‌Abnormal brain functions and altered network connectivity during visual sexual stimuli in patients with primary...

Lifelong premature ejaculation (LPE) is a prevalent male sexual dysfunction with unclear neurobiological mechanisms. Despite its high prevalence, the etiology of LPE remains debated, often attributed to psychological or biological factors. Recent neuroimaging studies have highlighted the role of central nervous system dysregulation in sexual behavior.

This study investigates abnormal brain functions and altered network connectivity in LPE patients after visual sexual stimuli (VSS) using functional magnetic resonance imaging.

Twenty-five LPE patients and 31 healthy controls (HCs) underwent resting-state and task-state functional magnetic resonance imaging (fMRI). Clinical data, including sexual history, self-reported intravaginal ejaculatory latency time, International Index of Erectile Function-5, the Chinese Index of Premature Ejaculation, anxiety/depression scores, and serum testosterone levels, were collected. Neuroimaging preprocessing and analysis focused on amplitude of low-frequency fluctuation, fractional ALFF, and regional homogeneity. Task-state fMRI compared brain activation patterns after VSS. Statistical analyses included voxel-based comparisons and network connectivity assessments using SPM12 and DPABI v3.0.

LPE patients demonstrate distinct neurofunctional abnormalities after VSS, particularly hyperactivation in the precuneus.

‌Clinical Data‌: LPE patients exhibited significantly lower International Index of Erectile Function-5 scores and higher depression rates compared to HCs, with no differences in age, BMI, or testosterone levels. Brain Activation‌: During VSS, LPE patients showed relative signal decrease in the middle cingulate cortex and left precentral gyrus compared to HCs. Regional homogeneity analysis revealed hyperactivation in the precuneus and fusiform gyrus post-stimulus. Network Connectivity‌: Altered connectivity in premature ejaculation patients involved the fusiform gyrus (linked to posterior cingulate, hippocampus, parahippocampus, and supplementary motor areas) and the superior parietal lobule (connected to the angular gyrus).

These findings suggest that aberrant central nervous system processing of sexual stimuli contributes to premature ejaculation pathophysiology, offering potential targets for neuromodulatory therapies.

The study focuses on the different activation patterns of patients with LPE from the perspective of sexual arousal. The methodological aspects of research, such as the use of images or videos in sexual stimulation, remain controversial. The findings of our network analysis only demonstrated a limited number of altered functional connections, and no established network metrics were provided to substantiate the claim of extensive network disruption. These factors collectively represent important limitations of the present study.

The hyperactivity in this brain region observed in patients could represent a unique response to VSS among those with LPE, ultimately leading to alterations in their ejaculatory behavior.‌‌‌.