence of clinical symptoms of dementia by about 4-5 years. Although regularly speaking more than one language does not protect against AD neuropathology, the delay in its clinical expression has a potentially significant impact on the lifelong morbidity from this age-related disease. Learning other languages may be an important modifiable factor for delaying the clinical expression of AD in later life.
阿尔茨海默病（AD）是一种与年龄相关的神经认知障碍，在老年人群中流行。目前，药物干预手段有限，这使得识别潜在的可预防或可改变的风险因素变得尤为紧迫，这些因素可以促进对 AD 神经病理学影响的适应能力。经常使用两种或更多种语言是一个这样的因素，它可以通过大脑中管理多种语言的长期执行控制来增加认知储备。有证据表明，双语与增加脑储备或维持有关，特别是在前额执行结构和网络中。这篇综述审查了目前关于双语和 AD 的有时相互矛盾的文献。这些研究在评估第二语言开始使用的年龄、语言熟练程度、语言使用以及确定 AD 的发病率或症状出现的年龄方面存在混杂的变化。尽管存在这些局限性，但大多数出版物支持存在增加的额执行储备，这可以补偿 AD 神经病理学的发展，从而将痴呆的临床症状出现延迟约 4-5 年。虽然经常说一种以上的语言并不能预防 AD 神经病理学，但它的临床表达延迟对这种与年龄相关的疾病的终身发病率有潜在的重大影响。学习其他语言可能是延缓晚年 AD 临床表达的一个重要可改变因素。
