UCLA Study shows how early diagnosis of Alzheimer's helps patients

October 04, 2002

For the first time, UCLA researchers have calculated how early diagnosis of Alzheimer's using positron emission tomography (PET) improves the treatment results of dementia patients. When used in conjunction with conventional diagnostic methods, PET can cut unnecessary drug therapy by half and reduce months in a nursing home by 60 percent. The latest issue of the journal of Molecular Imaging and Biology reports the study findings.

"With the introduction of promising new drugs to treat the mildest stages of Alzheimer's disease, diagnosing patients early is more important than ever before," said Dr. Dan Silverman, principal investigator, UCLA assistant professor of molecular and medical pharmacology and associate director of imaging for the UCLA Alzheimer's Disease Center.

"PET boosts the number of Alzheimer's cases that are detected early and can substantially reduce the number of elderly patients falsely diagnosed with Alzheimer's disease," he said.

Silverman and his colleagues modeled the value of two diagnostic strategies for evaluating whether Alzheimer's disease was responsible for early signs of dementia in elderly patients.

The first approach followed the American Academy of Neurology (AAN) 2001 recommendations for clinical evaluation of dementia.

The second approach followed the AAN recommendations, but also incorporated PET to measure the patient's brain metabolic pattern for evidence of early Alzheimer-type damage.

Patients in both groups were then treated according to the AAN 2001 recommendations for management of dementia.

Silverman and his associates studied both strategies for their range of accuracy in diagnosing Alzheimer's disease. The differences proved dramatic.

"Although both approaches accurately diagnosed most Alzheimer's patients, we found that the appropriate use of PET could reduce erroneous diagnoses by half," Silverman said.

The UCLA team examined the best current medical literature endorsed by the AAN on Alzheimer's diagnosis. For every 100 patients suffering early cognitive decline, the literature showed that conventional methods would have falsely attributed the patients' symptoms to early Alzheimer's disease in 23 cases, and overlooked eight cases of Alzheimer's.

Silverman's team then used clinical benefit-risk analysis to show that incorporating the use of PET in these patients' clinical evaluations would have prevented 11 of the 23 false positives and five of the eight false negatives.

Using these figures, Silverman next calculated how much PET would reduce months of unnecessary nursing-home care.

UCLA researchers knew that early drug therapy typically slows the cognitive decline caused by Alzheimer's disease by nine to 18 months without significantly affecting life expectancy. Multiplying by a conservative value of nine months, Silverman estimated that accurate identification of Alzheimer's disease in 5 percent more people would diminish institutionalization by at least 45 months for every 100 patients.

In the 11 per 100 people spared from a false diagnosis with Alzheimer's disease, Silverman and his colleagues estimated that adding PET to the patients' clinical evaluations would prevent more than 130 months per year of needless drug therapy per 100 people.

Although effective when taken properly, drugs to postpone Alzheimer's disease are costly and can cause significant gastrointestinal side effects, such as nausea, vomiting and diarrhea.

Overall, the benefit of introducing PET into dementia patients' assessments corresponded to a 62 percent decrease in avoidable months of nursing-home care and a 48 percent drop in unnecessary drug treatment.

"It's worse to diagnose someone with Alzheimer's later than earlier, because we now have drugs available to help delay progression of the disease," Silverman said. "Postponing drug therapy by as little as six months in people with Alzheimer's may have long-term consequences for their cognitive function."

At least 30 percent of people 85 and older suffer from Alzheimer's disease, the most common form of dementia. The disease exacts an enormous financial burden on families and society. In the United States alone, more than $90 billion will be spent on Alzheimer's-related expenses each year, according to the National Institute for Aging.

University of California - Los Angeles

Related Dementia Articles from Brightsurf:

The danger of Z-drugs for dementia patients
Strong sleeping pills known as 'Z-drugs' are linked with an increased risk of falls, fractures and stroke among people with dementia, according to new research.

The long road to dementia
Alzheimer's disease develops over decades. It begins with a fatal chain reaction in which masses of misfolded beta-amyloid proteins are produced that in the end literally flood the brain.

Why people with dementia go missing
People with dementia are more likely to go missing in areas where road networks are dense, complicated and disordered - according to new research from the University of East Anglia.

PTSD may double risk of dementia
People who have experienced post-traumatic stress disorder (PTSD) are up to twice as likely to develop dementia later in life, according to a new study by UCL researchers, published in the British Journal of Psychiatry.

Dementia education
School-based dementia education could deliver much needed empathy and understanding for older generations as new research from the University of South Australia shows it can significantly improve dementia knowledge and awareness among younger generations.

Building dementia friendly churches
A project to help church communities become more 'dementia friendly' has had a significant impact across the country.

A "feeling" for dementia?
A research team led by the DZNE concludes that personal perception can be an important indicator for the early detection of Alzheimer's disease.

New biomarker for dementia diagnosis
Medical researchers in the UK and Australia have identified a new marker which could support the search for novel preventative and therapeutic treatments for dementia.

Digital solutions for dementia care
Telehealth delivery of dementia care in the home can be as effective as face-to-face home visit services if carers and recipients take advantage of the technologies available, Australian researchers say.

Despite a marked reduction in the prevalence of dementia, the number of people with dementia is set to double by 2050 according to new Alzheimer Europe report
Today, at a European Parliament lunch debate, Alzheimer Europe launched a new report presenting the findings of its collaborative analysis of recent prevalence studies and setting out updated prevalence rates for dementia in Europe.

Read More: Dementia News and Dementia Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.