Experts have warned that blockages in the drainage pathways in the brain could be a warning sign of Alzheimer’s disease.
Experts from Singapore’s Nanyang Technological University (NTU) have said in their research that the ‘drainage pathways’ around blood vessels are filled with cerebrospinal fluid, which helps to remove nerve waste, but hardening of the arteries and high blood pressure can disrupt this pathway and cause waste to accumulate in the arteries. When this happens, these drainage pathways (perivascular spaces) expand.
The researchers said that expanded perivascular spaces (EPVS) are more common in people who are showing early signs of Alzheimer’s.
According to Associate Professor Nagendran Kandiya, who led the study and is affiliated with NTU’s Lee Kong Chian School of Medicine, these abnormal brain changes can be seen in routine MRI scans that are used to assess memory and cognitive decline, so their identification could help with the early diagnosis of Alzheimer’s with current methods without additional testing and costs.
According to study co-author and LKC Medicine student Justin Ong, early diagnosis of Alzheimer’s is crucial because it allows doctors to provide timely treatment, which can slow down the progression of problems such as memory loss, slow thinking speed and mood changes.
He said that the relationship between EPVS and Alzheimer’s was previously unclear, so the NTU team compared EPVS with other recognized indicators of Alzheimer’s disease.
The report said the study also fills an important gap because it includes people from different ethnic groups in Singapore. Many studies on Alzheimer’s focus on Western populations, but their results do not apply to all ethnic groups.
Researcher Professor Kandiya said that according to past research, the rate of a major risk gene associated with Alzheimer’s, apolipoprotein E4, is about 50 to 60 percent in Caucasian dementia patients, while this rate is less than 20 percent in Singaporean dementia patients.
The study studied 979 people in Singapore, comparing people with mild cognitive impairment with those without such impairment, and based on MRI scans, it was found that people with mild cognitive impairment were more likely to have EPVS.
According to the report, the researchers also examined 7 biomarkers associated with Alzheimer’s. In people who had EPVS, 4 out of 7 biomarkers were found to be higher, including amyloid plaques and tau tangles, which indicate a higher risk of Alzheimer’s.
Experts also examined damage to white matter, which is a common indicator of Alzheimer’s, and this damage was found to be associated with 6 out of 7 biomarkers. However, in people with mild cognitive impairment, Alzheimer’s biomarkers were more strongly associated with EPVS than with white matter damage, indicating that EPVS may be an early sign of Alzheimer’s.
According to Professor Kandiya, these results are very important clinically. Although white matter damage is more commonly used in the diagnosis of dementia because it can be easily identified on MRI scans, our results suggest that dilated perivascular spaces are uniquely important in identifying early signs of Alzheimer’s.
They said that this link between EPVS and Alzheimer’s suggests that in the future MRI could become an accessible tool that could help diagnose Alzheimer’s early and slow the disease before it progresses further.
The researchers said they will continue to monitor the people who were included in the study to see how many of them eventually develop Alzheimer’s and to further confirm whether EPVS can truly predict dementia risk.