With your good chance of getting dementia
this test should be prescribed by your doctor to establish a baseline
for you. And then if found implement THOSE EXACT DEMENTIA PREVENTION PROTOCOLS your doctor should have competently already set up. But I can't imagine your insurance company paying for a PET scan that would show you need even more interventions.
Your risk of dementia, has your doctor told you of this?
1. A documented 33% dementia chance post-stroke from an Australian study? May 2012.
2. Then this study came out and seems to have a range from 17-66%. December 2013.`
3. A 20% chance in this research. July 2013.
4. Dementia Risk Doubled in Patients Following Stroke September 2018
The latest here:
Time Until Dementia Symptoms Appear Can Be Estimated Via Brain Scan
Researchers have developed an approach to estimating when a person who
is likely to develop Alzheimer’s disease, but has no cognitive symptoms,
will start showing signs of Alzheimer’s dementia.
The algorithm, available online in the journal Neurology, uses data from an amyloid positron emission tomography (PET) to gauge brain levels of the key Alzheimer’s protein amyloid beta.
Amyloid PET scans already are used widely in Alzheimer’s research, and the new algorithm represents a new way of analysing such scans to approximate when symptoms will arise. Using a person’s age and data from a single amyloid PET scan, the algorithm yields an estimate of how far a person has progressed toward dementia, and how much time is left before cognitive impairment sets in.
“I perform amyloid PET scans for research studies, and when I tell cognitively normal individuals about positive results, the first question is always, ‘How long do I have until I get dementia?’” said senior author Suzanne Schindler, MD, Washington University School of Medicine, St. Louis, Missouri. “Until now, the answer I’d have to give was something like, ‘You have an increased risk of developing dementia in the next 5 years.’ But what does that mean? Individuals want to know when they are likely to develop symptoms, not just whether they are at higher risk.”
The researchers analysed amyloid PET scans from 236 people participating in Alzheimer’s research studies through Washington University’s Charles F. and Joanne Knight Alzheimer Disease Research Center. The participants had an average age of 67 years at the beginning of the study. All participants underwent at least 2 brain scans an average of 4.5 years apart. The researchers applied standard uptake value ratio (SUVR) to the scans to estimate the amount of amyloid in each participant’s brain at each time point.
The researchers also accessed over 1,300 clinical assessments on 180 of the participants. The assessments typically were performed every 1 to 3 years. Most participants were cognitively normal at the start of data collection, so the repeated assessments allowed the researchers to pinpoint when each participant’s cognitive skills began to slip.
Dr. Schindler spent years trying to figure out how to use the data in amyloid PET scans to estimate the age at which symptoms would appear. The breakthrough came when she realised that amyloid accumulation has a tipping point and that each individual hits that tipping point at a different age. After this tipping point, amyloid accumulation follows a reliable trajectory.
“You may hit the tipping point when you’re 50, it may happen when you’re 80 -- it may never happen,” said Dr. Schindler. “But once you pass the tipping point, you’re going to accumulate high levels of amyloid that are likely to cause dementia. If we know how much amyloid someone has right now, we can calculate how long ago they hit the tipping point and estimate how much longer it will be until they are likely to develop symptoms.”
People in the study who reached the tipping point at younger ages took longer to develop cognitive symptoms than those who reached it later in life. Participants who hit the tipping point at age 50 typically took nearly 20 years to develop symptoms; those who hit it at age 80 took less than 10 years.
“When we look at the brains of relatively young people who have died with Alzheimer’s, they typically look pretty healthy, other than Alzheimer’s,” said Dr. Schindler. “But older people more frequently have damage to the brain from other causes, so their cognitive reserves are lower, and it takes less amyloid to cause impairment.”
The power of this new technique is that it requires just 1 brain scan, plus the person’s age. With that data, the model can estimate the time to symptom onset, plus or minus several years. In this study, the correlation between the expected age of symptom onset and the true age at diagnosis was better than 0.9 on a scale of 0 (no correlation) to 1 (perfect correlation).
After age, the genetic variant APOE4 is the strongest risk factor for Alzheimer’s dementia. People who carry one copy of the variant are 2 to 3 times more likely to develop Alzheimer’s dementia than the general population, and people who carry 2 copies are 10 times more likely. In this study, people with the high-risk variant hit the tipping point younger, but once that point was passed, they followed the same trajectory as everyone else.
