Understanding Today’s Alzheimer’s Diagnostic Tools

Welcome back, everybody. You've tuned in to

the truth lies and Alzheimer's show Lisa Skinner, your host,

and if you tuned in last week, I brought you the most current and

accurate information regarding the use of PET scans to

definitively diagnose Alzheimer's disease. This week,

as promised, I'm going to share the most current information

about the other diagnostic tools that physicians currently use in

conjunction with PET scans to help them diagnose Alzheimer's

disease as accurately as they can with these tools that are

currently available. So what I talked about last week, we

learned that an absolute diagnosis of Alzheimer's disease

can still only be made at autopsy. However, physicians at

specialized centers can diagnose Alzheimer's disease with up to

90% certainty based on clinical information to make the

diagnosis as accurate as they possibly can, the following may

need to be conducted, a medical history and neurological exam,

neuropsychological testing that involves a careful analysis of a

person's memory, problem solving abilities, language, attention

and their visuospatial abilities, basic blood tests.

Blood tests may be used to help exclude other causes of memory

difficulties. For example, a person with a thyroid disorder

or a vitamin deficiency may have problems with his or her memory

that mimics dementia, but the cause is not due to a brain

disease and may be reversed if treated properly. Then there are

brain scans which, such as an MRI or CT or CAT scan, as it's

also known as, that may need to be done in certain patients to

detect brain tumors or strokes. These disorders can also cause

memory problems. Now, according to Dr Barry Rovner, who is a

Professor in the Departments of both Psychiatry and Neurology at

Jefferson Hospital for neuroscience in Philadelphia,

Pennsylvania, he states that quote, although no diagnostic

tests are currently available that have 100% accuracy for

Alzheimer's disease, experienced physicians can correctly

diagnose Alzheimer's disease about 90% of the time. This

happens when the physician obtains a history of gradual

cognitive decline, wherein family members also report that

a person's functional abilities have declined, for example, in

managing their finances, preparing meals and taking

medications competently that they are able to demonstrate

with objective evidence their cognitive deficits, particularly

in the short term memory department, they find no

neurological signs that suggest another condition, like

Parkinson's disease, a stroke, and sees no abnormalities on

brain imaging studies like the cat or CT scan or an MRI scan

and laboratory tests that would indicate an alternative

condition. He also says that an exciting new development are

biomarkers that indicate the presence of underlying

Alzheimer's disease pathology. These tests are now used to

increase diagnostic accuracy in research projects, but are not

generally used to diagnose individuals in the community.

These tests rely on the analysis of spinal fluid to measure

levels of beta amyloid and the tau protein which accumulate in

the brain with Alzheimer's disease. These new PET scans

that reveal the presence of amyloid in the brain suggest

that someday we will have tests that indicate disease pathology,

possibly before someone has developed symptoms. End quote,

so how do these biomarkers help diagnose dementia? Well,

biomarkers are measurable indicators of what's happening

in our bodies. These can be found in blood, other body

fluids, organs and in tissues, some can even be measured

digitally. Biomarkers help doctors and researchers track

healthy processes, diagnose diseases and other health

conditions, monitor responses to medications and identify health

risks in individual persons, for example, an increased level of

cholesterol in the blood is a biomarker for heart attack risk.

The following are the different types of biomarkers for dementia

detection and diagnosis, and when combined with other tests,

these biomarkers can help doctors determine whether a

person might have or be at risk of developing Alzheimer's or a

related brain disease that Causes dementia. But I do want

to emphasize what I uncovered, and that is that no single test

can diagnose these conditions. Biomarkers are only part of a

complex and complete assessment. In some cases, these biomarker

tests are only available through a specialty clinic or medical

research facility. Physicians with expertise in this area

include neurologists, geriatric psychiatrists,

neuropsychologists and geriatricians. So these are the

different types of biomarkers and tests that we have available

to use. There's brain imaging. Several types of brain scans

enable doctors and scientists to see different factors that may

help diagnose Alzheimer's or a related dementia. Doctors also

use brain scans to find evidence of other sources of damage in

the brain, such as tumors or strokes that may aid in

diagnosis. Brain scans used to help diagnose dementia include

the PET scan, the cat or CT scan and the MRI. So this is the

definition of what a CT or computerized tomography scan is.

