Elizabeth McKiernan, Elijah Mak, Maria Eleni-Dounavi, Katie Wells, Craig Ritchie, Guy Williams, Li Su, John O’Brien
Journal of Neurology, Neurosurgery and Psychiatry. 2020
DOI: http://dx.doi.org/10.1136/jnnp-2020-322924
Summary
This study explored the relationship between dementia and cerebral blood flow (CBF) as cerebral hypoperfusion (reduced blood flow in the brain) is characteristic of cognitive impairment and Alzheimer’s disease.
The current study used data from participants’ ASL MRI scans to investigate whether changes in CBF would be seen in our healthy mid life participants, and whether these would be associated with dementia risk, as defined by ones APOEe4 status, Family history and cognitive performance on the COGNITO assessment.
As expected, perfusion (blood flow) was correlated with the APOEe4 allele and participants family history, however not cognitive performance. Differences in the location of the CBF were found in participants carrying the APOEe4 allele compared to participants with a family history of dementia. However, intriguingly, the direction of change was opposite to what was expected. Rather than finding regional hypoperfusion, our at-risk participants showed regional hyperperfusion (increased blood flow) across these areas.
The impact of these findings is not yet clear, however further examination of longitudinal data, including that of full PREVENT-Dementia cohort will help to determine at what point CBF changes occur and what mechanisms are at play.
Key terms and abbreviations:
- ASL MRI= Arterial spin labelling Magnetic Resonance Imaging: a non-invasive perfusion imaging technique for the measurement of cerebral blood flow
- APOEe4 allele= One of the possible genetic risk factors for dementia
