Frontal aslant tract: Anatomy and tractography description in the Mexican population

Abstract

Background: The aim of the study was to describe the origin, course, and termination of frontal aslant tract (FAT) in the Mexican population of neurosurgical referral centers. Methods: From January 2018 to May 2019, we analyzed 50 magnetic resonance imaging (MRI) studies in diffusion tensor imaging sequences of patients of the National Institute of Neurology and Neurosurgery “Manuel Velasco Suárez.” Five brains were fixed by the Klingler method and dissected in the neurosurgery laboratory of the Hospital Civil de Guadalajara to identify the origin, trajectory, and ending of the FAT. Results: FAT was identified in 100% of the MRI and brain dissections. The origin of the FAT was observed in 63% from the supplementary premotor area, 24% from the supplementary motor area, and 13% in both areas. Its ending was observed in the pars opercularis in 81%, pars triangularis in 9%, and in both pars opercularis and ventral premotor area in 10% in the magnetic resonance images, with a left side predominance. In the hemispheres dissections, the origin of FAT was identified in 60% from the supplementary premotor area, 20% from the supplementary motor area, and 20% in both areas. Its ending was observed in the pars opercularis in 80% and the pars triangularis in 20%. It was not identified as an individual fascicle connected with the contralateral FAT. Conclusion: In the Mexican population, FAT has a left predominance; it is originated more frequently in the supplementary premotor area, passes dorsal to the superior longitudinal fascicle II and the superior periinsular sulcus, and ends more commonly in the pars opercularis.

Probabilistic Coverage of the Frontal Aslant Tract in Young Adults: Insights into Individual Variability, Lateralization, and Language Functions

“…Although previous studies have shed light on the structure and function of the FAT, a populationbased investigation of individual differences in FAT remains to be conducted. While several studies have suggested that the pars opercularis is the primary source of connectivity in the FAT 3,6 , other studies have shown that in some cases, the pars triangularis may be the primary contributor of fibers 7 . These discrepancies suggest that there could be substantial individual variation in the distribution of FAT fibers.…”

Probabilistic coverage of the frontal aslant tract in young adults: Insights into individual variability, lateralization, and language functions

“…Although previous studies have shed light on the structure and function of the FAT, a population‐based investigation of individual differences in FAT remains to be conducted. While several studies have suggested that the pars opercularis is the primary source of connectivity in the FAT (Catani et al, 2012 ; Szmuda et al, 2017 ), other studies have shown that in some cases, the pars triangularis may be the primary contributor of fibers (Marian‐Magaña et al, 2022 ). These discrepancies suggest that there could be substantial individual variation in the distribution of FAT fibers.…”