為什么治療癡呆如此困難

為什么治療癡呆如此困難

Finding a cure for neurodegenerative diseases such as Alzheimer's is challenging. They're difficult to diagnose, and drugs struggle to get into the brain as the brain's blood supply is largely separate to the rest of the body.

尋找治療阿爾茨海默癥等神經(jīng)退行性疾病的方法是一項挑戰(zhàn)。它們很難被診斷，而且由于大腦的血液供應在很大程度上與身體的其他部分分離，藥物很難進入大腦。

Not surprisingly, several companies have left this territory in recent years. Last week, pharmaceutical giant Pfizer announced it will stop research into developing drugs to treat Alzheimer's disease, after costly failed attempts over the past decade.

毫不奇怪，近年來有幾家公司已經(jīng)離開了這一領域。上周，制藥巨頭輝瑞公司宣布將停止研發(fā)治療阿爾茨海默氏癥的藥物，在此之前的10年里，輝瑞公司付出了巨大的代價，但都以失敗告終。

In recent years some clinical trials involving potential dementia drugs have had disappointing setbacks. In 2012, Pfizer and Johnson & Johnson halted development of the antibody drug bapineuzumab, after it failed in late-stage trials to treat patients with mild to moderate Alzheimer's.

近年來，一些涉及潛在癡呆藥物的臨床試驗出現(xiàn)了令人失望的挫折。2012年，輝瑞公司和強生公司停止了抗體藥物bapineuzumab的研發(fā)，因為它在治療輕度至中度阿爾茨海默病的后期試驗中失敗。

So what makes dementia such a difficult condition to treat with drugs, and is progress being made towards a treatment?

那么，是什么讓癡呆癥難以用藥物治療呢?治療的進展如何呢?

Why dementia is so hard to treat
為什么癡呆如此難以治療

Despite the vast number of people affected globally, with an estimated 46.8 million peoplecurrently living with dementia, there is currently no cure. While current treatments manage symptoms (the latest drug to gain FDA approval was memantine, in 2003) they offer no prospect of recovery.

盡管全球受影響的人數(shù)眾多，目前估計有4680萬人患有癡呆癥，但目前尚無治愈方法。雖然目前的治療可以控制癥狀(2003年獲得FDA批準的最新藥物是美金剛胺)，但它們沒有治愈的希望。

Part of the difficulty in finding treatments for dementia stems from the fact it's not a single disease, but a complex health problem with more than 50 underlying causes. Dementia can be better thought of as an umbrella term describing a range of conditions that cause parts of the brain to deteriorate progressively.

尋找治療癡呆癥的方法之所以困難，部分是因為它不是單一的疾病，而是一個有50多種潛在原因的復雜健康問題。癡呆癥可以被更好地理解為一個概括性術語，它描述了一系列導致大腦部分逐漸退化的情況。

Most drug treatments currently in development have targeted the pathology of Alzheimer's disease, the most common form of dementia, which accounts for about 60 to 70% of all cases.

目前正在開發(fā)的大多數(shù)藥物治療都針對阿爾茨海默氏病的病理學。阿爾茨海默氏病是癡呆癥最常見的一種，約占所有病例的60 - 70%。

Finding a successful treatment for Alzheimer's faces two major hurdles: the first being we still don't know enough about the disease's underlying biology,or why the disease progresses at different rates in different people.

找到治療阿爾茨海默氏癥的成功方法面臨著兩大障礙:第一，我們仍然對這種疾病的潛在生物學知之甚少，也不知道為什么不同的人的病情發(fā)展速度不同。

It doesn't help that symptoms of Alzheimer's develop gradually and slowly and a diagnosis might only be made years after the brain has started to undergo neurodegenerative changes.

阿爾茨海默癥的癥狀發(fā)展緩慢，可能只有在大腦開始發(fā)生神經(jīng)退行性變化數(shù)年后才會做出診斷，這一點也沒有幫助。

The second major hurdle to finding a treatment is that drugs need to first cross the blood-brain barrier. The blood-brain barrier provides a defence against disease-causing pathogens and toxins that may be present in our blood, and by design exists to keep out foreign substances from the brain. The downside is that it also keeps the vast majority of potential drug treatments from reaching the brain.

尋找治療方法的第二個主要障礙是，藥物必須首先穿過血腦屏障。血腦屏障為我們抵抗可能存在于血液中的致病病原體和毒素提供了一種防御機制，它的存在是為了阻止外來物質進入大腦。它的缺點是，它還阻止了絕大多數(shù)潛在的治療藥物到達大腦。