Multimodal Functional Magnetic Resonance Imaging Of Lifelong Premature Ejaculation

Background: Lifelong premature ejaculation(LPE)is a highly prevalent sexual dysfunction in men,leading to reductions in self-esteem,detrimentally affecting marital relationships and familial harmony.LPE patients typically also suffer from depression and other negative-thought emotions.Such a situation is characterized by challenging diagnosis,prolonged treatment cycles,elevated economic and social burdens.Several previous studies have shown that LPE has correlations to specific brain structural and functional alterations.However,there are lack of multimodal and subregional analyses for magnetic resonance imaging(MRI),and more importantly,the influence of depression upon LPE patients has not been focused in great detail by the scientific community.Aim: To explore the functional,structural and network changes in LPE based on a combined analysis of multimodal MRI data,and their correlation with clinical variables.Methods: One hundred and thirty-five volunteers were involved in this study,including68 LPE patients and 67 age-/ BMI-matched healthy control(HC)males,underwent multimodal MRI and clinical scale examination.(1)In order to explore shifts in gray matter volume(GMV)and white matter volume(WMV)within LPE,GMV and WMV variations in LPE and HC groups were comparatively analyzed based on voxel-based morphometry(VBM).(2)Variations of white matter microstructure and white matter network in LPE and HC groups were compared based on tract-based spatial statistics(TBSS)and topological characteristics of brain white matter network.(3)Resting-state blood oxygen level dependent(BOLD)functional magnetic resonance imaging(f MRI)was employed for comparing variations in localized brain activity and the brain-function network between LPE and HC groups.(4)Variations in cerebral blood flow(CBF)were compared between LPE and HC groups.(5)Variations within intra-/ inter-network functional connectivities for the sympathetic,parasympathetic and default mode networks were compared between LPE and HC groups,in order to explore the alterations in brain functional networking within LPE.(6)Correlation analyses between the mean value extracted by brain regions with inter-group variations,as well as abnormal topological characteristics of brain white matter network,and clinical indicators were conducted to explore the relationship between specific brain changes and clinical symptoms in LPE patients.(7)Previous studies indicated that depression symptoms can affect the cerebral structure and function within LPE patients.Consequently,inter-group comparisons for the above MRI parameters were repeated,under the condition of controlling of Beck Depression Inventory(BDI)scores,to exclude the potential impact of depression symptoms.Results:(1)Compared with the HC group,LPE group showed increased GMV in the left orbital middle frontal gyrus.All GMV analysis of middle frontal gyrus(MFG)at the sub-regional level indicate that the increase GMV of R-MFG-1,R-MFG-6 and L-MFG-7 in LPE group.(2)Compared with the HC group,LPE group showed higher axial diffusivity(AD)in bilateral anterior limb of internal capsule,together in the left posterior limb of internal capsule;and decreased betweenness centrality(Bc)in uncinate fasciculus.There were no significant group differences in WMV between LPE and HC group.(3)Compared with the HC group,lower f ALFF in the L-calcarine was found in LPE group.(4)Compared with the HC group,increased CBF in the right caudate nucleus and right putamen,as well as the right middle temporal gyrus(MTG),were all identified in LPE group.(5)In comparison with the HC group,LPE group exhibited decreased rs FC between the R-MFG-1 and bilateral middle occipital gyrus,right postcentral,right middle cingulum cortex;between the R-MFG-4 and right orbital inferior frontal gyrus;between the L-MFG-6 and right lingual;between the R-MFG-7 and right superior parietal;and between the L-calcarine and right precuneus as well as between the R-MTG-2 and left medial superior frontal gyrus.(6)There were no significant group differences in brain functional network between LPE and HC group.(7)GMV in the L-MFG-1,L-MFG-2,L-MFG-3,L-MFG-4,L-MFG-5,L-MFG-7,and R-MFG-4 subregions were negatively correlated with duration of condition in LPE.rs FC of R-MFG-4 and right orbital inferior frontal gyrus was positively correlated with duration of condition.(8)Validation analysis suggested that the ROI-based intergroup differences in above MRI parameters,excepte for betweenness centrality in uncinate fasciculus,were still significant between the LPE and HC groups after controlling for BDI scores.Conclusion:(1)LPE patients showed increased GMV in the brain regions involved in behavioral control and reward loop,and increased CBF in the brain regions related to reward loop,auditory-motor intergration and language;but the decrease of local activity and functional connectivity mainly distributed in the brain regions related to visual processing,sensorimotor and executive control.Brain imaging studies of LPE patients have revealed marked changes in brain structure and function simultaneously.(2)Abnormalities of brain white matter microstructural and structural connections were found in the emotion processing-related regions of LPE patients,which might be associated with rapid ejaculation or decreased ejaculation control.(3)The inconsistency of brain structure,function and structural network in LPE patients could be a compensatory mechanism.The increased GMV,CBF and AD may be the spontaneous protective mechanism of human brain against the decrease of local activity,rs FC and Bc.(4)The abnormal gray matter structure and functional connections in brain regions involved in inhibitory control processing,reward circuitry and visual processing were associated with illness duration.At the same time,the abnormal structural connections may be related to the accompanying depression symptoms in LPE patients.It could prove helpful for understanding the pathophysiological mechanisms of LPE patients.