Tuesday, April 15, 2008

Less than 2% of Early-Onset Dementia is Alzheimer’s

A great deal of press was generated a few years ago when The U.S. 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 Alzheimer’s Association specifically defined early-onset dementia as Alzheimer’s developed at an age below 65. Many in the research community rolled their eyes as this was unlikely to be the case and was unnecessarily alarmist and not based on scientific evidence.

Dr. Brendan J. Kelley, a neurologist at the Mayo Clinic in Rochester, Minnesota has conducted a study focused exclusively on 235 patients diagnosed with a form of dementia diagnosed 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. The results of the study is that early onset dementia is the result of inflammatory and neurodegenerative diseases such as multiple sclerosis, Huntington's, lupus or HIV infection.

The study’s data indicated that approximately:

33% of the cases were classified as frontotemporal dementia
20% of the cases of dementia were resulting from autoimmune and inflammatory disorders
10% of the cases of dementia resulted from metabolic disorders
20% could not be directly attributed to any cause.

Dr. Kelley is attempting to identify markers that would offer better diagnostic methods for early-onset dementia. He rightly believes that these types of dementia may be treated by combating the underlying disease mechanism.

Regrettably, this is just further evidence that dementia research has taken a back seat to Alzheimer’s research. Of the 5,5MM so-called Alzheimer’s patients in the United States, epidemiological evidence would argue a population that includes misclassified cases of vascular dementia, pharmaceutical dementia, Lewy Body Dementia, frontotemporal dementia, as well as, depression. Complicating matters is that many patients present with overlapping and co-morbid conditions. Research indicates that only 60% have Alzheimer’s involvement and only approximately 30% of patients present with Alzheimer’s solely. The tragedy is that many misclassified patients could benefit through known clinical interventions and that much of the research that has been conducted over the last two decades does not account for the true nature of dementia in the elderly.

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