Mendelian Randomization Reveals Causal Links Between Vertigo Types and structural characteristics of specific brain regions

Background Vertigo is a common clinical symptom that involves multiple neurobiological processes; however, its exact mechanism remains elusive. In neuroimaging studies focusing on vertigo and its central correlation, potential reverse causality and unmeasured confounding factors frequently introduce biases. Furthermore, the causal relationship between vertigo and specific neuroimaging features is not yet established. Employing the Mendelian randomization (MR) method can provide a more precise understanding of the causal relationships between vertigo and changes in brain structure and function. Methods Based on the large-scale genome-wide association study data from UK Biobank, this study employed bidirectional MR analysis to explore the causal relationships between brain MRI features associated with vertigo and the condition itself. The research focuses on brain imaging-derived phenotypes (IDPs) such as whole brain volume, and the volumes of both gray matter and white matter. Results In this study, MR analysis revealed that for benign paroxysmal positional vertigo (BPV), an increase in specific brain regions such as BA-exvivo lh volume BA2, aparc-Desikan rh area rostralmiddlefrontal, IDP dMRI TBSS L2 Corticospinal tract R, and rfMRI connectivity (ICA100 edge 1323) was significantly correlated with a reduction in BPV risk. Conversely, an increase in IDP dMRI TBSS MD Cingulum hippocampus L and rfMRI connectivity (ICA100 edge 82 and 357) was associated with an increased risk of BPV. For peripheral vertigo (PERIPHVERTIGO), an increase in aparc-a2009s rh volume Pole-occipital significantly increased the risk. For general vertigo (VERTIGO), increases in IDP dMRI TBSS FA Superior fronto-occipital fasciculus R and rfMRI connectivity (ICA100 edge 236) were associated with increased risk, while a decrease in rfMRI connectivity (ICA100 edge 184) was associated with decreased risk. For central vertigo (VERTIGOCENT), an increase in rfMRI connectivity (ICA100 edge 1387) and BA-exvivo rh thickness BA4a significantly reduced the risk, whereas an increase in aparc-Desikan rh area annularcingulate significantly increased the risk. Conclusion The genetic susceptibility of the vertigo network, extending from the vestibular labyrinth in the cerebellum and brainstem to the cerebral cortex, is causally related to an increase in white matter volume and total brain volume. Volume changes in several cortical regions may suggest a higher risk of vertigo; thus, further studies of causal inference at the sub-brain regional level are strongly recommended. Our results offer genetic evidence that helps elucidate the underlying pathophysiological mechanisms of neuroanatomical abnormalities related to vertigo.