Brain responses to virtual reality visual motion stimulation are affected by neurotic personality traits in patients with persistent postural-perceptual dizziness

OBJECTIVE: Persistent postural perceptual dizziness (PPPD) is a common vestibular disorder of persistent dizziness and unsteadiness, exacerbated by upright posture, self-motion, and exposure to complex or moving visual stimuli. Previous functional magnetic resonance imaging (fMRI) studies found dysfunctional activity in the visual-vestibular cortices in patients with PPPD. Clinical studies showed that the anxiety-related personality traits of neuroticism and introversion may predispose individuals to PPPD. However, the effects of these traits on brain function in patients with PPPD versus healthy controls (HCs) have not been studied. METHODS: To investigate potential differential effects of neuroticism and introversion on functioning of their visuovestibular networks, 15 patients with PPPD and 15 HCs matched for demographics and motion sickness susceptibility underwent fMRI during virtual reality simulation of a rollercoaster ride in vertical and horizontal directions. RESULTS: Neuroticism positively correlated with activity in the inferior frontal gyrus (IFg), and enhanced connectivity between the IFg and occipital regions in patients with PPPD relative to HCs during vertical versus horizontal motion comparison. CONCLUSIONS: In patients with PPPD, neuroticism increased the activity and connectivity of neural networks that mediate attention to visual motion cues during vertical motion. This mechanism may mediate visual control of balance in neurotic patients with PPPD.