More Efficient Approach: Independent Diagnostic Value of Audiovisual Sexual Stimulation for Psychogenic Erectile Dysfunction

The diagnostic value of audiovisual sexual stimulation (AVSS) for psychogenic erectile dysfunction (ED) is still unclear. We investigated the independent diagnostic value and optimal cut-off parameter of AVSS for psychogenic ED. All participants had received the AVSS test and nocturnal penile tumescence and rigidity (NPTR) monitoring at least twice. ED patients were divided into psychogenic ED and organic ED according to NPTR examination. The diagnostic accuracy of AVSS parameters was evaluated with the receiver operating characteristic (ROC) curve, and the Youden index was employed to determine the optimal diagnostic cut-off values. A total of 346 patients with ED and 60 healthy men were included in this study, among which 162 and 184 cases of psychogenic and organic ED were identified based on NPTR, respectively. When comparing the two ED groups, the area under the curve (AUC) of AVSS parameters was 0.85-0.89. Six-selected AVSS parameters could precisely diagnose psychogenic ED, exhibiting increased diagnostic specificity compared with corresponding sensitivity. When comparing psychogenic ED with the control group, the AUC of the tumescence of the tip was superior to the AUC other parameters (0.81 vs. 0.58, 0.66, 0.59, 0.53, 0.68), and the best determined diagnostic cut-off value was the tumescence of the tip < 29.87%. Independent AVSS could diagnose psychogenic ED objectively and effectively, and its diagnostic value was highest when 1.50% ≤ tumescence of the tip < 29.87%.

Decreased gray matter volume of the anterior insular cortex in patients with psychogenic erectile dysfunction: A voxel-based morphometry study

This study aimed to explore the gray matter morphological alteration and its correlation with the severity of symptoms in patients with psychogenic erectile dysfunction (pED). Fifty patients with pED and 50 healthy controls (HCs) were included. The whole-brain voxel-based morphometry analysis was conducted to compare the differences in gray matter volume (GMV) between patients with pED and HCs. And then, the region-of-interest-based correlation analyses were performed between the GMV of these regions with the most pronounced between-group differences and clinical symptoms in patients. The results demonstrated that patients with pED manifested decreased GMV in the bilateral anterior insula (aINS), bilateral precentral gyrus, left postcentral gyrus, bilateral anterior cingulate cortex, bilateral middle cingulate cortex, bilateral fusiform gyrus, and cerebellum when compared to HCs. Taking the bilateral aINS as the region-of-interest, the results of voxel-based correlation analyses showed that the GMV of the bilateral aINS were positively correlated with the International Index of Erectile Function 5 (IIEF-5) and Quality of Erection Questionnaire score, and the GMV of right aINS was positively associated with duration and sexual craving score in patients with pED. Furthermore, the significant correlations between the total GMV of the right aINS and IIEF-5 and sexual craving score, as well as between the total GMV of the left aINS and sexual craving score were also detected. In conclusion, these results suggested that the decreased GMV of aINS might be a critical neuropathological characteristic of pED, which provided new evidence for understanding the neurobiological basis of pED from the perspective of brain structure alterations.

Aberrant baseline brain activity in psychogenic erectile dysfunction patients: a resting state fMRI study

Recent neuroimaging studies have elucidated many interesting and promising findings on sexuality regarding the neural underpinnings of both normal and abnormal sexual processes. Psychogenic erectile dysfunction (pED) consists of a major part of male sexual dysfunction in China, but the understanding of the central mechanism of pED is still in its infancy. It is commonly appreciated that pED is a functional disorder, which can be attributed predominantly or exclusively to psychological factors, such as anxiety, depression, loss of self-esteem, and psychosocial stresses. Most previous studies probed the central response in the brain of pED patients using sexual-related stimuli. However, little concern has been given to a more fundamental issue whether the baseline brain activity is altered in pED or not. With rs-fMRI data, the current study aimed to explain the central mechanism behind pED by investigating the alterations in baseline brain activity in patients with pED, as indexed by the amplitude of low-frequency (0.01-0.08 Hz) fluctuation (ALFF). After the psychological screening and urological examination procedure, 26 pED patients and 26 healthy matched controls were enrolled. Our results explicated significantly lower baseline brain activity in the right anterior insula and right orbitofrontal cortex for pED patients (multiple comparison corrected). Additionally, the voxel-wise correlation analysis showed that ALFF of the right anterior insula was correlated with the outcomes of erectile function (multiple comparison corrected). Our results implied there was impaired cognitive and motivational processing of sexual stimuli in pED patients. Our current findings may shed light on the neural pathology underlying pED. We hope that our study has provided a new angle looking into pED research by investigating resting state brain activity. Furthermore, we suggest that the current study may put forward a more subtle conception of insular influence on pED, which may help foster new specific, mechanistic insights.