Anatomy and White Matter Connections of the Superior Frontal Gyrus

Abstract

The superior frontal gyrus (SFG) is an important region implicated in a variety of tasks including motor movement, working memory, resting‐state, and cognitive control. A detailed understanding of the subcortical white matter of the SFG could improve postoperative morbidity related to surgery around this gyrus. Through DSI‐based fiber tractography validated by gross anatomical dissection, we characterized the fiber tracts of the SFG based on their relationships to other well‐known neuroanatomic structures. Diffusion imaging from the Human Connectome Project from 10 healthy adult subjects was used for fiber tractography. We evaluated the SFG as a whole based on its connectivity with other regions. All tracts were mapped in both hemispheres, and a lateralization index was calculated based on resultant tract volumes. Ten cadaveric dissections were then performed using a modified Klingler technique to delineate the location of major tracts integrated within the SFG. We identified four major SFG connections: the frontal aslant tract connecting to the inferior frontal gyrus; the inferior fronto‐occipital fasciculus connecting to the cuneus, lingual gyrus, and superior parietal lobule; the cingulum connecting to the precuneus and parahippocampal gyrus/uncus; and a callosal fiber bundle connecting the SFG bilaterally. The functional networks of the SFG involve a complex series of white matter tracts integrated within the gyrus, including the FAT, IFOF, cingulum, and callosal fibers. Postsurgical outcomes related to this region may be better understood in the context of the fiber‐bundle anatomy highlighted in this study. Clin. Anat. 33:823–832, 2020. © 2019 Wiley Periodicals, Inc.

The supplementary motor area syndrome: a neurosurgical review

“…This may well correspond to the frequently encountered gyral bridges of the precentral sulcus connecting the gyrus with the prefrontal cortex [24]. The superior longitudinal fascicle (SLF I) connects the SMA region with the superior parietal lobule; minor contributions to the inferior frontooccipital fascicle (IFOF) might depart from the superior frontal gyrus as well [3,4,55].…”

Post mortem mapping of connectional anatomy for the validation of diffusion MRI

“…In most cases, however, the results of Klingler’s dissection have been compared to tractography results from in vivo dMRI scans of a different set of subjects (Lawes et al, 2008; Martino et al, 2011; Martino et al, 2013; Goryainov et al, 2017; Latini et al, 2017; Maffei et al, 2018; Briggs et al, 2019,2020,2021; Flores-Justa et al, 2019; Bernard et al, 2020; Li et al, 2020; Shinohara et al, 2020; Egemen et al, 2021; Weiller et al, 2021). In those cases, only qualitative comparisons between tractography and dissection have been possible.…”

Distinct Brain Functional Impairment Patterns Between Suspected Non-Alzheimer Disease Pathophysiology and Alzheimer’s Disease: A Study Combining Static and Dynamic Functional Magnetic Resonance Imaging

“…The decreased brain activity strength and stability in SFG represented the specific impairment pattern of SNAP, which differs from the compensatory function of SFG in AD patients (Maillet and Rajah, 2013;Franzmeier et al, 2018). Functionally, SFG works as the core structure of the ECN and contributes to high cognitive functions including working memory and executive function (du Boisgueheneuc et al, 2006;Alagapan et al, 2019;Briggs et al, 2020). A recent study showed that SNAP (A−T+) had worse frontal lobe function performance than AD (A+T+) in the dementia population (Takenoshita et al, 2019).…”