Brain white matter microstructure is associated with susceptibility to motion‐induced nausea

Abstract

Nausea is associated with significant morbidity, and there is a wide range in the propensity of individuals to experience nausea. The neural basis of this heterogeneity in nausea susceptibility is poorly understood. Our previous functional magnetic resonance imaging (fMRI) study in healthy adults showed that a visual motion stimulus caused activation in the right MT+/V5 area, and that increased sensation of nausea due to this stimulus was associated with increased activation in the right anterior insula. For the current study, we hypothesized that individual differences in visual motion-induced nausea are due to microstructural differences in the inferior fronto-occipital fasciculus (IFOF), the white-matter tract connecting the right visual motion processing area (MT+/V5) and right anterior insula. To test this hypothesis, we acquired diffusion tensor imaging data from 30 healthy adults who were subsequently dichotomized into high and low nausea susceptibility groups based on the Motion Sickness Susceptibility Scale. We quantified diffusion along the IFOF for each subject based on axial diffusivity (AD); radial diffusivity (RD), mean diffusivity (MD) and fractional anisotropy (FA), and evaluated between-group differences in these diffusion metrics. Subjects with high susceptibility to nausea rated significantly (p<0.001) higher nausea intensity to visual motion stimuli and had significantly (p<0.05) lower AD and MD along the right IFOF compared to subjects with low susceptibility to nausea. This result suggests that differences in white-matter microstructure within tracts connecting visual motion and nausea-processing brain areas may contribute to nausea susceptibility or may have resulted from an increased history of nausea episodes.

Corticospinal Tract Diffusion Abnormalities Early After Stroke Predict Motor Outcome

“…33 Furthermore, AD but not FA of white matter involved in transmitting information about visual motion differentiates adults with or without susceptibility to motion-induced nausea. 34 Collectively, these studies suggest that AD of functionally-relevant white matter tracts can provide greater clinical insight about some neurological conditions compared to FA.…”

Motion sickness increases functional connectivity between visual motion and nausea-associated brain regions

“…A follow-up diffusion tensor imaging study noted altered microstructure along the inferior fronto-occipital fasciculus, the white matter pathway connecting MT+/V5 with anterior insula, in subjects reporting high susceptibility to motion sickness [22]. In addition, a recent combined autonomic/fMRI analysis noted that greater sympathetic modulation (indexed by skin conductance response) during nausea perception was associated with fMRI signal in anterior insula [10].…”

Visually induced nausea causes characteristic changes in cerebral, autonomic and endocrine function in humans

“…) and fMRI (Napadow et al . , b ). In agreement with our findings, although using a different but comparable technique, Miller et al .…”

“…This is because in contrast to the plethora of functional neuroimaging studies that have focused on the identification of the cortical regions responsible for other gastrointestinal sensations, such as pain, there is a relative paucity of literature devoted to describing the areas involved in the genesis, maintenance and subsequent resolution of nausea (Napadow et al . a , b ). This paucity is probably due to significant methodological challenges in studying nausea in the confines of the brain imaging environment.…”