BRAIN DYNAMICS OF PERSISTENT PERCEPTUAL POSTURAL DIZZINESS AT REST REVEAL ALTERATIONS IN MULTISENSORY AND MOTOR HUBS

Background: Persistent Perceptual Postural Dizziness (PPPD) is characterized by chronic dizziness and vertigo, impacting everyday life, thought to stem from a disruption in higher-order integration of visual and vestibular signals. Currently, no resolutive treatment is available and the relationship between brain networks and postural alterations is unclear.
Aims: to characterize dynamic brain activity in PPPD patients and its relationships to objective postural measures, stress markers, and clinical self-reports.
Methods: A multi-modal, case-control study of 18 PPPD patients and 20 age- and gender-matched healthy controls (HC) was conducted. Participants underwent a resting state fMRI recording, postural assessments, and saliva sampling. The fMRI dataset was preprocessed using a standard pipeline and analysed using a co-activation patterns (CAPs) approach.
Results: PPPD patients have distinct brain-wide CAPs temporal characteristics compared to controls, seeded from the right temporo-parietal junction, similarly to other FNDs. Additionally, PPPD patients show altered CAPs dynamics seeded from the caudate nucleus and the hippocampus. Instead, no differences are found in CAPs seeded from the vestibular cortex OP2.
Conclusion: This study reveals a dynamic brain signature of altered high-level motor control and multisensory processing, and supports the absence of alterations in vestibular hubs. Next, the relationship between brain CAPs and features of posture, stress, and clinical self-reports will be assessed (ongoing).