Latency changes in penile somatosensory evoked potentials predict real-world efficacy of topical anesthesia

Based on our previous study using penile somatosensory evoked potentials (SEPs), we found that topical anesthetics prolong latency only in the hypersensitive areas of the penis.

To investigate whether prolongation of SEP latency is key to the treatment of premature ejaculation (PE).

56 patients with hypersensitive PE underwent penile SEP testing before and after topical anesthetic application. Real-world efficacy was assessed over 2 months via Premature Ejaculation Diagnostic Tool score, IIEF-5 score, and estimated intravaginal ejaculatory latency time (eIELT).

A correlation exists between changes in SEP latency following topical anesthetic application and its therapeutic efficacy in treating PE.

Following topical anesthetic application, sensory thresholds increased significantly (P < .001), while latency prolonged only in hypersensitive areas (P < .001). The overall consistency between SEP assessment and real-world efficacy (Premature Ejaculation Diagnostic Tool <11 and eIELT >3 min) was 78.57% (Kappa = 0.432, P = .001), with 90% sensitivity and 81.82% positive predictive value. Logistic regression showed that increased glans latency difference (OR = 2.78 per 1 ms, P = .004) and shaft latency difference (OR = 2.211 per 1 ms, P = .007) were positively correlated with real-world efficacy. IIEF-5 scores decreased significantly after treatment (P < .05). The incidence of erectile dysfunction (ED) was significantly higher with whole-penis application than with targeted application (45.9% vs. 10.5%, P = .025).

Prolongation of penile SEP latency is key to the treatment of PE and may predict the real-world effectiveness of topical anesthetics for PE. Precise application of the anesthetic exclusively to identified hypersensitive areas represents an important advantage, as it both prolongs SEP latency in sensitive regions and reduces the risk of inducing ED.

Strengths include the provision of objective neurophysiological data (SEP) to elucidate a subjective clinical condition and the identification of a potential biomarker for predicting treatment response. Limitations include the small sample size, single-center design. Predictions were based on a single neurophysiological parameter (latency) measured in the flaccid state, which does not fully replicate sexual activity, and did not account for psychological status, sexual frequency, or partner satisfaction.

Prolongation of SEP latency is key to the treatment of PE.