Krebs K, et al. - Researchers performed a pilot study to ascertain if a series of sphenopalatine ganglion (SPG) blockade treatments modulate the functional connectivity within the salience and central executive network (CEN) in chronic migraine with medication overuse headaches (CM^w/MOH). This longitudinal fMRI study suggests that a series of repetitive SPG blockades results in an improvement in functional connectivity within both networks, primarily involving connectivity between regions of the prefrontal cortex and limbic (cortical-limbic) structures, and between different cortical (cortical-cortical) regions. In addition, improved overall CEN strength was observed. Results thereby suggested improved functional connectivity in brain regions critical to pain processing in CM^w/MOH in association with recurrent parasympathetic inhibition via SPG.