[Correlation of betweenness centrality of the right hemispheric network with ejaculatory function in premature ejaculation patients].

Objective: To explore the topological properties of the betweenness centrality of the nodes and edges in the brain white matter network of premature ejaculation (PE) patients and analyze the correlation of the importance of the key brain regions and interregional white matter structural connectivity with the ejaculatory function of the patients.Method: We collected the demographic and clinical data, along with the T1 and MR diffusion tensor imaging (MR-DTI) data, on 18 PE patients and 22 normal controls matched in age, sex and education. After preprocessing of the data obtained, we divided the whole brain into 90 symmetrical cortical and subcortical regions (defined as nodes of the brain network) by automated anatomical labeling, examined the structural connectivity between different brain regions by probabilistic white matter fiber tracking (defined as edges of the brain network), and calculated the betweenness centrality of the nodes and edges using the brain connection toolbox. Then, we performed the Mann-Whitney U test on the betweenness centrality of the nodes and edges, subjected the results to false discovery rate (FDR) correction, and assessed the correlation of the attribute values of between-group differences with the ejaculatory function of the patients.

Results: Compared with the normal controls, the PE patients showed a significantly decreased betweenness centrality of the right superior occipital gyrus (SOG) (281.18 ± 255.26 vs 67.78 ± 58.98, Z = －3.49, FDR-corrected P < 0.05), but increased betweenness centrality of the right superior temporal gyrus (STG) (222.91 ± 155.60 vs 557.00 ± 322.65, Z = 3.55, FDR-corrected P < 0.05) and betweeness centrality of the edge between the right rolandic operculum and right insula (4.23 ± 8.39 vs 23.83 ± 23.91, Z = 3.84, FDR-corrected P < 0.05). The betweenness centrality of the right SOG was correlated negatively with the level of difficulty in delaying ejaculation (r = －0.51, P = 0.03) and the probability of ejaculation before expectation (r= －0.61, P = 0.01), while that of the right STG positively with PE-related frustration (r = 0.54, P = 0.02) and the level of concern about PE-related distress of the partner (r = 0.47, P = 0.04).

Conclusions: Abnormalities of structural connections were found in the visual stimulus- and emotion processing-related regions in the right cerebral hemisphere of PE patients, which might be associated with rapid ejaculation or decreased ejaculation control and lead to a series of psychological problems.