Structural neural connectivity of the vestibular nuclei in the human brain: a diffusion tensor imaging study

Many animal studies have reported on the neural connectivity of the vestibular nuclei (VN). However, little is reported on the structural neural connectivity of the VN in the human brain. In this study, we attempted to investigate the structural neural connectivity of the VN in 37 healthy subjects using diffusion tensor tractography. A seed region of interest was placed on the isolated VN using probabilistic diffusion tensor tractography. Connectivity was defined as the incidence of connection between the VN and each brain region. The VN showed 100% connectivity with the cerebellum, thalamus, oculomotor nucleus, trochlear nucleus, abducens nucleus, and reticular formation, irrespective of thresholds. At the threshold of 5 streamlines, the VN showed connectivity with the primary motor cortex (95.9%), primary somatosensory cortex (90.5%), premotor cortex (87.8%), hypothalamus (86.5%), posterior parietal cortex (75.7%), lateral prefrontal cortex (70.3%), ventromedial prefrontal cortex (51.4%), and orbitofrontal cortex (40.5%), respectively. These results suggest that the VN showed high connectivity with the cerebellum, thalamus, oculomotor nucleus, trochlear nucleus, abducens nucleus, and reticular formation, which are the brain regions related to the functions of the VN, including equilibrium, control of eye movements, conscious perception of movement, and spatial orientation.