Frontal Aslant Tract and Its Role in Language: A Journey Through Tractographies and Dissections

-BACKGROUND: The frontal aslant tract (FAT) is a bilateral tract located within each frontal lobe. It connects the supplementary motor area in the superior frontal gyrus with the pars opercularis in the inferior frontal gyrus. There is a new and broader conceptualization of this tract called the extended FAT (eFAT). The eFAT tract role is believed to be related to several brain functions, including verbal fluency as one of its main domains.-METHODS: Tractographies were performed by using DSI Studio software on a template of 1065 healthy human brains. The tract was observed in a three-dimensional plane. The Laterality Index was calculated based on the length, volume, and diameter of fibers. A t test was per-formed to verify the statistical significance of global asymmetry. The results were compared with cadaveric dissections performed according to the Klingler technique. An illustrative case enlightens the neurosurgical applica-tion of this anatomic knowledge.-RESULTS: The eFAT communicates the superior frontal gyrus with the Broca area (within the left hemisphere) or its contralateral homotopic area within the nondominant hemisphere. We measured the commisural fibers, traced cingulate, striatal, and insular connections and showed the existence of new frontal projections as part of the main structure. The tract did not show a significant asymmetry between the hemispheres.-CONCLUSIONS: The tract was successfully recon-structed, focusing on its morphology and anatomic characteristics.

Automated summary

The frontal aslant tract (FAT) connects the supplementary motor area with the pars opercularis and is now known as the extended FAT (eFAT). The eFAT is believed to play a role in various brain functions, including verbal fluency. This study successfully reconstructed and analyzed the morphology and anatomical characteristics of the eFAT.