White matter microstructural changes in psychogenic erectile dysfunction patients

Brain dysfunction in erectile dysfunction (ED) has been identified by multiple neuroimaging studies. A recent MRI study indicated grey matter alterations in ED patients. This study aims to investigate the microstructural changes of cerebral white matter (WM) in psychological ED patients and their possible correlations with clinical variables. Twenty-seven psychological ED patients and 27 healthy subjects (HS) were included and underwent a magnetic resonance (MR) diffusion tensor imaging (DTI) scan. The tract-based spatial statistics were employed to identify the WM structure alterations in psychological ED patients. The multiple DTI-derived indices ' [fractional anisotropy (FA), axial diffusivity (AD) and mean diffusivity (MD)] correlations with the symptoms and their durations, respectively, were analysed. The IIEF-5, quality of erection questionnaire (QEQ) and the self-esteem and relationship (SEAR) questionnaire were used to assess the symptoms of psychological ED patients. Compared with HS, the psychological ED patients showed increased FA values, reduced MD values and reduced AD values in multiple WM tracts including the corpus callosum (genu, body and splenium), corticospinal tract, internal capsule, corona radiata, external capsule and superior longitudinal fasciculus (p<0.05, threshold-free cluster enhancement corrected). Both of the IIEF scores and QEQ scores of ED patients showed a significantly negative correlation with the average FA values, and positive correlation with average AD values and MD values in the splenium of the corpus callosum (p<0.05). The results provided preliminary evidence of WM microstructural changes in patients with psychological ED. The morphological alterations in the splenium of the corpus callosum were related to the symptom severity.