Brain Functional Biomarkers Distinguishing Premature Ejaculation From Anejaculation by ALFF: A Resting-State fMRI Study

Introduction: Premature ejaculation (PE) and anejaculation (AJ) are 2 opposite disorders of male ejaculatory dysfunction. Recent studies have demonstrated that the process of ejaculation is mediated by certain neural circuits in the brain. However, different mechanisms between PE and AJ are still unclear. Aim: Therefore, we used resting-state functional magnetic resonance imaging (fMRI) to explore the underlying neural mechanisms in patients with PE and AJ by measuring the amplitude of low-frequency fluctuations (ALFF). Methods: Resting-state fMRI data were acquired in 17 PE, 20 AJ patients and 23 matched healthy controls (HC). Main Outcome Measure: Differences of ALFF values among the 3 groups were compared. We also explored the correlations between brain regions showing altered ALFF values and scores of Premature Ejaculation Diagnostic Tool (PEDT) in the PE group. Results: There were widespread differences of ALFF values among the 3 groups, which included left anterior cingulate gyrus, precentral and postcentral gyrus, paracentral lobule, superior temporal gyrus, calcarine fissure, putamen; right postcentral gyrus, paracentral lobule, middle temporal gyrus, putamen. Compared with HC, PE patients had greater ALFF in the right inferior frontal gyrus (opercular part), AJ patients had greater ALFF in the left postcentral gyrus. In addition, PE patients exhibited greater ALFF in the left Rolandic operculum, anterior cingulate gyrus, inferior frontal gyrus (orbital part), putamen, and right putamen when compared with AJ patients, as well as decreased ALFF in the right postcentral gyrus. Moreover, positive correlations were found between ALFF of left postcentral gyrus, inferior frontal gyrus (orbital part), right inferior frontal gyrus (opercular part), and PEDT scores. Clinical Implications: The differences in central pathophysiological mechanisms between PE and AJ might be useful for improving the clinical diagnosis of ejaculation dysfunction. Strength & Limitations: Our results showed that the method of fMRI could identify the differences of ALFF between PE and AJ and that these alterations in ALFF were related to clinical function. However, this was a relatively small sample study, and further multimodal neuroimaging studies with large samples were needed. Conclusion: The findings demonstrated that altered ALFF of frontal, parietal cortex, and putamen might help distinguish premature ejaculation from anejaculation. Abnormal function of these brain regions might play a critical role in the physiopathology of ejaculatory dysfunction of patients. Copyright (c) 2020, International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.