A diagnostic study on the application of segmental somatosensory evoked potential examination to acquired premature ejaculation.

Background: Premature ejaculation (PE), affecting approximate 5%, has an unclear pathogenesis, limited treatment efficacy, and a lack of effective diagnostic methods.

Aim: This prospective diagnostic study aimed to compare segmental dorsal penile nerve somatosensory evoked potentials (DNSEP) differences among patients with acquired premature ejaculation (APE), primary premature ejaculation (PPE), and healthy controls.

Method: This prospective diagnostic study examined patients suffering from PE who visited the outpatient clinic of the Department of Urology of the Second Affiliated Hospital of Zhejiang University School of Medicine from January 1, 2022 to February 28, 2023. According to the definition of PE by the ISSM, 16 cases comprised the healthy control group, 31 in the APE group, and 28 in the PPE group. Each group was examined based on the segmental DNSEP with electrodes recording at multiple locations (the selected location was at the Cz and the C7). The latency time of the evoked potential obtained at Cz was P40, and that obtained at C7 was P30. The P30/P40 ratios of P40, P30, and DNSEP wave amplitudes at C7 and Cz were compared among the 3 groups of patients.

Result: No group differences were found in P40 latency at Cz. However, PPE showed higher DNSEP amplitude at Cz, while APE showed lower amplitudes compared with controls. Both APE and PPE had significantly shorter P30 latency at C7 than controls. SEP amplitude at C7 was similar in APE and PPE but lower than in controls. The P30/P40 ratio was lower in APE compared with PPE and controls.

Clinical implications: Segmental SEP may offer more assistance in localizing neurological lesions, potentially guiding clinical treatment.

Strengths and limitations: In this study, the innovative use of the P30/P40 ratio was proposed, maintaining consistency in emotional states and measurement conditions for the same patient. However, limitations include a restricted number of patient cases and challenges in obtaining a diverse control group, potentially introducing bias. In addition, not considering subclinical premature ejaculation and the comorbidity of PE + ED (LCEE) in patient stratification is another limitation of this study. Results suggest a correlation between secondary PE and underlying conditions, such as obesity and lumbar spine injuries. The study validates multi-site somatosensory-evoked potential examination for locating neural lesions but acknowledges the need for future invasive needle electrode AEP testing to analyze neuropathological changes more comprehensively.

Conclusion: In conclusion, segmental DNSEP examination aids in localizing neuropathy in APE patients, and the P30/P40 ratio proves more accurate in diagnosing APE than P40 alone.