New way of defining Alzheimer's aims to find disease sooner

TECH

New way of defining Alzheimer's aims to find disease sooner

2018-04-11 12:09 Last Updated At：12:38

Government and other scientists are proposing a new way to define Alzheimer's disease — basing it on biological signs, such as brain changes, rather than memory loss and other symptoms of dementia that are used today.

The move is aimed at improving research, by using more objective criteria like brain scans to pick patients for studies and enroll them sooner in the course of their illness, when treatments may have more chance to help.

But it's too soon to use these scans and other tests in routine care, because they haven't been validated for that yet, experts stress. For now, doctors will still rely on the tools they've long used to evaluate thinking skills to diagnose most cases.

Regardless of what tests are used to make the diagnosis, the new definition will have a startling effect: Many more people will be considered to have Alzheimer's, because the biological signs can show up 15 to 20 years before symptoms do.

"The numbers will increase dramatically," said Dr. Clifford R. Jack Jr., a Mayo Clinic brain imaging specialist. "There are a lot more cognitively normal people who have the pathology in the brain who will now be counted as having Alzheimer's disease."

He led a panel of experts, working with the Alzheimer's Association and the National Institute on Aging, that updated guidelines on the disease, published Tuesday in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.

ABOUT ALZHEIMER'S

About 50 million people worldwide have dementia, and Alzheimer's is the most common form. In the U.S., about 5.7 million have Alzheimer's under its current definition, which is based on memory problems and other symptoms. About one-third of people over 70 who show no thinking problems actually have brain signs that suggest Alzheimer's, Jack said.

There is no cure — current medicines such as Aricept and Namenda just temporarily ease symptoms. Dozens of hoped-for treatments have failed, and doctors think one reason may be that the studies enrolled patients after too much brain damage had already occurred.

"By the time that you have the diagnosis of the disease, it's very late," said Dr. Eliezer Masliah, neuroscience chief at the Institute on Aging.

"What we've realized is that you have to go earlier and earlier and earlier," just as doctors found with treating cancer, he said.

Another problem: as many as 30 percent of people enrolled in Alzheimer's studies based on symptoms didn't actually have the disease — they had other forms of dementia or even other medical conditions. That doesn't give an accurate picture of whether a potential treatment might help, and the new definition aims to improve patient selection by using brain scans and other tests.

BETTER TESTS

Many other diseases, such as diabetes, already are defined by measuring a biomarker, an objective indicator such as blood sugar. That wasn't possible for Alzheimer's disease until a few years ago, when brain scans and spinal fluid tests were developed to do this.

They measure certain forms of two proteins — amyloid and tau — that form plaques and tangles in the brain — and signs of nerve injury, degeneration and brain shrinkage.

The guidelines spell out use of these biomarkers over a spectrum of mental decline, starting with early brain changes, through mild impairment and Alzheimer's dementia.

WHAT TO DO?

People may be worried and want these tests for themselves or a family member now, but Jack advises: "Don't bother. There's no proven treatment yet."

You might find a doctor willing to order them, but spinal fluid tests are somewhat invasive, and brain scans can cost up to $6,000. Insurance usually does not pay because they're considered experimental outside of research. A large study is underway now to see whether Medicare should cover them and when.

Anyone with symptoms or family history of dementia, or even healthy people concerned about the risk can consider enrolling in one of the many studies underway.

"We need more people in this pre-symptomatic stage" to see if treatments can help stave off decline, Masliah said.

A Chinese official meets North Korean leader Kim in Pyongyang in highest-level talks in years

2024-04-14 09:38 Last Updated At：09:40

BEIJING (AP) — A top ranking official Chinese official reaffirmed ties with North Korea during a meeting Saturday with the country’s leader Kim Jong Un in the capital Pyongyang, China's state media reported, in the highest-level talks between the allies in years.

The visit by Zhao Leji, who ranks third in the ruling Communist Party hierarchy and heads the ceremonial parliament, came as North Korea has test fired missiles to intimidate South Korea and its ally, the United States.

The Xinhua News Agency reported that Zhao told Kim at the meeting concluding his three-day visit that China, the North’s most important source of economic aid and diplomatic support, looked forward to further developing ties, but made no mention of the political situation on the peninsula or the region.

North Korea’s official Korean Central News Agency also confirmed the meeting on Sunday and said Kim held unspecified discussions with Zhao on “boosting the multi-faceted exchange and cooperation” and “other important issues of mutual concern.” KCNA said the Chinese delegation left the country later on Saturday.

Since the establishment of diplomatic ties 75 years ago, China and North Korea have been “good neighbors and struggled together to attain a common destiny and level of development,” Xinhua quoted Zhao as saying.

China fought on behalf of the reclusive Communist State against the U.S. and others during the 1950-1953 Korean War, and in recent years has helped prop up its weak economy, allegedly in violation of U.N. sanctions in response to Pyongyang's nuclear weapons program that Beijing had endorsed.

Zhao met his North Korean counterpart Choe Ryong Hae on Thursday and discussed how to promote exchanges and cooperation in all areas, the North’s official Korean Central News Agency reported.

North Korea closed its borders during the height of the COVID-19 pandemic amid reports of a major outbreak and food shortages. Zhao’s visit to North Korea marked the first bilateral exchange involving a Chinese Politburo Standing Committee member since the pandemic started. Prior to the outbreak, Kim and Chinese President Xi Jinping held two summits in 2019.

North Korea and China are expected to hold a number of exchanges this year to mark the anniversary of the establishment of diplomatic ties. North Korea has sought to boost its cooperation with Beijing and Russia in the face of a standoff with the U.S. and South Korea over its missile launches and nuclear program.

Kim traveled to Russia in September for a summit with Russian President Vladimir Putin. The U.S., South Korea and others accuse North Korea of supplying conventional weapons for Russia’s war in Ukraine in return for advanced weapons technologies and other support.

China has refused to criticize the Russian invasion and accused the U.S. and NATO of provoking Moscow, but says it will not provide Moscow with direct military support.

__ AP writer Kim Tong-hyung contributed from Seoul, South Korea.