Regional hyperperfusion in cognitively normal APOE ε4 allele carriers in mid-life: analysis of ASL pilot data from the PREVENT-Dementia cohort

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



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


Midlife alcohol consumption and longitudinal brain atrophy: the PREVENT-Dementia study

Michael Firbank, John O’Brien, Karen Ritchie, Katie Wells, Guy Williams, Li Su, Craig Ritchie

Journal of Neurology. 2020



Watch: Study Update Message

With study visits remaining on temporary pause due to the ongoing COVID-19 pandemic, we want to take this opportunity to update all our dedicated research participants on the latest progress and to share our thoughts on getting the study back up and running.

Craig Ritchie, Chief Investigator for the PREVENT Dementia Programme, has recorded the below video message for all our members.


Most importantly, we would like to thank all of our research participants for their continued commitment to PREVENT and for their patience at this time. We are working hard behind the scenes to determine when we can reopen the study. We are doing so in line with the latest government guidance across each of our sites, at all times keeping the safety of our participants as our number one priority.

Restarting a major research project safely involves many moving parts and unfortunately, at present we are not able to communicate any precise dates for the resumption of study visits. We do however promise to keep in touch regularly as soon as we have any updates to share.

We would also encourage anyone to please do get in touch with us if we can help with anything at all at this time.