Effect of Stellate Ganglion Block on the Cerebral Cortex: A Functional Magnetic Resonance Imaging Study

The objective of this study is to investigate the neural activities in the human brain after stellate ganglion block (SGB) treatment using functional magnetic resonance imaging (fMRI). Thirteen healthy female volunteers from the local community participated in the study. An echo planar imaging sequence for fMRI has used to examine the effect on the cerebral cortex before and after SGB stimulation at 1.5T MRI. We used 6 mL of 1 % mepivacaine hydrochloride as a local anesthetic. Two control groups with and without a saline injection were also included. FMRI data were processed using statistical parametric mapping. The blood-oxygen-level-dependent fMRI signal intensities increased in contralateral anterior cingulate cortex, hypothalamus, ventral putamen, and parahippocampal gyrus after SGB stimulation, while the signal intensities had decreased in contralateral thalamus and dorsal putamen, and ipsilateral caudate nucleus. In the saline control group, the signal intensities in ipsilateral posterior putamen and superior temporal gyrus and both insular cortices have increased significantly. The present study could show the changes by SGB in the several important brain areas associated with sympathetic nervous system. The non-invasive and repeatable imaging technique of fMRI could provide some useful information for better understanding of the neural mechanisms involved in SGB treatments.