Neuroimaging studies in persistent postural-perceptual dizziness and related disease: a systematic review

Background Persistent Postural-Perceptual Dizziness (PPPD) is one of the most common types of chronic dizziness. The pathogenesis remains unclear. Objective This study aimed to systematically review neuroimaging literature for investigating the central mechanism of PPPD and related disorders. Methods PubMed, EMBASE, Medline, Cochrane, and Web of Science were searched by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The articles analyzing structural and functional neuroimaging features of PPPD and related disorders were selected according to eligibility criteria. Results Fifteen articles, including 4 structural, 10 functional, and 1 multimodal imaging, were eligible for inclusion in this review. The whiter matter alterations in PPPD are not entirely consistent. The changes of grey matter mainly in multisensory vestibular cortices, visual cortex, cerebellum, as well as anxiety-related network. Consistent with structural imaging, functional imaging conducted during the specific tasks or in the resting state has both found abnormal functional activation and connectivity in the vestibular cortex, especially in the parieto-insular vestibular cortex (PIVC), visual cortex, cerebellum, and anxiety-related network in PPPD and related disorder. Conclusions The current review provides up-to-date knowledge and summarizes the possible central mechanism for PPPD and related disorders, and it is helpful to understanding the mechanism of PPPD.