For participants with chronic migraine with medication overuse headache (CMw/MOH), sphenopalatine ganglion (SPG) blockade treatment improves function connectivity in both the salience and central executive networks, according to results published in Headache.
The study included participants who fulfilled the International Classification of Headache Disorders-III criteria for CMw/MOH, had predominantly frontal and /or orbital pain, and were eligible for receiving SPG blockade (n=10) and control participants (n=10). The researchers used fMRI to determine resting state connectivity from predefined networks of nodes for the salience (27 nodes, 351 connections) and central executive networks (17 nodes, 136 connections). Participants were then given a series of SPG blockage treatments. After treatments, the researchers used a paired samples t-test to evaluate changes in intranetwork resting state connectivity within the salience and executive networks as well as overall network connectivity strength.
After comparing connectivity strength at baseline with strength at the end of treatment, participants with CMw/MOH had significant improvements among connections in 9 salience and 8 executive networks. After treatment, the overall central executive network was significantly improved (baseline, 0.00±0.08; 6 weeks, 0.03±0.09, P =.01). Still, the overall salience network connectivity did not have significant improvements (baseline, −0.01±0.10; 6 weeks, 0.01±0.12, P =.26).
In the salience network, the researchers observed improvements in connectivity between the prefrontal cortex and regions of the insula, basal ganglia, motor, and frontal cortex. They also observed changes in connectivity between regions of the temporal cortex and the basal ganglia and supramarginal gyrus.
In the central executive networks, the researchers observed improvements in connectivity between the prefrontal cortex and regions of the anterior thalamus, caudate, and frontal cortex.
Compared with baseline, participants had a significant reduction in the number of moderate/severe headache days per month, (baseline, 21.1±6.6; 6 weeks, 11.2±6.5, P <.001), Headache Impact Test scores, (baseline, 66.1±2.6; 6 weeks, 60.2±3.6, P <.001), and Patient Health Questionnaire scores (baseline, 12.1±5.7; 6 weeks, 6.1±3.6, P =.008) after treatment.
“Despite incomplete normalization of the functional brain networks, our results suggest that recurrent parasympathetic inhibition via a series of SPG blocks is associated with long term neuromodulatory effect in CMw/MOH,” the researchers wrote.
Krebs K, Rorden C, Androulakis M. Resting state functional connectivity after sphenopalatine ganglion blocks in chronic migraine with medication overuse headache: a pilot longitudinal fMRI study . Headache. 2018; 58:732-743.