Abstract
INTRODUCTION: Abnormal spontaneous neural activity has been detected in the brain of anejaculation patients. It has been confirmed that anejaculation may be associated with altered regional activation in the brain. AIM: This study aimed to explore the changes of grey matter in the brain of anejaculation patients. METHODS: Structural magnetic resonance imaging data were collected from 20 primary intravaginal anejaculation (PIAJ) patients and 16 matched healthy controls (HCs). The 3D high resolution T1 weighted images were processed to calculate the grey matter volume and density by the method of voxel-based morphometry analysis. OUTCOMES: Differences of grey matter volume and density were compared between groups, and receiver operating characteristic curve was performed to evaluate the values of altered brain regions in distinguishing PIAJ from HCs. RESULTS: PIAJ patients showed increased grey matter volume in the right supplementary motor area, right inferior temporal gyrus, right superior and inferior occipital gyrus, part of the left precuneus and decreased grey matter grey matter in another part of the left precuneus. In addition, increased grey matter density of the right supplementary motor area, right postcentral gyrus, right inferior temporal gyrus, left middle frontal gyrus, left inferior temporal gyrus and decreased grey matter density of the left precuneus were revealed in PIAJ patients. Both abnormal grey matter volume and altered grey matter density exhibited satisfactory performance in distinguishing PIAJ from HCs. CLINICAL IMPLICATIONS: These findings suggested that increased microstructural changes of grey matter might be associated with the increased inhibiting effect of the brain on ejaculation. STRENGTHS & LIMITATIONS: This study provided new insights into the pathological mechanism underlying PIAJ, These findings are exploratory and that future longitudinal or comparative studies (eg, PIAJ vs. premature ejaculation) will be necessary to clarify whether these changes are predisposing, consequential, or potentially modifiable. CONCLUSION: These findings indicated that patients suffering from PIAJ might exhibit abnormal grey matter volume and density in some brain regions, which might be linked to the inability to ejaculate intravaginally. PIAJ patient showed more increased indicators of grey matter when compared with premature ejaculation patients, which often had decreased brain function.