Testing memory and PET scans helps detect early signs of dementia

Extensive investigation in patients with mild cognitive impairment revealed that results from cognitive examination and brain scans may be an early warning system for developing dementia (Alzheimer's disease).

The study found that out of 85 participants with mild cognitive impairment, those who achieved low results in memory tests and had low levels of glucose exchange in some specific brain regions detected through positron scattering scan (PET scan), which will likely have Alzheimer's disease within two years, is 15 times higher than others in the survey.

The research results of scientists at the University of California, Berkeley, are reported at the International Conference of Alzeheimer's Association held in Vien on July 14 last.This is a big step in the early diagnosis of this impaired disease.

'Not everyone with a mild cognitive impairment will face dementia in the future, so it is very important to determine the risk level of each person with a clinical trial or medical measurement. useful, ' said study leader Susan Landau, a postdoctoral fellow at the Helen Wills Neuroscience Institute and Lawrence Berkeley National Laboratory at the University of California, Berkeley.

'In general, this field is moving towards identifying people at pre-insane stages, including those who have no expression of cognitive decline,' said Dr. William Jagust, member of the Institute of Neuroscience. Helen vWills, who participated in the study. 'By the time a patient is diagnosed with dementia, we can almost no longer intervene to stop, or reverse this impairment. Researchers are trying to determine whether the treatment of patients before the appearance of severe symptoms is more effective. This requires better diagnostic tools today. '

The positron scatter tomography (PET) scan can detect a decrease in glucose exchange associated with impaired cognitive ability, especially in the temporal and parietal lobe located next to and behind the brain, but The region is directly involved in language ability and memory formation. Researchers at the University of California at Berkeley are discovering that brain imaging promises to be a way to detect early signs of dementia. On the left is a PET scan showing normal glucose levels, shown in yellow and red pictures. The level of glucose exchange in the brain will be reduced in patients with mild cognitive impairments (gonad) and those with Alzheimer's dementia (right picture). (Photo: Cindee Madison and Susan Landau, University of California - Berkeley)

In the latest survey, the researchers compared many different measures that are thought to be promising in early detection of dementia. These measures include: examining the score of the test of language memorization, hippocampus size - the part of the brain directly related to the formation of memory, the presence of genes apolipoprotein E4 - a gene associated with high risk of Alzheimer's disease, some of the brain-marrow proteins, and glucose levels detected by PET scan.If the level of glucose exchange is low in a given brain region, it is considered a sign of neurological impairment, mainly due to the loss of synapses in the region.

'What's really new in this study is that we have evaluated all biomarkers in the same object, so it is easy to compare the estimated value of a measure with metrics. left, ' Landau said. 'The language memorization test, which tests memory retention and recall, together with the PET scan method, measures glucose exchange, which are two more effective measurements than the remaining measurements.'

Researchers have shown that other measurements - especially the size of the fish and marrow tissue - are also promising to predict the progression of the disease. However, when reviewing all measurements at the same time, PET scans and memory retention tests are still the two most reliable indicators.Researchers hope to have more complete information indicating which method is the best predictor of dementia within a year. Currently, the survey team is still collecting data.

Previous research conducted by Professor Jagust of the School of Public Health at the University of California at Berkeley discovered that PET scan and magnetic resonance (MRI) can detect neurological changes in people there are symptoms of illness, but then it will develop intellectual impairment, although it is still too early to say whether these people will suffer from Alzheimer's disease.

This study is part of the Alzheimer's Initiative program funded by the National Institute of Aging. The goal of innovation is to find a biomarker for Alzheimer's that can predict those who will suffer from Alzheimer's in the near future.Under ideal conditions, this index will identify the disease very early, even in people who do not have an intellectual impairment.

Jagust leads the study of PET imaging. The Berkeley University study included patients who performed all biomarker measurements.

Refer:

1. Landau et al.Comparing predictors of conversion: Data from the Alzheimer's Disease Neuroimaging Initiative.Alzheimer's and Dementia, 2009;5 (4): P125 DOI: 10.1016 / j.jalz.2009.05.421