Publications

The PREVENT Dementia Programme has a number of publications which have been published across a range of peer reviewed journals and can be accessed through the links in the categories below.

Imaging - View all [9]

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

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

 

Cognition - View all [5]

Higher midlife CAIDE score is associated with increased brain atrophy in a cohort of cognitively healthy middle-aged individuals

Xulin Liu, Maria-Eleni Dounavi, Karen Ritchie, Katie Wells, Craig W. Ritchie, Li Su, Graciela Muniz-Terrera & John T. O’Brien

Journal of Neurology. 2021

DOI: https://doi.org/10.1007/s00415-020-10383-8

Summary
Cardiovascular factors have a strong association with Alzheimer’s disease (AD) and brain atrophy. However, until recently, there has been limited longitudinal research in cognitive healthy middle-aged adults investigating these links. A recent PREVENT Dementia study used data from 167 participants in the PREVENT London cohort, to investigate associations between the CAIDE (Cardiovascular Risk Factors, Aging, and Dementia) score and structural MRI scans at both baseline and 2-year follow up. Participants in the high-risk group (i.e., those with a CAIDE score above 6) were on average, found to have a greater rate of brain atrophy. However, to identify the specific regions and structures driving this atrophy pattern, additional analysis was conducted using voxel based morphometry (VBM).

By using VBM to build on existing findings, the current study found significant associations between risk status determined based on the CAIDE score and grey matter atrophy in several regions, including the temporal, occipital, and fusiform cortex and lingual gyrus at baseline. Longitudinally, the supramarginal gyrus, angular gyrus, precuneus, lateral occipital cortex, superior parietal lobule and cingulate gyrus demonstrated accelerated atrophy over time. Many of these regions belong to the “AD signature cortical region” and are involved in processes such as consciousness and memory. This study highlights the potential for early interventions that focus on modifiable midlife vascular risk factors.

Key terms and abbreviations:

  • Atrophy= the progressive reduction in tissue
  • CAIDE score =Cardiovascular Risk Factors, Aging, and Incidence of Dementia score; A validated midlife dementia risk score, based on several factors, including age, gender, education, blood pressure, cholesterol, body mass index, physical activity and APOEe4 allele carriership.
  • VBM= Voxel based morphometry: An MRI technique that enables investigation of focal differences in anatomy throughout the brain
  • APOEe4 allele= One of the strongest genetic risk factors for Alzheimer’s disease​

Other - View all [6]

Associations between midlife chronic conditions and medication use with anxiety and depression: A cross-sectional analysis of the PREVENT Dementia study

Lucy E Stirland , Sarah Gregory, Tom C Russ, Craig W Ritchie, Graciela Muniz-Terrera
Journal of Comorbidity. 2020
10.1177/1471301218789307

Summary

There is evidence to suggest that brain health is associated with multimorbidity, polypharmacy, depression and anxiety. This study aimed to investigate the interactions between these four-potential dementia-risk factors (depression, anxiety, multimorbidity and polypharmacy) at mid-life.

By analysing data from our London site’s baseline measures, we discovered that having more chronic physical conditions (multimorbidity) was associated with both depression and anxiety in midlife. However, taking more medications (polypharmacy) was only associated with depression, not anxiety.

These findings highlight an interaction between physical health, medication and mental health at midlife. By following participants further over time and evaluating this interaction we may be able to use this information to inform mental and physical health strategies that may possibly prevent dementia in later life.