Is It A Case of Early Alzheimer's? Maybe Not
< Apr. 16, 2008 > -- New research suggests that the root cause of early-onset dementia is usually not Alzheimer's, but rather another neurodegenerative or autoimmune disorder.
The study authors acknowledge that - age aside - the most common forms of dementia are Alzheimer's disease, vascular dementia, and the brain damage-associated condition known as Lewy body dementia. However, their current work indicates that among patients below the age of 45, the problem is much more likely to be traced back to diseases such as multiple sclerosis, Huntington's, lupus, or HIV infection, among others.
"This is really a novel finding, because there hasn't really been a study that's looked at young-onset dementia in this way," says study author Dr. Brendan J. Kelley, a neurologist at the Mayo Clinic in Rochester, Minn. "And the message is that young-onset dementia is generally not related to Alzheimer's."
45 and Under Group Least Likely to Have Alzheimer's
The US Administration on Aging highlights 2006 estimates released by the Alzheimer's Association, which indicate that between 220,000 and 640,000 American men and women currently suffer from early-onset dementia. The association specifically defines "early-onset Alzheimer's" as referring to cases that develop before the age of 65.
However, in their study, Dr. Kelley and his team focused exclusively on 235 patients diagnosed with a form of dementia occurring between the ages of 17 and 45 - citing statistics suggesting that 12 in 100,000 people develop some form of early-onset dementia before the age of 45.
Patients in the study sample had sought care at the Mayo Clinic between 1996 and 2006, and all had normal cognitive function prior to their dementia diagnosis.
A medical record analysis revealed that despite the fact that most adult dementia is a function of Alzheimer's, less than 2 percent of the cases among the under-45 group was attributable to that disease.
Dr. Kelley and his colleagues found that other neurodegenerative conditions - such as frontotemporal dementia, a group of diseases commonly misdiagnosed as Alzheimer's - were at play in almost one-third of the cases.
Disease Markers May Help Identify Various Types of Dementia
Autoimmune and inflammatory disorders - such as MS - accounted for just over 20 percent of the dementia cases. Metabolic abnormalities were cited in just over 10 percent of the diagnoses, while for another 20 percent, no cause for dementia could be established.
Dr. Kelley says his work is ongoing. And he adds that he and his colleagues are now trying to identify specific disease markers for early-onset dementia to help physicians distinguish those cases prompted by causes other than Alzheimer's.
"Because some of the other disorders linked to early dementia have treatable profiles that allow targeting not just of the symptoms but of the underlying disease process," he notes. "So, we really should be looking to identify them quickly when they are the cause, because the research suggests that treatment could result in a direct improvement of the patient's cognition and behavior."
Can Dementia Be Treated So It Goes Into Remission?
Dr. Greg M. Cole, associate director of the Alzheimer's Disease Research Center at the UCLA David Geffen School of Medicine, describes the findings as "interesting, but not completely unexpected."
"We know that Alzheimer's gets rarer and rarer the younger you go," he says. "So, when you're focused as this study is on people between 17 and 45 - really before middle-age - it's more likely you'll find some other cause for the dementia, which can be a variety of different things."
"But if you're looking at these other autoimmune causes - multiple sclerosis, lupus, HIV - the real question is, can you treat any of this?" Dr. Cole wonders. "Because you can get lupus and MS to go into remission. So, in this case, if patients are getting dementia caused by either disease, can the dementia also go into remission? If they can get that to happen, that would be very interesting."
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More on Dementia
According to the National Institute of Neurological Disorders and Stroke (NINDS), dementia is not a specific disease. It is a term that describes a collection of symptoms that can be caused by a number of disorders that affect the brain.
People with dementia do not think clearly and this interferes with their normal activities and relationships.
Dementia symptoms appear with the following diseases:
Physicians have identified other conditions that can cause dementia or dementia-like symptoms including:
Although it is common in very elderly individuals, dementia is not a normal part of the aging process.
Medications to treat Alzheimer’s disease and some other progressive dementias are available. Although these drugs do not stop the disease from progressing or reverse existing brain damage, they can improve symptoms and slow disease progression.
This may improve an individual’s quality of life, ease the burden on caregivers, or delay admission to a nursing home. Researchers are also conducting studies to determine if these medications may be useful for treating other types of dementia.
Some diseases that cause dementia, such as Alzheimer’s disease or Huntington’s disease, can lead to a progressive loss of mental functions. Other types of dementia can be halted or reversed with appropriate treatment.
People with moderate or advanced dementia typically need round-the-clock care and supervision to prevent them from harming themselves or others. They also may need assistance with daily activities such as eating, bathing, and dressing.
Always consult your physician for more information.