Researchers at Johns Hopkins University have found that changes in the ratio of two proteins in spinal fluid may predict whether people will develop memory problems, many years before the symptoms appear. The research is published on 16 October in the journal Neurology.
The relative inaccessibility of the human brain can pose a real challenge to clinicians trying to make an accurate diagnosis of the diseases that cause dementia. While current diagnostic methods often couple memory and thinking tests with brain scans, researchers have been investigating whether specific changes in blood or spinal fluid could also act as an indicator of diseases like Alzheimer’s.
To investigate this further, the team used spinal fluid samples collected from 265 volunteers with an average age of 57. The samples were collected between 1995 and 2005 and participants were given memory and thinking tests, along with a physical exam, every year during the period and again from 2009 onwards.
The team found that the ratio of two proteins in spinal fluid – called tau and amyloid – could be a predictor of mild cognitive impairment (MCI). MCI is a condition characterised by memory and thinking problems not severe enough to be diagnosed as dementia, but is a risk factor for the development of Alzheimer’s. The spinal fluid changes could predict MCI more than five years before symptoms became apparent.
Dr Laura Phipps of Alzheimer’s Research UK, the UK’s leading dementia research charity, said:
“We know that amyloid and tau are key proteins involved in Alzheimer’s, but we still need to know more about how each contributes to the disease. This study found that changes in amyloid and tau in spinal fluid may predict mild cognitive impairment, but not everyone with this condition will go on to develop Alzheimer’s. Any potential new diagnostic tool for memory problems would need rigorous testing in people before it could be used in the clinic, to check it was sensitive and accurate. While this research suggests a useful avenue for investigation, there is a long way to go before it could be available in the clinic.
“Alzheimer’s Research UK is currently investing in research to develop accurate ways to detect or track diseases like Alzheimer’s at their early stages. Characterising the early changes in the brain that precede conditions like MCI and Alzheimer’s can help researchers to understand what triggers them, provide people with timely access to information and support, and aid the development of new and effective treatments.”