Alzheimer's Research Making Leaps and Bounds

From the WebMD Archives

July 7, 2000 -- "There's something wrong with my mind, but I don't know what," was how Lottie Sowinski's grandmother described what they both would soon know was Alzheimer's disease.

Similarly, the medical community knows what Alzheimer's ultimately does to people's minds, but they don't know what causes Alzheimer's, or how to prevent or stop it. About four million Americans suffer from this degenerative brain disease that usually begins after age 65.

"We are sitting on the edge of an epidemic of Alzheimer's disease," says Bill Thies, PhD, because in the next 40 years, "the baby boom population bubble, which has dominated our society since it was born," is about to go through the age where it is the most susceptible to Alzheimer's disease.

However, experts see some signs of hope. Researchers from around the world will present their findings at the World Alzheimer Congress 2000 in Washington, which starts this Sunday, and will include the latest results from early human trials of an Alzheimer's disease vaccine that was shown to be effective in mice.

Thies, the Alzheimer's Association vice president of medical and scientific affairs, says if we don't become better at stopping the disease, then the number of people with the disease by 2040 could grow to 14 million.

"If you couple that with the fact that [Alzheimer's] is expensive and causes a lot of disruption in families that has the potential to not only bankrupt us, but exhaust us emotionally as well, [these] are all alternatives that nobody wants to see," Thies says.

Caring for a loved one with Alzheimer's disease can be traumatic, something Sowinski says she dealt with through the help of support groups. As the disease eats away at the thought functions of the brain, it slowly turns victims back into children, incapable of caring for themselves. The patient may suffer from sleeplessness, wandering, agitation, and depression. But the slow erosion of memories, past and present, can often be the hardest symptom to deal with, for all concerned.

Sowinski says her grandmother is "at the stage now where at least 45% of the time, she looks at me and knows that she knows me, but she doesn't know I'm her granddaughter."

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That may be the past and present of Alzheimer's disease, but it is not necessarily the future. Research in the pipeline is cutting away at the disease from various angles.

"There are so many bright lights now compared to 25 years ago," says Marcelle Morrison-Bogorad, PhD. Back then, Alzheimer's was often thought to be an inevitable, normal part of aging. Morrison-Bogorad, the associate director of the National Institute on Aging's Neuroscience and Neuropsychology of Aging program, agrees that the possible growth of Alzheimer's disease could be phenomenal in the next decades.

But, like Thies, she's optimistic. "The way research is going, I think we'll have a much better handle on Alzheimer's disease long before 2050," Morrison-Bogorad tells WebMD.

Thies tells WebMD the missing pieces of the jigsaw puzzle are falling into place on a daily basis. "... But there's still some holes in there about what the initial [problem is] ... that starts the disease," and, he says, we still don't understand the genetics of it.

Morrison-Bogorad says Alzheimer's disease is believed to be spurred by a complex mixture of things that could contribute to the risk of getting the disease -- such as age, genetics, head injuries, high levels of cholesterol in the blood, or heart disease. "It's random luck of the draw," she says.

It's probable that both an environmental and a genetic set of factors determine whether a person gets the disease because two different types of brain abnormalities are characteristics of Alzheimer's. Researchers are unsure if the disease causes these abnormalities, or if the abnormalities cause the disease.

There are two medications in trials now that try to reduce one of these abnormalities -- the plaque build-up in the brain of a protein called beta amyloid.

One drug inhibits an enzyme that's a key step in the formation of beta amyloid. "It's like a cholesterol-lowering" drug, according to Thies. "The other trial is the vaccine trial, where a purified beta-amyloid is given, and its been shown in animals ... that you can decrease the amyloid burden on the brain by giving this vaccination," says Thies.

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There is also a lot of work underway on the genetic front. For example, it's known that people who carry a gene that expresses a specific protein called "ApoE4" have a higher likelihood of developing the disease -- but researchers are still unsure why most people who get Alzheimer's disease haven't inherited the gene.

Some scientists are taking their research down to the molecular level, and looking at the cellular abnormalities that could lead to the disease. Researchers at the University of Virginia suggest that abnormal mitochondrial genes -- which are responsible for cells' converting food into usable energy -- may increase the damage caused by naturally occurring elements in the body called oxygen-free radicals. These free radicals, in turn, start a process that ends up creating beta amyloid plaque build-up in the brain.

The importance of this kind of research is that it opens up new avenues for possibly stopping the development of Alzheimer's. "Time will tell," says Morrison-Bogorad.

Another drug being tested, memantine, comes at Alzheimer's disease from a different angle, according to Thies. Memantine is currently used in some parts of the world to treat Parkinson's disease and dementia in the elderly, among other conditions. The drug inhibits the destruction of nerve cells. Results from a trial using this drug on Alzheimer's patients will also be presented at the upcoming World Alzheimer's Congress.

Currently, the only drugs approved for Alzheimer's disease work to help nerves transmit impulses in the brain. The class of drugs includes Cognex (tacrine), Aricept (donepezil), Exelon (rivastigmine), and one under consideration by the FDA called galantamine, the latest in the evolution of current therapy.

Thies says all these drugs only help treat symptoms of the disease, such as problems with thinking and remembering, in people with mild to moderate Alzheimer's disease. They only last for a short while, and they are not a cure, according to Thies.

However, Thies says there are current trials testing substances like vitamin E (an antioxidant, which prevents damage from free radicals), estrogen, and even the herb ginkgo biloba, to fight the progression of the disease. Morrison-Bogorad also notes the need for research into using anti-inflammatory drugs like ibuprofen to fight Alzheimer's disease.

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"So, one of the things we have to do," she says, "is good [human experiments], so we can know if over-the-counter medications work." That's important because if "things that people already take [can be used for Alzheimer's disease], they don't have to be developed."

All in all, it's an "incredibly exciting time ... only limited by the imagination of scientists," Morrison-Bogorad says

For more information from WebMD, visit our Diseases and Conditions Alzheimer's page.

WebMD Health News Reviewed by Jacqueline Brooks, MBBCH, MRCPsych
© 2000 WebMD, Inc. All rights reserved.

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