Peter Davies, Ph.D., is an international leader in Alzheimer’s disease research. His work at the Litwin-Zucker Center for Research on Alzheimer’s focuses on prevention and slowing the progression of the disease. This is an edited transcript from an interview conducted on February 10, 2009.
The early symptoms of Alzheimer’s disease can be difficult to recognize.
The early symptoms of Alzheimer’s disease are particularly difficult to recognize, especially in older people, because they involve loss of short-term memory. Healthy adults do forget things, so that can be quite difficult to discriminate from the early stages of Alzheimer’s disease, where patients would start losing things, misplacing things. The problems in Alzheimer’s disease go deeper — problems in intellectual function, they don’t think very well, they don’t have the ability to plan out a series of actions to get to where they want to go.
We all have these problems from time to time but these become significant in Alzheimer’s patients. They really impair their ability to interact socially, to do their work if they’re still working – this becomes a major issue when you can’t do your job anymore. Those are the kinds of subtle early signs. In the very early stages, the doctor will say, “Well, I think you may have a problem, but come back in six months and let’s see what’s going on.” If it’s Alzheimer’s disease, the patient will be significantly worse.
Alzheimer’s patients don’t look physically ill.
Often they look physically fine. Alzheimer’s disease is a brain disorder; there’s no real manifestation that’s physical. I mean, patients who have quite advanced Alzheimer’s disease can play golf and they can still hit the ball straight, and you’ve got to help them find the ball because they’ll forget where it went. And they can often play the violin, a motor skill learned a long time ago, playing the violin even at the point where they really can’t speak to you anymore. But physically, they appear OK. In the later stages, they really become totally incapacitated. They don’t move and you end up with a bedridden patient, usually, at that point, institutionalized.
Other medical conditions can mimic the symptoms of Alzheimer’s disease.
There are nearly 60 different conditions that could end up producing the same set of problems with memory, with orientation, with planning and accomplishing a task. There’s a whole range of disorders that could cause those symptoms. So we’ve got to tease out who has Alzheimer’s disease from who has, perhaps, depression, vitamin deficiencies, strokes , or a wealth of other problems that could cause the same symptoms.
Early diagnosis is important.
You don’t want to prolong the disease in its late stages. You want to prevent the decline by going in as early as you can. That’s why diagnostics plays a big role here. It’s not an easy disease to diagnose very early, but that’s obviously the way you want to treat it. And today it doesn’t really matter which stage the patients are at; we give them the drugs that we have and they’re a little bit brighter regardless of the stage. We’re really changing what we’re trying to do now, from treating symptoms to treating the progress of the disease.
There are long-term benefits to early diagnosis.
There is a huge benefit in at least knowing what – you’re going to have to deal with moving forward. If my mother develops Alzheimer’s disease, I need to make a plan for what I am going to do with her over the years. Many of the families ask me what to expect and over the next three years, the next five years, we can tell them what to expect. You know that it won’t be long before you have to take the car keys away. It won’t be long before you know this patient will no longer be able to live alone, and many of our elderly do live alone. When dealing with a married couple where one spouse of the two has Alzheimer’s disease, the other one needs to make some plans, as well as financial support plans. There is a real need to know here.
Testing is important for diagnosis, as well as for documenting both disease progression and treatment results.
It’s really a very extensive process to make this diagnosis. We begin with the patient’s history. In the history of the patient, something may clue you in that there may be something else going on. Neuro-psychologic tests are very important to document if the patient really does have problems. Almost anybody over 60 or 65 thinks they have a bad memory. Almost everybody. When we test them, very few people actually have a poor memory. So you really need to document what the deficits this patient has are and how bad they really are. And that’s important, too, because six months from now we’re going to want to look at those test scores and see which way they’re moving.
If the test scores have remained stable or perhaps even returned to normal six months from now, this is probably not Alzheimer’s. If the test scores have gone down, then it’s more indicative of Alzheimer’s. We usually do fairly comprehensive blood work-ups looking specifically for problems with cholesterol, which might indicate vascular disease, looking for vitamin deficiencies, thyroid problems. Thyroid problems are one of those things that can cause changes in intellectual performance, so we’ve got to look. We do an MRI scan, but a good CAT scan or MRI is essential to this process.
The microscopic changes to the brain of an Alzheimer’s patient are unmistakable.
You see immediately the pathology of the disease and there are really four more elements you look for. First is cell loss, cell death. Alzheimer’s disease results in the death of those cells. Next are two abnormal structures that have to be present if it’s Alzheimer’s disease. They’re called the senile neuritic plaque and the neurofibrillary tangle. And fourth, look for some injured scar-type reaction in the brain. You’d see these four things in a very characteristic distribution in the brain. They’re not everywhere; it’s not every nerve cell that’s vulnerable. Just certain cell groups you look at, if you see plaques, tangles, cell loss, scar formation, you know you’re dealing with Alzheimer’s disease. It’s actually still true that definitive diagnosis of Alzheimer’s disease can only be made by direct examination of the brain tissue.
Steps you can take that may lower your risk of getting Alzheimer’s disease.
There are really three things that you can do to lower your risk. One is to consume a heart-healthy diet. That means doing the same things we’re doing to reduce our risk of heart disease, maintaining a normal weight, eating a really balanced diet that’s relatively low in fat, or following the Mediterranean style diets, which seem to be associated with a lower risk of disease. The second thing is to maintain activity, both physical and mental activity. Elderly individuals who are engaged in physical and mental activity have a lower risk of developing Alzheimer’s. That’s been reported by dozens of different groups. This can be a simple as dancing twice a week or doing the New York Times crossword puzzle, for example. This is the kind of activity that lowers risk. The third thing, which is probably fairly clear from all of the studies that have been done, is to take antioxidants. Vitamin E and vitamin C together reduce the risk of developing Alzheimer’s disease. So if we all maintained a good level of activity, ate a heart-healthy diet, and took vitamin E and vitamin C, we could probably make a significant dent in the number of people who have been developing Alzheimer’s.
It is a myth that aluminum causes Alzheimer’s.
Aluminum is the one thing we know does not cause Alzheimer’s disease. We know this because there were a large number of patients, mostly in Europe, in the ‘70s and ‘80s, who were on kidney dialysis and, more or less accidentally, received huge doses of intravenous aluminum. For many years, this stuff was flowing through the dialysis. It was processed into their system for years and some of those patients got very sick from aluminum poisoning, but not one of those patients ever developed Alzheimer’s disease. So the one thing we know is that you can poison people over decades with intravenous aluminum and they will not develop Alzheimer’s disease. So we know that that’s not true, then.