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DAVID MARKS, MD: Hi, and welcome to our webcast. I'm Dr. David Marks. Up to four million Americans suffer from Alzheimer's disease, and believe it or not, it's the fourth leading cause of death in this country. What is Alzheimer's disease? Who does it affect, and how do you diagnose it?
Joining us to talk about these issues are two experts. First is Dr. Norman Relkin. He's Director of the Cornell Memory Disorders Program at the Weill Cornell Medical College. Welcome.
NORMAN RELKIN, MD: Thank you, David.
DAVID MARKS, MD: Also we have Dr. Peter Davies, the Resnick Professor of Alzheimer's disease research at Albert Einstein School of Medicine. Welcome. Norm, let's start off by talking about what Alzheimer's disease is.
NORMAN RELKIN, MD: Alzheimer's disease is the leading cause of dementia in the elderly, dementia being defined as a decline from a previously attained state of cognitive accomplishment, that's sufficiently severe to interfere with daily life. Dementia also has to be progressive, and Alzheimer's disease is slowly progressive, often over about a decade.
DAVID MARKS, MD: How widespread is this problem?
PETER DAVIES, PhD: All over the Western world, the disease appears to have about the same incidence. We would see perhaps 6-7% of the over-65s affected, and that number may be as high as 30-40% of the over-85s. Very, very large consumer of healthcare dollars, of course.
DAVID MARKS, MD: My impression is, we've heard a lot more about Alzheimer's over the last decade or two. Is that because the population is aging?
PETER DAVIES, PhD: Oh, most definitely. At the turn of the century, life expectancy was only about 60. And, of course, Alzheimer's disease, happily, is very rare prior to age 60.
DAVID MARKS, MD: How did it get the name Alzheimer's disease?
NORMAN RELKIN, MD: Dr. Alois Alzheimer was a German neurologist, and he did describe both the first patient and the pathology that we use to this day to diagnose the disease after the person has died. Dr. Alzheimer's first case was a woman who was relatively young, and as a consequence, his name was attached originally to what was called pre-senile dementia, or dementia that took its onset before age 65. We now recognize that the form of the disease that occurs later in life and the one that occurs early shares the same pathology, and Alzheimer's name is applied to both.
DAVID MARKS, MD: You mention "early." Younger people can get it.
NORMAN RELKIN, MD: There have been cases described as young as their 20s. These, fortunately, as Peter mentioned earlier, are rare. They're due to genetic mutations that occur in less than 2% of all Alzheimer's disease. Nevertheless, it's a very virulent form of the disease, and certainly when it occurs at that very young age, it shortens the life expectancy considerably.
PETER DAVIES, PhD: Most people didn't consider Alzheimer's disease in somebody who was, let's say, 70 or 75. The word "senility", "organic brain syndrome", hardening of the arteries of the brain, those are the terms that we used 10-15 years ago in the older age group.
DAVID MARKS, MD: How do you diagnose it? What are the symptoms or the signs, for the person out there who may be worried about a family member who's maybe forgetting things a little too frequently?
NORMAN RELKIN, MD: Alzheimer's is called an amnestic dementia, and that's because in the majority of cases the first symptom is forgetfulness. It's a particular kind of forgetfulness. It's very, very rapid, such that something that a person has heard, maybe forgotten within a few seconds or a few minutes. That leads to repetitiveness in conversation, and a tendency to forget day-to-day types of activities.
DAVID MARKS, MD: You're talking about short-term memory there.
NORMAN RELKIN, MD: It is short term in the initial stages, to a greater degree than remote, autobiographic memory. But as the disease progresses, most domains of memory become involved. The initial symptoms, though, tend to be confined to the recently learned things.
But not only memory is affected, and I think that one very characteristic feature of the disease is a loss of insight. Whereas the person with a stroke or with another form of brain disease might recognize that they're having a problem, the typical patient with Alzheimer's disease doesn't know, and will not recognize that they're becoming ill, and generally have to be brought to medical attention as a consequence.
DAVID MARKS, MD: Any other symptoms that people should look for?
PETER DAVIES, PhD: I think it's important to remember that we all are forgetful. I'm notorious for losing my car keys and my coffee cup and my glasses. That's not the kind of forgetfulness we're talking about. It's asking you the same question four times in a row within a five-minute space, because I simply can't remember the answer you gave me. This is much more typical of the Alzheimer patient.
Of course, as Norman said, the impairment of other activities is also noticeable. Failure to balance a checkbook, when you've done this all your life. Forgetting important issues, things that you do every day. That's when you start looking for medical attention.
DAVID MARKS, MD: What does a doctor look for? Once the signs have been recognized, are there any tests that can tell you that Alzheimer's is the right diagnosis?
NORMAN RELKIN, MD: It used to be said that Alzheimer's couldn't be diagnosed during life, but certainly in recent years that view has changed. We now view the patterns of mental disturbance that occur in Alzheimer's disease as being recognizable. So, actually, the mainstay of diagnosis is not high technology or laboratory tests, but a skilled examiner interviewing both the patient and a caregiver, maybe a friend or a relative, to corroborate what history they get from the individual.
Often one of the biggest clues that there is an incipient dementia, is that the patient themselves are not able to convey their own medical history. Once the history has been collected, then it is a matter of performing some kind of a mental status examination. It's not always the case that a clinician has time to do a full and complete assessment of mentation, but they have to do enough to establish that the person has impairment which, as Peter points out, goes beyond day-to-day normal forgetfulness.
Once that's been established, they'll want to look for other potential contributing factors, the most common being medication-induced changes in cognition, and affective changes such as depression, which can often masquerade with symptoms of memory loss very similar to Alzheimer's, but can be distinguished by a good clinician.
DAVID MARKS, MD: But there are other, more dangerous factors. Tumors, vascular problems also. Is that routinely checked?
NORMAN RELKIN, MD: It's checked when it's deemed necessary from the standpoint of the patient's presentation. But testing can be overdone, too. Again, in the old days, we were taught that dementia was a matter of diagnosis by exclusion. You would rule out everything, and what you were left with, you would consider to be Alzheimer's.
We take a more direct and informed approach now, and we do the tests that are appropriate to the patient's particular presentation. If they have symptoms that are suggestive of a brain tumor, then by all means brain imaging would be absolutely indicated. But there are some cases in which that type of an evaluation may not be necessary to come to a diagnosis of probable Alzheimer's.
DAVID MARKS, MD: Very briefly, what are some of the potential causes of this disease? When I was a medical resident, there was a lot of talk about aluminum. Everybody was worried about their pots and pans. Is that a possible cause?
PETER DAVIES, PhD: I think that's the one cause that can be excluded. I think there's a lot of very good evidence that aluminum does not and cannot cause Alzheimer's disease. There probably are multiple causes of this disease. It's very difficult to identify any one environment factor or any single event in the history of a patient which invariably leads to Alzheimer's disease. There are almost certainly multiple factors.
We mentioned genetics, and clearly the disease is inherited in a very small number of cases, probably 2%. In 98% of cases, we don't know what the cause is. As I said, there's probably multiple causes.
DAVID MARKS, MD: Okay, good. Thank you both for sharing some very important information. Thanks for being here. And thank you for joining our webcast. I'm Dr. David Marks.
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