Widespread age-related differences in the human brain microstructure revealed by quantitative magnetic resonance imaging

Neurobiology of Aging, 2014 · DOI: http://dx.doi.org/10.1016/j.neurobiolaging.2014.02.008 · Published: February 15, 2014

Neuroimaging Aging Neurology

Simple Explanation

This study investigates how the brain's structure changes with age in healthy individuals using quantitative MRI. The goal is to distinguish normal aging from neurodegenerative diseases. The researchers looked at markers for myelination and iron levels in the brain, which are known to be affected by aging. They analyzed MRI scans from 138 healthy adults aged 19 to 75. The study found that as people age, there is a general pattern of brain tissue breakdown, particularly in the white matter, which is linked to myelin. Iron levels also change in specific brain regions.

Study Duration

Not specified

Participants

138 healthy volunteers (age range: 19e75 years)

Evidence Level

Level 3, Cross-sectional study

Key Findings

1
Significant demyelination occurs primarily in the white matter, with anatomically specific age-related differences in myelination observed.
2
Iron levels significantly increase in the basal ganglia, red nucleus, and extensive cortical regions with age.
3
Iron levels decreased along the superior occipitofrontal fascicle and optic radiation.

Research Summary

The study uses quantitative multiparameter mapping (MPM) to identify widespread age-related differences in the microstructure of the human brain. MPM quantifies R1, R2*, MT, and PD*. Significant demyelination was observed in the white matter, particularly in frontal and parietal regions. The genu of the corpus callosum showed greater age-related differences than the splenium. Iron levels increased in the basal ganglia, red nucleus, and cortical regions, while decreasing in the superior occipitofrontal fascicle and optic radiation. These changes provide insight into the neurobiology of aging.

Practical Implications

Differentiating Healthy Aging from Disease

The results help establish a quantitative baseline for distinguishing between normal aging and pathological neurodegeneration.

Understanding Age-Related Microstructural Changes

The findings provide insight into the specific ways that brain microstructure changes with age, affecting myelination and iron levels.

Potential for Monitoring Disease Progression

The quantitative MPM approach offers a way to monitor disease progression and treatment response in neurodegenerative disorders.

Study Limitations

1
The study only considered linear age-related differences, potentially missing nonlinear trajectories.
2
The sampling was sparse in the 35 to 55 age range, making the analysis more sensitive to linear differences.
3
The effective proton density measure (PD*) used does not account for multi-exponential signal decay and has residual T2* weighting.

Your Feedback

Was this summary helpful?

Back to Neuroimaging