It's said that everything comes with a price. The average American now lives almost thirty years longer than a hundred years ago. But for millions of people, the price of longevity has been Alzheimer's disease. The greatest fear my patients express to me is, "I think I'm losing my mind." They usually relate small lapses of memory. "I was making a phone call and I couldn't remember who I was calling." "I saw somebody I know like the back of my hand and I couldn't think of her name." "I lost my train of thought mid-sentence." Are they overloading their synapses with all the multi-tasking they do, is it normal aging, or is the beginning of Alzheimer's, the most common form of dementia? Researchers now have some tools that can help them answer this question -- and some ideas on how we all might be able to prevent or delay Alzheimer's.
For the past several months, I have been preparing the most extensive segment I have been involved with since becoming a medical correspondent for the CBS Evening News with Katie Couric in 2006. CBS is leaving no doubt about its commitment to covering a disease that affects over five million Americans and could afflict as many as 16 million by 2050. It's devoting six minutes out of a 22 minute broadcast to "CBS Reports: Where America Stands" -- a look at the latest research in Alzheimer's that will air tonight.
There is no cure for Alzheimer's disease. Average lifespan is about eight years. The five Alzheimer's drugs currently approved usually don't help for long and only treat symptoms. There are medications that can help treat the anger, anxiety, and depression that often accompany the disease. But so far, no medication has been proven to slow the progression of Alzheimer's.
CBS producer Amy Burkholder and I flew down to New Orleans, where we met three generations of women in one family who have been devastated by the disease. Two of the women have Alzheimer's and are in the cruel stage where they can still understand what they have lost and can see the silhouette of what's to come. All three sat together across from me at their kitchen table, clutching each other's hands, talking about their love for each other and their fears of what the future might hold. It was a snapshot of scenes that are playing out all across America and the world.
In order to understand the latest thinking about the diagnosis, treatment, and prevention of Alzheimer's, we spoke to experts, combed the world's literature and visited several laboratories doing cutting edge research. The Alzheimer's Association and the National Institute on Aging have been especially helpful. We visited Dr. Dennis Selkoe, Professor of Neurology at Brigham and Women's Hospital, who has spent decades pursuing the cause of Alzheimer's. He explained that a sticky protein called amyloid is present in all patients with Alzheimer's and described his efforts to prove that removing it from the brains of mice and humans can improve memory. We had unprecedented access to mice studies looking at whether exercise and a stimulating environment can help prevent or reverse the disease.
What about my patients who complain of mild memory loss? Much of the time such lapses do turn out to be just a normal part of aging. But doctors can be too dismissive of such complaints, saying, "That happens to me, too." It's important for patients to discuss all their symptoms -- including memory issues -- with their healthcare providers. And doctors need to become better educated about how to recognize and evaluate memory problems. There can be easily treatable causes for dementia, such as low thyroid or overmedication. Relatively simple "neurocognitive" testing, including the use of standardized mental status scales such as the Mini-Mental State Examination (MMSE), can help screen patients and determine whether further evaluation by a specialist is indicated.
It turns out that changes in the brain probably start to occur about 10-15 years before the onset of Alzheimer's disease symptoms. Dr. Reisa Sperling, Associate Professor of Neurology, Harvard Medical School and Director of Clinical Research, Memory Disorders Unit at Brigham and Women's Hospital, has done extensive research into ways of detecting Alzheimer's early -- even before there is obvious memory loss. She's using special imaging tests called "PET scans" to detect amyloid in the brains of living patients; previously it could only be found at autopsy. She's also using a brain scan called a "functional MRI" that can measure how well the brain is working and spot problems much sooner than the CT's and MRI's of the head that are currently in wide use.
The hope of Dr. Sperling and others is that diagnosing and treating Alzheimer's much earlier will give medications a better chance of working. Dr. Sperling compared preventing and treating Alzheimer's to preventing and treating heart disease. You need to identify patients at high risk and treat them early. If you wait until somebody has had five heart attacks and is in heart failure, giving Lipitor isn't going to do much good.
The "Alzheimer's Disease Neuroimaging Initiative" (ADNI) is a nationwide effort studying scanning and other ways to diagnose patients and see if treatment is working. Eventually simple tests -- perhaps of blood, urine, spinal fluid, or even skin -- may help predict Alzheimer's disease before symptoms begin.
We met Adrian Ivinson, PhD, the Director of the Harvard Neurodiscovery Center. He's not willing to bet the farm that getting rid of amyloid is all that's needed to successfully treat Alzheimer's. He wants alternatives in case anti-amyloid drugs don't work. So, using robots, he's sifting through thousands of chemicals that theoretically might interrupt crucial steps in the development of the disease. "Here we have 150,000 mostly anonymous chemicals," he told me, "but among them may be the starting blocks -- first steps -- to developing drugs." In two weeks, his robots can do what used to take humans a year. He's looking to develop a new pipeline of medications.
Is it possible to prevent Alzheimer's with lifestyle? That is one of the most fascinating areas of investigation and one that is very hard to test scientifically. "What's good for the heart is good for the brain" is a common slogan right now. Elevated cholesterol, diabetes, hypertension, obesity, smoking, poor diet, and lack of exercise have all been linked to an increased risk of Alzheimer's. A recent study found that patients in their late 70's who exercised the most and adhered to a Mediterranean diet had a nine percent risk of Alzheimer's. Those who didn't had a twenty-one percent risk. And research suggests that exercise improves the function of memory centers in the brain.
Despite all the recent progress, there are way too many unanswered questions. Dr. Richard J. Hodes, Director, National Institute on Aging, says the need to make progress in Alzheimer's disease is increasingly urgent: "As the population ages, the numbers of people developing Alzheimer's disease is expected to increase dramatically without more effective interventions soon." How will the country afford the financial and emotional cost? With Alzheimer's, annual Medicare costs triple. And it's impossible to put a price tag on the extraordinarily difficult and heart-wrenching issue of caregiving. To get an idea of what people go through, I suggest you take a look at the message board of the Alzheimer's Association website or check out the caregiving section of the AARP website.
It's clear we need to make curing Alzheimer's disease a national priority and devote sufficient resources to head off what is obviously an impending disaster.
Finally, there is an island where Alzheimer's disease is virtually unheard of. To find out where that is and what clues it might hold for us, tune in tonight to the CBS Evening News with Katie Couric. In the meantime, please click below to see this week's CBS Doc Dot Com, an interview with the Alzheimer's Association Chief Medical Officer, Dr. William Thies: