Research led by Dr Matt Paradise at the Centre for Healthy Brain Ageing (CHeBA), UNSW Sydney, has developed a rating scale to better understand the effects of certain aspects of cerebrovascular disease and its association with dementia. Findings were published in the Journal of the Neurological Sciences.
The research, which assessed 414 community dwelling older adults aged between 70 and 90 found that perivascular spaces are a common MRI finding in the elderly.
Perivascular spaces surround small blood vessels as they penetrate into the brain tissue. They have a normal physiological role in homeostasis of the cerebral environment, including draining of tissue fluid and removal of toxins. With improved imaging technology and better resolution of MRI, they are increasingly seen in routine scans, particularly when dilated.
“Dilation of perivascular spaces may be due to a number of pathological processes including hypertension, obstruction, inflammation and atrophy,” said Dr Paradise.
Dilated perivascular spaces are also a feature of small vessel disease – cerebrovascular disease affecting small blood vessels.
Co-author on the research and Co-Director of the Centre for Healthy Brain Ageing (CHeBA), Professor Perminder Sachdev, said that there has been increasing recognition of the many deleterious effects of small vessel disease including its association with cognitive impairment and dementia.
“Accurate identification and quantification of perivascular spaces may therefore help us better understand these processes and help with diagnosis and prognosis of dementia,” said Professor Sachdev.
Currently, there is no widely used rating scale for perivascular spaces and the researchers found poor inter-rater reliability when using existing scales.
“We therefore developed our own visually rated perivascular space scale, based on the number of perivascular spaces in two representative slices, where they are likely to occur,” said Dr Paradise.
The new rating scale is easy to use, quick, has good psychometric properties and performs better than existing scales in community dwelling older individuals.
Although further studies are needed to validate the scale in more diverse populations with greater cerebrovascular burden, the hope is that other research groups will adopt the new scale when looking at the associations between perivascular spaces and cognitive impairment.
“Perivascular spaces may turn out to be a useful biomarker of cerebrovascular disease and help inform dementia diagnosis and treatment in the future,” said Dr Paradise.