New brain scan analysis may help predict stroke-related dementia

A new kind of MRI brain scan analysis could spot patients who have suffered damage to the small blood vessels in the brain that can predict cognitive problems and even dementia, research from Goldsmiths, University of London suggests.

‘Small vessel disease’ occurs when a stroke or other disease damages tiny blood vessels in the brain. This condition is the most common cause of thinking problems, such as planning, organising information and processing speed, and can lead to dementia. Although early treatment could help patients at risk, no effective test is available to identify those most at risk.

A new study co-authored by Goldsmiths’ Dr Rebecca Charlton evaluated the accuracy of diffusion tensor imaging (DTI) - a MRI analysis technique - in predicting thinking problems and dementia related to small vessel disease.

A single scan measured the brain in fine detail to reveal damaged areas. By comparing these images to a healthy person’s, researchers were able to classify the brain into areas of healthy versus damaged tissue.

Results showed that participants with the most brain damage were much more likely to develop thinking problems. The analysis also helped predict three-fourths of the dementia cases that occurred during the study.

A report of the research has been published in Stroke, a journal of the American Stroke Association, a division of the American Heart Association.

Dr Charlton, Reader in Psychology at Goldsmiths, said: “We have developed a useful tool for monitoring patients at risk of developing dementia and could target those who need early treatment.

“This advanced MRI analysis offers a highly accurate and sensitive marker of small vessel disease severity in a single measure that can be used to detect who will and will not go on the develop dementia in a five-year period.”

The study included 99 patients with small vessel disease caused by ischemic stroke, a type of stroke that blocks the blood vessels deep within the brain. Slightly more than one-third were female, with an average age of 68, and most were Caucasian. All participants were enrolled in the St George's Cognition and Neuroimaging in Stroke (SCANS) study from 2007 to 2015 in London.

Participants received the MRI scans annually for three years and thinking tests annually for five years. Eighteen participants developed dementia during the study, with an average time to onset of approximately three years and four months.

The healthy brain scans used for comparison were from one individual and may not represent the true range of all healthy brains. In addition, the study’s relatively small number of participants all had small vessel disease resulting from one type of stroke, so the results may not apply to people with different forms of the disease. 

Research was funded by the charity Research into Aging, Alzheimer’s Research UK, and the English National Institute for Health. The Wellcome Trust, the English National Institute of Health Research, and the Clinical Stroke Research Network supported the SCANS research study.

The research team were based at Goldsmiths, St George’s University of London, Imperial College NHS Trust, UCL, University of Cambridge, St George’s NHS Healthcare Trust and King’s College London. 

Predicting Dementia in Cerebral Small Vessel Disease using an Automatic Diffusion Tensor Image Segmentation Technique by Owen Williams, Eva Zeestraten, Philip Benjamin, Christian Lambert, Andrew Lawrence, Andrew MacKinnon, Robin Morris, Hugh Markus, Thomas Barrick, and Rebecca Charlton, is published in the journal Stroke on Thursday 12 September 2019 and available online via AHA Journals. 

This story is based on an original press release from the American Heart Association.