It's a type of X ray that uses radiation to produce images of

the brain and other parts of the body. A head CT scan can show

shrinkage or atrophy of brain regions that may occur in

dementia, as well as signs of other possible sources of the

disease, such as an infection or even a blood clot, then we have

the magnetic resonance imaging or MRI. Now, the MRI uses

magnetic fields and radio waves to produce detailed images of

body structures, including the size and shape of the brain and

the brain regions, and similar to a CAT scan, MRI show whether

areas of the brain have atrophied or shrunk. And repeat

scans can show how a person's brain changes over time. So the

first one would set a baseline to measure the changes in future

scans, evidence of shrinkage may support a diagnosis of

Alzheimer's or another one of the neurodegenerative diseases

that cause dementia, but cannot indicate a specific diagnosis.

MRI also provides a detailed picture of our blood

vessels in the brain. So before making a dementia diagnosis,

doctors often. You MRI results to rule out other causes of

memory changes, such as bleeding or a buildup of fluid in the

brain. PET scans use small amounts of radioactive substance

called a tracer to measure specific activity, such as

energy use or a specific molecule in different brain

regions. PET scans take pictures of our brains, revealing regions

of normal and abnormal chemical activity. There are several

types of PET scans that can help doctors diagnose dementia. There

is the Cerebro spinal fluid biomarker, aka CSF. CSF is a

clear fluid that surrounds the brain and spinal cord, and it

provides protection and insulation. Doctors perform a

lumbar puncture, also called a spinal tap, to get this fluid

the most widely used CSF biomarkers for Alzheimer's

disease measure beta amyloid 42 which is the major component of

amyloid plaques in our brains, also tau and phospho tau, which

are the major components of tau tangles in our brains, which

happens to be another hallmark of Alzheimer's disease. We use

blood tests. These blood biomarkers have historically

been less accurate than the spinal fluid biomarkers for

identifying Alzheimer's and related dementia. However,

thanks to more research advances, improved methods to

measure these brain derived proteins are actually now

available. There's genetic testing. Our genes are

structures in a body, cells that are passed down from a person's

birth parents. They carry information that determine a

person's traits and keep the body's cells healthy. Now,

mutations in genes can lead to diseases such as Alzheimer's, so

a genetic test is a type of medical test that analyzes our

DNA from blood or saliva to determine a person's genetic

makeup, a number of genetic combinations, may change the

risk of developing a disease that causes dementia. Advances

in biomarkers during the past decade have led to exciting new

findings. Researchers can now see Alzheimer's related changes

in our brains while people are alive, track the disease's onset

and progression and test the effectiveness of promising drugs

and other potential treatments. There are two main categories of

Alzheimer's disease. One is called familial, and the other

is called sporadic, familiar. Alzheimer's disease refers to

the genetic form of the disease that is transmitted from one

generation to the next. Only 5% of all cases of Alzheimer's

disease have been associated with a genetic component. We've

heard this as early onset Alzheimer's disease. Now these

individuals come from families in which as many as half of the

members eventually develop Alzheimer's disease.

Fortunately, this form of the disease, the disorder and the

disease are a much rarer form of Alzheimer's. The remaining 95%

of Alzheimer's disease cases are fall into the sporadic category,

or randomly occurring in the population. So what if a

physician could diagnose Alzheimer's before major

symptoms appear? Guess what? That's actually possible now,

with an FDA approved test now being offered just recently,

this in the latter part of 2025 for people experiencing mild

cognitive issues, the test helps their neurologist learn if the

symptoms are related to Alzheimer's disease. Disease. So

a negative test can help rule out Alzheimer's disease with a

96.2 accuracy rate. A positive test can allow patients to

receive a diagnosis and potentially have access to new

drugs to slow the disease's progression, while in a very

early stage of the disease. So it was May of 2025 when the FDA

approved the first blood test as a tool to help diagnose

Alzheimer's disease. And this test is called Lumi pulse. These

blood tests offer a less expensive and less invasive

option for helping to diagnose Alzheimer's disease. So how does

this newly approved blood test by the FDA test for Alzheimer's

disease work? I'll tell you. I'm not going to keep it a secret.

