To investigate spontaneous brain activity and functional connectivity alterations in patients with persistent postural-perceptual dizziness (PPPD).
Approach:
Participants: Twenty-one patients with PPPD and 23 healthy controls underwent 3.0 Tesla resting-state functional magnetic resonance imaging.
Methods: Regional spontaneous brain activity and local synchronization were assessed using low-frequency fluctuation and regional homogeneity measures. Seed-based functional connectivity analyses were performed using specific brain regions.
Analysis: Between-group differences were tested with age and sex as covariates, and exploratory clinical–imaging correlation analyses were conducted in the patient group.
Key Findings:
Patients with PPPD showed altered spontaneous activity and local synchronization in the cerebellum, occipital and temporal cortices, frontal and parietal regions, anterior cingulate cortex, insula, precuneus, and motor-related areas.
Functional connectivity analyses revealed abnormal connections among the insula, caudate nucleus, prefrontal cortex, supplementary motor area, anterior and posterior cingulate cortices, precuneus, fusiform gyrus, and superior temporal gyrus.
Clinical–imaging correlation analyses indicated associations between disease duration, dizziness handicap, anxiety severity, and cognitive performance with functional changes in visual, cerebellar, supplementary motor, superior parietal, cuneus, and precuneus regions.
Interpretation:
PPPD involves distributed functional abnormalities in brain regions responsible for vestibular and postural integration, visual–spatial processing, emotional and salience monitoring, motor regulation, and self-referential cognitive processing.
Limitations:
The study is cross-sectional, limiting causal inferences.
Sample size may restrict the generalizability of findings.
Conclusion:
PPPD may be better understood as a distributed network disorder involving disrupted visual–vestibular–postural integration and maladaptive functional reorganization.
