Age-related differences in the structural complexity of subcortical and ventricular structures

Area of Science:

• Neuroscience
• Radiology
• Gerontology

Background:

• Age-related volume reduction is a known phenomenon in subcortical brain structures.
• Cortical structure metrics like volume, thickness, and surface area capture distinct interindividual differences.
• Assessing multiple structural measures is crucial for a comprehensive understanding of aging.

Purpose of the Study:

• To compare age-related differences in subcortical and ventricular volume with those found using fractal dimensionality (structural complexity).
• To investigate whether structural complexity offers greater sensitivity to age-related changes than volumetric measures.

Main Methods:

• Analysis of three large datasets comprising nearly 900 individuals across the adult lifespan (18-94 years).
• Comparison of age-related differences in subcortical and ventricular volume against fractal dimensionality.
• Quantification of structural complexity using fractal dimensionality.

Main Results:

• Greater age-related differences were observed in the structural complexity compared to the volume of subcortical structures, especially the caudate and thalamus.
• The structural complexity of ventricular structures did not show a stronger relationship with age than their volume.
• Fractal dimensionality revealed more pronounced age-related changes in specific subcortical regions.

Conclusions:

• Considering shape-related characteristics, such as fractal dimensionality, improves the sensitivity for detecting age-related differences in subcortical brain structures.
• Structural complexity is a valuable metric for understanding neuroanatomical changes associated with aging.
• The findings highlight the importance of multi-faceted approaches in studying brain aging.