Evaluation of the white matter integrity in morbidly obese patients before and after bariatric surgery; a diffusion tensor imaging study.

Purpose: To investigate the difference in FA (Fractional anisotropy), ADC (Apparent diffusion coefficient), RD (Radial diffusivity) and AD (axial diffusivity) values of white matter (WM) tracts in morbidly obese subjects before and after bariatric surgery (BS).

Materials And Methods: A group of thirty-nine morbidly obese subjects are evaluated before and 4-6 months after BS. ADC, FA, RD and AD values of 17 distinct neuroanatomic localizations are measured and DTI parameters are analyzed.

Results: Following the BS, the patients' mean BMI decreased from 47.665.21 to 31.723.97. A significant difference is displayed between the pre-surgery and post-surgery FA values of SLF, SFOF, ALIC, fornix, ILF, CST, MCP (p = 0.010, p < 0.001, p = 0.048, p = 0.014, p = 0.012, p = 0.012, p = 0.040 respectively). Following BS, decrease in FA values in the mentioned areas are detected. ADC values obtained from MCP are significantly lower in the post-BS period compared to pre-BS period (p = 0.018). There was a statistically significant difference between the pre-surgery and post-surgery AD values of SLF, SFOF, ILF, ALIC, EC, CST, and MCP (p = 0.001, p = 0.022, p = 0.001, p = 0.011, p = 0.001, p = 0.000, p = 0.000, respectively). Following the BS, AD values of the SLF, SFOF, ILF, ALIC, EC, CST, and MCP are decreased. RD values measured from GCC are significantly lower in the post-BS period compared to pre-BS period (p = 0.008).

Conclusion: Our study supported the hypothesis of the BS-induced reversibility of the low-grade inflammation in WM tracts in the morbidly obese group following BS. Our DTI results may represent the subacute period findings of the reversal of low-grade inflammation after BS.