Alzheimer's disease could affect twice as many people as it was thought after studies that millions of other people might have toxic brain changes that could cause memory impairment.
- Researcher at Mayo Clinic says dementia symptoms should not be the first sign
- He said that many more people have biological signs of Alzheimer's disease before they notice
- Diagnosing patients earlier can improve treatment prospects
According to one expert, the number of people with Alzheimer's disease could be twice as high as scientists think.
Dr. Clifford Jack, a researcher on Alzheimer's disease at the Mayo Clinic in Minnesota, said many sufferers had early and asymptomatic signs of the disease.
At the present time, doctors only diagnose Alzheimer's disease in patients who exhibit physical signs of memory impairment.
But Dr. Jack and his colleagues found in a study of 2,500 people that twice as many cases had biological signs of brain disease as those with symptoms.
Alzheimer's disease, the most common cause of dementia, is caused by a toxic accumulation of proteins in the brain that cause nerve damage. Many more people may have early signs of this accumulation than signs of dementia, said an expert (image of the reserve)
Changing the diagnosis mode of Alzheimer's could help doctors detect it earlier and improve treatments, Dr. Jack said.
Alzheimer's disease is the most common cause of dementia and affects an estimated 527,000 people in the United Kingdom and 5.8 million Americans.
This is thought to be due to the formation of certain proteins – called amyloid and tau – in the brain.
This buildup causes irreversible nerve damage and leaves patients with memory, communication and movement problems – and is ultimately fatal.
Diagnosing people with early signs of accumulation, instead of waiting until they have apparent dementia, could help millions of others with the disease to improve their vision.
THE DRUG TEST ALZHEIMER PROMISING ABANDON
Biogen, a US-based pharmaceutical multinational, gave up last month's trial of a promising drug against Alzheimer's disease.
This failure marks the last setback of a race to an industry aimed at developing treatments for the disease that destroys memory.
During the trial that was in the second phase of the human tests, said its leaders, the data showed that the drug, aducanumab, would not succeed .
As a result, Biogen and its partner, Eisai Co Ltd, decided to unplug the cable.
The decision overturned 26 percent of Biogen's share price, which equates to about $ 17 billion (£ 12.9 billion).
Experts predict that a company that successfully creates Alzheimer's disease treatment will generate billions of dollars each year, but none has succeeded so far despite more than 100 attempts .
The trial ended just two weeks after the CEO of Eisai had expressed confidence in this drug.
"I believe we have already gone through the riskiest phase," said Haruo Naito at a press conference.
Dr. Jack told The Telegraph newspaper: "The prevalence of Alzheimer's disease is based on … the question" do you have dementia? "
He said: "Alzheimer's disease, defined in a traditional way, underestimates people with the pathology but showing no symptoms.
"Many more people suffer from the disease but do not show symptoms, just as many more people with hypertension than people who have had a stroke, or many more people with diabetes than the blind. "
Treatments exist for Alzheimer's disease and can slow down – but not stop – the accumulation of amyloid proteins and tau proteins.
But they are almost always given too late, said Dr. Jack.
Many people may not realize that something is wrong until they or a member of their family realizes that they are becoming forgetful or more fragile.
And because Alzheimer's disease is common in the elderly, it is possible that these symptoms go away until it becomes apparent that something serious is wrong.
For this reason, drug trials have failed. Recently, a company called Biogen abandoned the trial of a promising drug because of its failure.
Patients who try treatments or enroll in clinical trials almost always have signs of the disease, which means it's too late, Dr. Jack said.
He said, "You really have a narrow window to select people at the right time.
"You need to find evidence of amyloid when people are returning to their normal cognitive state, so they're in that ideal place where, hopefully, if you treat people for three to five years you will be able to detect a slowing down of cognitive decline. "
He added that many people suspected of having Alzheimer's could have similar brain diseases causing the same symptoms or being a victim of a minor stroke.
WHAT IS ALZHEIMER?
Alzheimer's disease is a progressive degenerative brain disorder in which an accumulation of abnormal proteins causes the death of nerve cells.
This disturbs transmitters that transmit messages and causes contraction of the brain.
More than 5 million people suffer from the disease in the United States, where it is the 6th leading cause of death.
When brain cells die, the functions they provide are lost.
This includes memory, orientation and the ability to think and reason.
The progression of the disease is slow and gradual.
On average, patients live five to seven years after diagnosis, but some may live for ten to 15 years.
- Short-term memory loss
- Behavioral changes
- Mood swings
- Difficulty managing money or phoning
- Loss of serious memory, forgetfulness of close family members, objects or familiar places
- Becoming anxious and frustrated with an inability to understand the world, leading to aggressive behavior
- Finally lose the ability to walk
- May have problems eating
- The majority will eventually need 24-hour care
Source: Alzheimer's Association