The Lumi pulse test uses a blood sample drawn at your doctor's

office, and the test measures certain proteins, including a

specific form of the tau protein, and that can indicate

the presence of amyloid plaques in our brains, an amyloid plaque

is a buildup of protein that is considered the Hallmark sign of

Alzheimer's. This blood test, along with other diagnostic

tools such as PET scan, can help diagnose Alzheimer's, while the

blood test can detect changes even before memory problems

begin. It is recommended to only be used clinically in people who

are showing symptoms of Alzheimer's disease. Usually

you'll get the results from the test within about two to five

days. So why is this new blood test for Alzheimer's disease, an

important finding. Previously, the only test to detect amyloid

plaques were through a PET scan and a lumbar puncture. In a

lumbar puncture a sample of the cerebrospinal fluid or CSF was

taken from the spinal column. These tests can be expensive,

and a lumbar puncture is invasive. How accurate is this

new test? Some studies are showing that the Lumi pulse test

is over 90% accurate in detecting Alzheimer's related

changes. However, the test is still being refined and cannot

diagnose Alzheimer's disease on its own. The Lumi pulse test is

meant to be part of an evaluation for Alzheimer's

disease, including an extensive and complex physical and medical

history and imaging scans of the brain. The accuracy rate is

different between Lumi pulse and other blood tests used to help

diagnose Alzheimer's disease. So you should discuss with your

health care professional which test is going to be most

appropriate for your specific situation. Who should even

consider taking this test? Well, the test is approved for adults,

age 50 or older, who have early memory or thinking problems such

as forgetting names, misplacing things or even repeating

questions in the same conversation. It's not yet

recommended for general screening in people who are

showing no symptoms, you and your healthcare professional can

decide if this test is appropriate for you. What are

the results going to mean? A positive result means there are

changes in your brain that may suggest Alzheimer's, but the

results alone do not mean that you have the disease. So your

health care professional may recommend more tests, such as

imaging scans or tests of your memory and thinking, or he could

suggest he or she could suggest lifestyle changes to support

your brain health.

He can also, he or she can also help you plan your next steps,

including treatment options or even a clinical trial that you

can participate in if you and your healthcare profession.

Professional decide that a blood test is appropriate for you. It

can be ordered right in your doctor's office. Talking with

your health care professional can help you understand what the

test can and cannot tell you. Decide if it's the right time

for testing, make a plan for what to do with your results.

You can mention it during your annual checkup or make a

separate appointment if you're really, really concerned about

the symptoms that you feel you are displaying. So what

questions should you ask your healthcare professional? Ask him

if he thinks this test is right for you. Why or why not? What

are the risks or downsides of getting this test? What will we

do if the test shows signs of Alzheimer's disease? Is this

test covered by insurance, or is it going to be an out of pocket

expense for me. Are there other tests that we should be

considering instead or along with this blood test? So in

conclusion, yes, a brain autopsy is still the only way to

definitively confirm Alzheimer's disease by examining brain

tissue for plaques and tangles, because it does involve

microscopic evaluation of brain tissue to find The definitive

signs of Alzheimer's. In other words, the plaques and tangles,

modern techniques like biomarker tests that I went over with you,

including blood and spinal fluid and PET scans, now allow doctors

to diagnose with high accuracy up to 90% while a person is

living, ruling out other causes, while not 100% certain without

an autopsy, these advanced tests alongside clinical evaluations

do provide strong evidence for a probable diagnosis, guiding

Treatment and Research. So there you have it, the most updated

and current information that was available. And I went to about

10 different resources that were all scientific resources that

you will be able to see in the show notes, including NIH and

the lancet review. And these are all they all pretty much said

exactly the same thing. So I hope this has been really

helpful for you, and you'll know how to approach a conversation

with your doctor if you are displaying mild or moderate

symptomology for cognitive decline. So thanks again for

being here with me today. I'll be back next week with another

episode of the truth lies in Alzheimer's show. And if you

have a chance, please go to our website. It's actually a new

website just completely redesigned. It's called mining

dementia.com you can subscribe to our free weekly newsletter by

hitting the subscribe button, and that goes out every Monday,

and it provides you with other currently researched information

on Alzheimer's disease and other related dementia. And we have

also uploaded other tips, tools and strategies that could help

you in your Alzheimer's journey. So don't forget to check that

out minding dementia.com. Hope you all have beautiful, healthy

and happy rest of your week, and I'll be back again next week

with another new episode of the truth lies in Alzheimer's show.

I'm Lisa Skinner, your host, Take care for now. Bye, bye.