Research Of Functional And Effective Connectivity Of Bell’s Palsy Based On FMRI

Functional magnetic resonance imaging (fMRI) is an important tool for studying the rehabilitation mechanism of Bell’s palsy (BP). At present, researchers study BP by using functional connectivity. Functional connectivity only indirectly measures the correlation between brain regions. It is not able to reflect dynamic interactions between brain regions. So, it is insufficient to investigate the BP’s brain by simply using functional connectivity. Therefore, this article combines methods of functional and effective connectivity to study the brain network of BP.In this article, the relationship was studied between the functional connectivity strength of anterior cingulate cortex (ACC) and facial paralysis rehabilitation process. First, bilateral ACC was located as seed points based on the activation map in healthy individuals. Functional connectivity for bilateral ACC was then calculated with the whole brain based on the method of correlation analysis. The correlation between the strength of ACC’s connectivity with the rehabilitation process was finally acquired with analysis of covariance. The results demonstrated that functional connectivity of ACC ipsilateral to lesioned side was enforced as the recovery time prolonged. These findings suggested that the enforced connectivity modulated brain functional reorganization in the rehabilitation process, which played important role in rehabilitation of BP.In order to further study the brain information interaction of BP, this study examines the effective connectivity of facial motor system based on structural equation modeling (SEM). SEM was used to derive an optimal effective connectivity model in healthy individuals, and then this model was applied to BP dataset. The results illustrated that effective connectivity changed among facial motor regions, and also effective connectivity from facial motor system to lesioned-side cerebellum was disordered in BP. These findings suggested that characterizing the deficits in effective connectivity of top-down processes in BP might help clinical therapies by individually targeting specific neural pathway.