Quantitative analysis of representation asymmetry in human cadaveric white matter dissection literature

Human cadaveric white matter dissection studies constitute a fundamental component of microsurgical neuroanatomy. However, whether individual white matter pathways are represented uniformly across the cadaveric dissection literature has not been systematically quantified. This study aimed to construct a tract-level anatomical dataset and to examine how major white matter pathways are represented across published human cadaveric dissection studies, with particular attention to fiber-class differences and potential methodological sources of uneven representation. A literature-based quantitative anatomical analysis was conducted using published human cadaveric cerebral white matter dissection studies identified through a structured study selection process. Twenty predefined major white matter pathways were classified into association, projection, and commissural fiber systems. Tract demonstration status was extracted and organized into a standardized representation matrix. Tract-level prevalence, fiber-class differences, study-level asymmetry, effect size estimates, and inequality-based representation metrics were analyzed using nonparametric statistical methods. Forty-two studies, encompassing 691 cerebral hemispheres, were included. Tract representation varied considerably across anatomically distinct fiber systems. Association pathways demonstrated greater overall representation frequencies compared with commissural systems, while nonparametric analyses confirmed significant differences among fiber classes (Kruskal-Wallis H = 9.27, p = 0.0097). The inferior fronto-occipital fasciculus demonstrated the highest overall representation prevalence, whereas deep projection and smaller commissural pathways, particularly the auditory radiation, posterior commissure, and habenular commissure, exhibited markedly limited representation. The present study shows that tract representation in the cadaveric white matter dissection literature is uneven and appears to be shaped by both anatomical organization and methodological factors, favoring superficially accessible pathways. These findings provide a novel quantitative framework for evaluating representation patterns, methodological bias, and tract-level variability within microsurgical white matter dissection research.