“APOE4 seems to have a seeding effect,” said Dr. Schindler. “At very low levels, below the tipping point, you see amyloid rising in people with APOE4 while it’s not changing in people without APOE4. That means APOE4 carriers are going to hit the tipping point sooner. People with two copies of APOE4 hit the tipping point about 10 years earlier than people with no copies. But after that point, we see no difference between the APOE4 carriers and noncarriers.”
Reference: https://n.neurology.org/content/early/2021/09/09/WNL.0000000000012775
SOURCE: Washington University School of Medicine
The algorithm, available online in the journal Neurology, uses data from an amyloid positron emission tomography (PET) to gauge brain levels of the key Alzheimer’s protein amyloid beta.
Amyloid PET scans already are used widely in Alzheimer’s research, and the new algorithm represents a new way of analysing such scans to approximate when symptoms will arise. Using a person’s age and data from a single amyloid PET scan, the algorithm yields an estimate of how far a person has progressed toward dementia, and how much time is left before cognitive impairment sets in.
“I perform amyloid PET scans for research studies, and when I tell cognitively normal individuals about positive results, the first question is always, ‘How long do I have until I get dementia?’” said senior author Suzanne Schindler, MD, Washington University School of Medicine, St. Louis, Missouri. “Until now, the answer I’d have to give was something like, ‘You have an increased risk of developing dementia in the next 5 years.’ But what does that mean? Individuals want to know when they are likely to develop symptoms, not just whether they are at higher risk.”
The researchers analysed amyloid PET scans from 236 people participating in Alzheimer’s research studies through Washington University’s Charles F. and Joanne Knight Alzheimer Disease Research Center. The participants had an average age of 67 years at the beginning of the study. All participants underwent at least 2 brain scans an average of 4.5 years apart. The researchers applied standard uptake value ratio (SUVR) to the scans to estimate the amount of amyloid in each participant’s brain at each time point.
The researchers also accessed over 1,300 clinical assessments on 180 of the participants. The assessments typically were performed every 1 to 3 years. Most participants were cognitively normal at the start of data collection, so the repeated assessments allowed the researchers to pinpoint when each participant’s cognitive skills began to slip.
Dr. Schindler spent years trying to figure out how to use the data in amyloid PET scans to estimate the age at which symptoms would appear. The breakthrough came when she realised that amyloid accumulation has a tipping point and that each individual hits that tipping point at a different age. After this tipping point, amyloid accumulation follows a reliable trajectory.
“You may hit the tipping point when you’re 50, it may happen when you’re 80 -- it may never happen,” said Dr. Schindler. “But once you pass the tipping point, you’re going to accumulate high levels of amyloid that are likely to cause dementia. If we know how much amyloid someone has right now, we can calculate how long ago they hit the tipping point and estimate how much longer it will be until they are likely to develop symptoms.”
People in the study who reached the tipping point at younger ages took longer to develop cognitive symptoms than those who reached it later in life. Participants who hit the tipping point at age 50 typically took nearly 20 years to develop symptoms; those who hit it at age 80 took less than 10 years.
“When we look at the brains of relatively young people who have died with Alzheimer’s, they typically look pretty healthy, other than Alzheimer’s,” said Dr. Schindler. “But older people more frequently have damage to the brain from other causes, so their cognitive reserves are lower, and it takes less amyloid to cause impairment.”
The power of this new technique is that it requires just 1 brain scan, plus the person’s age. With that data, the model can estimate the time to symptom onset, plus or minus several years. In this study, the correlation between the expected age of symptom onset and the true age at diagnosis was better than 0.9 on a scale of 0 (no correlation) to 1 (perfect correlation).
After age, the genetic variant APOE4 is the strongest risk factor for Alzheimer’s dementia. People who carry one copy of the variant are 2 to 3 times more likely to develop Alzheimer’s dementia than the general population, and people who carry 2 copies are 10 times more likely. In this study, people with the high-risk variant hit the tipping point younger, but once that point was passed, they followed the same trajectory as everyone else.
“APOE4 seems to have a seeding effect,” said Dr. Schindler. “At very low levels, below the tipping point, you see amyloid rising in people with APOE4 while it’s not changing in people without APOE4. That means APOE4 carriers are going to hit the tipping point sooner. People with two copies of APOE4 hit the tipping point about 10 years earlier than people with no copies. But after that point, we see no difference between the APOE4 carriers and noncarriers.”
Reference: https://n.neurology.org/content/early/2021/09/09/WNL.0000000000012775
SOURCE: Washington University School of Medicine
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