Altered Brain Functional Connectivity in Postherpetic Neuralgia and Its Association With Neuropathic Pain.

background and purposePostherpetic neuralgia (PHN) is a chronic neuropathic pain condition that can occur after herpes zoster, but the relationship between the brain network organization and the clinical symptoms of PHN remains unclear.

methodsResting-state functional magnetic resonance imaging data were acquired from 42 patients with PHN and 41 sex-matched healthy controls. Graph-theoretical analyses were used to assess global network measures including the characteristic path length, mean clustering coefficient, eccentricity, global efficiency, and local efficiency across 132 brain regions, while regional properties were evaluated using the betweenness centrality. Group comparisons were performed between healthy controls and PHN patients stratified by Douleur Neuropathique 4 (DN4) scores. Correlations with clinical variables were examined, with the results corrected for multiple comparisons using the family-wise error rate.

resultsAt the global network level, the mean clustering coefficient, eccentricity, and local efficiency were lower in patients with PHN than in healthy controls after correction for multiple comparisons (all adjusted

conclusionsPHN was associated with reductions in local clustering and efficiency as well as hubness of the ACC, indicating alterations to the brain network organization. Conversely, in the PHN patients, higher DN4 scores were associated with higher local efficiency. These findings suggest that symptom-informed connectomic profiling can capture clinically relevant heterogeneity that provides insights into network reorganization linked to the neuropathic symptom burden.