研究:白天过度打盹可能是老年痴呆症的早期征兆

Needing to nap could be an early warning sign of Alzheimer’s disease, according to new research.

根据一项新的研究，需要午睡可能是老年痴呆症的早期预警信号。

Experts found that the brain cells that keep us awake during the day are among the first to be targeted by the neurological disease.

专家们发现，让我们白天保持清醒的脑细胞，是神经系统疾病的第一个目标。

It was previously thought the cells were destroyed by a protein called beta-amyloid, but scientists have now concluded the culprit is toxic clumps of a protein called tau.

以前人们认为这些细胞被一种叫做β-淀粉样蛋白的蛋白质破坏了，但现在科学家已经得出结论，罪魁祸首是一种叫做tau的有毒蛋白质团块。

They say the discovery could lead to earlier diagnosis when drugs and lifestyle changes are more likely to work and may also lead to better treatments.

他们说，这一发现可以让病症更早诊断，并因药物和生活方式的介入，而获得更好的治疗效果及生活改善。

Regular dozing in patients has been reported by both researchers and caregivers long before their memory problems begin to unfold.

早在病人的记忆问题开始显现之前，研究人员和护理人员就已经报道过病人经常打瞌睡。

But it was unclear if disturbed sleep put people at risk of Alzheimer’s — or if disease-related brain changes lead to it.

但是，目前还不清楚睡眠障碍是否会使人们患上老年痴呆症——或者是与疾病相关的大脑改变导致了老年痴呆症。

The team at the University of California at San Francisco analyzed the brains of 13 deceased patients who had Alzheimer’s disease at the time of death.

旧金山加利福尼亚大学的研究小组，分析了13名死于阿尔茨海默氏症的患者的大脑。

They found the three brain areas that boost wakefulness — the locus coeruleus, lateral hypothalamic area and tuberomammillary nucleus — had lost as many as 75 percent of their neurons.

他们发现，大脑中促进觉醒的三个区域——蓝斑、下丘脑外侧区和下丘脑结节核——已经失去了多达75%的神经元。

They also had a significant buildup of tau. The results are significant as they could lead to better treatments by targeting tau instead of beta-amyloid.

他们也有大量tau蛋白的积累。这一结果很有意义，因为它们可以通过靶向tau蛋白，而不是β-淀粉样蛋白来实现更好的治疗。

It also provides a reason for the regular dozing reported by Alzheimer’s patients and their caregivers, long before the development of memory problems. The research was published in Alzheimer’s & Dementia.

它也为老年痴呆症患者和他们的护理者报告提供了一个规律，早在记忆问题发展之前，病人就经常性打盹。这项研究发表在《老年痴呆症》上。

Lead author Dr. Jun Oh, based at the Memory and Ageing Centre at UCSF, said: “It is remarkable because it is not just a single brain nucleus that is degenerating, but the whole wakefulness-promoting network.

研究报告的主要撰写者、加州大学旧金山分校记忆与衰老中心的Oh Jun博士说:“这很了不起，因为不仅仅是一个单一的大脑核在退化，整个促进睡眠的网络也在退化。”

“Crucially this means the brain has no way to compensate because all of these functionally related cell types are being destroyed at the same time.”

“关键的是，这意味着大脑没有办法进行补偿，因为所有这些功能相关的细胞类型都在同时被破坏。”

Alzheimer’s can take root up to 20 years before symptoms appear and it’s believed existing medications are failing because they are given to patients far too late.

阿尔茨海默病可以在症状出现前20年即生根，据了解，现有的药物正在失效，因为给病人吃的时间太晚了。