We classify cancer into different stages and now researchers are doing something similar with Alzheimer’s disease. It could mean a much earlier diagnosis for many.
Sister Barbara Schlatter has been a nun for 50 years.
“I entered the convent in 1963,” Sister Barbara told Ivanhoe.
She’s helped a lot of people during that time, but two people she couldn’t help were her parents. They both passed away with Alzheimer’s. Now, Sister Barbara worries about her aging brain.
“When I can’t get a word, I think, uh oh, is this it?” Sister Barbara said.
Recently, investigators found a way to “stage” the disease during a period they call “pre-clinical Alzheimer’s.”
“The data suggests that, the pathology starts anywhere from 10 to 20 years before any sign of clinical symptoms,” Anne Fagan, PhD, Research Professor, Washington University in St. Louis, told Ivanhoe.
Researchers divide preclinical Alzheimer’s into three stages based on results from spinal fluid and imaging tests.
They studied 311 patients. The preclinical stages are based on biomarkers that indicates how much amyloid plaque and tangle-related proteins are found in the brain and whether or not patients eventually go on to show symptoms of memory decline.
“Once you get dementia, that is actually the end stage,” Dr. Fagan said.
Sister Barbara hopes the research will one day save others from the heartache she felt watching her parents fade away.
About 31 percent of the 311 patients studied fell into one of the stages. This percentage matched findings from autopsy studies, suggesting that Alzheimer’s starts long before symptoms develop.
Researchers believe patients with preclinical Alzheimer’s could be an important target for new therapies. Interestingly, the investigators found individuals with preclinical Alzheimer’s were six times more likely to die over the next decade, but they aren’t sure why.
BACKGROUND: Alzheimer’s disease is an irreparable brain condition that slowly affects brain functioning, eventually leading to dementia. The disease is named after Dr. Alois Alzheimer, who, in 1906, while studying the brain of a recently-deceased woman, found abnormal clumps and tangled bundles of fibers in her brain. These are now called amyloid plaques and neurofibrillary tangles, respectively, and make up two of the three main features of Alzheimer’s. The other is the breakdown of neurons, or connections between nerves, in the brain. Together, these three conditions affect key areas of the brain, including the hippocampus, responsible for memories. As more neurons run less efficiently, they eventually die, and brain tissue beings to shrink. (Source: http://www.nia.nih.gov/alzheimers/topics/alzheimers-basics?utm_source=ad_fact_sheet&utm_medium=web&utm_content=basics&utm_campaign=top_promo_box)
CAUSES: There is no known cause or cure for Alzheimer’s. Despite this, the most important factor to consider with Alzheimer’s is that it is a progressive disease. The biggest risk factor for the disease is age. Every five years after the age of 65, your risk of developing the disease doubles, and after age 85 the risk of the disease is 50 percent. Another risk factor is family history. Those with family members who had the disease have a higher risk, and those with multiple family members who had it are at an even higher risk. There is also a belief that head trauma may play a role in causing the disease later in life. Research is also growing relating to heart health and the disease, perhaps linking cardiovascular health and an increased risk of the disease. (Source: http://www.alz.org/alzheimers_disease_causes_risk_factors.asp)
NEW TECHNOLOGY: Starting in 2011, the National Institute on Aging together with Alzheimer’s Association, proposed a classification system for the disease. Researchers at Washington University studied the need for such a classification, and not only validated the system, but also developed another system to define what they called preclinical Alzheimer’s. Those with preclinical Alzheimer’s may seem cognitively normal, but have certain biomarkers believed to associated with Alzheimer’s later in life. Split into three stages, preclinical Alzheimer’s is the start of a potentially decades long process that ends with the presence of symptoms of Alzheimer’s or dementia. (Source: http://news.wustl.edu/news/Pages/25876.aspx)
Anne Fagan, PhD, Research Professor, Washington University in St. Louis, talks about staging Alzheimer’s.
How early can you detect Alzheimer’s?
Dr. Fagan: That is the question of the day. We don’t know exactly, however, we estimate, and the data suggests, that the underlying brain pathology start to develop anywhere from 10 to 20 years before any sign of clinical symptoms, any sign of memory loss or thinking problems.
What’s the earliest you’ve seen it?
Dr. Fagan: We have seen biomarker evidence of pathology in people as young as in their fifties. And these changes can be seen in cognitively normal people. We don’t know if or when they’re going to develop dementia. So that’s why longitudinal biomarker studies are going to be very informative, to be able to actually look within a person over time as they progress through their disease, to see how early we can detect their pathology, and what happens to these pathologic changes over time. We will be able to compare the changes we see in their cerebrospinal fluid with the imaging changes observed in their brain as well as when they start developing symptoms.
How does the brain physically change?