Special anatomy series: Updates in structural, functional, and clinical relevance of the corpus callosum: What new imaging techniques have revealed

Introduction: The human corpus callosum (CC) is a primary commissural tract in the brain and serves as a major communication pathway between the cerebral hemispheres. Objective: The objective of this paper is to enhance understanding of the anatomic structure, topographic organization, function, and clinical relevance of the CC. Methods: To achieve this, we reviewed the literature for pertinent histological, anatomical, and advanced neuroimaging studies, and the findings were synthesized to provide the basis for the creation of novel color-coded schematic diagrams. Results: A standard midline sagittal magnetic resonance image was used to illustrate schematics of the CC partitioned into seven anatomic segments and the vascular supply of the CC from the anterior and posterior cerebral circulation. We further highlighted the microstructural features across each segment of the CC as well as the topographical organization of callosal fibers in connection with cortical regions of the brain. Finally, we applied these visual summaries as a guide for the discussion of the clinical relevance of the CC. Summary: Understanding the microstructural properties and related functional capacities of the CC is critical to understanding its clinical relevance. Consequently, having a clear and concise visual representation of complex callosal microstructural and anatomical features may be useful to the rehabilitation clinician in understanding overall clinical patterns seen in healthy populations across all ages and patients with neurologic injuries and pathologies with possible callosal involvement.