Ask Dr. Hallberg: Screening for Alzheimer's disease

Alzheimer's damage
The scan on the left shows a healthy brain. The one on the right shows the damage caused by Alzheimer's disease.
Image courtesy of the National Institute on Aging

New proposed screening guidelines for Alzheimer's are aimed at detecting the disease earlier in patients concerned about memory loss. But would you want to know if you have the disease if there isn't much you can do to prevent its onset?

MPR News medical analyst Dr. Jon Hallberg joined All Things Considered's Tom Crann on Wednesday to discuss key issues raised by the new guidelines.

Hallberg is a physician in family medicine at the University of Minnesota and medical director of the Mill City Clinic in Minneapolis.

Tom Crann: First let's deal with the term Alzheimer's. There's dementia, senility, Alzheimer's. Sort that out for us.

Dr. Jon Hallberg: Well, I think of it as an umbrella. Dementia is the big broad term, and it refers to memory loss. And what we're really getting at is memory loss that gets so bad that people can't carry out activities of daily living.

Alzheimer's disease is one form of dementia, and it probably accounts for about eighty percent of the cases of dementia. You can almost think of them as synonymous terms, though they're technically not the same.

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Crann: And right now, how in the clinic do you detect Alzheimer's disease?

Hallberg: You'd think that with a disease that is as devastating as this is that we would have a blood test or that there'd be a sophisticated imaging test we could do, but we don't. In fact, it comes down to administering a survey, a Mini Mental Status Exam.

Crann: And you've brought a copy of this. It's basically a test, and it has questions like, 'Earlier, I told you the name of three things. Can you tell me what those were?' Or, 'Repeat the phrase 'no if, ands, or buts.'' It seems like a very low-tech way.

Hallberg: Yes, and people are often surprised when we administer this, and they're worried that they're starting to forget the names of the kids that live two doors down, or they've misplaced their keys, and they're worried that they might have something like Alzheimer's, I'll administer this. And they're heartened because they'll score 30 out of 30 very easily, and they're very reassured by that.

But it's really devastating when I give a test that seems so simple on the surface of it, and patients can't answer the questions properly. That's really frightening when you see that.

Dr. Jon Hallberg
Dr. Jon Hallberg, Assistant Professor, Department of Family Medicine and Community Health Medical Director at the University of Minnesota. He is a regular medical analyst on MPR's All Things Considered.
Photo courtesy of Dr. Jon Hallberg

Crann: How would you go about detecting Alzheimer's under these new proposed guidelines? It was from the Alzheimer's Association meeting recently, right?

Hallberg: That's right, and it was also with the National Institute on Aging. And these folks are thinking that the trouble is we administer tests like this when problems are already there. They're well entrenched.

The fact is Alzheimer's might start 10 years or even more before we can detect it from a testing standpoint.

So they're hoping that with some blood testing, for example, looking for biomarkers the way we do with diabetes or high cholesterol or certain forms of heart disease -- and that we have also better imaging techniques -- that maybe we can detect these plaques and tangles, these sort of characteristic findings that are normally seen on autopsy after someone's died from Alzheimer's.

Could we detect that way, way in advance and then let a person and a family, of course, know that Alzheimer's might be coming?

Crann: Would you still wait for people to come in with concerns about memory or symptoms? Or would these be tests administered to everybody after a certain age?

Hallberg: I think that's one of the things that has to be determined. Right now, we have certain kind of hard and fast guidelines that when someone turns 50 years of age, we really start to talk about colon cancer screening, and sooner of course if there's a positive family history. And I think that that would be similar with Alzheimer's.

If there's a family history, we'd start sooner rather than later, but it raises all kinds of questions.

Crann: Such as?

Hallberg: Well, they're not just talking about MRI scans. Those are expensive in and of themselves, but they're actually talking about PET scans.

Crann: Very expensive?

Hallberg: Very expensive. I think of that as an experimental thing. Major university centers, major hospitals have these, but most places in the country don't have access to those. And unlike diabetes, we don't have an easy biomarker.

There is no blood test that's been widely accepted or widely done yet that would for sure give us the sense that there's Alzheimer's in the making.

Crann: What do we have when it comes to treatment right now for Alzheimer's? How is it treated?

Hallberg: We have a couple, literally a very small handful, of medications that work in a similar way to slow the progression down. They don't alter the course.

So in other words, they don't change you from having it to not having it, or to basically making it as though you don't have it. I've got some patients on these meds. Some do quite well, but they all progress to Alzheimer's.

So the answer is we really don't have much. It really boils down to memory clinics and neurologists who take a special interest in this and family support. It's a devastating disease in its later stages.

Crann: Is it true that by the time a patient is showing signs of dementia that it's too late?

Hallberg: Well, if by too late, I suppose if we mean that there's nothing that can be done, that's true. It is too late. Can things be done? Absolutely. Do we know what the course will be, in terms of how fast it will progress? We don't.

I suppose it depends a little bit on age. It's always devastating when someone in their forties or fifties develops it. That's a horrible prognosis. If they get it when they're in their eighties, well, it's kind of expected. And I think that's what years ago we referred to as senility or someone's losing their memory. It's almost expected at a certain point.

Crann: New guidelines to detect this earlier are all well and good, but it sounds like there aren't a whole lot of sure methods here, and there isn't much of a cure you can give earlier. So, what does it mean?

Hallberg: The people who are commenting on this study and these new guidelines are suggesting that, 'Look, don't submit this without concurrently releasing some medications that can make a difference. If you release the one and don't have the other, then what good does it really do?'

I have to admit that I'm probably more in that school that it's fine to have guidelines. And also, these are recommendations. They're guidelines. I think insurance companies will have to jump on board and agree that they're going to pay for some of these tests. People have to have access to them. So it raises all kinds of financial and ethical questions, I think.

Crann: So is there a downside to early detection?

Hallberg: If you know that you have a disease that eventually will take your life, and there's nothing you can do about it, I think that it's going to raise a tremendous amount of anxiety. I think it takes a very special person to have that diagnosis and to look at it in a constructive way.

(Interview edited and transcribed by MPR News reporter Madeleine Baran.)