Measuring Blood Delivery To The Brain May Help To Predict Risk Of Dementia

Research from Switzerland and the Netherlands has discovered that a brain scanning technique measuring delivery of blood to the brain may help to identify people who are at risk of developing memory problems later on. The study is published on 7 October in the journal Radiology.

The investigation involved 148 people in their 70s who had no reported memory problems at the time the study began. The research also included an additional 65 volunteers who had been diagnosed with mild cognitive impairment (MCI) – a condition where someone has memory problems but these are not as severe as in dementia.

Participants initially took a range of tests for memory function and other traits that are affected by dementia, for example fluency of speech. The volunteers were then given a type of magnetic resonance imaging (MRI) brain scan called arterial spin labelling (ASL). Researchers use ASL to measure the delivery of blood to the brain, known as perfusion.

After 18 months, the volunteers’ memories were reassessed. The researchers found that during this time, 73 of the participants developed some small memory or language problems and 75 people showed no change. The ASL scans taken at the beginning of the study were then compared between people who had some changes in memory during the 18 month time period, those who showed no changes and those who had been diagnosed at the start of the study with MCI. This allowed the researchers to assess whether ASL scans measuring perfusion could accurately detect changes linked to risk of future memory or language problems.

The scans showed that the level of perfusion in people who developed minor memory or language problems was lower than in those who did not have any changes. People with MCI had a similar level of perfusion to those who developed memory problems after the initial assessment. This change was most strongly seen in an area of the brain called the posterior cingulate cortex which is involved in several key functions, including memory retrieval.

Dr Simon Ridley, Head of Research at Alzheimer’s Research UK, the UK’s leading dementia research charity, said:
“There is a growing amount of research into using various brain scanning techniques to accurately detect changes to the brain before dementia symptoms show. This study was very small and the volunteers were not diagnosed with dementia so it is not possible to tell at this stage whether this technique can be used to identify those at risk of the condition. Larger and longer-term studies are needed to determine whether this type of brain scanning has the potential to detect dementia early.

“Current methods can only accurately diagnose the condition long after the damage to the brain has started. There are no drugs available at the moment that can stop or slow dementia. Detecting changes in the brain as early as possible will allow people to enter clinical trials for much-needed new treatments before their symptoms have progressed too far and when they’re most likely to benefit.”