Structural changes in brain regions involved in executive-control and self-referential processing after sleeve gastrectomy in obese patients

Abstract

Obesity-related brain gray (GM) and white matter (WM) abnormalities have been reported in regions associated with food-intake control and cognitive-emotional regulation. Bariatric surgery (BS) is the most effective way to treat obesity and induce structural recovery of GM/WM density and WM integrity. It is unknown whether the surgery can promote structural changes in cortical morphometry along with weight-loss. Structural Magnetic Resonance Imaging and surface-based morphometry analysis were used to investigate BS-induced alterations of cortical morphometry in 22 obese participants who were tested before and one month post-BS, and in 21 obese controls (Ctr) without surgery who were tested twice (Baseline and One-month). Results showed that fasting plasma ghrelin, insulin, and leptin levels were significantly reduced post-BS (P < 0.001). Post-BS there were significant decreases in cortical thickness in the precuneus (P < 0.05) that were associated with decreases in BMI. There were also significant increases post-BS in cortical thickness in middle (MFG) and superior (SFG) frontal gyri, superior temporal gyrus (STG), insula and ventral anterior cingulate cortex (vACC); and in cortical volume in left postcentral gyrus (PostCen) and vACC (P < 0.05). Post-BS changes in SFG were associated with decreases in BMI. These findings suggest that structural changes in brain regions implicated in executive control and self-referential processing are associated with BS-induced weight-loss.

Laparoscopic sleeve gastrectomy induces sustained changes in gray and white matter brain volumes and resting functional connectivity in obese patients

“…Tuulari et al [7] reported similar findings, where bariatric surgery induced increased GM densities in several brain regions. Furthermore, surface-based morphometry analysis, which is a brain morphometric technique used to construct and analyze surfaces that represent structural boundaries within the brain, revealed postLSG increases in cortical thickness in the INS and ACC [11]. These suggest a causal link between weight loss and brain tissue integrity, which might reflect improved brain cognitive performance along with weight loss postsurgery [9].…”

“…Those aforementioned studies provided evidence that bariatric surgery (i.e., LSG) promoted alterations in both brain structures and function along with concomitant weight loss [4,11,14,15]. It remains unclear whether LSG-induced changes in RSFC are associated with structural alterations.…”

Bariatric Surgery and Brain Health—A Longitudinal Observational Study Investigating the Effect of Surgery on Cognitive Function and Gray Matter Volume

“…Tuulari et al [58], for instance, found an increase of global white matter density six months after surgery, as well as an increase of GM volume in occipital and inferior temporal brain regions. Another study by Liu et al [60] investigated cortical thickness before and one month after BARS and reported a number of increases and decreases in various brain regions, which are thought to be implicated in executive control and self-referential processing, including the frontal, temporal, and cingulate cortex.…”

Neuroimaging correlates of cognitive changes after bariatric surgery

“…Tuulari et al [15] using voxel-based morphometry showed widespread baseline gray matter densities in 47 obese patients relative to controls, and 6 months after bariatric surgery there was significantly increased white matter volume and focal occipital lobe and inferior temporal lobe gray matter increases. Liu et al [16] found that 1 month after bariatric surgery there were significant changes in cortical thickness for several brain regions implicated in executive control and self-referential processing. Our results may differ from these prior studies due to differences in the analysis technique used or because of differences in subject baseline characteristics.…”

“…Prior neuroimaging studies using magnetic resonance imaging (MRI) have shown regional and global structural brain differences, such as gray matter thickness, between obese patients and their nonobese counterparts, and changes in these measures after bariatric surgery [14][15][16], but have not associated these structural changes with improvements in cognitive function. Single-photon energy computed tomography brain perfusion has been used to demonstrate that obesity can be associated with reduced prefrontal cortex blood flow [17]; but the study did not assess longitudinal changes of blood flow from weight loss or correlate them with cognitive function.…”