Searching for a better screen for early Alzheimer’s disease, researchers think they have found a marker of change in the brain that precedes the onset of the disease by five to 10 years.
The indicator of trouble to come, they say, is a shift in the levels of specific components of the cerebrospinal fluid (CSF) in the brain and spinal cord. Among patients already diagnosed with mild cognitive impairment, a drop in such levels appears to be a sign of Alzheimer’s years before symptoms develop.
The discovery, published in the January issue of Archives of General Psychiatry, could potentially aid in the use of disease-modifying therapies, which are designed to work best if applied when a patient is still in the early stages of disease.
“These markers can identify individuals at high risk for future [Alzheimer’s disease] at least five to 10 years before conversion to dementia,” study author Dr. Peder Buchhave, of Lund University and Skane University in Sweden, noted in a journal news release. “Hopefully, new therapies that can retard or even halt progression of the disease will soon be available. Together with an early and accurate diagnosis, such therapies could be initiated before neuronal degeneration is too widespread and patients are already demented.”
The study results stem from more than nine years of follow-up to prior research that had involved 137 patients diagnosed with mild cognitive impairment, a mental state that often precedes dementia.
Over the course of the study, nearly 54 percent of the patients went on to develop Alzheimer’s, while another 16 percent were ultimately diagnosed with different forms of dementia.
Memory loss that disrupts daily life
One of the most common signs of Alzheimer’s is memory loss, especially forgetting recently learned information. Others include forgetting important dates or events; asking for the same information over and over; relying on memory aides (e.g., reminder notes or electronic devices) or family members for things they used to handle on their own.
What’s a typical age-related change? Sometimes forgetting names or appointments, but remembering them later.
Challenges in planning or solving problems
Some people may experience changes in their ability to develop and follow a plan or work with numbers. They may have trouble following a familiar recipe or keeping track of monthly bills. They may have difficulty concentrating and take much longer to do things than they did before.
What’s a typical age-related change? Making occasional errors when balancing a checkbook.
Difficulty completing familiar tasks at home, at work or at leisure
People with Alzheimer’s often find it hard to complete daily tasks. Sometimes, people may have trouble driving to a familiar location, managing a budget at work or remembering the rules of a favorite game.
What’s a typical age-related change? Occasionally needing help to use the settings on a microwave or to record a
Specifically, among those who developed Alzheimer’s, the researchers found that key aspects of their cerebrospinal fluid dropped off in the years before. In addition, other fluid properties actually went up.
The study team said that they believe that about nine out of every 10 patients with mild cognitive impairment who experience such fluid shifts will eventually go on to develop Alzheimer’s disease.
Commenting on the study, one expert in the United States said that the new research “provides confirmation of the general concept that CSF can predict the progression of mild memory loss to mild dementia.”
Researchers have found that people whose brains show early signs of Alzheimer’s are twice as likely to fall as healthy people, according to Reuters reports Monday.
The research findings were presented on Sunday at the Alzheimer’s Association International Conference in Paris.
The new study involved 125 older adults, who took brain scans and contributed samples of their spinal fluid, and were also asked to keep a journal of how many times they fell during an eight-month period.
Participants whose scans showed early signs of Alzheimer’s reported an increased risk of falls.
“To our knowledge, this is the first study to identify a risk of increased falls related to a diagnosis of preclinical Alzheimer’s disease,” said the study author Susan Stark, who is also an assistant professor of occupational therapy and neurology at Washington University in St. Louis.
Dr. Sam Gandy, associate director of the Mount Sinai Alzheimer’s Disease Research Center at Mount Sinai School of Medicine in New York City, added that the results of the European study largely echo those of a trial reported by researchers at the U.S. National Institutes of Health in 2010.
He noted that methods of early detection might prove valuable for research into the treatment of Alzheimer’s disease.
“Most new Alzheimer’s drugs are aimed at reducing amyloid [protein plaque] accumulation, and the general consensus is that these drugs will only work at early or presymptomatic stages of disease,” said Gandy, who is also Mount Sinai Chair in Alzheimer’s Disease Research. “The new paper strengthens the likelihood that CSF biomarkers can be useful for identifying that population of subjects with early or presymptomatic disease in order to recruit them into trials.”