Brain Imaging and Alzheimer's Disease Prediction

Enhanced early detection of risk for Alzheimer's dementia and other forms of dementia is key to prevention and early intervention.

Brain imaging holds promise as a pre-clinical disease risk assessment tool in Alzeimer's dementia.

Dementia risk has been linked to several brain imaging abnormalities found with magnetic resonance imaging. These abnormalities have included atrophy of the brain hippocampus, medial temporal lobe as well as white matter hyperintensities.

A recent study from France examined whether brain MRI findings can improve Alzheimer's and other dementia prediction over conventional known risk factors.

Here are the key elements of the design of this study:
Subjects: French citizens 65 years and old living at home participating in a longitudinal study of dementia with interviews two, four, six and ten years after baseline interview
Brain imaging: 1.5 Tesla MRI with estimation of white matter lesion volume, hippocampal volume (right and left summed) and total brain volume
Dementia diagnosis: all subjects screened at each interview, with targeted neuropsychological testing and neurologist consensus assessment
Standard dementia risk model variables: age, gender, education, smoking status, alcohol use, functional daily living skills, cognition screening tests, cardiovascular disease, diabetes status, systolic blood pressure and apolipoprotein epsilon 4 status.

The research team found a statistically significant smaller hippocampal and total brain volume at baseline in those later developing dementia. White matter lesion scores showed a trend (p.076) with later dementia.

However, adding the imaging data to the standard dementia risk model did not add statistically to the predictive power for all-cause dementia to the model.

The baseline imaging in this study took place around the year 1999 to 2000. Since then, more specific brain imaging tools targeted towards Alzheimer's have emerged including amyloid plaque markers. 

These enhanced imaging tools may have better power at adding power to our prediction models.

Readers with more interest in this research study can access the free full-text manuscript by clicking on the link in the citation below.

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Stephan BC, Tzourio C, Auriacombe S, Amieva H, Dufouil C, Alpérovitch A, & Kurth T (2015). Usefulness of data from magnetic resonance imaging to improve prediction of dementia: population based cohort study. BMJ (Clinical research ed.), 350 PMID: 26099688