Mid-Sagittal MRI Morphometry of the Corpus Callosum in High-Altitude Tibetan Populations: A Novel Quantitative...

The corpus callosum plays a crucial role in interhemispheric communication. Although callosal circularity has demonstrated promise as a marker for differentiating a range of neurological conditions, research investigating the impact of chronic high-altitude hypoxia on corpus callosum morphology remains limited. This study aims to investigate the circularity and eccentricity of the corpus callosum in Tibetan adults, as well as their interrelationship, to assess how the hypoxic environment influences corpus callosum morphology.

This study enrolled 262 Tibetan adults. MRI scans were employed to obtain measurements of callosal length, height, perimeter, and area, from which circularity and eccentricity values were derived. Statistical analyses involved Mann-Whitney U tests to evaluate sex differences, partial correlation analyses to assess age effects, and quadratic regression models to elucidate the relationship between circularity and eccentricity.

The analysis revealed no statistically significant sex differences in either circularity or eccentricity. Circularity exhibited a biphasic, inverted U-shaped trajectory across the lifespan, reaching a peak at 22.8 years, with men attaining peak values earlier than women. Moreover, a significant quadratic relationship between circularity and eccentricity was identified, delineating a critical threshold at an eccentricity value of 0.939.

Although the high-altitude hypoxic environment does not markedly alter the overall stability of callosal circularity and eccentricity, deviations from normative values may serve as sensitive biomarkers for neurological anomalies. These novel morphological metrics provide valuable quantitative insights into corpus callosum integrity, potentially facilitating the early detection of neurodegenerative and neuropsychiatric disorders.