Short-term Effect of Acupuncture on Functional Brain Connectivity of Bell's Palsy

Abstract

Purpose: Bell’s palsy (BP), a peripheral idiopathic disease affecting facial nerve (CN VII), has been cured with acupuncture for long time. This study investigates acupuncture short-term effects on sensorimotor network (SMN) and default-mode network (DMN) during resting states for BP patients. Methods: Two resting state functional MRI (preand postacupuncture) were performed over 35 healthy and 58 BP patients (Some participated multiple times). Patients’ scans were assigned to three different groups based on disease duration (D) and House-Brackmann score (HBS) as early (HB>I, D I, D>14days), recovered (HB=I, D>14days) groups. Patients were treated using acupuncture (three times/week). Dual regression-ICA approach for brain functional connectivity analysis was performed. All individual maps of right-sided BP patients were flipped around y-axis. Results: In early group, SMN connectivity to bilateral SI, MI and SII; ipsilateral (left) insula; and contralateral (right) cuneus and lingual gyrus were decreased in post-acup, while it was increased with contralateral SI, MI, Insula and SII in late group. For DMN, early group had increased connectivity in bilateral dorsolateral prefrontal cortex, cerebellum, and anterior cingulate cortex; ipsilateral insula and ventro-lateral prefrontal cortex; and contralateral DMN area (dorso-medial pre frontal cortex, angular gyrus and para-hippocampus) in post-acup. Recovered group had increased connectivity in motor area (bilateral cerebellum, ipsilateral MI, premotor) and facial processing area (superior temporal gyrus). Conclusion: Acupuncture decreased SMN connectivity to bilateral sensori-motor regions in early stage and increased it to contralateral side in late stage to compensate the brain connectivity changes that we found in other study of BP. Also, DMN connectivity was increased with DMN area itself, motor, emotional and cognitive areasmaybe to improvemotor function. In addition, DMN connectivity to motor and facial processing areas was increased in recovered stage because there is still negative neuroplasticity effect to be treated by acupuncture. Contact: Abdalla Z. Mohamed, bio.abdallah2012@gmail.com