Alterations in neuroplasticity and functional connectivity of striatal subregions in Bell’s palsy patients after acupuncture

Background: Bell's palsy (BP) is an acute facial palsy caused by the inflammation of the facial nerve. Previous research indicates that the striatum may be involved following acute peripheral nerve injury, and acupuncture is a recognized treatment for BP. However, it remains unclear whether the striatum is functionally engaged during the recovery process with acupuncture. Method: Using resting-state functional MRI (fMRI), we investigated striatum-related neural activity in BP patients by measuring two key metrics of local brain function: regional homogeneity (ReHo, reflecting local neural synchrony) and fractional amplitude of low-frequency fluctuations (fALFFs, reflecting the intensity of spontaneous neural activity). We further examined corticostriatal and internal striatal functional connectivity. Patients underwent fMRI scans before and immediately after (15 min following needle withdrawal) an acupuncture treatment session to capture dynamic changes. Results: The post-treatment scan was associated with significant alterations in both ReHo and fALFFs, including increased fALFFs in the left postcentral gyrus and the precentral gyrus and increased ReHo in the right cerebellum (Crus2). Several striatal subregions also exhibited significantly enhanced internal connectivity. Conclusion: Our results indicate that the striatum undergoes functional alterations during the recovery period, which may provide preliminary insight into neural processes associated with treatment for BP.