Dissecting the Heterogeneity Between Anejaculation and Premature Ejaculation: Insights from Neurological, Structural, and Psychological Dimensions

Background: Anejaculation (AE) and premature ejaculation (PE) are distinct ejaculatory disorders with divergent underlying mechanisms, yet objective markers to differentiate them remain undefined. Vibration perception threshold (VPT) testing evaluates peripheral sensory function but its utility in distinguishing AE from PE has not been validated. Objective: To determine whether VPT testing can discriminate AE from PE and to identify additional clinical factors that differentiate these two ejaculatory disorders. Methods: We retrospectively analysed 103 men presenting with AE (n = 21) or PE (n = 82). VPT was measured at ten standardized sites on the glans penis, penile root and fingertips, and a composite mean VPT was derived. Cervical (C3–C8) and lumbar (T12–L2) MRI scans were reviewed for structural abnormalities. Chronic prostatitis was diagnosed by expressed prostatic secretion microscopy and seminal vesicle ultrasound. Psychological status was assessed using PHQ‑9 (depression), GAD‑7 (anxiety) and SDI‑2 (sexual desire). Group differences were tested with Mann–Whitney U, χ² or Fisher’s exact tests, with VPT p‑values corrected by the Benjamini–Hochberg method. Variables with univariate p <  0.05 and the composite mean VPT were entered into a multivariable Firth‑penalized logistic regression. Model discrimination was assessed by area under the receiver operating characteristic curve (AUC).Results: After correction, no individual VPT site differed between AE and PE (all q＞0.05). Univariate comparisons showed higher lumbar MRI abnormalities (57.1% vs 25.6%; p = 0.01), chronic prostatitis (52.4% vs 22.0%; p = 0.01) and depressive symptoms (PHQ‑9 median 10.0 vs 6.5; p = 0.01) in AE. Cervical MRI, anxiety and sexual desire were similar. In multivariable analysis, lumbar MRI abnormalities (OR = 5.73; 95% CI 1.14–28.83; p = 0.04) and depressive symptom severity (per‑point PHQ‑9: OR = 1.05; 95% CI 1.00–1.09; p = 0.04) independently differentiated AE from PE. The composite mean VPT was inversely associated with AE (per‑unit increase: OR = 0.97; 95% CI 0.94–1.00; p = 0.03). Chronic prostatitis did not remain significant (OR = 3.35; 95% CI 0.63–17.90; p = 0.17). The model demonstrated good discrimination (AUC = 0.80). Conclusions: Individual VPT assessments cannot distinguish AE from PE. Although a composite mean VPT exhibits a modest inverse association with AE, its discriminative value is eclipsed by lumbar spinal pathology and depressive symptom burden, which emerge as the principal independent differentiators. These findings advocate a multidimensional diagnostic framework—combining targeted spinal MRI, structured psychological evaluation and comprehensive sensory testing—to accurately characterize and manage ejaculatory disorders.