White matter variability, cognition, and disorders: a systematic review.

Area of Science:

• Neuroscience
• Neuroimaging
• Computational Anatomy

Background:

• Inter-individual anatomical variations are often overlooked in brain studies, despite their impact on function and treatment.
• Cerebral white matter tracts are crucial for functional organization, and their study can reveal structural and functional variability.

Purpose of the Study:

• To systematically review studies correlating cognitive functions and clinical symptoms with individual white matter tracts using diffusion tractography.
• To assess the potential of tract-function correlations as biomarkers for precision medicine.

Main Methods:

• Systematic literature review of studies employing diffusion tractography to analyze white matter tracts.
• Analysis of associations between individual tracts, cognitive functions, and clinical symptoms across neurology, psychiatry, and healthy populations.

Main Results:

• Diffusion tractography is sensitive to inter-individual variability in brain structure and function.
• Commonly studied tracts may not be the most sensitive to cognitive functions or pathologies.
• Tract-function correlations often involve multiple cognitive domains or pathologies, and laterality is frequently unreported.

Conclusions:

• Despite methodological limitations like potential bias and neglect of laterality, tract-function correlations show promise for identifying biomarkers in precision medicine.
• Characterizing variations in brain anatomy and functional organization through tractography can predict patient resilience and recovery.