The latest research in detection and diagnosis
By Kirsty Marais | Wednesday 11 March 2015
There has been lots of discussion, both within the popular press and the research community, about the importance of early detection and diagnosis of the diseases that cause dementia. While some question the merits of an early dementia diagnosis, as there are currently few effective treatment options, there are many ways that people can benefit from a timely and accurate diagnosis.
These include access to current treatments and support, the ability to make decisions about future care, and also the opportunity to get involved in research studies. For those with rarer dementias, who may have struggled to get an accurate diagnosis, it may mark the end of a period of intense anxiety.
Currently there is no diagnostic test that is 100% accurate and doctors use a series of different approaches to make a diagnosis. Many of these include ruling out other potential causes of memory or behaviour problems e.g. stress, stroke or a brain tumour.
However there is a real need to advance the current detection techniques we have for the diseases that cause dementia – not just to help diagnose them earlier but to more accurately distinguish between different diseases like Alzheimer’s and dementia with Lewy bodies.
As research into new treatments gains momentum it will be increasingly important for researchers to have accurate ways to detect and track the earliest changes in the brain, when future treatments are likely to bring the largest benefits.
Cutting edge brain scanning
At the Alzheimer’s Research UK Conference today, we heard from Prof Nick Fox, an expert in brain imaging at University College London. He spoke about the great importance of brain imaging, not only for helping diagnose patients, but for understanding diseases like Alzheimer’s. New precision scanning techniques are now able to compare images of the brain at different time-points, to show patterns of brain shrinkage over time. This type of scanning provides valuable insights for helping researchers to understand the progression of the disease.
He also highlighted how people who carry rare genes that cause early-onset Alzheimer’s have helped provide new insight into our understanding of the disease – something that’s been underlined in the news today with the story of 39-year-old Chris Graham, who has volunteered to take part in research after being diagnosed with a genetic form of Alzheimer’s. Studies involving this group of people have been particularly important with recent advances in brain imaging techniques, including brain scans that detect the hallmark Alzheimer’s protein, amyloid, in the brain. While not currently being widely used by doctors in the clinic, these scans are being used by researchers to understand the disease, and have been used to plot how amyloid accumulates in the brain over time.
This research has shown that amyloid build-up starts over a decade before symptoms appear, and this knowledge is behind recent moves to test anti-amyloid treatments in clinical trials at a much earlier stage in the disease. Brain imaging techniques are already revealing important information about previous clinical trials, and will be increasingly important for monitoring the effectiveness of the next generation of treatments in trials.
Another speaker Prof Frederik Barkhof came from the VU University Medical Centre in the Netherlands to share the latest developments in MRI scanning to detect changes in blood vessels inside the brain. Damage to blood vessels in the brain becomes more apparent as we age and has been linked to poorer memory and thinking skills. This damage can show up as small ‘white flecks’ on MRI brain scans and Prof Barkhof’s team is using this information to learn more about how these plumbing changes in the brain contribute to both vascular dementia and Alzheimer’s. He described imaging research which shows that problems with the carotid arteries, which supply blood to the brain, appear to affect other brain changes associated with Alzheimer’s. It’s interesting work, suggesting that the vascular system could be an important target in the search for treatments to fight the disease.
Chemical signals in blood and spinal fluid
Another fast-moving area of research into detection is the search for biochemical fingerprints in blood or spinal fluid that could detect and track diseases like Alzheimer’s. We’ve blogged previously about progress in developing a blood test that could identify those most likely to develop the disease and today we heard from Prof Henrik Zetterberg from the University of Gothenburg in Sweden who gave an overview on progress in research looking at spinal fluid. He explained that tests to look at levels of two hallmark Alzheimer’s proteins, amyloid and tau, in spinal fluid seem to be able to distinguish with some accuracy between those with and without Alzheimer’s, as well as predict those most likely to progress on to Alzheimer’s from early memory problems. There is lots of work underway to standardise methods using this technique, which will be important for it to become more widely used as a method to detect diseases like Alzheimer’s, either in the clinic or as part of clinical trials.
This is a fast-paced area of research and as Prof Fox emphasised in his talk, it really needs to be. We must make sure that our ability to accurately detect dementia early keeps up with progress in developing new clinical trials. These two developments must go hand in hand if we have the best chance of changing the lives of people with dementia.