Selective Functional Hyperconnectivity in the Middle Temporal Gyrus Subregions in Lifelong Premature Ejaculation

Abstract

Background: Lifelong premature ejaculation (LPE) has been linked to altered brain function and structure. Although the middle temporal gyrus (MTG) is consistently more affected in LPE, its functional and structural changes have yet to be determined at the subregional level.

Aim: To explore the functional and structural changes of MTG in LPE at the subregional level based on a combined analysis of multimodal magnetic resonance imaging data.

Methods: 25 patients with LPE and 21 healthy controls underwent resting-state functional and structural magnetic resonance imaging scans. The MTG was parcellated into the anterior part of the MTG (aMTG), middle part of the MTG, posterior part of the MTG, and sulcus part of the MTG. Resting-state functional connectivity (rsFC) and gray matter volume (GMV) of each MTG subregion were calculated and compared between the 2 groups.

Outcomes: The functional and structural changes of MTG at the subregional level were assessed in patients with LPE and controls, as well as the correlation of them with premature ejaculation diagnostic tool and Beck Depression Inventory.

Results: Despite similar rsFC patterns of each MTG subregion in both groups, quantitative comparison analyses revealed that patients with LPE showed increased rsFC between the left aMTG and the right cuneus (0.34 ± 0.12 vs 0.17 ± 0.17), between the right aMTG and the right parahippocampal gyrus (0.36 ± 0.16 vs 0.15 ± 0.10), and between the right middle MTG and the left MTG (0.40 ± 0.14 vs 0.18 ± 0.15) relative to controls (P < .05, cluster-level family-wise error corrected). Moreover, validation analyses revealed that these results remained significant after adjusting for depression. However, there were no significant group differences in GMV in all the MTG subregions (P > .05, Bonferroni corrected). In addition, no significant correlations between rsFC and GMV of the MTG subregions and the clinical variables were found in patients with LPE (P > .05, Bonferroni corrected).

Clinical implications: Functional hyperconnectivity in the MTG subregions may facilitate a more sophisticated understanding of the neuropathological mechanism underlying LPE.

Strengths and limitations: There are no previous studies examining functional and structural changes in LPE at the MTG subregional level. The main limitation is the small sample size.

Conclusions: We present evidence that individuals with LPE have a selective functional hyperconnectivity yet preserved structural integrity in the MTG subregions, which may facilitate a more sophisticated understanding of the neuropathological mechanism underlying LPE by highlighting the critical role of the MTG in this disorder. Zhang T, Tang D, Cai H, et al. Selective Functional Hyperconnectivity in the Middle Temporal Gyrus Subregions in Lifelong Premature Ejaculation. J Sex Med 2020;17:1457-1466.

Keywords: Functional Connectivity; Gray Matter Volume; Lifelong Premature Ejaculation; Magnetic Resonance Imaging; Middle Temporal Gyrus.